For Pediatric LGS, Cenobamate Shows Promise

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Changed
Thu, 05/09/2024 - 15:35

A retrospective analysis of pediatric patients with Lennox-Gastaut syndrome (LGS) suggests that the antiseizure medication cenobamate (SK Life Sciences) in combination with existing lines of therapy may be associated with fewer hospital in-patient days and emergency room visits. The conclusions were reached by comparing outcomes to patient historical data, though they were not analyzed statistically.

A Proof-of-Concept Study

In an interview, Karen Keough, MD, who presented the study during a poster session at the 2024 annual meeting of the American Academy of Neurology, conceded the key limitation was that the researchers were not able to perform statistical analysis due to the nature of the data. “It’s just showing trends. It’s proof of concept that cenobamate can be effective in one of the most refractory forms of epilepsy, which always includes focal seizures. That’s what led to the initial FDA indication, but we also know that this medication has a lot of promise and is probably going to be effective in other forms of epilepsy and probably in other seizure types,” said Dr. Keough, who is a neurologist at Pediatrix Child Neurology Consultants of Austin, Texas.

Although she has seen significant improvements in many patients, Dr. Keough reported that most patients become refractory again. “Unfortunately, honeymoons are probably real in cenobamate. Continuing to follow those patients as I do, since they’re my own patients, I have quite a few who had more than a year of seizure freedom, [but] their seizures are back, though not as bad as they were before cenobamate. I just can’t get them back to that 100% control category. I do have a few that are still in the 100% control category, but not very many,” she said.

She also presented a retrospective chart review of 36 LGS patients between the ages of 1 and 27 years at the American Epilepsy Society in December 2023, which showed that addition of cenobamate was associated with a reduction in seizure frequency in 85% of patients. “It was a profound number of patients who had long periods of seizure freedom,” she said.
 

A Promising Treatment Option

Dr. Keough is considering moving cenobamate up in the treatment sequence of new LGS patients. “I don’t use cenobamate first line in anyone because we have good first-line agents for simple epilepsy in Lennox-Gastaut, but I’m bringing out cenobamate pretty early in the course, because I do think it has superior efficacy compared with most other drugs that we have available. Most of my patients are very established and they’ve seen lots of other drugs. For many patients, there are only a couple of drugs left on the list that [they] have never tried, but we’re going to put cenobamate at the top of that. For my newer diagnoses, I’m going to bring it out much earlier,” she said, though other drugs such as clobazam (Onfi) would still rank ahead of cenobamate.

The study was drawn from records of the HealthVerity Marketplace Database, which includes more than 150 commercial, Medicare, and Medicaid payers. It included 76 patients aged 17 or under who took at least one antiseizure medication between May 2020 and December 2022, and who had filled at least two prescriptions of cenobamate and had 180 or more days of medical and pharmacy enrollment. The mean age was 13.4 years (5.3% 0-5 years, 15.8% 6-11 years, 78.9% 12-17 years), and 40.8% were female. Seizure types included absence (17.1%), focal (75.0%), and generalized tonic-clonic (86.8%). All patients had a history of intractable seizures, 80.3% had a history of status epilepticus, and 28.9% had a history of infantile seizures. A little more than one fourth (27.6%) of patients had commercial insurance. In the previous 90 days, 21.1% had had an emergency room visit or in-patient hospital stay.

Common antiseizure medications taken with cenobamate included cannabidiol (n = 14), clobazam (n = 8), and levetiracetam (n = 18).

During the cenobamate treatment period, patients had a lower incidence of epilepsy-related inpatient days per year (3.36 vs 3.94), epilepsy-related ER visits per year (0.66 vs 1.19), and likelihood of requiring a new line of epilepsy therapy (35.5% vs 100%).
 

 

 

‘Promising’ Results, but More Research Is Needed

The fact that cenobamate was used in combination with other therapies, plus the lack of a control group, makes it difficult to determine if cenobamate was actually responsible for the improvements, according to Nassim Zecavati, MD, who was asked for comment on the study. “I think the results are promising, but there’s obviously a need for a randomized, controlled trial to understand whether it was this medication or the combination of cenobamate with [other medications]. How do we know that this isn’t a compound effect, that it’s multifactorial, and a combination of multiple medications versus the cenobamate?” she said.

Still, she noted that LGS patients are highly vulnerable to hospital admissions and status epilepticus, making the parameters examined in the study valid and important. “I think that this drug likely has a role in the treatment of patients with LGS, particularly pediatric patients. I think we just need more data,” said Dr. Zecavati, who is director of Epilepsy at the Children’s Hospital of Richmond in Virginia and associate professor of Neurology at Virginia Commonwealth University.

Dr. Keough is a speaker for SK Life Sciences. Dr. Zecavati has no relevant financial disclosures.

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A retrospective analysis of pediatric patients with Lennox-Gastaut syndrome (LGS) suggests that the antiseizure medication cenobamate (SK Life Sciences) in combination with existing lines of therapy may be associated with fewer hospital in-patient days and emergency room visits. The conclusions were reached by comparing outcomes to patient historical data, though they were not analyzed statistically.

A Proof-of-Concept Study

In an interview, Karen Keough, MD, who presented the study during a poster session at the 2024 annual meeting of the American Academy of Neurology, conceded the key limitation was that the researchers were not able to perform statistical analysis due to the nature of the data. “It’s just showing trends. It’s proof of concept that cenobamate can be effective in one of the most refractory forms of epilepsy, which always includes focal seizures. That’s what led to the initial FDA indication, but we also know that this medication has a lot of promise and is probably going to be effective in other forms of epilepsy and probably in other seizure types,” said Dr. Keough, who is a neurologist at Pediatrix Child Neurology Consultants of Austin, Texas.

Although she has seen significant improvements in many patients, Dr. Keough reported that most patients become refractory again. “Unfortunately, honeymoons are probably real in cenobamate. Continuing to follow those patients as I do, since they’re my own patients, I have quite a few who had more than a year of seizure freedom, [but] their seizures are back, though not as bad as they were before cenobamate. I just can’t get them back to that 100% control category. I do have a few that are still in the 100% control category, but not very many,” she said.

She also presented a retrospective chart review of 36 LGS patients between the ages of 1 and 27 years at the American Epilepsy Society in December 2023, which showed that addition of cenobamate was associated with a reduction in seizure frequency in 85% of patients. “It was a profound number of patients who had long periods of seizure freedom,” she said.
 

A Promising Treatment Option

Dr. Keough is considering moving cenobamate up in the treatment sequence of new LGS patients. “I don’t use cenobamate first line in anyone because we have good first-line agents for simple epilepsy in Lennox-Gastaut, but I’m bringing out cenobamate pretty early in the course, because I do think it has superior efficacy compared with most other drugs that we have available. Most of my patients are very established and they’ve seen lots of other drugs. For many patients, there are only a couple of drugs left on the list that [they] have never tried, but we’re going to put cenobamate at the top of that. For my newer diagnoses, I’m going to bring it out much earlier,” she said, though other drugs such as clobazam (Onfi) would still rank ahead of cenobamate.

The study was drawn from records of the HealthVerity Marketplace Database, which includes more than 150 commercial, Medicare, and Medicaid payers. It included 76 patients aged 17 or under who took at least one antiseizure medication between May 2020 and December 2022, and who had filled at least two prescriptions of cenobamate and had 180 or more days of medical and pharmacy enrollment. The mean age was 13.4 years (5.3% 0-5 years, 15.8% 6-11 years, 78.9% 12-17 years), and 40.8% were female. Seizure types included absence (17.1%), focal (75.0%), and generalized tonic-clonic (86.8%). All patients had a history of intractable seizures, 80.3% had a history of status epilepticus, and 28.9% had a history of infantile seizures. A little more than one fourth (27.6%) of patients had commercial insurance. In the previous 90 days, 21.1% had had an emergency room visit or in-patient hospital stay.

Common antiseizure medications taken with cenobamate included cannabidiol (n = 14), clobazam (n = 8), and levetiracetam (n = 18).

During the cenobamate treatment period, patients had a lower incidence of epilepsy-related inpatient days per year (3.36 vs 3.94), epilepsy-related ER visits per year (0.66 vs 1.19), and likelihood of requiring a new line of epilepsy therapy (35.5% vs 100%).
 

 

 

‘Promising’ Results, but More Research Is Needed

The fact that cenobamate was used in combination with other therapies, plus the lack of a control group, makes it difficult to determine if cenobamate was actually responsible for the improvements, according to Nassim Zecavati, MD, who was asked for comment on the study. “I think the results are promising, but there’s obviously a need for a randomized, controlled trial to understand whether it was this medication or the combination of cenobamate with [other medications]. How do we know that this isn’t a compound effect, that it’s multifactorial, and a combination of multiple medications versus the cenobamate?” she said.

Still, she noted that LGS patients are highly vulnerable to hospital admissions and status epilepticus, making the parameters examined in the study valid and important. “I think that this drug likely has a role in the treatment of patients with LGS, particularly pediatric patients. I think we just need more data,” said Dr. Zecavati, who is director of Epilepsy at the Children’s Hospital of Richmond in Virginia and associate professor of Neurology at Virginia Commonwealth University.

Dr. Keough is a speaker for SK Life Sciences. Dr. Zecavati has no relevant financial disclosures.

A retrospective analysis of pediatric patients with Lennox-Gastaut syndrome (LGS) suggests that the antiseizure medication cenobamate (SK Life Sciences) in combination with existing lines of therapy may be associated with fewer hospital in-patient days and emergency room visits. The conclusions were reached by comparing outcomes to patient historical data, though they were not analyzed statistically.

A Proof-of-Concept Study

In an interview, Karen Keough, MD, who presented the study during a poster session at the 2024 annual meeting of the American Academy of Neurology, conceded the key limitation was that the researchers were not able to perform statistical analysis due to the nature of the data. “It’s just showing trends. It’s proof of concept that cenobamate can be effective in one of the most refractory forms of epilepsy, which always includes focal seizures. That’s what led to the initial FDA indication, but we also know that this medication has a lot of promise and is probably going to be effective in other forms of epilepsy and probably in other seizure types,” said Dr. Keough, who is a neurologist at Pediatrix Child Neurology Consultants of Austin, Texas.

Although she has seen significant improvements in many patients, Dr. Keough reported that most patients become refractory again. “Unfortunately, honeymoons are probably real in cenobamate. Continuing to follow those patients as I do, since they’re my own patients, I have quite a few who had more than a year of seizure freedom, [but] their seizures are back, though not as bad as they were before cenobamate. I just can’t get them back to that 100% control category. I do have a few that are still in the 100% control category, but not very many,” she said.

She also presented a retrospective chart review of 36 LGS patients between the ages of 1 and 27 years at the American Epilepsy Society in December 2023, which showed that addition of cenobamate was associated with a reduction in seizure frequency in 85% of patients. “It was a profound number of patients who had long periods of seizure freedom,” she said.
 

A Promising Treatment Option

Dr. Keough is considering moving cenobamate up in the treatment sequence of new LGS patients. “I don’t use cenobamate first line in anyone because we have good first-line agents for simple epilepsy in Lennox-Gastaut, but I’m bringing out cenobamate pretty early in the course, because I do think it has superior efficacy compared with most other drugs that we have available. Most of my patients are very established and they’ve seen lots of other drugs. For many patients, there are only a couple of drugs left on the list that [they] have never tried, but we’re going to put cenobamate at the top of that. For my newer diagnoses, I’m going to bring it out much earlier,” she said, though other drugs such as clobazam (Onfi) would still rank ahead of cenobamate.

The study was drawn from records of the HealthVerity Marketplace Database, which includes more than 150 commercial, Medicare, and Medicaid payers. It included 76 patients aged 17 or under who took at least one antiseizure medication between May 2020 and December 2022, and who had filled at least two prescriptions of cenobamate and had 180 or more days of medical and pharmacy enrollment. The mean age was 13.4 years (5.3% 0-5 years, 15.8% 6-11 years, 78.9% 12-17 years), and 40.8% were female. Seizure types included absence (17.1%), focal (75.0%), and generalized tonic-clonic (86.8%). All patients had a history of intractable seizures, 80.3% had a history of status epilepticus, and 28.9% had a history of infantile seizures. A little more than one fourth (27.6%) of patients had commercial insurance. In the previous 90 days, 21.1% had had an emergency room visit or in-patient hospital stay.

Common antiseizure medications taken with cenobamate included cannabidiol (n = 14), clobazam (n = 8), and levetiracetam (n = 18).

During the cenobamate treatment period, patients had a lower incidence of epilepsy-related inpatient days per year (3.36 vs 3.94), epilepsy-related ER visits per year (0.66 vs 1.19), and likelihood of requiring a new line of epilepsy therapy (35.5% vs 100%).
 

 

 

‘Promising’ Results, but More Research Is Needed

The fact that cenobamate was used in combination with other therapies, plus the lack of a control group, makes it difficult to determine if cenobamate was actually responsible for the improvements, according to Nassim Zecavati, MD, who was asked for comment on the study. “I think the results are promising, but there’s obviously a need for a randomized, controlled trial to understand whether it was this medication or the combination of cenobamate with [other medications]. How do we know that this isn’t a compound effect, that it’s multifactorial, and a combination of multiple medications versus the cenobamate?” she said.

Still, she noted that LGS patients are highly vulnerable to hospital admissions and status epilepticus, making the parameters examined in the study valid and important. “I think that this drug likely has a role in the treatment of patients with LGS, particularly pediatric patients. I think we just need more data,” said Dr. Zecavati, who is director of Epilepsy at the Children’s Hospital of Richmond in Virginia and associate professor of Neurology at Virginia Commonwealth University.

Dr. Keough is a speaker for SK Life Sciences. Dr. Zecavati has no relevant financial disclosures.

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Beyond Increased Risk: Is APOE4 a Direct Cause of Alzheimer’s disease?

Article Type
Changed
Wed, 05/08/2024 - 12:53

Having two copies of the APOE4 gene may be the genetic cause of up to one fifth of all Alzheimer’s disease cases, a new study suggests.

More than 95% of those with two copies of the gene (APOE4 homozygotes) in a large multicohort study had higher levels of Alzheimer’s disease biomarkers by age 55 years than did those with other APOE gene variants. By age 65 years, most had developed Alzheimer’s disease symptoms and showed abnormal amyloid levels in cerebrospinal fluid and on PET.

Investigators said that such a high penetrance of Alzheimer’s disease pathology in this group suggests that APOE4 may not be just a risk factor for Alzheimer’s disease but also a distinct genetic form of the disease. 

“Sometimes, we say we don’t know the cause of Alzheimer’s disease, but this would be behind 15%-20% of the population of people with Alzheimer’s disease,” lead investigator Juan Fortea, MD, PhD, director of the Memory Unit of the Neurology Department at the Hospital of Sant Pau, Barcelona, Spain, said at a press briefing.

Although some experts urge caution in interpreting these results, investigators and others say the findings, published online in Nature Medicine, could lead to calls for more widespread testing for APOE4 and may spur drug development.
 

High AD Penetrance

Mutations in the APP, PSEN1, and PSEN2 genes are linked to risk for early-onset autosomal-dominant Alzheimer’s disease, and dozens of other genes are associated with greater odds of late-onset disease. Among all these genes, APOE is considered the strongest genetic risk factor for late-onset Alzheimer’s disease. 

Prior studies found that APOE4 homozygotes have a 60% lifetime risk for Alzheimer’s disease by age 85 years, a risk higher than that found with other gene variants or in single APOE carriers or noncarriers. 

Despite that, no previous study had examined the predictability of symptom onset in APOE4 homozygotes, which make up about 2%-3% of the general population and 15-20% of those with Alzheimer’s disease. And because most biomarker studies have combined single- and double-carrier APOE4 carriers into one group, very little was known about the penetrance or disease progression in APOE4 homozygotes.

Investigators analyzed data from 3200 brain donors from the National Alzheimer’s Coordinating Center and more than 10,000 people with Alzheimer’s disease biomarkers from five multicenter cohorts in the United States and Europe.

Nearly all APOE4 homozygotes had either high or intermediate Alzheimer’s disease neuropathologic change scores compared with about 50% among APOE3 homozygotes and was the same regardless of age at time of death. 

Beginning at age 55 years, APOE4 homozygotes exhibited higher levels of abnormal Alzheimer’s disease biomarkers than did APOE3 homozygotes. By age 65 years, nearly everyone with two copies of APOE4 showed abnormal levels of amyloid in cerebrospinal fluid and 75% had positive amyloid scans. 

Other biomarkers showed a biologic penetrance of Alzheimer’s disease that increased with age. By age 80 years, penetrance for all amyloid and tau biomarkers reached 88%. 

Postmortem analysis revealed Alzheimer’s disease and dementia symptoms were evident in APOE4 homozygotes 7-10 years before APOE3 homozygotes, with Alzheimer’s disease symptoms present at age 65 years, minor cognitive impairment at 72 years, dementia at 74 years, and death at 77 years (P <.05 differences).

When they limited analysis to only those who developed Alzheimer’s disease dementia, investigators found no difference in amyloid or tau accumulation between APOE3 and APOE4 homozygotes. That was surprising given the much earlier presentation of clinical symptoms and biomarkers in those who carried two copies of APOE4.
 

 

 

More Than a Risk Factor

Overall, study findings provide evidence that APOE4 homozygotes represent another form of genetically determined Alzheimer’s disease, similar to autosomal-dominant Alzheimer’s disease and down syndrome-associated Alzheimer’s disease, investigators said.

“Our work showed that APOE4 homozygotes meet the three main characteristics of genetically determined Alzheimer’s disease, namely near-full penetrance, symptom onset predictability and a predictable sequence of biomarker and clinical changes,” they wrote. 

Based on the results, investigators recommend that future clinical trials avoid combining single and double APOE4 carriers into one study group. 

Because the global average proportion of APOE4 homozygotes is estimated to be approximately 2%, APOE4-homozygous Alzheimer’s disease may represent one of the most frequently occurring Mendelian diseases worldwide. This could have implications for genetic counseling and genetic screening recommendations, they said. 

“We may need to start treating these homozygotes as a separate group in our research so we can really understand the relation between amyloid and tau and symptoms in E4 homozygotes in a way that we have not been able to because of our practice in the field of thinking that APOE4 is this unitary risk effect,” co-investigator Sterling Johnson, PhD, professor of geriatrics and dementia, University of Wisconsin-Madison, said at a press briefing.

The findings may also have implications for Alzheimer’s disease prevention, investigators added.

“What’s particularly important is the promise that perhaps we could treat people before symptoms, particularly in people who already have the disease in their brain such as APOE4 homozygotes, which reliably predicts that they will have impairment and try to treat them beforehand,” co-investigator Reisa Sperling, MD, director of the Center for Alzheimer Research and Treatment at Brigham and Women›s Hospital and Massachusetts General Hospital, Boston, said at a press briefing. 

“This is important for preventing Alzheimer’s-related dementia and a real movement forward in defining the disease on the basis of genetics and biomarkers,” she added. 
 

Experts Offer Mixed Reactions

Commenting on the findings, Paul Mathews, MD, DPhil, group leader of the UK Dementia Research Institute Centre at Imperial College, said that the data point to a need to look at APOE4 differently. 

“One implication of this work is that testing for APOE4 gene homozygosity should be assessed for use clinically, when late middle-aged people present to their doctors with symptoms of dementia,” Dr. Mathews, who was not part of the study, said in a statement. 

In an accompany editorial, Yadong Huang, MD, PhD, Departments of Neurology and Pathology, University of California, San Francisco, and co-authors noted that the findings also have implications for clinical drug trials.

“So far, APOE4 homozygotes have not been treated as a separate predefined treatment group in clinical trials,” they wrote. “Following this study, APOE4 status must be recognized as a crucial parameter in trial design, patient recruitment and data analysis, with APOE4 homozygotes and heterozygotes being clearly separated. Such an approach may enhance the treatment efficacy and help tailor therapeutic interventions more effectively towards genetically defined patient populations.”

Other experts urge caution when interpreting the findings. 

“It is clear that APOE4 homozygosity is tightly linked to the appearance of Alzheimer’s-related pathology, but even at age 80, 12% of people with APOE4/E4 did not have amyloid/tau biomarkers,” said Yuko Hara, PhD, director of aging and Alzheimer’s disease prevention at the Alzheimer’s Drug Discovery Foundation. “Also, having two copies of APOE4 does not mean you will definitely develop symptoms of Alzheimer’s disease in your lifetime,” Dr. Hara added. 

Researchers have long known that APOE4 is a strong risk factor for Alzheimer’s disease and that people with two copies of the gene are at especially high risk, David Curtis, MD, PhD, Genetics Institute at University of College London, England, said in a statement.

“I do not see anything in this paper to justify the claim that carrying two copies of APOE4 represents some ‘distinct genetic form’ of Alzheimer’s disease,” Dr. Curtis said. “No matter how many alleles of APOE4 one carries, the underlying disease processes seem similar across cases of Alzheimer’s disease, suggesting that any effective treatment and prevention strategies, which have yet to be developed would have broad applicability.” 

Study funders included Fondo de Investigaciones Sanitario, Carlos III Health Institute, Fondo Europeo de Desarrollo Regional, Unión Europea, National Institutes of Health, the Department de Salut de la Generalitat de Catalunya, Horizon 2020–Research and Innovation Framework Programme from the European Union, La Caixa Foundation, EIT Digital, and the Alzheimer Association. Dr. Fortea reported receiving personal fees for service on the advisory boards, adjudication committees or speaker honoraria from AC Immune, Adamed, Alzheon, Biogen, Eisai, Esteve, Fujirebio, Ionis, Laboratorios Carnot, Life Molecular Imaging, Lilly, Lundbeck, Perha, Roche, and outside the submitted work. Dr. Johnson has served at scientific advisory boards for ALZPath, Enigma and Roche Diagnostics. Dr. Sperling has received personal consulting fees from AbbVie, AC Immune, Acumen, Alector, Bristol Myers Squibb, Janssen, Genentech, Ionis and Vaxxinity outside the submitted work. Dr. Huang is a co-founder and scientific advisory board member of GABAeron, Inc. Dr. Mathews reports consultancies with Sudo Biosciences, Nimbus, Redburn. Dr. Hara and Dr. Curtis reported no conflicts. Complete funding sources and disclosures are included in the original articles. 

A version of this article appeared on Medscape.com.

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Having two copies of the APOE4 gene may be the genetic cause of up to one fifth of all Alzheimer’s disease cases, a new study suggests.

More than 95% of those with two copies of the gene (APOE4 homozygotes) in a large multicohort study had higher levels of Alzheimer’s disease biomarkers by age 55 years than did those with other APOE gene variants. By age 65 years, most had developed Alzheimer’s disease symptoms and showed abnormal amyloid levels in cerebrospinal fluid and on PET.

Investigators said that such a high penetrance of Alzheimer’s disease pathology in this group suggests that APOE4 may not be just a risk factor for Alzheimer’s disease but also a distinct genetic form of the disease. 

“Sometimes, we say we don’t know the cause of Alzheimer’s disease, but this would be behind 15%-20% of the population of people with Alzheimer’s disease,” lead investigator Juan Fortea, MD, PhD, director of the Memory Unit of the Neurology Department at the Hospital of Sant Pau, Barcelona, Spain, said at a press briefing.

Although some experts urge caution in interpreting these results, investigators and others say the findings, published online in Nature Medicine, could lead to calls for more widespread testing for APOE4 and may spur drug development.
 

High AD Penetrance

Mutations in the APP, PSEN1, and PSEN2 genes are linked to risk for early-onset autosomal-dominant Alzheimer’s disease, and dozens of other genes are associated with greater odds of late-onset disease. Among all these genes, APOE is considered the strongest genetic risk factor for late-onset Alzheimer’s disease. 

Prior studies found that APOE4 homozygotes have a 60% lifetime risk for Alzheimer’s disease by age 85 years, a risk higher than that found with other gene variants or in single APOE carriers or noncarriers. 

Despite that, no previous study had examined the predictability of symptom onset in APOE4 homozygotes, which make up about 2%-3% of the general population and 15-20% of those with Alzheimer’s disease. And because most biomarker studies have combined single- and double-carrier APOE4 carriers into one group, very little was known about the penetrance or disease progression in APOE4 homozygotes.

Investigators analyzed data from 3200 brain donors from the National Alzheimer’s Coordinating Center and more than 10,000 people with Alzheimer’s disease biomarkers from five multicenter cohorts in the United States and Europe.

Nearly all APOE4 homozygotes had either high or intermediate Alzheimer’s disease neuropathologic change scores compared with about 50% among APOE3 homozygotes and was the same regardless of age at time of death. 

Beginning at age 55 years, APOE4 homozygotes exhibited higher levels of abnormal Alzheimer’s disease biomarkers than did APOE3 homozygotes. By age 65 years, nearly everyone with two copies of APOE4 showed abnormal levels of amyloid in cerebrospinal fluid and 75% had positive amyloid scans. 

Other biomarkers showed a biologic penetrance of Alzheimer’s disease that increased with age. By age 80 years, penetrance for all amyloid and tau biomarkers reached 88%. 

Postmortem analysis revealed Alzheimer’s disease and dementia symptoms were evident in APOE4 homozygotes 7-10 years before APOE3 homozygotes, with Alzheimer’s disease symptoms present at age 65 years, minor cognitive impairment at 72 years, dementia at 74 years, and death at 77 years (P <.05 differences).

When they limited analysis to only those who developed Alzheimer’s disease dementia, investigators found no difference in amyloid or tau accumulation between APOE3 and APOE4 homozygotes. That was surprising given the much earlier presentation of clinical symptoms and biomarkers in those who carried two copies of APOE4.
 

 

 

More Than a Risk Factor

Overall, study findings provide evidence that APOE4 homozygotes represent another form of genetically determined Alzheimer’s disease, similar to autosomal-dominant Alzheimer’s disease and down syndrome-associated Alzheimer’s disease, investigators said.

“Our work showed that APOE4 homozygotes meet the three main characteristics of genetically determined Alzheimer’s disease, namely near-full penetrance, symptom onset predictability and a predictable sequence of biomarker and clinical changes,” they wrote. 

Based on the results, investigators recommend that future clinical trials avoid combining single and double APOE4 carriers into one study group. 

Because the global average proportion of APOE4 homozygotes is estimated to be approximately 2%, APOE4-homozygous Alzheimer’s disease may represent one of the most frequently occurring Mendelian diseases worldwide. This could have implications for genetic counseling and genetic screening recommendations, they said. 

“We may need to start treating these homozygotes as a separate group in our research so we can really understand the relation between amyloid and tau and symptoms in E4 homozygotes in a way that we have not been able to because of our practice in the field of thinking that APOE4 is this unitary risk effect,” co-investigator Sterling Johnson, PhD, professor of geriatrics and dementia, University of Wisconsin-Madison, said at a press briefing.

The findings may also have implications for Alzheimer’s disease prevention, investigators added.

“What’s particularly important is the promise that perhaps we could treat people before symptoms, particularly in people who already have the disease in their brain such as APOE4 homozygotes, which reliably predicts that they will have impairment and try to treat them beforehand,” co-investigator Reisa Sperling, MD, director of the Center for Alzheimer Research and Treatment at Brigham and Women›s Hospital and Massachusetts General Hospital, Boston, said at a press briefing. 

“This is important for preventing Alzheimer’s-related dementia and a real movement forward in defining the disease on the basis of genetics and biomarkers,” she added. 
 

Experts Offer Mixed Reactions

Commenting on the findings, Paul Mathews, MD, DPhil, group leader of the UK Dementia Research Institute Centre at Imperial College, said that the data point to a need to look at APOE4 differently. 

“One implication of this work is that testing for APOE4 gene homozygosity should be assessed for use clinically, when late middle-aged people present to their doctors with symptoms of dementia,” Dr. Mathews, who was not part of the study, said in a statement. 

In an accompany editorial, Yadong Huang, MD, PhD, Departments of Neurology and Pathology, University of California, San Francisco, and co-authors noted that the findings also have implications for clinical drug trials.

“So far, APOE4 homozygotes have not been treated as a separate predefined treatment group in clinical trials,” they wrote. “Following this study, APOE4 status must be recognized as a crucial parameter in trial design, patient recruitment and data analysis, with APOE4 homozygotes and heterozygotes being clearly separated. Such an approach may enhance the treatment efficacy and help tailor therapeutic interventions more effectively towards genetically defined patient populations.”

Other experts urge caution when interpreting the findings. 

“It is clear that APOE4 homozygosity is tightly linked to the appearance of Alzheimer’s-related pathology, but even at age 80, 12% of people with APOE4/E4 did not have amyloid/tau biomarkers,” said Yuko Hara, PhD, director of aging and Alzheimer’s disease prevention at the Alzheimer’s Drug Discovery Foundation. “Also, having two copies of APOE4 does not mean you will definitely develop symptoms of Alzheimer’s disease in your lifetime,” Dr. Hara added. 

Researchers have long known that APOE4 is a strong risk factor for Alzheimer’s disease and that people with two copies of the gene are at especially high risk, David Curtis, MD, PhD, Genetics Institute at University of College London, England, said in a statement.

“I do not see anything in this paper to justify the claim that carrying two copies of APOE4 represents some ‘distinct genetic form’ of Alzheimer’s disease,” Dr. Curtis said. “No matter how many alleles of APOE4 one carries, the underlying disease processes seem similar across cases of Alzheimer’s disease, suggesting that any effective treatment and prevention strategies, which have yet to be developed would have broad applicability.” 

Study funders included Fondo de Investigaciones Sanitario, Carlos III Health Institute, Fondo Europeo de Desarrollo Regional, Unión Europea, National Institutes of Health, the Department de Salut de la Generalitat de Catalunya, Horizon 2020–Research and Innovation Framework Programme from the European Union, La Caixa Foundation, EIT Digital, and the Alzheimer Association. Dr. Fortea reported receiving personal fees for service on the advisory boards, adjudication committees or speaker honoraria from AC Immune, Adamed, Alzheon, Biogen, Eisai, Esteve, Fujirebio, Ionis, Laboratorios Carnot, Life Molecular Imaging, Lilly, Lundbeck, Perha, Roche, and outside the submitted work. Dr. Johnson has served at scientific advisory boards for ALZPath, Enigma and Roche Diagnostics. Dr. Sperling has received personal consulting fees from AbbVie, AC Immune, Acumen, Alector, Bristol Myers Squibb, Janssen, Genentech, Ionis and Vaxxinity outside the submitted work. Dr. Huang is a co-founder and scientific advisory board member of GABAeron, Inc. Dr. Mathews reports consultancies with Sudo Biosciences, Nimbus, Redburn. Dr. Hara and Dr. Curtis reported no conflicts. Complete funding sources and disclosures are included in the original articles. 

A version of this article appeared on Medscape.com.

Having two copies of the APOE4 gene may be the genetic cause of up to one fifth of all Alzheimer’s disease cases, a new study suggests.

More than 95% of those with two copies of the gene (APOE4 homozygotes) in a large multicohort study had higher levels of Alzheimer’s disease biomarkers by age 55 years than did those with other APOE gene variants. By age 65 years, most had developed Alzheimer’s disease symptoms and showed abnormal amyloid levels in cerebrospinal fluid and on PET.

Investigators said that such a high penetrance of Alzheimer’s disease pathology in this group suggests that APOE4 may not be just a risk factor for Alzheimer’s disease but also a distinct genetic form of the disease. 

“Sometimes, we say we don’t know the cause of Alzheimer’s disease, but this would be behind 15%-20% of the population of people with Alzheimer’s disease,” lead investigator Juan Fortea, MD, PhD, director of the Memory Unit of the Neurology Department at the Hospital of Sant Pau, Barcelona, Spain, said at a press briefing.

Although some experts urge caution in interpreting these results, investigators and others say the findings, published online in Nature Medicine, could lead to calls for more widespread testing for APOE4 and may spur drug development.
 

High AD Penetrance

Mutations in the APP, PSEN1, and PSEN2 genes are linked to risk for early-onset autosomal-dominant Alzheimer’s disease, and dozens of other genes are associated with greater odds of late-onset disease. Among all these genes, APOE is considered the strongest genetic risk factor for late-onset Alzheimer’s disease. 

Prior studies found that APOE4 homozygotes have a 60% lifetime risk for Alzheimer’s disease by age 85 years, a risk higher than that found with other gene variants or in single APOE carriers or noncarriers. 

Despite that, no previous study had examined the predictability of symptom onset in APOE4 homozygotes, which make up about 2%-3% of the general population and 15-20% of those with Alzheimer’s disease. And because most biomarker studies have combined single- and double-carrier APOE4 carriers into one group, very little was known about the penetrance or disease progression in APOE4 homozygotes.

Investigators analyzed data from 3200 brain donors from the National Alzheimer’s Coordinating Center and more than 10,000 people with Alzheimer’s disease biomarkers from five multicenter cohorts in the United States and Europe.

Nearly all APOE4 homozygotes had either high or intermediate Alzheimer’s disease neuropathologic change scores compared with about 50% among APOE3 homozygotes and was the same regardless of age at time of death. 

Beginning at age 55 years, APOE4 homozygotes exhibited higher levels of abnormal Alzheimer’s disease biomarkers than did APOE3 homozygotes. By age 65 years, nearly everyone with two copies of APOE4 showed abnormal levels of amyloid in cerebrospinal fluid and 75% had positive amyloid scans. 

Other biomarkers showed a biologic penetrance of Alzheimer’s disease that increased with age. By age 80 years, penetrance for all amyloid and tau biomarkers reached 88%. 

Postmortem analysis revealed Alzheimer’s disease and dementia symptoms were evident in APOE4 homozygotes 7-10 years before APOE3 homozygotes, with Alzheimer’s disease symptoms present at age 65 years, minor cognitive impairment at 72 years, dementia at 74 years, and death at 77 years (P <.05 differences).

When they limited analysis to only those who developed Alzheimer’s disease dementia, investigators found no difference in amyloid or tau accumulation between APOE3 and APOE4 homozygotes. That was surprising given the much earlier presentation of clinical symptoms and biomarkers in those who carried two copies of APOE4.
 

 

 

More Than a Risk Factor

Overall, study findings provide evidence that APOE4 homozygotes represent another form of genetically determined Alzheimer’s disease, similar to autosomal-dominant Alzheimer’s disease and down syndrome-associated Alzheimer’s disease, investigators said.

“Our work showed that APOE4 homozygotes meet the three main characteristics of genetically determined Alzheimer’s disease, namely near-full penetrance, symptom onset predictability and a predictable sequence of biomarker and clinical changes,” they wrote. 

Based on the results, investigators recommend that future clinical trials avoid combining single and double APOE4 carriers into one study group. 

Because the global average proportion of APOE4 homozygotes is estimated to be approximately 2%, APOE4-homozygous Alzheimer’s disease may represent one of the most frequently occurring Mendelian diseases worldwide. This could have implications for genetic counseling and genetic screening recommendations, they said. 

“We may need to start treating these homozygotes as a separate group in our research so we can really understand the relation between amyloid and tau and symptoms in E4 homozygotes in a way that we have not been able to because of our practice in the field of thinking that APOE4 is this unitary risk effect,” co-investigator Sterling Johnson, PhD, professor of geriatrics and dementia, University of Wisconsin-Madison, said at a press briefing.

The findings may also have implications for Alzheimer’s disease prevention, investigators added.

“What’s particularly important is the promise that perhaps we could treat people before symptoms, particularly in people who already have the disease in their brain such as APOE4 homozygotes, which reliably predicts that they will have impairment and try to treat them beforehand,” co-investigator Reisa Sperling, MD, director of the Center for Alzheimer Research and Treatment at Brigham and Women›s Hospital and Massachusetts General Hospital, Boston, said at a press briefing. 

“This is important for preventing Alzheimer’s-related dementia and a real movement forward in defining the disease on the basis of genetics and biomarkers,” she added. 
 

Experts Offer Mixed Reactions

Commenting on the findings, Paul Mathews, MD, DPhil, group leader of the UK Dementia Research Institute Centre at Imperial College, said that the data point to a need to look at APOE4 differently. 

“One implication of this work is that testing for APOE4 gene homozygosity should be assessed for use clinically, when late middle-aged people present to their doctors with symptoms of dementia,” Dr. Mathews, who was not part of the study, said in a statement. 

In an accompany editorial, Yadong Huang, MD, PhD, Departments of Neurology and Pathology, University of California, San Francisco, and co-authors noted that the findings also have implications for clinical drug trials.

“So far, APOE4 homozygotes have not been treated as a separate predefined treatment group in clinical trials,” they wrote. “Following this study, APOE4 status must be recognized as a crucial parameter in trial design, patient recruitment and data analysis, with APOE4 homozygotes and heterozygotes being clearly separated. Such an approach may enhance the treatment efficacy and help tailor therapeutic interventions more effectively towards genetically defined patient populations.”

Other experts urge caution when interpreting the findings. 

“It is clear that APOE4 homozygosity is tightly linked to the appearance of Alzheimer’s-related pathology, but even at age 80, 12% of people with APOE4/E4 did not have amyloid/tau biomarkers,” said Yuko Hara, PhD, director of aging and Alzheimer’s disease prevention at the Alzheimer’s Drug Discovery Foundation. “Also, having two copies of APOE4 does not mean you will definitely develop symptoms of Alzheimer’s disease in your lifetime,” Dr. Hara added. 

Researchers have long known that APOE4 is a strong risk factor for Alzheimer’s disease and that people with two copies of the gene are at especially high risk, David Curtis, MD, PhD, Genetics Institute at University of College London, England, said in a statement.

“I do not see anything in this paper to justify the claim that carrying two copies of APOE4 represents some ‘distinct genetic form’ of Alzheimer’s disease,” Dr. Curtis said. “No matter how many alleles of APOE4 one carries, the underlying disease processes seem similar across cases of Alzheimer’s disease, suggesting that any effective treatment and prevention strategies, which have yet to be developed would have broad applicability.” 

Study funders included Fondo de Investigaciones Sanitario, Carlos III Health Institute, Fondo Europeo de Desarrollo Regional, Unión Europea, National Institutes of Health, the Department de Salut de la Generalitat de Catalunya, Horizon 2020–Research and Innovation Framework Programme from the European Union, La Caixa Foundation, EIT Digital, and the Alzheimer Association. Dr. Fortea reported receiving personal fees for service on the advisory boards, adjudication committees or speaker honoraria from AC Immune, Adamed, Alzheon, Biogen, Eisai, Esteve, Fujirebio, Ionis, Laboratorios Carnot, Life Molecular Imaging, Lilly, Lundbeck, Perha, Roche, and outside the submitted work. Dr. Johnson has served at scientific advisory boards for ALZPath, Enigma and Roche Diagnostics. Dr. Sperling has received personal consulting fees from AbbVie, AC Immune, Acumen, Alector, Bristol Myers Squibb, Janssen, Genentech, Ionis and Vaxxinity outside the submitted work. Dr. Huang is a co-founder and scientific advisory board member of GABAeron, Inc. Dr. Mathews reports consultancies with Sudo Biosciences, Nimbus, Redburn. Dr. Hara and Dr. Curtis reported no conflicts. Complete funding sources and disclosures are included in the original articles. 

A version of this article appeared on Medscape.com.

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High Olive Oil Intake Linked to Lower Dementia-Related Death

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Wed, 05/08/2024 - 12:04

High olive oil consumption is associated with a significant decreased risk for dementia-related mortality, regardless of overall diet quality, a new study suggested.

Data from a prospective study of more than 92,000 people showed consuming at least 7 g of olive oil a day — about half a tablespoon — was associated with a 28% lower risk for dementia-related death.

Replacing one teaspoon of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8%-14% lower risk for dementia-related mortality.

“Opting for olive oil, a natural product, instead of more processed fats such as margarine and mayonnaise, is a safe choice and may reduce risk of fatal dementia,” said lead investigator Anne-Julie Tessier, RD, PhD, research associate, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston.

However, “intervention studies are needed to confirm causal effect and optimal quantity of olive oil intake,” she added.

The study was published online in JAMA Network Open.
 

A Spoonful of Olive Oil

A growing body of evidence has shown a link between the Mediterranean diet and preserved cognitive function and lower risk for cardiovascular disease (CVD). But its association with dementia mortality was unknown.

Investigators analyzed data on over 92,000 participants (66% women; mean age, 56 years) in the Nurses’ Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) who were free of CVD and cancer at baseline.

Both studies were conducted between 1990 and 2018, with olive oil intake assessed every 4 years using a food frequency questionnaire. Dementia-related mortality was ascertained from death records.

The researchers also evaluated the joint association of diet quality (particularly adherence to the Mediterranean diet and Alternative Healthy Eating Index score) and olive oil consumption with the risk for dementia-related mortality. And they estimated the difference in the risk for dementia-related mortality when other dietary fats were substituted with an equivalent amount of olive oil.

There were 4751 dementia-related deaths during the 28-year follow-up period. People with two copies of the apolipoprotein epsilon-4 (APOE epsilon-4) allele — a known risk factor for Alzheimer’s disease — had a fivefold to ninefold greater likelihood of dementia-related death.

Compared with no or rare olive oil intake, consumption of 7 g of olive oil or more per day was associated with a 28% lower risk for dementia-related mortality (adjusted hazard ratio [HR], 0.72; P < .001), after adjusting for lifestyle and socioeconomic factors. The finding remained consistent even with further adjustment for the APOE epsilon-4 allele.

Each 5-g increment in olive oil consumption had an inverse association with dementia-related death in women (HR, 0.88; 95% CI, 0.84-0.93) but not in men (HR, 0.96; 95% CI, 0.88-1.04).

No interaction by diet quality scores was found.
 

No Link With Diet Quality

“Typically, people who use olive oil for cooking or as a dressing have an overall better quality of their diet, but interestingly, we found the association between more olive oil and reduced risk of dementia-related death to be regardless of this factor,” Dr. Tessier said.

Replacing 5 g per day of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8%-14% lower risk for dementia mortality. Substitutions for other vegetable oils or butter were not significant.

“Some antioxidant compounds in olive oil can cross the blood-brain barrier, potentially having a direct effect on the brain,” Dr. Tessier said. “It is also possible that olive oil has an indirect effect on brain health by benefiting cardiovascular health.”

The authors noted several study limitations, including the possibility of reverse causation, due to the observational nature of the study.

It is also plausible that higher olive oil intake could be indicative of a healthier diet and higher socioeconomic status, although the results remained consistent after accounting these factors, the authors noted.

The study population included only healthcare professionals and was primarily non-Hispanic White people, which could limit generalizability.
 

 

 

Causality Versus Connection

Commenting on the findings, Rebecca M. Edelmayer, PhD, senior director of scientific engagement for the Alzheimer’s Association, cautioned that the study was designed to show correlation, not causation.

Other notable limitations include measuring prevalence or incidence of dementia from death records because dementia and Alzheimer’s disease are often underreported as a cause of death.

Moreover, people in the highest olive oil consumption group also had better diet quality, higher alcohol intake, were more physically active, and less likely to smoke, Dr. Edelmayer said.

“All of these factors may have an impact on risk of cognitive decline and dementia, separately from or in addition to olive oil consumption,” said Dr. Edelmayer, who was not involved with the study.

She echoed the authors’ concerns that the study was conducted in predominantly non-Hispanic White people and noted that the protective benefits of olive oil were no longer statistically significant for men after adjusting for potential confounders.

It “would be wonderful if a particular food could delay or prevent Alzheimer’s disease, but we do not have scientific evidence that these claims are true,” Dr. Edelmayer said. “We need randomized controlled clinical trials to evaluate whether any foods have a scientifically proven beneficial effect.”

This study is supported by a research grant from the National Institutes of Health to the senior author. The NHS, NHSII, and HPFS are supported by grants from the National Institutes of Health. Tessier is supported by the Canadian Institutes of Health Research Postdoctoral Fellowship Award. Senior author Guasch-Ferré is supported by a Novo Nordisk Foundation grant. Dr. Tessier reported no other relevant financial relationships. The other authors’ disclosures are listed on the original paper. Dr. Edelmayer reported no relevant financial relationships.

A version of this article appeared on Medscape.com.

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High olive oil consumption is associated with a significant decreased risk for dementia-related mortality, regardless of overall diet quality, a new study suggested.

Data from a prospective study of more than 92,000 people showed consuming at least 7 g of olive oil a day — about half a tablespoon — was associated with a 28% lower risk for dementia-related death.

Replacing one teaspoon of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8%-14% lower risk for dementia-related mortality.

“Opting for olive oil, a natural product, instead of more processed fats such as margarine and mayonnaise, is a safe choice and may reduce risk of fatal dementia,” said lead investigator Anne-Julie Tessier, RD, PhD, research associate, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston.

However, “intervention studies are needed to confirm causal effect and optimal quantity of olive oil intake,” she added.

The study was published online in JAMA Network Open.
 

A Spoonful of Olive Oil

A growing body of evidence has shown a link between the Mediterranean diet and preserved cognitive function and lower risk for cardiovascular disease (CVD). But its association with dementia mortality was unknown.

Investigators analyzed data on over 92,000 participants (66% women; mean age, 56 years) in the Nurses’ Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) who were free of CVD and cancer at baseline.

Both studies were conducted between 1990 and 2018, with olive oil intake assessed every 4 years using a food frequency questionnaire. Dementia-related mortality was ascertained from death records.

The researchers also evaluated the joint association of diet quality (particularly adherence to the Mediterranean diet and Alternative Healthy Eating Index score) and olive oil consumption with the risk for dementia-related mortality. And they estimated the difference in the risk for dementia-related mortality when other dietary fats were substituted with an equivalent amount of olive oil.

There were 4751 dementia-related deaths during the 28-year follow-up period. People with two copies of the apolipoprotein epsilon-4 (APOE epsilon-4) allele — a known risk factor for Alzheimer’s disease — had a fivefold to ninefold greater likelihood of dementia-related death.

Compared with no or rare olive oil intake, consumption of 7 g of olive oil or more per day was associated with a 28% lower risk for dementia-related mortality (adjusted hazard ratio [HR], 0.72; P < .001), after adjusting for lifestyle and socioeconomic factors. The finding remained consistent even with further adjustment for the APOE epsilon-4 allele.

Each 5-g increment in olive oil consumption had an inverse association with dementia-related death in women (HR, 0.88; 95% CI, 0.84-0.93) but not in men (HR, 0.96; 95% CI, 0.88-1.04).

No interaction by diet quality scores was found.
 

No Link With Diet Quality

“Typically, people who use olive oil for cooking or as a dressing have an overall better quality of their diet, but interestingly, we found the association between more olive oil and reduced risk of dementia-related death to be regardless of this factor,” Dr. Tessier said.

Replacing 5 g per day of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8%-14% lower risk for dementia mortality. Substitutions for other vegetable oils or butter were not significant.

“Some antioxidant compounds in olive oil can cross the blood-brain barrier, potentially having a direct effect on the brain,” Dr. Tessier said. “It is also possible that olive oil has an indirect effect on brain health by benefiting cardiovascular health.”

The authors noted several study limitations, including the possibility of reverse causation, due to the observational nature of the study.

It is also plausible that higher olive oil intake could be indicative of a healthier diet and higher socioeconomic status, although the results remained consistent after accounting these factors, the authors noted.

The study population included only healthcare professionals and was primarily non-Hispanic White people, which could limit generalizability.
 

 

 

Causality Versus Connection

Commenting on the findings, Rebecca M. Edelmayer, PhD, senior director of scientific engagement for the Alzheimer’s Association, cautioned that the study was designed to show correlation, not causation.

Other notable limitations include measuring prevalence or incidence of dementia from death records because dementia and Alzheimer’s disease are often underreported as a cause of death.

Moreover, people in the highest olive oil consumption group also had better diet quality, higher alcohol intake, were more physically active, and less likely to smoke, Dr. Edelmayer said.

“All of these factors may have an impact on risk of cognitive decline and dementia, separately from or in addition to olive oil consumption,” said Dr. Edelmayer, who was not involved with the study.

She echoed the authors’ concerns that the study was conducted in predominantly non-Hispanic White people and noted that the protective benefits of olive oil were no longer statistically significant for men after adjusting for potential confounders.

It “would be wonderful if a particular food could delay or prevent Alzheimer’s disease, but we do not have scientific evidence that these claims are true,” Dr. Edelmayer said. “We need randomized controlled clinical trials to evaluate whether any foods have a scientifically proven beneficial effect.”

This study is supported by a research grant from the National Institutes of Health to the senior author. The NHS, NHSII, and HPFS are supported by grants from the National Institutes of Health. Tessier is supported by the Canadian Institutes of Health Research Postdoctoral Fellowship Award. Senior author Guasch-Ferré is supported by a Novo Nordisk Foundation grant. Dr. Tessier reported no other relevant financial relationships. The other authors’ disclosures are listed on the original paper. Dr. Edelmayer reported no relevant financial relationships.

A version of this article appeared on Medscape.com.

High olive oil consumption is associated with a significant decreased risk for dementia-related mortality, regardless of overall diet quality, a new study suggested.

Data from a prospective study of more than 92,000 people showed consuming at least 7 g of olive oil a day — about half a tablespoon — was associated with a 28% lower risk for dementia-related death.

Replacing one teaspoon of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8%-14% lower risk for dementia-related mortality.

“Opting for olive oil, a natural product, instead of more processed fats such as margarine and mayonnaise, is a safe choice and may reduce risk of fatal dementia,” said lead investigator Anne-Julie Tessier, RD, PhD, research associate, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston.

However, “intervention studies are needed to confirm causal effect and optimal quantity of olive oil intake,” she added.

The study was published online in JAMA Network Open.
 

A Spoonful of Olive Oil

A growing body of evidence has shown a link between the Mediterranean diet and preserved cognitive function and lower risk for cardiovascular disease (CVD). But its association with dementia mortality was unknown.

Investigators analyzed data on over 92,000 participants (66% women; mean age, 56 years) in the Nurses’ Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) who were free of CVD and cancer at baseline.

Both studies were conducted between 1990 and 2018, with olive oil intake assessed every 4 years using a food frequency questionnaire. Dementia-related mortality was ascertained from death records.

The researchers also evaluated the joint association of diet quality (particularly adherence to the Mediterranean diet and Alternative Healthy Eating Index score) and olive oil consumption with the risk for dementia-related mortality. And they estimated the difference in the risk for dementia-related mortality when other dietary fats were substituted with an equivalent amount of olive oil.

There were 4751 dementia-related deaths during the 28-year follow-up period. People with two copies of the apolipoprotein epsilon-4 (APOE epsilon-4) allele — a known risk factor for Alzheimer’s disease — had a fivefold to ninefold greater likelihood of dementia-related death.

Compared with no or rare olive oil intake, consumption of 7 g of olive oil or more per day was associated with a 28% lower risk for dementia-related mortality (adjusted hazard ratio [HR], 0.72; P < .001), after adjusting for lifestyle and socioeconomic factors. The finding remained consistent even with further adjustment for the APOE epsilon-4 allele.

Each 5-g increment in olive oil consumption had an inverse association with dementia-related death in women (HR, 0.88; 95% CI, 0.84-0.93) but not in men (HR, 0.96; 95% CI, 0.88-1.04).

No interaction by diet quality scores was found.
 

No Link With Diet Quality

“Typically, people who use olive oil for cooking or as a dressing have an overall better quality of their diet, but interestingly, we found the association between more olive oil and reduced risk of dementia-related death to be regardless of this factor,” Dr. Tessier said.

Replacing 5 g per day of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8%-14% lower risk for dementia mortality. Substitutions for other vegetable oils or butter were not significant.

“Some antioxidant compounds in olive oil can cross the blood-brain barrier, potentially having a direct effect on the brain,” Dr. Tessier said. “It is also possible that olive oil has an indirect effect on brain health by benefiting cardiovascular health.”

The authors noted several study limitations, including the possibility of reverse causation, due to the observational nature of the study.

It is also plausible that higher olive oil intake could be indicative of a healthier diet and higher socioeconomic status, although the results remained consistent after accounting these factors, the authors noted.

The study population included only healthcare professionals and was primarily non-Hispanic White people, which could limit generalizability.
 

 

 

Causality Versus Connection

Commenting on the findings, Rebecca M. Edelmayer, PhD, senior director of scientific engagement for the Alzheimer’s Association, cautioned that the study was designed to show correlation, not causation.

Other notable limitations include measuring prevalence or incidence of dementia from death records because dementia and Alzheimer’s disease are often underreported as a cause of death.

Moreover, people in the highest olive oil consumption group also had better diet quality, higher alcohol intake, were more physically active, and less likely to smoke, Dr. Edelmayer said.

“All of these factors may have an impact on risk of cognitive decline and dementia, separately from or in addition to olive oil consumption,” said Dr. Edelmayer, who was not involved with the study.

She echoed the authors’ concerns that the study was conducted in predominantly non-Hispanic White people and noted that the protective benefits of olive oil were no longer statistically significant for men after adjusting for potential confounders.

It “would be wonderful if a particular food could delay or prevent Alzheimer’s disease, but we do not have scientific evidence that these claims are true,” Dr. Edelmayer said. “We need randomized controlled clinical trials to evaluate whether any foods have a scientifically proven beneficial effect.”

This study is supported by a research grant from the National Institutes of Health to the senior author. The NHS, NHSII, and HPFS are supported by grants from the National Institutes of Health. Tessier is supported by the Canadian Institutes of Health Research Postdoctoral Fellowship Award. Senior author Guasch-Ferré is supported by a Novo Nordisk Foundation grant. Dr. Tessier reported no other relevant financial relationships. The other authors’ disclosures are listed on the original paper. Dr. Edelmayer reported no relevant financial relationships.

A version of this article appeared on Medscape.com.

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Proton Pump Inhibitors Tied to Migraine, Other Severe Headache Types

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Changed
Tue, 05/07/2024 - 13:37

Proton pump inhibitors (PPIs), which are used to control acid reflux, are associated with an increased risk for migraine and other severe headache types, new research showed. 

Using data from the National Health and Nutrition Examination Survey (NHANES), investigators conducted a cross-sectional analysis and found all types of acid-suppression therapy were associated with an increased risk for severe headache including migraine but that PPIs conferred the greatest risk.

“It’s important to note that many people do need acid-reducing medications to manage acid reflux or other conditions, and people with migraine or severe headache who are taking these drugs or supplements should talk with their doctors about whether they should continue,” lead author Margaret Slavin, PhD, of the University of Maryland in College Park, said in a press release

The findings were published online  in Neurology Clinical Practice
 

New Look at Old Data

Previous research has shown that headache is listed among the most common adverse reactions in adults taking PPIs and histamine receptor agonists (H2RAs), which include cimetidine, famotidine, and nizatidine.

Other large studies of health databases have shown increased headache risk within a week of PPI exposure.

To compare the risk from PPIs versus H2RAs and other generics, researchers analyzed data from the NHANES for those who used PPIs, H2RAs, and generic antacids to learn more about the potential link between acid-suppression therapy and headache.

They used survey data from 1999 to 2004, the only years the NHANES included a question about migraine and other headache during the past 3 months. 

Investigators analyzed data for 11,800 participants aged 20 years or older who used prescription drugs, over-the-counter medications, and nutritional supplements during the past month. 

Participants who used acid-suppressing medications had an increased risk for migraine or severe headache versus those who did not use these agents. Investigators found PPIs were tied to a 70% increased risk, while H2RAs and antacids were associated with 40% and 30% higher risks, respectively. Use of any type of acid-suppression therapy was tied to a 47% increased risk for severe headache.
 

Magnesium a Risk Factor?

While magnesium supplements are sometimes prescribed as a “natural” headache prevention therapy to prevent migraine and other headache types, the investigators noted they were surprised to find individuals taking H2RAs who met the dietary reference intake for magnesium had a nearly threefold increased risk for migraine or severe headache (odds ratio, 2.80; 95% CI, 1.02-1.45; P = .025).

However, there was no association between magnesium and the other acid-reducing medications. 

The study’s limitations included the use of a single question to identify migraine or severe headache, which may have resulted in some misclassification of the outcome. The authors also pointed out that dietary and drug-intake data may be subject to recall bias. 

“These results suggest that there is a need for more intentionally designed prospective work to inform the extent to which associations between migraine and acid-suppression therapy are merely detecting comorbidities or to what extent migraine is an adverse event associated with the medications,” the authors wrote. 

There was no targeted funding. Disclosures are noted in the original article.

A version of this article appeared on Medscape.com.

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Proton pump inhibitors (PPIs), which are used to control acid reflux, are associated with an increased risk for migraine and other severe headache types, new research showed. 

Using data from the National Health and Nutrition Examination Survey (NHANES), investigators conducted a cross-sectional analysis and found all types of acid-suppression therapy were associated with an increased risk for severe headache including migraine but that PPIs conferred the greatest risk.

“It’s important to note that many people do need acid-reducing medications to manage acid reflux or other conditions, and people with migraine or severe headache who are taking these drugs or supplements should talk with their doctors about whether they should continue,” lead author Margaret Slavin, PhD, of the University of Maryland in College Park, said in a press release

The findings were published online  in Neurology Clinical Practice
 

New Look at Old Data

Previous research has shown that headache is listed among the most common adverse reactions in adults taking PPIs and histamine receptor agonists (H2RAs), which include cimetidine, famotidine, and nizatidine.

Other large studies of health databases have shown increased headache risk within a week of PPI exposure.

To compare the risk from PPIs versus H2RAs and other generics, researchers analyzed data from the NHANES for those who used PPIs, H2RAs, and generic antacids to learn more about the potential link between acid-suppression therapy and headache.

They used survey data from 1999 to 2004, the only years the NHANES included a question about migraine and other headache during the past 3 months. 

Investigators analyzed data for 11,800 participants aged 20 years or older who used prescription drugs, over-the-counter medications, and nutritional supplements during the past month. 

Participants who used acid-suppressing medications had an increased risk for migraine or severe headache versus those who did not use these agents. Investigators found PPIs were tied to a 70% increased risk, while H2RAs and antacids were associated with 40% and 30% higher risks, respectively. Use of any type of acid-suppression therapy was tied to a 47% increased risk for severe headache.
 

Magnesium a Risk Factor?

While magnesium supplements are sometimes prescribed as a “natural” headache prevention therapy to prevent migraine and other headache types, the investigators noted they were surprised to find individuals taking H2RAs who met the dietary reference intake for magnesium had a nearly threefold increased risk for migraine or severe headache (odds ratio, 2.80; 95% CI, 1.02-1.45; P = .025).

However, there was no association between magnesium and the other acid-reducing medications. 

The study’s limitations included the use of a single question to identify migraine or severe headache, which may have resulted in some misclassification of the outcome. The authors also pointed out that dietary and drug-intake data may be subject to recall bias. 

“These results suggest that there is a need for more intentionally designed prospective work to inform the extent to which associations between migraine and acid-suppression therapy are merely detecting comorbidities or to what extent migraine is an adverse event associated with the medications,” the authors wrote. 

There was no targeted funding. Disclosures are noted in the original article.

A version of this article appeared on Medscape.com.

Proton pump inhibitors (PPIs), which are used to control acid reflux, are associated with an increased risk for migraine and other severe headache types, new research showed. 

Using data from the National Health and Nutrition Examination Survey (NHANES), investigators conducted a cross-sectional analysis and found all types of acid-suppression therapy were associated with an increased risk for severe headache including migraine but that PPIs conferred the greatest risk.

“It’s important to note that many people do need acid-reducing medications to manage acid reflux or other conditions, and people with migraine or severe headache who are taking these drugs or supplements should talk with their doctors about whether they should continue,” lead author Margaret Slavin, PhD, of the University of Maryland in College Park, said in a press release

The findings were published online  in Neurology Clinical Practice
 

New Look at Old Data

Previous research has shown that headache is listed among the most common adverse reactions in adults taking PPIs and histamine receptor agonists (H2RAs), which include cimetidine, famotidine, and nizatidine.

Other large studies of health databases have shown increased headache risk within a week of PPI exposure.

To compare the risk from PPIs versus H2RAs and other generics, researchers analyzed data from the NHANES for those who used PPIs, H2RAs, and generic antacids to learn more about the potential link between acid-suppression therapy and headache.

They used survey data from 1999 to 2004, the only years the NHANES included a question about migraine and other headache during the past 3 months. 

Investigators analyzed data for 11,800 participants aged 20 years or older who used prescription drugs, over-the-counter medications, and nutritional supplements during the past month. 

Participants who used acid-suppressing medications had an increased risk for migraine or severe headache versus those who did not use these agents. Investigators found PPIs were tied to a 70% increased risk, while H2RAs and antacids were associated with 40% and 30% higher risks, respectively. Use of any type of acid-suppression therapy was tied to a 47% increased risk for severe headache.
 

Magnesium a Risk Factor?

While magnesium supplements are sometimes prescribed as a “natural” headache prevention therapy to prevent migraine and other headache types, the investigators noted they were surprised to find individuals taking H2RAs who met the dietary reference intake for magnesium had a nearly threefold increased risk for migraine or severe headache (odds ratio, 2.80; 95% CI, 1.02-1.45; P = .025).

However, there was no association between magnesium and the other acid-reducing medications. 

The study’s limitations included the use of a single question to identify migraine or severe headache, which may have resulted in some misclassification of the outcome. The authors also pointed out that dietary and drug-intake data may be subject to recall bias. 

“These results suggest that there is a need for more intentionally designed prospective work to inform the extent to which associations between migraine and acid-suppression therapy are merely detecting comorbidities or to what extent migraine is an adverse event associated with the medications,” the authors wrote. 

There was no targeted funding. Disclosures are noted in the original article.

A version of this article appeared on Medscape.com.

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Robotic Pet Therapy in the Intensive Care Unit

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Critical illness is commonly associated with interrelated conditions including pain, agitation, delirium, immobility, and sleep disruption (PADIS). Managing PADIS is often complex and includes pharmacologic and nonpharmacologic interventions.1 Incorporating multifaceted practices to enhance PADIS management has been shown to improve several intensive care unit (ICU)-related outcomes.2

Many pharmacologic PADIS treatments are ineffective or associated with adverse effects. For example, antipsychotics used for treating ICU-related delirium have not shown improved outcomes.3,4 Commonly used medications for agitation, such as benzodiazepines, increase delirium risk.5,6 Because of these limitations, several nonpharmacologic interventions for PADIS have been evaluated.

Pet therapy has been implemented in some ICU settings, but is not widely adopted.7 Also referred to as animal-assisted activities, animal-assisted therapy, or animal-assisted interventions, pet therapy typically involves interaction between a patient and a live animal (most commonly a dog) under the direction of an animal handler, with the intention of providing therapeutic benefit. Interactions frequently include meet and greet activities such as petting, but also could include walking or other activities. Pet therapy has been reported to reduce pain, agitation, and stress among ICU patients.8 Introducing a pet therapy program with live animals in the ICU could be challenging because of factors such as identifying trained, accredited animals and handlers, and managing infection control and other risks.9 As an alternative to live pets, robotic pet therapy has been shown to be beneficial—mostly outside the ICU—in settings such as long-term care.10,11 Although uncommon, robotic pets have been used in the ICU and hospital settings for therapeutic purposes.12 Robotic pets reduce many concerns associated with live animals while mimicking the behaviors of live animals and potentially offering many of the same benefits.

 

OBSERVATIONS

figure

The North Florida/South Georgia Veterans Health System (NF/SGVHS) implemented a novel robotic pet therapy program for patients requiring ICU care to improve the treatment of PADIS. Funding was provided through a Veterans Health Administration Innovation Grant procured by a clinical pharmacy specialist as the program’s champion. Goals of the robotic pet therapy program include reductions in: distressing symptoms associated with PADIS, use of psychoactive drugs and physical restraints, and ICU length of stay. The ICU team developed standard operating procedures and an order menu, which were integrated into the ICU prescriber ordering menu. Patients were selected for pet therapy based on PADIS scores and potential for positive response to pet therapy as assessed by the ICU team.Patients in medical and surgical ICU settings were eligible for the program. The robotic pets used in the program were Joy for AllCompanion Pets (Ageless Innovation LLC). Robotic cats and dogs were available and pets were “adopted’ by each patient (Figure). As an infection control measure, pets were not reissued or shared amongpatients and pets could be cleaned with a disinfectant solution. Nurses were primarily responsible for monitoring and documenting responses to robotic pet therapy.

table

It was necessary to secure buy-in from several services to successfully implement the program. The critical care clinical pharmacy specialists were responsible for ordering, storing, and dispensing the robotic pets. The NF/SGVHS innovation specialist helped secure funding, procure the robotic pet, and promote the program. The standard operating procedures for the program were developed by a multidisciplinary team with input from critical care nurses, intensivists, pharmacists, patient safety, and infection control (Table 1). Success of the program also required buy-in from ICU team members.

 

 

Program Impact

A retrospective cohort study was conducted to assess for improvements in PADIS symptoms and medication use post-intervention. Patients were included if they received robotic pet therapy in the ICU from July 10, 2019, to February 1, 2021. Individuals aged < 18 years or > 89 years, were pregnant, or were not receiving ICU-level care were excluded. Outcomes assessed included improvement in pain scores, agitation scores, sleep quality, resolution of delirium, and use of pain or psychoactive medications during patients’ ICU stay.

table 2

Thirty patients were included in the study (Table 2). After receiving a robotic pet, 9 (30%) patients recorded decreased pain scores, 15 (50%) recorded decreased agitation scores, 8 (27%) had resolution of delirium, and 2 (7%) described improvement in sleep. Pain medication use decreased in 12 (40%) patients and psychoactive medication use was reduced in 7 (23%) patients.

Limitations

The robotic pet therapy program has shown promising results; however, some aspects merit discussion. Evaluation of this program is limited by factors such as the observational study design, single-center patient sample, and lack of comparator group. Although no known adverse effects of robotic pet therapy were seen, it is possible that some patients may not have a favorable response. Challenges of implementing a robotic pet therapy program include cost and additional operational activities (storage, ordering, dispensing) necessary to maintain the program. Additional research is needed to evaluate the impact of robotic pet therapy on other outcomes including cost, ICU length of stay, and patient satisfaction.

 

CONCLUSIONS

Robotic pet therapy can be successfully implemented in the ICU and appears to provide a simple, safe, beneficial, nonpharmacologic intervention for PADIS. This study showed that many patients had favorable response to robotic pet therapy, indicating that it may be a viable alternative to traditional pet therapy. Other health systems could benefit from implementing programs similar to the robotic pet therapy program at NF/SGVHS.

Acknowledgments

The author would like to acknowledge Simran Panesar, PharmD, and Theresa Faison, PharmD, for their contributions to this project.

References

1. Devlin JW, Skrobik Y, Gélinas C, et al. Clinical practice guidelines for the prevention and management of pain, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU. Crit Care Med. 2018;46:e825-e873. doi:10.1097/CCM.0000000000003299

2. Pun BT, Balas MC, Barnes-Daly MA, et al. Caring for critically ill patients with the ABCDEF bundle: results of the ICU Liberation Collaborative in over 15,000 adults. Crit Care Med. 2019;47:3-14. doi:10.1097/CCM.0000000000003482

3. Andersen-Ranberg NC, Poulsen LM, Perner A, et al; AID-ICU Trial Group. Haloperidol for the treatment of delirium in ICU patients. N Engl J Med. 2022;387:2425-2435. doi:10.1056/NEJMoa2211868

4. Girard TD, Exline MC, Carson SS, et al; MIND-USA Investigators. Haloperidol and ziprasidone for treatment of delirium in critical illness. N Engl J Med. 2018;379:2506-2516. doi:10.1056/NEJMoa1808217

5. Riker RR, Shehabi Y, Bokesch PM, et al; SEDCOM (Safety and Efficacy of Dexmedetomidine Compared With Midazolam) Study Group. Dexmedetomidine vs midazolam for sedation of critically ill patients: a randomized trial. JAMA. 2009;301:489-499. doi:10.1001/jama.2009.56

6. Pandharipande P, Shintani A, Peterson J, et al. Lorazepam is an independent risk factor for transitioning to delirium in intensive care unit patients. Anesthesiology. 2006;104:21-26. doi:10.1097/00000542-200601000-00005

7. Society of Critical Care Medicine. ICU liberation bundle. Accessed February 27, 2024. https://www.sccm.org/ICULiberation/Home/ABCDEF-Bundles

8. Lovell T, Ranse K. Animal-assisted activities in the intensive care unit: a scoping review. Intensive Crit Care Nurs. 2022;73:103304. doi:10.1016/j.iccn.2022.103304

9. Hosey MM, Jaskulski J, Wegener ST, Chlan LL, Needham DM. Animal-assisted intervention in the ICU: a tool for humanization. Crit Care. 2018;22:22. doi:10.1186/s13054-018-1946-8

10. Jøranson N, Pedersen I, Rokstad AM, Ihlebæk C. Effects on symptoms of agitation and depression in persons with dementia participating in robot-assisted activity: a cluster-randomized controlled trial. J Am Med Dir Assoc. 2015;16:867-873. doi:10.1016/j.jamda.2015.05.002

11. Robinson H, Macdonald B, Kerse N, Broadbent E. The psychosocial effects of a companion robot: a randomized controlled trial. J Am Med Dir Assoc. 2013;14:661-667. doi:10.1016/j.jamda.2013.02.007

12. Schulman-Marcus J, Mookherjee S, Rice L, Lyubarova R. New approaches for the treatment of delirium: a case for robotic pets. Am J Med. 2019;132:781-782. doi:10.1016/j.amjmed.2018.12.039

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aNorth Florida/South Georgia Veterans Health System, Gainesville

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Correspondence:  Andrew Franck  ([email protected])

aNorth Florida/South Georgia Veterans Health System, Gainesville

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Disclaimer
The opinions expressed herein are those of the author and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

Author and Disclosure Information

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Correspondence:  Andrew Franck  ([email protected])

aNorth Florida/South Georgia Veterans Health System, Gainesville

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The author reports no actual or potential conflicts of interest or outside sources of funding with regard to this article.

Disclaimer
The opinions expressed herein are those of the author and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

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Related Articles

Critical illness is commonly associated with interrelated conditions including pain, agitation, delirium, immobility, and sleep disruption (PADIS). Managing PADIS is often complex and includes pharmacologic and nonpharmacologic interventions.1 Incorporating multifaceted practices to enhance PADIS management has been shown to improve several intensive care unit (ICU)-related outcomes.2

Many pharmacologic PADIS treatments are ineffective or associated with adverse effects. For example, antipsychotics used for treating ICU-related delirium have not shown improved outcomes.3,4 Commonly used medications for agitation, such as benzodiazepines, increase delirium risk.5,6 Because of these limitations, several nonpharmacologic interventions for PADIS have been evaluated.

Pet therapy has been implemented in some ICU settings, but is not widely adopted.7 Also referred to as animal-assisted activities, animal-assisted therapy, or animal-assisted interventions, pet therapy typically involves interaction between a patient and a live animal (most commonly a dog) under the direction of an animal handler, with the intention of providing therapeutic benefit. Interactions frequently include meet and greet activities such as petting, but also could include walking or other activities. Pet therapy has been reported to reduce pain, agitation, and stress among ICU patients.8 Introducing a pet therapy program with live animals in the ICU could be challenging because of factors such as identifying trained, accredited animals and handlers, and managing infection control and other risks.9 As an alternative to live pets, robotic pet therapy has been shown to be beneficial—mostly outside the ICU—in settings such as long-term care.10,11 Although uncommon, robotic pets have been used in the ICU and hospital settings for therapeutic purposes.12 Robotic pets reduce many concerns associated with live animals while mimicking the behaviors of live animals and potentially offering many of the same benefits.

 

OBSERVATIONS

figure

The North Florida/South Georgia Veterans Health System (NF/SGVHS) implemented a novel robotic pet therapy program for patients requiring ICU care to improve the treatment of PADIS. Funding was provided through a Veterans Health Administration Innovation Grant procured by a clinical pharmacy specialist as the program’s champion. Goals of the robotic pet therapy program include reductions in: distressing symptoms associated with PADIS, use of psychoactive drugs and physical restraints, and ICU length of stay. The ICU team developed standard operating procedures and an order menu, which were integrated into the ICU prescriber ordering menu. Patients were selected for pet therapy based on PADIS scores and potential for positive response to pet therapy as assessed by the ICU team.Patients in medical and surgical ICU settings were eligible for the program. The robotic pets used in the program were Joy for AllCompanion Pets (Ageless Innovation LLC). Robotic cats and dogs were available and pets were “adopted’ by each patient (Figure). As an infection control measure, pets were not reissued or shared amongpatients and pets could be cleaned with a disinfectant solution. Nurses were primarily responsible for monitoring and documenting responses to robotic pet therapy.

table

It was necessary to secure buy-in from several services to successfully implement the program. The critical care clinical pharmacy specialists were responsible for ordering, storing, and dispensing the robotic pets. The NF/SGVHS innovation specialist helped secure funding, procure the robotic pet, and promote the program. The standard operating procedures for the program were developed by a multidisciplinary team with input from critical care nurses, intensivists, pharmacists, patient safety, and infection control (Table 1). Success of the program also required buy-in from ICU team members.

 

 

Program Impact

A retrospective cohort study was conducted to assess for improvements in PADIS symptoms and medication use post-intervention. Patients were included if they received robotic pet therapy in the ICU from July 10, 2019, to February 1, 2021. Individuals aged < 18 years or > 89 years, were pregnant, or were not receiving ICU-level care were excluded. Outcomes assessed included improvement in pain scores, agitation scores, sleep quality, resolution of delirium, and use of pain or psychoactive medications during patients’ ICU stay.

table 2

Thirty patients were included in the study (Table 2). After receiving a robotic pet, 9 (30%) patients recorded decreased pain scores, 15 (50%) recorded decreased agitation scores, 8 (27%) had resolution of delirium, and 2 (7%) described improvement in sleep. Pain medication use decreased in 12 (40%) patients and psychoactive medication use was reduced in 7 (23%) patients.

Limitations

The robotic pet therapy program has shown promising results; however, some aspects merit discussion. Evaluation of this program is limited by factors such as the observational study design, single-center patient sample, and lack of comparator group. Although no known adverse effects of robotic pet therapy were seen, it is possible that some patients may not have a favorable response. Challenges of implementing a robotic pet therapy program include cost and additional operational activities (storage, ordering, dispensing) necessary to maintain the program. Additional research is needed to evaluate the impact of robotic pet therapy on other outcomes including cost, ICU length of stay, and patient satisfaction.

 

CONCLUSIONS

Robotic pet therapy can be successfully implemented in the ICU and appears to provide a simple, safe, beneficial, nonpharmacologic intervention for PADIS. This study showed that many patients had favorable response to robotic pet therapy, indicating that it may be a viable alternative to traditional pet therapy. Other health systems could benefit from implementing programs similar to the robotic pet therapy program at NF/SGVHS.

Acknowledgments

The author would like to acknowledge Simran Panesar, PharmD, and Theresa Faison, PharmD, for their contributions to this project.

Critical illness is commonly associated with interrelated conditions including pain, agitation, delirium, immobility, and sleep disruption (PADIS). Managing PADIS is often complex and includes pharmacologic and nonpharmacologic interventions.1 Incorporating multifaceted practices to enhance PADIS management has been shown to improve several intensive care unit (ICU)-related outcomes.2

Many pharmacologic PADIS treatments are ineffective or associated with adverse effects. For example, antipsychotics used for treating ICU-related delirium have not shown improved outcomes.3,4 Commonly used medications for agitation, such as benzodiazepines, increase delirium risk.5,6 Because of these limitations, several nonpharmacologic interventions for PADIS have been evaluated.

Pet therapy has been implemented in some ICU settings, but is not widely adopted.7 Also referred to as animal-assisted activities, animal-assisted therapy, or animal-assisted interventions, pet therapy typically involves interaction between a patient and a live animal (most commonly a dog) under the direction of an animal handler, with the intention of providing therapeutic benefit. Interactions frequently include meet and greet activities such as petting, but also could include walking or other activities. Pet therapy has been reported to reduce pain, agitation, and stress among ICU patients.8 Introducing a pet therapy program with live animals in the ICU could be challenging because of factors such as identifying trained, accredited animals and handlers, and managing infection control and other risks.9 As an alternative to live pets, robotic pet therapy has been shown to be beneficial—mostly outside the ICU—in settings such as long-term care.10,11 Although uncommon, robotic pets have been used in the ICU and hospital settings for therapeutic purposes.12 Robotic pets reduce many concerns associated with live animals while mimicking the behaviors of live animals and potentially offering many of the same benefits.

 

OBSERVATIONS

figure

The North Florida/South Georgia Veterans Health System (NF/SGVHS) implemented a novel robotic pet therapy program for patients requiring ICU care to improve the treatment of PADIS. Funding was provided through a Veterans Health Administration Innovation Grant procured by a clinical pharmacy specialist as the program’s champion. Goals of the robotic pet therapy program include reductions in: distressing symptoms associated with PADIS, use of psychoactive drugs and physical restraints, and ICU length of stay. The ICU team developed standard operating procedures and an order menu, which were integrated into the ICU prescriber ordering menu. Patients were selected for pet therapy based on PADIS scores and potential for positive response to pet therapy as assessed by the ICU team.Patients in medical and surgical ICU settings were eligible for the program. The robotic pets used in the program were Joy for AllCompanion Pets (Ageless Innovation LLC). Robotic cats and dogs were available and pets were “adopted’ by each patient (Figure). As an infection control measure, pets were not reissued or shared amongpatients and pets could be cleaned with a disinfectant solution. Nurses were primarily responsible for monitoring and documenting responses to robotic pet therapy.

table

It was necessary to secure buy-in from several services to successfully implement the program. The critical care clinical pharmacy specialists were responsible for ordering, storing, and dispensing the robotic pets. The NF/SGVHS innovation specialist helped secure funding, procure the robotic pet, and promote the program. The standard operating procedures for the program were developed by a multidisciplinary team with input from critical care nurses, intensivists, pharmacists, patient safety, and infection control (Table 1). Success of the program also required buy-in from ICU team members.

 

 

Program Impact

A retrospective cohort study was conducted to assess for improvements in PADIS symptoms and medication use post-intervention. Patients were included if they received robotic pet therapy in the ICU from July 10, 2019, to February 1, 2021. Individuals aged < 18 years or > 89 years, were pregnant, or were not receiving ICU-level care were excluded. Outcomes assessed included improvement in pain scores, agitation scores, sleep quality, resolution of delirium, and use of pain or psychoactive medications during patients’ ICU stay.

table 2

Thirty patients were included in the study (Table 2). After receiving a robotic pet, 9 (30%) patients recorded decreased pain scores, 15 (50%) recorded decreased agitation scores, 8 (27%) had resolution of delirium, and 2 (7%) described improvement in sleep. Pain medication use decreased in 12 (40%) patients and psychoactive medication use was reduced in 7 (23%) patients.

Limitations

The robotic pet therapy program has shown promising results; however, some aspects merit discussion. Evaluation of this program is limited by factors such as the observational study design, single-center patient sample, and lack of comparator group. Although no known adverse effects of robotic pet therapy were seen, it is possible that some patients may not have a favorable response. Challenges of implementing a robotic pet therapy program include cost and additional operational activities (storage, ordering, dispensing) necessary to maintain the program. Additional research is needed to evaluate the impact of robotic pet therapy on other outcomes including cost, ICU length of stay, and patient satisfaction.

 

CONCLUSIONS

Robotic pet therapy can be successfully implemented in the ICU and appears to provide a simple, safe, beneficial, nonpharmacologic intervention for PADIS. This study showed that many patients had favorable response to robotic pet therapy, indicating that it may be a viable alternative to traditional pet therapy. Other health systems could benefit from implementing programs similar to the robotic pet therapy program at NF/SGVHS.

Acknowledgments

The author would like to acknowledge Simran Panesar, PharmD, and Theresa Faison, PharmD, for their contributions to this project.

References

1. Devlin JW, Skrobik Y, Gélinas C, et al. Clinical practice guidelines for the prevention and management of pain, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU. Crit Care Med. 2018;46:e825-e873. doi:10.1097/CCM.0000000000003299

2. Pun BT, Balas MC, Barnes-Daly MA, et al. Caring for critically ill patients with the ABCDEF bundle: results of the ICU Liberation Collaborative in over 15,000 adults. Crit Care Med. 2019;47:3-14. doi:10.1097/CCM.0000000000003482

3. Andersen-Ranberg NC, Poulsen LM, Perner A, et al; AID-ICU Trial Group. Haloperidol for the treatment of delirium in ICU patients. N Engl J Med. 2022;387:2425-2435. doi:10.1056/NEJMoa2211868

4. Girard TD, Exline MC, Carson SS, et al; MIND-USA Investigators. Haloperidol and ziprasidone for treatment of delirium in critical illness. N Engl J Med. 2018;379:2506-2516. doi:10.1056/NEJMoa1808217

5. Riker RR, Shehabi Y, Bokesch PM, et al; SEDCOM (Safety and Efficacy of Dexmedetomidine Compared With Midazolam) Study Group. Dexmedetomidine vs midazolam for sedation of critically ill patients: a randomized trial. JAMA. 2009;301:489-499. doi:10.1001/jama.2009.56

6. Pandharipande P, Shintani A, Peterson J, et al. Lorazepam is an independent risk factor for transitioning to delirium in intensive care unit patients. Anesthesiology. 2006;104:21-26. doi:10.1097/00000542-200601000-00005

7. Society of Critical Care Medicine. ICU liberation bundle. Accessed February 27, 2024. https://www.sccm.org/ICULiberation/Home/ABCDEF-Bundles

8. Lovell T, Ranse K. Animal-assisted activities in the intensive care unit: a scoping review. Intensive Crit Care Nurs. 2022;73:103304. doi:10.1016/j.iccn.2022.103304

9. Hosey MM, Jaskulski J, Wegener ST, Chlan LL, Needham DM. Animal-assisted intervention in the ICU: a tool for humanization. Crit Care. 2018;22:22. doi:10.1186/s13054-018-1946-8

10. Jøranson N, Pedersen I, Rokstad AM, Ihlebæk C. Effects on symptoms of agitation and depression in persons with dementia participating in robot-assisted activity: a cluster-randomized controlled trial. J Am Med Dir Assoc. 2015;16:867-873. doi:10.1016/j.jamda.2015.05.002

11. Robinson H, Macdonald B, Kerse N, Broadbent E. The psychosocial effects of a companion robot: a randomized controlled trial. J Am Med Dir Assoc. 2013;14:661-667. doi:10.1016/j.jamda.2013.02.007

12. Schulman-Marcus J, Mookherjee S, Rice L, Lyubarova R. New approaches for the treatment of delirium: a case for robotic pets. Am J Med. 2019;132:781-782. doi:10.1016/j.amjmed.2018.12.039

References

1. Devlin JW, Skrobik Y, Gélinas C, et al. Clinical practice guidelines for the prevention and management of pain, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU. Crit Care Med. 2018;46:e825-e873. doi:10.1097/CCM.0000000000003299

2. Pun BT, Balas MC, Barnes-Daly MA, et al. Caring for critically ill patients with the ABCDEF bundle: results of the ICU Liberation Collaborative in over 15,000 adults. Crit Care Med. 2019;47:3-14. doi:10.1097/CCM.0000000000003482

3. Andersen-Ranberg NC, Poulsen LM, Perner A, et al; AID-ICU Trial Group. Haloperidol for the treatment of delirium in ICU patients. N Engl J Med. 2022;387:2425-2435. doi:10.1056/NEJMoa2211868

4. Girard TD, Exline MC, Carson SS, et al; MIND-USA Investigators. Haloperidol and ziprasidone for treatment of delirium in critical illness. N Engl J Med. 2018;379:2506-2516. doi:10.1056/NEJMoa1808217

5. Riker RR, Shehabi Y, Bokesch PM, et al; SEDCOM (Safety and Efficacy of Dexmedetomidine Compared With Midazolam) Study Group. Dexmedetomidine vs midazolam for sedation of critically ill patients: a randomized trial. JAMA. 2009;301:489-499. doi:10.1001/jama.2009.56

6. Pandharipande P, Shintani A, Peterson J, et al. Lorazepam is an independent risk factor for transitioning to delirium in intensive care unit patients. Anesthesiology. 2006;104:21-26. doi:10.1097/00000542-200601000-00005

7. Society of Critical Care Medicine. ICU liberation bundle. Accessed February 27, 2024. https://www.sccm.org/ICULiberation/Home/ABCDEF-Bundles

8. Lovell T, Ranse K. Animal-assisted activities in the intensive care unit: a scoping review. Intensive Crit Care Nurs. 2022;73:103304. doi:10.1016/j.iccn.2022.103304

9. Hosey MM, Jaskulski J, Wegener ST, Chlan LL, Needham DM. Animal-assisted intervention in the ICU: a tool for humanization. Crit Care. 2018;22:22. doi:10.1186/s13054-018-1946-8

10. Jøranson N, Pedersen I, Rokstad AM, Ihlebæk C. Effects on symptoms of agitation and depression in persons with dementia participating in robot-assisted activity: a cluster-randomized controlled trial. J Am Med Dir Assoc. 2015;16:867-873. doi:10.1016/j.jamda.2015.05.002

11. Robinson H, Macdonald B, Kerse N, Broadbent E. The psychosocial effects of a companion robot: a randomized controlled trial. J Am Med Dir Assoc. 2013;14:661-667. doi:10.1016/j.jamda.2013.02.007

12. Schulman-Marcus J, Mookherjee S, Rice L, Lyubarova R. New approaches for the treatment of delirium: a case for robotic pets. Am J Med. 2019;132:781-782. doi:10.1016/j.amjmed.2018.12.039

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Small Fiber Neuropathy in Veterans With Gulf War Illness

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Mon, 05/13/2024 - 14:10

Following deployment to operations Desert Shield and Desert Storm (Gulf War) in 1990 and 1991, many Gulf War veterans (GWVs) developed chronic, complex symptoms, including pain, dyscognition, and fatigue, with gastrointestinal, skin, and respiratory manifestations. This Gulf War Illness (GWI) is reported to affect about 30% of those deployed. More than 30 years later, there is no consensus as to the etiology of GWI, although some deployment-related exposures have been implicated.1

Accepted research definitions for GWI include the Centers for Disease Control and Prevention and Kansas definitions.2 The US Department of Veterans Affairs (VA) uses the terminology chronic multisymptom illness (CMI), which is an overarching diagnosis under which GWI falls. Although there is no consensus case definition for CMI, there is overlap with conditions such as fibromyalgia, myalgic encephalomyelitis/chronic fatigue syndrome, and irritable bowel syndrome; the VA considers these as qualifying clinical diagnoses.3 The pathophysiology of GWI is also unknown, though a frequently reported unifying feature is that of autonomic nervous system (ANS) dysfunction. Studies have demonstrated differences between veterans with GWI and those without GWI in both the reporting of symptoms attributable to ANS dysfunction and in physiologic evaluations of the ANS.4-10

Small fiber neuropathy (SFN), a condition with damage to the A-δ and C small nerve fibers, has been proposed as a potential mechanism for the pain and ANS dysfunction experienced in GWI.11-13 Symptoms of SFN are similar to those of GWI, with pain and ANS symptoms commonly reported.14,15 There are multiple diagnostic criteria for SFN, the most commonly used requiring the presence of appropriate symptoms in the absence of large fiber neuropathy and a skin biopsy demonstrating reduced intraepidermal nerve fiber density.16-19 Several conditions reportedly cause SFN, most notably diabetes/prediabetes. Autoimmune disease, vitamin B12 deficiency, monoclonal gammopathies, celiac disease, paraneoplastic syndromes, and sodium channel gene mutations may also contribute to SFN.20 Hyperlipidemia has been identified as a contributor, although it has been variably reported.21,22

Idiopathic neuropathies, SFN included, may be secondary to neurotoxicant exposures. Agents whose exposure or consumption have been associated with SFN include alcohol most prominently, but also the organic solvent n-hexane, heavy metals, and excess vitamin B6.20,23-25 Agents associated with large fiber neuropathy may also have relevance for SFN, as small fibers have been likened to the “canary in the coal mine” in that they may be more susceptible to neurotoxicants and are affected earlier in the disease process.26 In this way, SFN may be the harbinger of large fiber neuropathy in some cases. Of specific relevance for GWVs, organophosphates and carbamates are known to produce a delayed onset large fiber neuropathy.27-30 Exposure to petrochemical solvents has also been associated with large fiber neuropathies.31,32

The War Related Illness and Injury Study Center (WRIISC) is a clinical, research, and education center established by Congress in 2001. Its primary focus is on military exposures and postdeployment health of veterans. It is located at 3 sites: East Orange, New Jersey; Washington, DC; and Palo Alto, California. The New Jersey WRIISC began a program to evaluate GWVs with characteristic symptoms for possible SFN with use of a skin biopsy.

We hypothesize that SFN may underly much of GWI symptomatology and may not be accounted for by the putative etiologies detailed in review of the medical literature. This retrospective review of clinical evaluations for SFN in GWVs who sought care at the New Jersey WRIISC explored and addressed the following questions: (1) how common is biopsy-confirmed SFN in veterans with GWI; (2) do veterans with GWI and SFN report more symptoms attributable to ANS dysfunction when compared with veterans with GWI and no SFN; and (3) can SFN in veterans with GWI and SFN be explained by conditions and substances commonly associated with SFN? Institutional review board approval and waiver of consent was obtained from the Veterans Affairs New Jersey Health Care Center for the study.

 

 

Methods

A retrospective chart review was conducted on veterans evaluated at the WRIISC from March 1, 2015, to January 31, 2019. Inclusion criteria were: deployment to operations Desert Shield and Desert Storm between August 2, 1990, and February 28, 1991, and skin biopsy conducted at the WRIISC. Skin biopsies were obtained at the discretion of an examining clinician based on clinical indications, including neuropathic pain, ANS symptoms, and/or a fibromyalgia/chronic pain–type presentation.

Electronic health record review explicitly abstracted GWI status, results of the skin biopsy, and ANS symptom burden as determined by the Composite Autonomic Symptom Scale 31 (COMPASS 31) completed at the time of the WRIISC evaluation. Determination of GWI was established as per the clinical opinion of the WRIISC lead clinician or environmental exposure clinician as evidenced by a diagnosis of fibromyalgia or chronic fatigue syndrome, or explicit statement of CMI/GWI in the patient assessment. A diagnosis of SFN was established if clinical signs were present and an intraepidermal nerve fiber density below the lower limits, as compared to normative data from the clinical diagnostic laboratory (Therapath Neuropathology), was documented.

COMPASS 31 assesses symptoms across 6 domains (orthostatic, vasomotor, secretomotor, gastrointestinal, bladder, andpupillomotor). Patients are asked about symptom frequency (rarely to almost always), severity (mild to severe), and improvement (much worse to completely gone). Individual domain scores and a total weighted score (0-100) have demonstrated good validity, reliability, and consistency in SFN.33,34

appendix

In veterans with GWI and documented SFN, a health record review was performed to identify potential etiologies for SFN (Appendix).

 

Statistical Analysis

Microsoft Excel and IBM SPSS 12.0.1 for Windows were used for data collection and statistical analysis. Fisher exact test was used for comparing the prevalence of SFN in veterans with GWI vs without GWI. The independent samples t test was used for comparing COMPASS 31 scores for veterans with GWI by SFN status. α < .05 was used for determining statistical significance. For those GWVs documented with SFN and GWI, potential explanations were documented in total and by condition.

Results

table 1

figure

From March 1, 2015, to January 31, 2019, 141 GWVs received a comprehensive in person clinical evaluation at the WRIISC and 51 veterans (36%) received a skin biopsy and were included in this retrospective observational study (Figure). The mean age was 48.6 years, and the majority were male and served in the US Army. Skin biopsies met clinical criteria for GWI for 42 (82%) and 24 of 42 (57%) were determined to have SFN. Four of 9 (44%) veterans without GWI had positive SFN biopsies, though this difference was not statistically significant (Table 1). Veterans with SFN but no GWI were not included in the further analysis.

table 2

Thirty-five veterans with GWI—18 with SFN and 17 without SFN—completed the COMPASS 31 (Table 2). COMPASS 31 data were not analyzed for veterans without GWI. Individual domain scores and the difference in COMPASS 31 scores for veterans with GWI and SFN vs GWI and no SFN (38.3 vs 37.8, respectively) were not statistically significant.

table 3

Sixteen of 24 veterans with GWI and SFN (67%) had ≥ 1 conditions that could potentially be responsible for SFN (Table 3), including 11 veterans (46%) with prediabetes/diabetes. Hyperlipidemia is only variably reported as a cause of SFN; when included, 19 of 24 (79%) SFN cases were accounted for. We could not identify a medical explanation for SFN in 5 of 24 veterans (21%) with GWI, which were deemed to be idiopathic.

 

 

Discussion

Biopsy-confirmed SFN was present in more than half of our sample of veterans with GWI, which is broadly consistent with what has been reported in the literature.13,35-38 In this clinical observation study, SFN was similarly prevalent in veterans with and without GWI; although it should be noted that biopsies only were obtained when there was a strong clinical suspicion for SFN. Almost half of patients with GWI did not have SFN, so our study does not support SFN as the underlying explanation for all GWI. Although our data cannot provide clinical guidance as to when skin biopsy may be indicated in GWI, work done in fibromyalgia found symptoms of dysautonomia and paresthesias are more specific for SFN and may be useful to help guide medical decision making.39

Veterans with GWI in our clinical sample reported a high burden of clinical symptoms conceivably attributable to ANS dysfunction. This symptom reporting is consistent with that seen in other GWI studies, as well as in other studies of SFN.4,5,7-9,14,15,34,38,40 Our clinical sample of veterans with GWI found no differences in the ANS symptom reporting between those with and without SFN. Therefore, our study cannot support SFN alone as accounting for ANS symptom burden in patients with GWI.

Two-thirds of biopsy-confirmed SFN in our clinical sample of veterans with GWI could potentially be explained by established medical conditions. As in other studies of SFN, prediabetes and diabetes represented a plurality (46%). Even after considering hyperlipidemia as a potential explanation, about 21% of SFN cases in veterans with GWI still were deemed idiopathic.

Evidence supports certain environmental agents as causal factors for GWI. Neurotoxicants reportedly related to GWI include pesticides (particularly organophosphates and carbamates), pyridostigmine bromide (used during the Gulf War as a prophylactic agent against the use of chemical weapons), and low levels of the nerve agent sarin from environmental contamination due to chemical weapons detonations.1 Some of these agents have been implicated in neuropathy as well.1,28-30 It is biologically plausible that deployment-related exposures could trigger SFN, though the traditional consensus has been that remote exposure to neurotoxic substances is unlikely to produce neuropathy that presents many years after the exposure.41 In the WRIISC clinical experience, however, veterans often report that their neuropathic symptoms predate the diagnosis of the associated medical conditions, sometimes by decades. It is conceivable that remote exposures may trigger the condition that is then potentiated by ongoing exposures, metabolic factors, and/or other medical conditions. These may perpetuate neuropathic symptoms and the illness experience of affected veterans. Our clinical observation study cannot clarify the extent to which this may be the case. Despite these findings and arguments, an environmental contribution to SFN cannot be discounted, and further research is needed to explore a potential relationship.

Limitations

This study’s conclusions are limited by its observational/retrospective design in a relatively small clinical sample of veterans evaluated at a tertiary referral center for postdeployment exposure-related health concerns. The WRIISC clinical sample is not representative of all GWVs or even of all veterans with GWI, as there is inherent selection bias as to who gets referred to and evaluated at the WRIISC. As with studies based on retrospective chart review, data are reliant on clinical documentation andaccuracy/consistency of the reviewer. Evaluation for SFN with skin biopsy is an invasive procedure and was performed when a high index of clinical suspicion for this condition existed, possibly representing confirmation bias. Therefore, the relatively high prevalence ofbiopsy-confirmed SFN seen in our clinical sample cannot be generalized to GWVs as a whole or even to veterans with GWI.

 

 

Assessment of autonomic dysfunction was based on COMPASS 31 symptom reporting by an small subset of the clinical cohort. Symptom reporting may not be reflective of true abnormality in ANS function. Physiologic tests of the ANS were not performed; such studies could more objectively establish whether ANS dysfunction is more prevalent in GWI veterans with SFN.

Evaluation for all potential etiologic/contributory conditions to SFN was not exhaustive. For example, sodium channel gene mutations have been documented to account for up to one-third of all cases of idiopathic SFN.42 For those cases in which no compelling etiology was identified, it is plausible that medical explanations for SFN may be found on further investigation.

Clinical assessments at the WRIISC were performed on GWVs ≥ 26 years after their deployment-related exposures. Other conditions/exposures may have occurred in the interim. What is not clear is whether the SFN predated the onset of any of these medical conditions or other putative contributors. This observational study is not able to tease out a temporal association to make a cause-and-effect assessment.

 

Conclusions

Retrospective analysis of clinical data of veterans evaluated at a specialized center for postdeployment health demonstrated that skin biopsy–confirmed SFN was prevalent, but not ubiquitous, in veterans with GWI. Symptom that may be attributed to ANS dysfunction in this clinical sample was consistent with literature on SFN and with GWI, but we could not definitively attribute ANS symptoms to SFN. Our study does not support the hypothesis that GWI symptoms are solely due to SFN, though it may still be relevant in a subset of veterans with GWI with strongly suggestive clinical features. We were able to identify a potential etiology for SFN in most veterans with GWI. Further investigations are recommended to explore any potential relationship between Gulf War exposures and SFN.

References

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2. Committee on the Development of a Consensus Case Definition for Chronic Multisymptom Illness in 1990-1991 Gulf War Veterans, Board on the Health of Select Populations, Institute of Medicine. Chronic Multisymptom Illness in Gulf War Veterans: Case Definitions Reexamined. National Academies Press; 2014.

3. Robbins R, Helmer D, Monahan P, et al. Management of chronic multisymptom illness: synopsis of the 2021 US Department of Veterans Affairs and US Department of Defense Clinical Practice Guideline. Mayo Clin Proc. 2022;97(5):991-1002. doi:10.1016/j.mayocp.2022.01.031

4. Fox A, Helmer D, Tseng CL, Patrick-DeLuca L, Osinubi O. Report of autonomic symptoms in a clinical sample of veterans with Gulf War Illness. Mil Med. 2018;183(3-4):e179-e185. doi:10.1093/milmed/usx052

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6. Reyes L, Falvo M, Blatt M, Ghobreal B, Acosta A, Serrador J. Autonomic dysfunction in veterans with Gulf War illness [abstract]. FASEB J. 2014;28(S1):1068.19. doi:10.1096/fasebj.28.1_supplement.1068.19

7. Haley RW, Charuvastra E, Shell WE, et al. Cholinergic autonomic dysfunction in veterans with Gulf War illness: confirmation in a population-based sample. JAMA Neurol. 2013;70(2):191-200. doi:10.1001/jamaneurol.2013.596

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9. Avery TJ, Mathersul DC, Schulz-Heik RJ, Mahoney L, Bayley PJ. Self-reported autonomic dysregulation in Gulf War Illness. Mil Med. Published online December 30, 2021. doi:10.1093/milmed/usab546

10. Verne ZT, Fields JZ, Zhang BB, Zhou Q. Autonomic dysfunction and gastroparesis in Gulf War veterans. J Investig Med. 2023;71(1):7-10. doi:10.1136/jim-2021-002291

11. Levine TD. Small fiber neuropathy: disease classification beyond pain and burning. J Cent Nerv Syst Dis. 2018;10:1179573518771703. doi:10.1177/1179573518771703

12. Novak P. Autonomic disorders. Am J Med. 2019;132(4):420-436. doi:10.1016/j.amjmed.2018.09.027

13. Oaklander AL, Klein MM. Undiagnosed small-fiber polyneuropathy: is it a component of Gulf War Illness? Defense Technical Information Center. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/ADA613891

<--pagebreak-->14. Sène D. Small fiber neuropathy: diagnosis, causes, and treatment. Joint Bone Spine. 2018;85(5):553-559. doi:10.1016/j.jbspin.2017.11.002

15. Novak V, Freimer ML, Kissel JT, et al. Autonomic impairment in painful neuropathy. Neurology. 2001;56(7):861-868. doi:10.1212/wnl.56.7.861

16. Myers MI, Peltier AC. Uses of skin biopsy for sensory and autonomic nerve assessment. Curr Neurol Neurosci Rep. 2013;13(1):323. doi:10.1007/s11910-012-0323-2

17. Haroutounian S, Todorovic MS, Leinders M, et al. Diagnostic criteria for idiopathic small fiber neuropathy: a systematic review. Muscle Nerve. 2021;63(2):170-177. doi:10.1002/mus.27070

18. Levine TD, Saperstein DS. Routine use of punch biopsy to diagnose small fiber neuropathy in fibromyalgia patients. Clin Rheumatol. 2015;34(3):413-417. doi:10.1007/s10067-014-2850-5

19. England JD, Gronseth G S, Franklin G, et al. Practice parameter: the evaluation of distal symmetric polyneuropathy: the role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review). Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. PM R. 2009;1(1):14-22. doi:10.1016/j.pmrj.2008.11.011

20. de Greef BTA, Hoeijmakers JGJ, Gorissen-Brouwers CML, Geerts M, Faber CG, Merkies ISJ. Associated conditions in small fiber neuropathy - a large cohort study and review of the literature. Eur J Neurol. 2018;25(2):348-355. doi:10.1111/ene.13508

21. Morkavuk G, Leventoglu A. Small fiber neuropathy associated with hyperlipidemia: utility of cutaneous silent periods and autonomic tests. ISRN Neurol. 2014;2014:579242. doi:10.1155/2014/579242

22. Bednarik J, Vlckova-Moravcova E, Bursova S, Belobradkova J, Dusek L, Sommer C. Etiology of small-fiber neuropathy. J Peripher Nerv Syst. 2009;14(3):177-183. doi:10.1111/j.1529-8027.2009.00229.x

23. Kokotis P, Papantoniou M, Schmelz M, Buntziouka C, Tzavellas E, Paparrigopoulos T. Pure small fiber neuropathy in alcohol dependency detected by skin biopsy. Alcohol Fayettev N. 2023;111:67-73. doi:10.1016/j.alcohol.2023.05.006

24. Guimarães-Costa R, Schoindre Y, Metlaine A, et al. N-hexane exposure: a cause of small fiber neuropathy. J Peripher Nerv Syst. 2018;23(2):143-146. doi:10.1111/jns.12261

25. Koszewicz M, Markowska K, Waliszewska-Prosol M, et al. The impact of chronic co-exposure to different heavy metals on small fibers of peripheral nerves. A study of metal industry workers. J Occup Med Toxicol. 2021;16(1):12. doi:10.1186/s12995-021-00302-6

26. Johns Hopkins Medicine. Small nerve fibers defy neuropathy conventions. April 11, 2016. Accessed February 21, 2024. https://www.hopkinsmedicine.org/news/media/releases/small_nerve_fibers_defy_neuropathy_conventions

27. Jett DA. Neurotoxic pesticides and neurologic effects. Neurol Clin. 2011;29(3):667-677. doi:10.1016/j.ncl.2011.06.002

28. Berger AR, Schaumburg HH. Human toxic neuropathy caused by industrial agents. In: Dyck PJ, Thomas PK, eds. Peripheral Neuropathy. 4th ed. Saunders; 2005:2505-2525. doi:10.1016/B978-0-7216-9491-7.50115-0

29. Herskovitz S, Schaumburg HH. Neuropathy caused by drugs. In: Dyck PJ, Thomas PK, eds. Peripheral Neuropathy. 4th ed. Saunders; 2005:2553-2583.

30. Katona I, Weis J. Chapter 31 - Diseases of the peripheral nerves. Handb Clin Neurol. 2017;145:453-474. doi:10.1016/B978-0-12-802395-2.00031-6

31. Matikainen E, Juntunen J. Autonomic nervous system dysfunction in workers exposed to organic solvents. J Neurol Neurosurg Psychiatry. 1985;48(10):1021-1024. doi:10.1136/jnnp.48.10.1021

32. Murata K, Araki S, Yokoyama K, Maeda K. Autonomic and peripheral nervous system dysfunction in workers exposed to mixed organic solvents. Int Arch Occup Environ Health. 1991;63(5):335-340. doi:10.1007/BF00381584

33. Sletten DM, Suarez GA, Low PA, Mandrekar J, Singer W. COMPASS 31: a refined and abbreviated Composite Autonomic Symptom Score. Mayo Clin Proc. 2012;87(12):1196-1201. doi:10.1016/j.mayocp.2012.10.013

34. Treister R, O’Neil K, Downs HM, Oaklander AL. Validation of the Composite Autonomic Symptom Scale-31 (COMPASS-31) in patients with and without small-fiber polyneuropathy. Eur J Neurol. 2015;22(7):1124-1130. doi:10.1111/ene.12717

35. Joseph P, Arevalo C, Oliveira RKF, et al. Insights from invasive cardiopulmonary exercise testing of patients with myalgic encephalomyelitis/chronic fatigue syndrome. Chest. 2021;160(2):642-651. doi:10.1016/j.chest.2021.01.082

36. Giannoccaro MP, Donadio V, Incensi A, Avoni P, Liguori R. Small nerve fiber involvement in patients referred for fibromyalgia. Muscle Nerve. 2014;49(5):757-759. doi:10.1002/mus.24156

37. Oaklander AL, Herzog ZD, Downs HM, Klein MM. Objective evidence that small-fiber polyneuropathy underlies some illnesses currently labeled as fibromyalgia. Pain. 2013;154(11):2310-2316. doi:10.1016/j.pain.2013.06.001

38. Serrador JM. Diagnosis of late-stage, early-onset, small-fiber polyneuropathy. Defense Technical Information Center. December 1, 2019. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/AD1094831

39. Lodahl M, Treister R, Oaklander AL. Specific symptoms may discriminate between fibromyalgia patients with vs without objective test evidence of small-fiber polyneuropathy. Pain Rep. 2018;3(1):e633. doi:10.1097/PR9.0000000000000633

40. Sastre A, Cook MR. Autonomic dysfunction in Gulf War veterans. Defense Technical Information Center. April 1, 2004. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/ADA429525

41. Little AA, Albers JW. Clinical description of toxic neuropathies. Handb Clin Neurol. 2015;131:253-296. doi:10.1016/B978-0-444-62627-1.00015-9

42. Faber CG, Hoeijmakers JGJ, Ahn HS, et al. Gain of function NaV1.7 mutations in idiopathic small fiber neuropathy. Ann Neurol. 2012;71(1):26-39.

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Author and Disclosure Information

Edward C. Shadiack III, DO, MPHa,b; Omowunmi Osinubi, MD, MPHa,b; Apollonia Gruber-Fox, PhDb; Chinmoy Bhate, MDa;  Lydia Patrick-DeLuca, MSN, RNa,b; Philip Cohen, MDa; Drew A. Helmer, MD, MSb,c

Correspondence:  Edward Shadiack  ([email protected])

aVeterans Affairs New Jersey Health Care Systems, East Orange

bWar Related Illness and Injury Study Center, East Orange, New Jersey

cMichael E. DeBakey Veterans Affairs Medical Center, Houston, Texas

Author contributions

Concept: Shadiack.

Data collection: Shadiack, Osinubi, Bhate, Patrick-DeLuca, Cohen.

Data analysis: Shadiack, Gruber-Fox, Helmer.

Drafting of manuscript: Shadiack, Osinubi.

Critical review of manuscript: Gruber-Fox, Patrick-DeLuca, Cohen, Helmer.

Author disclosures

The authors report no actual or potential conflicts of interest or outside sources of funding with regard to this article.

Disclaimer

The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

Funding and ethics

This study was reviewed and approved by the Veterans Affairs New Jersey Health Care System Institutional Review Board (IRB# 01497). Funding provided by Veterans Affairs War Related Illness and Injury Study Center-New Jersey clinical resources; US Department of Veterans Affairs Health Services Research & Development (CIN 13-413). Poster presented virtually at the American Autonomic Society’s annual meeting, November 2020.

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Edward C. Shadiack III, DO, MPHa,b; Omowunmi Osinubi, MD, MPHa,b; Apollonia Gruber-Fox, PhDb; Chinmoy Bhate, MDa;  Lydia Patrick-DeLuca, MSN, RNa,b; Philip Cohen, MDa; Drew A. Helmer, MD, MSb,c

Correspondence:  Edward Shadiack  ([email protected])

aVeterans Affairs New Jersey Health Care Systems, East Orange

bWar Related Illness and Injury Study Center, East Orange, New Jersey

cMichael E. DeBakey Veterans Affairs Medical Center, Houston, Texas

Author contributions

Concept: Shadiack.

Data collection: Shadiack, Osinubi, Bhate, Patrick-DeLuca, Cohen.

Data analysis: Shadiack, Gruber-Fox, Helmer.

Drafting of manuscript: Shadiack, Osinubi.

Critical review of manuscript: Gruber-Fox, Patrick-DeLuca, Cohen, Helmer.

Author disclosures

The authors report no actual or potential conflicts of interest or outside sources of funding with regard to this article.

Disclaimer

The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

Funding and ethics

This study was reviewed and approved by the Veterans Affairs New Jersey Health Care System Institutional Review Board (IRB# 01497). Funding provided by Veterans Affairs War Related Illness and Injury Study Center-New Jersey clinical resources; US Department of Veterans Affairs Health Services Research & Development (CIN 13-413). Poster presented virtually at the American Autonomic Society’s annual meeting, November 2020.

Author and Disclosure Information

Edward C. Shadiack III, DO, MPHa,b; Omowunmi Osinubi, MD, MPHa,b; Apollonia Gruber-Fox, PhDb; Chinmoy Bhate, MDa;  Lydia Patrick-DeLuca, MSN, RNa,b; Philip Cohen, MDa; Drew A. Helmer, MD, MSb,c

Correspondence:  Edward Shadiack  ([email protected])

aVeterans Affairs New Jersey Health Care Systems, East Orange

bWar Related Illness and Injury Study Center, East Orange, New Jersey

cMichael E. DeBakey Veterans Affairs Medical Center, Houston, Texas

Author contributions

Concept: Shadiack.

Data collection: Shadiack, Osinubi, Bhate, Patrick-DeLuca, Cohen.

Data analysis: Shadiack, Gruber-Fox, Helmer.

Drafting of manuscript: Shadiack, Osinubi.

Critical review of manuscript: Gruber-Fox, Patrick-DeLuca, Cohen, Helmer.

Author disclosures

The authors report no actual or potential conflicts of interest or outside sources of funding with regard to this article.

Disclaimer

The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

Funding and ethics

This study was reviewed and approved by the Veterans Affairs New Jersey Health Care System Institutional Review Board (IRB# 01497). Funding provided by Veterans Affairs War Related Illness and Injury Study Center-New Jersey clinical resources; US Department of Veterans Affairs Health Services Research & Development (CIN 13-413). Poster presented virtually at the American Autonomic Society’s annual meeting, November 2020.

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Related Articles

Following deployment to operations Desert Shield and Desert Storm (Gulf War) in 1990 and 1991, many Gulf War veterans (GWVs) developed chronic, complex symptoms, including pain, dyscognition, and fatigue, with gastrointestinal, skin, and respiratory manifestations. This Gulf War Illness (GWI) is reported to affect about 30% of those deployed. More than 30 years later, there is no consensus as to the etiology of GWI, although some deployment-related exposures have been implicated.1

Accepted research definitions for GWI include the Centers for Disease Control and Prevention and Kansas definitions.2 The US Department of Veterans Affairs (VA) uses the terminology chronic multisymptom illness (CMI), which is an overarching diagnosis under which GWI falls. Although there is no consensus case definition for CMI, there is overlap with conditions such as fibromyalgia, myalgic encephalomyelitis/chronic fatigue syndrome, and irritable bowel syndrome; the VA considers these as qualifying clinical diagnoses.3 The pathophysiology of GWI is also unknown, though a frequently reported unifying feature is that of autonomic nervous system (ANS) dysfunction. Studies have demonstrated differences between veterans with GWI and those without GWI in both the reporting of symptoms attributable to ANS dysfunction and in physiologic evaluations of the ANS.4-10

Small fiber neuropathy (SFN), a condition with damage to the A-δ and C small nerve fibers, has been proposed as a potential mechanism for the pain and ANS dysfunction experienced in GWI.11-13 Symptoms of SFN are similar to those of GWI, with pain and ANS symptoms commonly reported.14,15 There are multiple diagnostic criteria for SFN, the most commonly used requiring the presence of appropriate symptoms in the absence of large fiber neuropathy and a skin biopsy demonstrating reduced intraepidermal nerve fiber density.16-19 Several conditions reportedly cause SFN, most notably diabetes/prediabetes. Autoimmune disease, vitamin B12 deficiency, monoclonal gammopathies, celiac disease, paraneoplastic syndromes, and sodium channel gene mutations may also contribute to SFN.20 Hyperlipidemia has been identified as a contributor, although it has been variably reported.21,22

Idiopathic neuropathies, SFN included, may be secondary to neurotoxicant exposures. Agents whose exposure or consumption have been associated with SFN include alcohol most prominently, but also the organic solvent n-hexane, heavy metals, and excess vitamin B6.20,23-25 Agents associated with large fiber neuropathy may also have relevance for SFN, as small fibers have been likened to the “canary in the coal mine” in that they may be more susceptible to neurotoxicants and are affected earlier in the disease process.26 In this way, SFN may be the harbinger of large fiber neuropathy in some cases. Of specific relevance for GWVs, organophosphates and carbamates are known to produce a delayed onset large fiber neuropathy.27-30 Exposure to petrochemical solvents has also been associated with large fiber neuropathies.31,32

The War Related Illness and Injury Study Center (WRIISC) is a clinical, research, and education center established by Congress in 2001. Its primary focus is on military exposures and postdeployment health of veterans. It is located at 3 sites: East Orange, New Jersey; Washington, DC; and Palo Alto, California. The New Jersey WRIISC began a program to evaluate GWVs with characteristic symptoms for possible SFN with use of a skin biopsy.

We hypothesize that SFN may underly much of GWI symptomatology and may not be accounted for by the putative etiologies detailed in review of the medical literature. This retrospective review of clinical evaluations for SFN in GWVs who sought care at the New Jersey WRIISC explored and addressed the following questions: (1) how common is biopsy-confirmed SFN in veterans with GWI; (2) do veterans with GWI and SFN report more symptoms attributable to ANS dysfunction when compared with veterans with GWI and no SFN; and (3) can SFN in veterans with GWI and SFN be explained by conditions and substances commonly associated with SFN? Institutional review board approval and waiver of consent was obtained from the Veterans Affairs New Jersey Health Care Center for the study.

 

 

Methods

A retrospective chart review was conducted on veterans evaluated at the WRIISC from March 1, 2015, to January 31, 2019. Inclusion criteria were: deployment to operations Desert Shield and Desert Storm between August 2, 1990, and February 28, 1991, and skin biopsy conducted at the WRIISC. Skin biopsies were obtained at the discretion of an examining clinician based on clinical indications, including neuropathic pain, ANS symptoms, and/or a fibromyalgia/chronic pain–type presentation.

Electronic health record review explicitly abstracted GWI status, results of the skin biopsy, and ANS symptom burden as determined by the Composite Autonomic Symptom Scale 31 (COMPASS 31) completed at the time of the WRIISC evaluation. Determination of GWI was established as per the clinical opinion of the WRIISC lead clinician or environmental exposure clinician as evidenced by a diagnosis of fibromyalgia or chronic fatigue syndrome, or explicit statement of CMI/GWI in the patient assessment. A diagnosis of SFN was established if clinical signs were present and an intraepidermal nerve fiber density below the lower limits, as compared to normative data from the clinical diagnostic laboratory (Therapath Neuropathology), was documented.

COMPASS 31 assesses symptoms across 6 domains (orthostatic, vasomotor, secretomotor, gastrointestinal, bladder, andpupillomotor). Patients are asked about symptom frequency (rarely to almost always), severity (mild to severe), and improvement (much worse to completely gone). Individual domain scores and a total weighted score (0-100) have demonstrated good validity, reliability, and consistency in SFN.33,34

appendix

In veterans with GWI and documented SFN, a health record review was performed to identify potential etiologies for SFN (Appendix).

 

Statistical Analysis

Microsoft Excel and IBM SPSS 12.0.1 for Windows were used for data collection and statistical analysis. Fisher exact test was used for comparing the prevalence of SFN in veterans with GWI vs without GWI. The independent samples t test was used for comparing COMPASS 31 scores for veterans with GWI by SFN status. α < .05 was used for determining statistical significance. For those GWVs documented with SFN and GWI, potential explanations were documented in total and by condition.

Results

table 1

figure

From March 1, 2015, to January 31, 2019, 141 GWVs received a comprehensive in person clinical evaluation at the WRIISC and 51 veterans (36%) received a skin biopsy and were included in this retrospective observational study (Figure). The mean age was 48.6 years, and the majority were male and served in the US Army. Skin biopsies met clinical criteria for GWI for 42 (82%) and 24 of 42 (57%) were determined to have SFN. Four of 9 (44%) veterans without GWI had positive SFN biopsies, though this difference was not statistically significant (Table 1). Veterans with SFN but no GWI were not included in the further analysis.

table 2

Thirty-five veterans with GWI—18 with SFN and 17 without SFN—completed the COMPASS 31 (Table 2). COMPASS 31 data were not analyzed for veterans without GWI. Individual domain scores and the difference in COMPASS 31 scores for veterans with GWI and SFN vs GWI and no SFN (38.3 vs 37.8, respectively) were not statistically significant.

table 3

Sixteen of 24 veterans with GWI and SFN (67%) had ≥ 1 conditions that could potentially be responsible for SFN (Table 3), including 11 veterans (46%) with prediabetes/diabetes. Hyperlipidemia is only variably reported as a cause of SFN; when included, 19 of 24 (79%) SFN cases were accounted for. We could not identify a medical explanation for SFN in 5 of 24 veterans (21%) with GWI, which were deemed to be idiopathic.

 

 

Discussion

Biopsy-confirmed SFN was present in more than half of our sample of veterans with GWI, which is broadly consistent with what has been reported in the literature.13,35-38 In this clinical observation study, SFN was similarly prevalent in veterans with and without GWI; although it should be noted that biopsies only were obtained when there was a strong clinical suspicion for SFN. Almost half of patients with GWI did not have SFN, so our study does not support SFN as the underlying explanation for all GWI. Although our data cannot provide clinical guidance as to when skin biopsy may be indicated in GWI, work done in fibromyalgia found symptoms of dysautonomia and paresthesias are more specific for SFN and may be useful to help guide medical decision making.39

Veterans with GWI in our clinical sample reported a high burden of clinical symptoms conceivably attributable to ANS dysfunction. This symptom reporting is consistent with that seen in other GWI studies, as well as in other studies of SFN.4,5,7-9,14,15,34,38,40 Our clinical sample of veterans with GWI found no differences in the ANS symptom reporting between those with and without SFN. Therefore, our study cannot support SFN alone as accounting for ANS symptom burden in patients with GWI.

Two-thirds of biopsy-confirmed SFN in our clinical sample of veterans with GWI could potentially be explained by established medical conditions. As in other studies of SFN, prediabetes and diabetes represented a plurality (46%). Even after considering hyperlipidemia as a potential explanation, about 21% of SFN cases in veterans with GWI still were deemed idiopathic.

Evidence supports certain environmental agents as causal factors for GWI. Neurotoxicants reportedly related to GWI include pesticides (particularly organophosphates and carbamates), pyridostigmine bromide (used during the Gulf War as a prophylactic agent against the use of chemical weapons), and low levels of the nerve agent sarin from environmental contamination due to chemical weapons detonations.1 Some of these agents have been implicated in neuropathy as well.1,28-30 It is biologically plausible that deployment-related exposures could trigger SFN, though the traditional consensus has been that remote exposure to neurotoxic substances is unlikely to produce neuropathy that presents many years after the exposure.41 In the WRIISC clinical experience, however, veterans often report that their neuropathic symptoms predate the diagnosis of the associated medical conditions, sometimes by decades. It is conceivable that remote exposures may trigger the condition that is then potentiated by ongoing exposures, metabolic factors, and/or other medical conditions. These may perpetuate neuropathic symptoms and the illness experience of affected veterans. Our clinical observation study cannot clarify the extent to which this may be the case. Despite these findings and arguments, an environmental contribution to SFN cannot be discounted, and further research is needed to explore a potential relationship.

Limitations

This study’s conclusions are limited by its observational/retrospective design in a relatively small clinical sample of veterans evaluated at a tertiary referral center for postdeployment exposure-related health concerns. The WRIISC clinical sample is not representative of all GWVs or even of all veterans with GWI, as there is inherent selection bias as to who gets referred to and evaluated at the WRIISC. As with studies based on retrospective chart review, data are reliant on clinical documentation andaccuracy/consistency of the reviewer. Evaluation for SFN with skin biopsy is an invasive procedure and was performed when a high index of clinical suspicion for this condition existed, possibly representing confirmation bias. Therefore, the relatively high prevalence ofbiopsy-confirmed SFN seen in our clinical sample cannot be generalized to GWVs as a whole or even to veterans with GWI.

 

 

Assessment of autonomic dysfunction was based on COMPASS 31 symptom reporting by an small subset of the clinical cohort. Symptom reporting may not be reflective of true abnormality in ANS function. Physiologic tests of the ANS were not performed; such studies could more objectively establish whether ANS dysfunction is more prevalent in GWI veterans with SFN.

Evaluation for all potential etiologic/contributory conditions to SFN was not exhaustive. For example, sodium channel gene mutations have been documented to account for up to one-third of all cases of idiopathic SFN.42 For those cases in which no compelling etiology was identified, it is plausible that medical explanations for SFN may be found on further investigation.

Clinical assessments at the WRIISC were performed on GWVs ≥ 26 years after their deployment-related exposures. Other conditions/exposures may have occurred in the interim. What is not clear is whether the SFN predated the onset of any of these medical conditions or other putative contributors. This observational study is not able to tease out a temporal association to make a cause-and-effect assessment.

 

Conclusions

Retrospective analysis of clinical data of veterans evaluated at a specialized center for postdeployment health demonstrated that skin biopsy–confirmed SFN was prevalent, but not ubiquitous, in veterans with GWI. Symptom that may be attributed to ANS dysfunction in this clinical sample was consistent with literature on SFN and with GWI, but we could not definitively attribute ANS symptoms to SFN. Our study does not support the hypothesis that GWI symptoms are solely due to SFN, though it may still be relevant in a subset of veterans with GWI with strongly suggestive clinical features. We were able to identify a potential etiology for SFN in most veterans with GWI. Further investigations are recommended to explore any potential relationship between Gulf War exposures and SFN.

Following deployment to operations Desert Shield and Desert Storm (Gulf War) in 1990 and 1991, many Gulf War veterans (GWVs) developed chronic, complex symptoms, including pain, dyscognition, and fatigue, with gastrointestinal, skin, and respiratory manifestations. This Gulf War Illness (GWI) is reported to affect about 30% of those deployed. More than 30 years later, there is no consensus as to the etiology of GWI, although some deployment-related exposures have been implicated.1

Accepted research definitions for GWI include the Centers for Disease Control and Prevention and Kansas definitions.2 The US Department of Veterans Affairs (VA) uses the terminology chronic multisymptom illness (CMI), which is an overarching diagnosis under which GWI falls. Although there is no consensus case definition for CMI, there is overlap with conditions such as fibromyalgia, myalgic encephalomyelitis/chronic fatigue syndrome, and irritable bowel syndrome; the VA considers these as qualifying clinical diagnoses.3 The pathophysiology of GWI is also unknown, though a frequently reported unifying feature is that of autonomic nervous system (ANS) dysfunction. Studies have demonstrated differences between veterans with GWI and those without GWI in both the reporting of symptoms attributable to ANS dysfunction and in physiologic evaluations of the ANS.4-10

Small fiber neuropathy (SFN), a condition with damage to the A-δ and C small nerve fibers, has been proposed as a potential mechanism for the pain and ANS dysfunction experienced in GWI.11-13 Symptoms of SFN are similar to those of GWI, with pain and ANS symptoms commonly reported.14,15 There are multiple diagnostic criteria for SFN, the most commonly used requiring the presence of appropriate symptoms in the absence of large fiber neuropathy and a skin biopsy demonstrating reduced intraepidermal nerve fiber density.16-19 Several conditions reportedly cause SFN, most notably diabetes/prediabetes. Autoimmune disease, vitamin B12 deficiency, monoclonal gammopathies, celiac disease, paraneoplastic syndromes, and sodium channel gene mutations may also contribute to SFN.20 Hyperlipidemia has been identified as a contributor, although it has been variably reported.21,22

Idiopathic neuropathies, SFN included, may be secondary to neurotoxicant exposures. Agents whose exposure or consumption have been associated with SFN include alcohol most prominently, but also the organic solvent n-hexane, heavy metals, and excess vitamin B6.20,23-25 Agents associated with large fiber neuropathy may also have relevance for SFN, as small fibers have been likened to the “canary in the coal mine” in that they may be more susceptible to neurotoxicants and are affected earlier in the disease process.26 In this way, SFN may be the harbinger of large fiber neuropathy in some cases. Of specific relevance for GWVs, organophosphates and carbamates are known to produce a delayed onset large fiber neuropathy.27-30 Exposure to petrochemical solvents has also been associated with large fiber neuropathies.31,32

The War Related Illness and Injury Study Center (WRIISC) is a clinical, research, and education center established by Congress in 2001. Its primary focus is on military exposures and postdeployment health of veterans. It is located at 3 sites: East Orange, New Jersey; Washington, DC; and Palo Alto, California. The New Jersey WRIISC began a program to evaluate GWVs with characteristic symptoms for possible SFN with use of a skin biopsy.

We hypothesize that SFN may underly much of GWI symptomatology and may not be accounted for by the putative etiologies detailed in review of the medical literature. This retrospective review of clinical evaluations for SFN in GWVs who sought care at the New Jersey WRIISC explored and addressed the following questions: (1) how common is biopsy-confirmed SFN in veterans with GWI; (2) do veterans with GWI and SFN report more symptoms attributable to ANS dysfunction when compared with veterans with GWI and no SFN; and (3) can SFN in veterans with GWI and SFN be explained by conditions and substances commonly associated with SFN? Institutional review board approval and waiver of consent was obtained from the Veterans Affairs New Jersey Health Care Center for the study.

 

 

Methods

A retrospective chart review was conducted on veterans evaluated at the WRIISC from March 1, 2015, to January 31, 2019. Inclusion criteria were: deployment to operations Desert Shield and Desert Storm between August 2, 1990, and February 28, 1991, and skin biopsy conducted at the WRIISC. Skin biopsies were obtained at the discretion of an examining clinician based on clinical indications, including neuropathic pain, ANS symptoms, and/or a fibromyalgia/chronic pain–type presentation.

Electronic health record review explicitly abstracted GWI status, results of the skin biopsy, and ANS symptom burden as determined by the Composite Autonomic Symptom Scale 31 (COMPASS 31) completed at the time of the WRIISC evaluation. Determination of GWI was established as per the clinical opinion of the WRIISC lead clinician or environmental exposure clinician as evidenced by a diagnosis of fibromyalgia or chronic fatigue syndrome, or explicit statement of CMI/GWI in the patient assessment. A diagnosis of SFN was established if clinical signs were present and an intraepidermal nerve fiber density below the lower limits, as compared to normative data from the clinical diagnostic laboratory (Therapath Neuropathology), was documented.

COMPASS 31 assesses symptoms across 6 domains (orthostatic, vasomotor, secretomotor, gastrointestinal, bladder, andpupillomotor). Patients are asked about symptom frequency (rarely to almost always), severity (mild to severe), and improvement (much worse to completely gone). Individual domain scores and a total weighted score (0-100) have demonstrated good validity, reliability, and consistency in SFN.33,34

appendix

In veterans with GWI and documented SFN, a health record review was performed to identify potential etiologies for SFN (Appendix).

 

Statistical Analysis

Microsoft Excel and IBM SPSS 12.0.1 for Windows were used for data collection and statistical analysis. Fisher exact test was used for comparing the prevalence of SFN in veterans with GWI vs without GWI. The independent samples t test was used for comparing COMPASS 31 scores for veterans with GWI by SFN status. α < .05 was used for determining statistical significance. For those GWVs documented with SFN and GWI, potential explanations were documented in total and by condition.

Results

table 1

figure

From March 1, 2015, to January 31, 2019, 141 GWVs received a comprehensive in person clinical evaluation at the WRIISC and 51 veterans (36%) received a skin biopsy and were included in this retrospective observational study (Figure). The mean age was 48.6 years, and the majority were male and served in the US Army. Skin biopsies met clinical criteria for GWI for 42 (82%) and 24 of 42 (57%) were determined to have SFN. Four of 9 (44%) veterans without GWI had positive SFN biopsies, though this difference was not statistically significant (Table 1). Veterans with SFN but no GWI were not included in the further analysis.

table 2

Thirty-five veterans with GWI—18 with SFN and 17 without SFN—completed the COMPASS 31 (Table 2). COMPASS 31 data were not analyzed for veterans without GWI. Individual domain scores and the difference in COMPASS 31 scores for veterans with GWI and SFN vs GWI and no SFN (38.3 vs 37.8, respectively) were not statistically significant.

table 3

Sixteen of 24 veterans with GWI and SFN (67%) had ≥ 1 conditions that could potentially be responsible for SFN (Table 3), including 11 veterans (46%) with prediabetes/diabetes. Hyperlipidemia is only variably reported as a cause of SFN; when included, 19 of 24 (79%) SFN cases were accounted for. We could not identify a medical explanation for SFN in 5 of 24 veterans (21%) with GWI, which were deemed to be idiopathic.

 

 

Discussion

Biopsy-confirmed SFN was present in more than half of our sample of veterans with GWI, which is broadly consistent with what has been reported in the literature.13,35-38 In this clinical observation study, SFN was similarly prevalent in veterans with and without GWI; although it should be noted that biopsies only were obtained when there was a strong clinical suspicion for SFN. Almost half of patients with GWI did not have SFN, so our study does not support SFN as the underlying explanation for all GWI. Although our data cannot provide clinical guidance as to when skin biopsy may be indicated in GWI, work done in fibromyalgia found symptoms of dysautonomia and paresthesias are more specific for SFN and may be useful to help guide medical decision making.39

Veterans with GWI in our clinical sample reported a high burden of clinical symptoms conceivably attributable to ANS dysfunction. This symptom reporting is consistent with that seen in other GWI studies, as well as in other studies of SFN.4,5,7-9,14,15,34,38,40 Our clinical sample of veterans with GWI found no differences in the ANS symptom reporting between those with and without SFN. Therefore, our study cannot support SFN alone as accounting for ANS symptom burden in patients with GWI.

Two-thirds of biopsy-confirmed SFN in our clinical sample of veterans with GWI could potentially be explained by established medical conditions. As in other studies of SFN, prediabetes and diabetes represented a plurality (46%). Even after considering hyperlipidemia as a potential explanation, about 21% of SFN cases in veterans with GWI still were deemed idiopathic.

Evidence supports certain environmental agents as causal factors for GWI. Neurotoxicants reportedly related to GWI include pesticides (particularly organophosphates and carbamates), pyridostigmine bromide (used during the Gulf War as a prophylactic agent against the use of chemical weapons), and low levels of the nerve agent sarin from environmental contamination due to chemical weapons detonations.1 Some of these agents have been implicated in neuropathy as well.1,28-30 It is biologically plausible that deployment-related exposures could trigger SFN, though the traditional consensus has been that remote exposure to neurotoxic substances is unlikely to produce neuropathy that presents many years after the exposure.41 In the WRIISC clinical experience, however, veterans often report that their neuropathic symptoms predate the diagnosis of the associated medical conditions, sometimes by decades. It is conceivable that remote exposures may trigger the condition that is then potentiated by ongoing exposures, metabolic factors, and/or other medical conditions. These may perpetuate neuropathic symptoms and the illness experience of affected veterans. Our clinical observation study cannot clarify the extent to which this may be the case. Despite these findings and arguments, an environmental contribution to SFN cannot be discounted, and further research is needed to explore a potential relationship.

Limitations

This study’s conclusions are limited by its observational/retrospective design in a relatively small clinical sample of veterans evaluated at a tertiary referral center for postdeployment exposure-related health concerns. The WRIISC clinical sample is not representative of all GWVs or even of all veterans with GWI, as there is inherent selection bias as to who gets referred to and evaluated at the WRIISC. As with studies based on retrospective chart review, data are reliant on clinical documentation andaccuracy/consistency of the reviewer. Evaluation for SFN with skin biopsy is an invasive procedure and was performed when a high index of clinical suspicion for this condition existed, possibly representing confirmation bias. Therefore, the relatively high prevalence ofbiopsy-confirmed SFN seen in our clinical sample cannot be generalized to GWVs as a whole or even to veterans with GWI.

 

 

Assessment of autonomic dysfunction was based on COMPASS 31 symptom reporting by an small subset of the clinical cohort. Symptom reporting may not be reflective of true abnormality in ANS function. Physiologic tests of the ANS were not performed; such studies could more objectively establish whether ANS dysfunction is more prevalent in GWI veterans with SFN.

Evaluation for all potential etiologic/contributory conditions to SFN was not exhaustive. For example, sodium channel gene mutations have been documented to account for up to one-third of all cases of idiopathic SFN.42 For those cases in which no compelling etiology was identified, it is plausible that medical explanations for SFN may be found on further investigation.

Clinical assessments at the WRIISC were performed on GWVs ≥ 26 years after their deployment-related exposures. Other conditions/exposures may have occurred in the interim. What is not clear is whether the SFN predated the onset of any of these medical conditions or other putative contributors. This observational study is not able to tease out a temporal association to make a cause-and-effect assessment.

 

Conclusions

Retrospective analysis of clinical data of veterans evaluated at a specialized center for postdeployment health demonstrated that skin biopsy–confirmed SFN was prevalent, but not ubiquitous, in veterans with GWI. Symptom that may be attributed to ANS dysfunction in this clinical sample was consistent with literature on SFN and with GWI, but we could not definitively attribute ANS symptoms to SFN. Our study does not support the hypothesis that GWI symptoms are solely due to SFN, though it may still be relevant in a subset of veterans with GWI with strongly suggestive clinical features. We were able to identify a potential etiology for SFN in most veterans with GWI. Further investigations are recommended to explore any potential relationship between Gulf War exposures and SFN.

References

1. White RF, Steele L, O’Callaghan JP, et al. Recent research on Gulf War illness and other health problems in veterans of the 1991 Gulf War: effects of toxicant exposures during deployment. Cortex. 2016;74:449-475. doi:10.1016/j.cortex.2015.08.022

2. Committee on the Development of a Consensus Case Definition for Chronic Multisymptom Illness in 1990-1991 Gulf War Veterans, Board on the Health of Select Populations, Institute of Medicine. Chronic Multisymptom Illness in Gulf War Veterans: Case Definitions Reexamined. National Academies Press; 2014.

3. Robbins R, Helmer D, Monahan P, et al. Management of chronic multisymptom illness: synopsis of the 2021 US Department of Veterans Affairs and US Department of Defense Clinical Practice Guideline. Mayo Clin Proc. 2022;97(5):991-1002. doi:10.1016/j.mayocp.2022.01.031

4. Fox A, Helmer D, Tseng CL, Patrick-DeLuca L, Osinubi O. Report of autonomic symptoms in a clinical sample of veterans with Gulf War Illness. Mil Med. 2018;183(3-4):e179-e185. doi:10.1093/milmed/usx052

5. Fox A, Helmer D, Tseng CL, McCarron K, Satcher S, Osinubi O. Autonomic symptoms in Gulf War veterans evaluated at the War Related Illness and Injury Study Center. Mil Med. 2019;184(3-4):e191-e196. doi:10.1093/milmed/usy227

6. Reyes L, Falvo M, Blatt M, Ghobreal B, Acosta A, Serrador J. Autonomic dysfunction in veterans with Gulf War illness [abstract]. FASEB J. 2014;28(S1):1068.19. doi:10.1096/fasebj.28.1_supplement.1068.19

7. Haley RW, Charuvastra E, Shell WE, et al. Cholinergic autonomic dysfunction in veterans with Gulf War illness: confirmation in a population-based sample. JAMA Neurol. 2013;70(2):191-200. doi:10.1001/jamaneurol.2013.596

8. Haley RW, Vongpatanasin W, Wolfe GI, et al. Blunted circadian variation in autonomic regulation of sinus node function in veterans with Gulf War syndrome. Am J Med. 2004;117(7):469-478. doi:10.1016/j.amjmed.2004.03.041

9. Avery TJ, Mathersul DC, Schulz-Heik RJ, Mahoney L, Bayley PJ. Self-reported autonomic dysregulation in Gulf War Illness. Mil Med. Published online December 30, 2021. doi:10.1093/milmed/usab546

10. Verne ZT, Fields JZ, Zhang BB, Zhou Q. Autonomic dysfunction and gastroparesis in Gulf War veterans. J Investig Med. 2023;71(1):7-10. doi:10.1136/jim-2021-002291

11. Levine TD. Small fiber neuropathy: disease classification beyond pain and burning. J Cent Nerv Syst Dis. 2018;10:1179573518771703. doi:10.1177/1179573518771703

12. Novak P. Autonomic disorders. Am J Med. 2019;132(4):420-436. doi:10.1016/j.amjmed.2018.09.027

13. Oaklander AL, Klein MM. Undiagnosed small-fiber polyneuropathy: is it a component of Gulf War Illness? Defense Technical Information Center. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/ADA613891

<--pagebreak-->14. Sène D. Small fiber neuropathy: diagnosis, causes, and treatment. Joint Bone Spine. 2018;85(5):553-559. doi:10.1016/j.jbspin.2017.11.002

15. Novak V, Freimer ML, Kissel JT, et al. Autonomic impairment in painful neuropathy. Neurology. 2001;56(7):861-868. doi:10.1212/wnl.56.7.861

16. Myers MI, Peltier AC. Uses of skin biopsy for sensory and autonomic nerve assessment. Curr Neurol Neurosci Rep. 2013;13(1):323. doi:10.1007/s11910-012-0323-2

17. Haroutounian S, Todorovic MS, Leinders M, et al. Diagnostic criteria for idiopathic small fiber neuropathy: a systematic review. Muscle Nerve. 2021;63(2):170-177. doi:10.1002/mus.27070

18. Levine TD, Saperstein DS. Routine use of punch biopsy to diagnose small fiber neuropathy in fibromyalgia patients. Clin Rheumatol. 2015;34(3):413-417. doi:10.1007/s10067-014-2850-5

19. England JD, Gronseth G S, Franklin G, et al. Practice parameter: the evaluation of distal symmetric polyneuropathy: the role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review). Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. PM R. 2009;1(1):14-22. doi:10.1016/j.pmrj.2008.11.011

20. de Greef BTA, Hoeijmakers JGJ, Gorissen-Brouwers CML, Geerts M, Faber CG, Merkies ISJ. Associated conditions in small fiber neuropathy - a large cohort study and review of the literature. Eur J Neurol. 2018;25(2):348-355. doi:10.1111/ene.13508

21. Morkavuk G, Leventoglu A. Small fiber neuropathy associated with hyperlipidemia: utility of cutaneous silent periods and autonomic tests. ISRN Neurol. 2014;2014:579242. doi:10.1155/2014/579242

22. Bednarik J, Vlckova-Moravcova E, Bursova S, Belobradkova J, Dusek L, Sommer C. Etiology of small-fiber neuropathy. J Peripher Nerv Syst. 2009;14(3):177-183. doi:10.1111/j.1529-8027.2009.00229.x

23. Kokotis P, Papantoniou M, Schmelz M, Buntziouka C, Tzavellas E, Paparrigopoulos T. Pure small fiber neuropathy in alcohol dependency detected by skin biopsy. Alcohol Fayettev N. 2023;111:67-73. doi:10.1016/j.alcohol.2023.05.006

24. Guimarães-Costa R, Schoindre Y, Metlaine A, et al. N-hexane exposure: a cause of small fiber neuropathy. J Peripher Nerv Syst. 2018;23(2):143-146. doi:10.1111/jns.12261

25. Koszewicz M, Markowska K, Waliszewska-Prosol M, et al. The impact of chronic co-exposure to different heavy metals on small fibers of peripheral nerves. A study of metal industry workers. J Occup Med Toxicol. 2021;16(1):12. doi:10.1186/s12995-021-00302-6

26. Johns Hopkins Medicine. Small nerve fibers defy neuropathy conventions. April 11, 2016. Accessed February 21, 2024. https://www.hopkinsmedicine.org/news/media/releases/small_nerve_fibers_defy_neuropathy_conventions

27. Jett DA. Neurotoxic pesticides and neurologic effects. Neurol Clin. 2011;29(3):667-677. doi:10.1016/j.ncl.2011.06.002

28. Berger AR, Schaumburg HH. Human toxic neuropathy caused by industrial agents. In: Dyck PJ, Thomas PK, eds. Peripheral Neuropathy. 4th ed. Saunders; 2005:2505-2525. doi:10.1016/B978-0-7216-9491-7.50115-0

29. Herskovitz S, Schaumburg HH. Neuropathy caused by drugs. In: Dyck PJ, Thomas PK, eds. Peripheral Neuropathy. 4th ed. Saunders; 2005:2553-2583.

30. Katona I, Weis J. Chapter 31 - Diseases of the peripheral nerves. Handb Clin Neurol. 2017;145:453-474. doi:10.1016/B978-0-12-802395-2.00031-6

31. Matikainen E, Juntunen J. Autonomic nervous system dysfunction in workers exposed to organic solvents. J Neurol Neurosurg Psychiatry. 1985;48(10):1021-1024. doi:10.1136/jnnp.48.10.1021

32. Murata K, Araki S, Yokoyama K, Maeda K. Autonomic and peripheral nervous system dysfunction in workers exposed to mixed organic solvents. Int Arch Occup Environ Health. 1991;63(5):335-340. doi:10.1007/BF00381584

33. Sletten DM, Suarez GA, Low PA, Mandrekar J, Singer W. COMPASS 31: a refined and abbreviated Composite Autonomic Symptom Score. Mayo Clin Proc. 2012;87(12):1196-1201. doi:10.1016/j.mayocp.2012.10.013

34. Treister R, O’Neil K, Downs HM, Oaklander AL. Validation of the Composite Autonomic Symptom Scale-31 (COMPASS-31) in patients with and without small-fiber polyneuropathy. Eur J Neurol. 2015;22(7):1124-1130. doi:10.1111/ene.12717

35. Joseph P, Arevalo C, Oliveira RKF, et al. Insights from invasive cardiopulmonary exercise testing of patients with myalgic encephalomyelitis/chronic fatigue syndrome. Chest. 2021;160(2):642-651. doi:10.1016/j.chest.2021.01.082

36. Giannoccaro MP, Donadio V, Incensi A, Avoni P, Liguori R. Small nerve fiber involvement in patients referred for fibromyalgia. Muscle Nerve. 2014;49(5):757-759. doi:10.1002/mus.24156

37. Oaklander AL, Herzog ZD, Downs HM, Klein MM. Objective evidence that small-fiber polyneuropathy underlies some illnesses currently labeled as fibromyalgia. Pain. 2013;154(11):2310-2316. doi:10.1016/j.pain.2013.06.001

38. Serrador JM. Diagnosis of late-stage, early-onset, small-fiber polyneuropathy. Defense Technical Information Center. December 1, 2019. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/AD1094831

39. Lodahl M, Treister R, Oaklander AL. Specific symptoms may discriminate between fibromyalgia patients with vs without objective test evidence of small-fiber polyneuropathy. Pain Rep. 2018;3(1):e633. doi:10.1097/PR9.0000000000000633

40. Sastre A, Cook MR. Autonomic dysfunction in Gulf War veterans. Defense Technical Information Center. April 1, 2004. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/ADA429525

41. Little AA, Albers JW. Clinical description of toxic neuropathies. Handb Clin Neurol. 2015;131:253-296. doi:10.1016/B978-0-444-62627-1.00015-9

42. Faber CG, Hoeijmakers JGJ, Ahn HS, et al. Gain of function NaV1.7 mutations in idiopathic small fiber neuropathy. Ann Neurol. 2012;71(1):26-39.

References

1. White RF, Steele L, O’Callaghan JP, et al. Recent research on Gulf War illness and other health problems in veterans of the 1991 Gulf War: effects of toxicant exposures during deployment. Cortex. 2016;74:449-475. doi:10.1016/j.cortex.2015.08.022

2. Committee on the Development of a Consensus Case Definition for Chronic Multisymptom Illness in 1990-1991 Gulf War Veterans, Board on the Health of Select Populations, Institute of Medicine. Chronic Multisymptom Illness in Gulf War Veterans: Case Definitions Reexamined. National Academies Press; 2014.

3. Robbins R, Helmer D, Monahan P, et al. Management of chronic multisymptom illness: synopsis of the 2021 US Department of Veterans Affairs and US Department of Defense Clinical Practice Guideline. Mayo Clin Proc. 2022;97(5):991-1002. doi:10.1016/j.mayocp.2022.01.031

4. Fox A, Helmer D, Tseng CL, Patrick-DeLuca L, Osinubi O. Report of autonomic symptoms in a clinical sample of veterans with Gulf War Illness. Mil Med. 2018;183(3-4):e179-e185. doi:10.1093/milmed/usx052

5. Fox A, Helmer D, Tseng CL, McCarron K, Satcher S, Osinubi O. Autonomic symptoms in Gulf War veterans evaluated at the War Related Illness and Injury Study Center. Mil Med. 2019;184(3-4):e191-e196. doi:10.1093/milmed/usy227

6. Reyes L, Falvo M, Blatt M, Ghobreal B, Acosta A, Serrador J. Autonomic dysfunction in veterans with Gulf War illness [abstract]. FASEB J. 2014;28(S1):1068.19. doi:10.1096/fasebj.28.1_supplement.1068.19

7. Haley RW, Charuvastra E, Shell WE, et al. Cholinergic autonomic dysfunction in veterans with Gulf War illness: confirmation in a population-based sample. JAMA Neurol. 2013;70(2):191-200. doi:10.1001/jamaneurol.2013.596

8. Haley RW, Vongpatanasin W, Wolfe GI, et al. Blunted circadian variation in autonomic regulation of sinus node function in veterans with Gulf War syndrome. Am J Med. 2004;117(7):469-478. doi:10.1016/j.amjmed.2004.03.041

9. Avery TJ, Mathersul DC, Schulz-Heik RJ, Mahoney L, Bayley PJ. Self-reported autonomic dysregulation in Gulf War Illness. Mil Med. Published online December 30, 2021. doi:10.1093/milmed/usab546

10. Verne ZT, Fields JZ, Zhang BB, Zhou Q. Autonomic dysfunction and gastroparesis in Gulf War veterans. J Investig Med. 2023;71(1):7-10. doi:10.1136/jim-2021-002291

11. Levine TD. Small fiber neuropathy: disease classification beyond pain and burning. J Cent Nerv Syst Dis. 2018;10:1179573518771703. doi:10.1177/1179573518771703

12. Novak P. Autonomic disorders. Am J Med. 2019;132(4):420-436. doi:10.1016/j.amjmed.2018.09.027

13. Oaklander AL, Klein MM. Undiagnosed small-fiber polyneuropathy: is it a component of Gulf War Illness? Defense Technical Information Center. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/ADA613891

<--pagebreak-->14. Sène D. Small fiber neuropathy: diagnosis, causes, and treatment. Joint Bone Spine. 2018;85(5):553-559. doi:10.1016/j.jbspin.2017.11.002

15. Novak V, Freimer ML, Kissel JT, et al. Autonomic impairment in painful neuropathy. Neurology. 2001;56(7):861-868. doi:10.1212/wnl.56.7.861

16. Myers MI, Peltier AC. Uses of skin biopsy for sensory and autonomic nerve assessment. Curr Neurol Neurosci Rep. 2013;13(1):323. doi:10.1007/s11910-012-0323-2

17. Haroutounian S, Todorovic MS, Leinders M, et al. Diagnostic criteria for idiopathic small fiber neuropathy: a systematic review. Muscle Nerve. 2021;63(2):170-177. doi:10.1002/mus.27070

18. Levine TD, Saperstein DS. Routine use of punch biopsy to diagnose small fiber neuropathy in fibromyalgia patients. Clin Rheumatol. 2015;34(3):413-417. doi:10.1007/s10067-014-2850-5

19. England JD, Gronseth G S, Franklin G, et al. Practice parameter: the evaluation of distal symmetric polyneuropathy: the role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review). Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. PM R. 2009;1(1):14-22. doi:10.1016/j.pmrj.2008.11.011

20. de Greef BTA, Hoeijmakers JGJ, Gorissen-Brouwers CML, Geerts M, Faber CG, Merkies ISJ. Associated conditions in small fiber neuropathy - a large cohort study and review of the literature. Eur J Neurol. 2018;25(2):348-355. doi:10.1111/ene.13508

21. Morkavuk G, Leventoglu A. Small fiber neuropathy associated with hyperlipidemia: utility of cutaneous silent periods and autonomic tests. ISRN Neurol. 2014;2014:579242. doi:10.1155/2014/579242

22. Bednarik J, Vlckova-Moravcova E, Bursova S, Belobradkova J, Dusek L, Sommer C. Etiology of small-fiber neuropathy. J Peripher Nerv Syst. 2009;14(3):177-183. doi:10.1111/j.1529-8027.2009.00229.x

23. Kokotis P, Papantoniou M, Schmelz M, Buntziouka C, Tzavellas E, Paparrigopoulos T. Pure small fiber neuropathy in alcohol dependency detected by skin biopsy. Alcohol Fayettev N. 2023;111:67-73. doi:10.1016/j.alcohol.2023.05.006

24. Guimarães-Costa R, Schoindre Y, Metlaine A, et al. N-hexane exposure: a cause of small fiber neuropathy. J Peripher Nerv Syst. 2018;23(2):143-146. doi:10.1111/jns.12261

25. Koszewicz M, Markowska K, Waliszewska-Prosol M, et al. The impact of chronic co-exposure to different heavy metals on small fibers of peripheral nerves. A study of metal industry workers. J Occup Med Toxicol. 2021;16(1):12. doi:10.1186/s12995-021-00302-6

26. Johns Hopkins Medicine. Small nerve fibers defy neuropathy conventions. April 11, 2016. Accessed February 21, 2024. https://www.hopkinsmedicine.org/news/media/releases/small_nerve_fibers_defy_neuropathy_conventions

27. Jett DA. Neurotoxic pesticides and neurologic effects. Neurol Clin. 2011;29(3):667-677. doi:10.1016/j.ncl.2011.06.002

28. Berger AR, Schaumburg HH. Human toxic neuropathy caused by industrial agents. In: Dyck PJ, Thomas PK, eds. Peripheral Neuropathy. 4th ed. Saunders; 2005:2505-2525. doi:10.1016/B978-0-7216-9491-7.50115-0

29. Herskovitz S, Schaumburg HH. Neuropathy caused by drugs. In: Dyck PJ, Thomas PK, eds. Peripheral Neuropathy. 4th ed. Saunders; 2005:2553-2583.

30. Katona I, Weis J. Chapter 31 - Diseases of the peripheral nerves. Handb Clin Neurol. 2017;145:453-474. doi:10.1016/B978-0-12-802395-2.00031-6

31. Matikainen E, Juntunen J. Autonomic nervous system dysfunction in workers exposed to organic solvents. J Neurol Neurosurg Psychiatry. 1985;48(10):1021-1024. doi:10.1136/jnnp.48.10.1021

32. Murata K, Araki S, Yokoyama K, Maeda K. Autonomic and peripheral nervous system dysfunction in workers exposed to mixed organic solvents. Int Arch Occup Environ Health. 1991;63(5):335-340. doi:10.1007/BF00381584

33. Sletten DM, Suarez GA, Low PA, Mandrekar J, Singer W. COMPASS 31: a refined and abbreviated Composite Autonomic Symptom Score. Mayo Clin Proc. 2012;87(12):1196-1201. doi:10.1016/j.mayocp.2012.10.013

34. Treister R, O’Neil K, Downs HM, Oaklander AL. Validation of the Composite Autonomic Symptom Scale-31 (COMPASS-31) in patients with and without small-fiber polyneuropathy. Eur J Neurol. 2015;22(7):1124-1130. doi:10.1111/ene.12717

35. Joseph P, Arevalo C, Oliveira RKF, et al. Insights from invasive cardiopulmonary exercise testing of patients with myalgic encephalomyelitis/chronic fatigue syndrome. Chest. 2021;160(2):642-651. doi:10.1016/j.chest.2021.01.082

36. Giannoccaro MP, Donadio V, Incensi A, Avoni P, Liguori R. Small nerve fiber involvement in patients referred for fibromyalgia. Muscle Nerve. 2014;49(5):757-759. doi:10.1002/mus.24156

37. Oaklander AL, Herzog ZD, Downs HM, Klein MM. Objective evidence that small-fiber polyneuropathy underlies some illnesses currently labeled as fibromyalgia. Pain. 2013;154(11):2310-2316. doi:10.1016/j.pain.2013.06.001

38. Serrador JM. Diagnosis of late-stage, early-onset, small-fiber polyneuropathy. Defense Technical Information Center. December 1, 2019. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/AD1094831

39. Lodahl M, Treister R, Oaklander AL. Specific symptoms may discriminate between fibromyalgia patients with vs without objective test evidence of small-fiber polyneuropathy. Pain Rep. 2018;3(1):e633. doi:10.1097/PR9.0000000000000633

40. Sastre A, Cook MR. Autonomic dysfunction in Gulf War veterans. Defense Technical Information Center. April 1, 2004. Accessed February 21, 2024. https://apps.dtic.mil/sti/citations/ADA429525

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42. Faber CG, Hoeijmakers JGJ, Ahn HS, et al. Gain of function NaV1.7 mutations in idiopathic small fiber neuropathy. Ann Neurol. 2012;71(1):26-39.

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Hereditary Amyloidosis: 5 Things to Know

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Amyloidosis is a condition marked by the accumulation of insoluble beta-sheet fibrillar protein aggregates in tissues that can be acquired or hereditary. Hereditary amyloidogenic transthyretin (hATTR) amyloidosis is an autosomal-dominant disease caused by pathogenic variants in the TTR gene. The TTR protein is essential for transporting thyroxine and retinol-binding protein and is primarily synthesized in the liver, becoming unstable as a result of the pathogenic mutations. Inherited pathogenic variants lead to the protein’s misfolding, aggregation, and deposition as amyloid fibrils in different organs, resulting in progressive multisystem dysfunction. hATTR amyloidosis is a heterogenous disease, characterized by a wide range of clinical manifestations affecting the peripheral (both somatic and autonomic) nervous system, heart, kidneys, and central nervous system (CNS); however, the heart and peripheral nerves appear to be the main targets of the TTR-related pathologic process. Without treatment, the prognosis is poor, with an average life expectancy of 7-11 years; however, in recent years, the development of new therapeutics has brought new hope to patients.

Here are five things to know about hereditary amyloidosis.
 

1. Diagnosis of hereditary amyloidosis requires a high level of suspicion.

The diagnosis of hATTR amyloidosis presents a significant challenge, particularly in nonendemic regions where a lack of family history and heterogeneity of clinical presentation can delay diagnosis by 4-5 years. A timely diagnosis requires clinicians to maintain a high index of suspicion, especially when evaluating patients with neuropathic symptoms. Early diagnosis is crucial to begin patients on recently available disease-modifying therapies that can slow the disease course. Failure to recognize is the major barrier to improved patient outcomes.

Confirming the diagnosis involves detecting amyloid deposits in tissue biopsy specimens from various possible sites, including the skin, nerves, myocardium, and others. However, the diagnosis can be challenging owing to the uneven distribution of amyloid fibrils, sometimes requiring multiple biopsies or alternative diagnostic approaches, such as TTR gene sequencing, to confirm the presence of an amyloidogenic pathogenic variant. Biopsy for hATTR amyloidosis is not required if imaging of the clinical phenotype and genetic testing are consistent.

Once diagnosed, the assessment of organ involvement is essential, using nerve conduction studies, cardiac investigations (eg, echocardiographyECG, scintigraphy), ophthalmologic assessments, and complete renal function evaluations to fully understand the extent of disease impact.
 

2. Hereditary amyloidosis diseases are classified into two primary categories.

Hereditary amyloidosis represents a group of diseases caused by inherited gene mutations and is classified into two main types: ATTR (transthyretin-related) and non-TTR. Most cases of hereditary amyloidosis are associated with the TTR gene. Mutations in this protein lead to different forms of ATTR amyloidosis, categorized on the basis of the specific mutation involved, such as hATTR50M (genotype Val50Met), which is the most prevalent form.

ATTR mutations result in a variety of health issues, manifesting in three primary forms:

  • Neuropathic ATTR (genotype Val50Met): Early symptoms include sensorimotor polyneuropathy of the legs, carpal tunnel syndrome, autonomic dysfunction, constipation/diarrhea, and impotence; late symptoms include cardiomyopathy, vitreous opacities, glaucoma, nephropathy, and CNS symptoms.
  • Cardiac ATTR (genotype Val142Ile): This type is characterized by cardiomegaly, conduction block, arrhythmia, anginal pain, congestive heart failure, and sudden death.
  • Leptomeningeal ATTR (genotype Asp38Gly): This is characterized by transient focal neurologic episodes, intracerebral and/or subarachnoid hemorrhages, dementia, ataxia, and psychosis.

Non-TTR amyloidoses are rarer than are ATTR variations and involve mutations in different genes that also have significant health impacts. These include proteins such as apolipoprotein AI, fibrinogen A alpha, lysozyme, apolipoprotein AII, gelsolin, and cystatin C. Each type contributes to a range of symptoms and requires individualized management approaches.
 

3. Heightened disease awareness has increased the recognized prevalence of hereditary amyloidosis.

hATTR amyloidosis has historically been recognized as a rare disease, with significant clusters in Portugal, Brazil, Sweden, and Japan and alongside smaller foci in regions such as Cyprus and Majorca. This disease›s variable incidence across Europe is now perceived to be on the rise. It is attributed to heightened disease awareness among healthcare providers and the broader availability of genetic testing, extending its recognized impact to at least 29 countries globally. The genetic landscape of hATTR amyloidosis is diverse, with over 140 mutations identified in the TTR gene. Among these, the Val50Met mutation is particularly notable for its association with large patient clusters in the endemic regions.

Morbidity and mortality associated with hATTR amyloidosis are significant, with an average lifespan of 7-11 years post diagnosis; however, survival rates can vary widely depending on the specific genetic variant and organ involvement. Early diagnosis can substantially improve outcomes; yet, for many, the prognosis remains poor, especially in cases dominated by cardiomyopathy. Genetics play a central role in the disease›s transmission, with autosomal-dominant inheritance patterns and high penetrance among carriers of pathogenic mutations. Research continues to uncover the broad spectrum of genetic variations contributing to hATTR amyloidosis, with ongoing studies poised to expand our understanding of its molecular underpinnings and potential treatment options.

4. The effect on quality of life is significant both in patients living with hATTR amyloidosis and their caregivers.

hATTR amyloidosis imposes a multifaceted burden on patients and their caregivers as the disease progresses. Symptoms range from sensorimotor impairment and gastrointestinal or autonomic dysfunction to heart failure, leading to significant health-related quality-of-life deficits. The systemic nature of hATTR amyloidosis significantly affects patients› lifestyles, daily activities, and general well-being, especially because it typically manifests in adulthood — a crucial time for occupational changes. The progression of hATTR amyloidosis exacerbates the challenges in maintaining employment and managing household chores, with symptomatic patients often unable to work and experiencing difficulties with absenteeism and presenteeism when they are able to work.

hATTR amyloidosis leads to physical, mental, occupational, and social limitations for patients, and it also places a considerable strain on their families and caregivers, who report poor mental health, work impairment, and a high time commitment (mean, 45.9 h/wk) to providing care.

5. There have been significant advancements in therapeutic options for early-stage hATTR amyloidosis.

After diagnosis, prompt initiation of treatment is recommended to delay the progression of hATTR amyloidosis; a multidisciplinary approach is essential, incorporating anti-amyloid therapy to inhibit further production and/or deposition of amyloid aggregates. Treatment strategies also include addressing symptomatic therapy and managing cardiac, renal, and ocular involvement. Although many therapies have been developed, especially for the early stages of hATTR amyloidosis, therapeutic benefits for patients with advanced disease remain limited.

Recent advancements in the treatment of hATTR amyloidosis have introduced RNA-targeted therapies including patisiranvutrisiran, and eplontersen, which have shown efficacy in reducing hepatic TTR synthesis and the aggregation of misfolded monomers into amyloid deposits. These therapies, ranging from small interfering RNA formulations to antisense oligonucleotides, offer benefits in managing both cardiomyopathy and neuropathy associated with hATTR amyloidosis , administered through various methods, including intravenous infusions and subcutaneous injections. In addition, the stabilization of TTR tetramers with the use of drugs such as tafamidis and diflunisal has effectively prevented the formation of amyloidogenic monomers. Moreover, other investigational agents, including TTR stabilizers like acoramidis and tolcapone, as well as novel compounds that inhibit amyloid formation and disrupt fibrils, are expanding the therapeutic landscape for hATTR amyloidosis , providing hope for improved management of this complex condition.

Dr. Gertz is a professor and consultant in the Department of Hematology, Mayo Clinic, Rochester, Minnesota. He has disclosed the following relevant financial relationships: Received income in an amount equal to or greater than $250 from AstraZeneca, Ionis, and Alnylym.

A version of this article appeared on Medscape.com.

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Amyloidosis is a condition marked by the accumulation of insoluble beta-sheet fibrillar protein aggregates in tissues that can be acquired or hereditary. Hereditary amyloidogenic transthyretin (hATTR) amyloidosis is an autosomal-dominant disease caused by pathogenic variants in the TTR gene. The TTR protein is essential for transporting thyroxine and retinol-binding protein and is primarily synthesized in the liver, becoming unstable as a result of the pathogenic mutations. Inherited pathogenic variants lead to the protein’s misfolding, aggregation, and deposition as amyloid fibrils in different organs, resulting in progressive multisystem dysfunction. hATTR amyloidosis is a heterogenous disease, characterized by a wide range of clinical manifestations affecting the peripheral (both somatic and autonomic) nervous system, heart, kidneys, and central nervous system (CNS); however, the heart and peripheral nerves appear to be the main targets of the TTR-related pathologic process. Without treatment, the prognosis is poor, with an average life expectancy of 7-11 years; however, in recent years, the development of new therapeutics has brought new hope to patients.

Here are five things to know about hereditary amyloidosis.
 

1. Diagnosis of hereditary amyloidosis requires a high level of suspicion.

The diagnosis of hATTR amyloidosis presents a significant challenge, particularly in nonendemic regions where a lack of family history and heterogeneity of clinical presentation can delay diagnosis by 4-5 years. A timely diagnosis requires clinicians to maintain a high index of suspicion, especially when evaluating patients with neuropathic symptoms. Early diagnosis is crucial to begin patients on recently available disease-modifying therapies that can slow the disease course. Failure to recognize is the major barrier to improved patient outcomes.

Confirming the diagnosis involves detecting amyloid deposits in tissue biopsy specimens from various possible sites, including the skin, nerves, myocardium, and others. However, the diagnosis can be challenging owing to the uneven distribution of amyloid fibrils, sometimes requiring multiple biopsies or alternative diagnostic approaches, such as TTR gene sequencing, to confirm the presence of an amyloidogenic pathogenic variant. Biopsy for hATTR amyloidosis is not required if imaging of the clinical phenotype and genetic testing are consistent.

Once diagnosed, the assessment of organ involvement is essential, using nerve conduction studies, cardiac investigations (eg, echocardiographyECG, scintigraphy), ophthalmologic assessments, and complete renal function evaluations to fully understand the extent of disease impact.
 

2. Hereditary amyloidosis diseases are classified into two primary categories.

Hereditary amyloidosis represents a group of diseases caused by inherited gene mutations and is classified into two main types: ATTR (transthyretin-related) and non-TTR. Most cases of hereditary amyloidosis are associated with the TTR gene. Mutations in this protein lead to different forms of ATTR amyloidosis, categorized on the basis of the specific mutation involved, such as hATTR50M (genotype Val50Met), which is the most prevalent form.

ATTR mutations result in a variety of health issues, manifesting in three primary forms:

  • Neuropathic ATTR (genotype Val50Met): Early symptoms include sensorimotor polyneuropathy of the legs, carpal tunnel syndrome, autonomic dysfunction, constipation/diarrhea, and impotence; late symptoms include cardiomyopathy, vitreous opacities, glaucoma, nephropathy, and CNS symptoms.
  • Cardiac ATTR (genotype Val142Ile): This type is characterized by cardiomegaly, conduction block, arrhythmia, anginal pain, congestive heart failure, and sudden death.
  • Leptomeningeal ATTR (genotype Asp38Gly): This is characterized by transient focal neurologic episodes, intracerebral and/or subarachnoid hemorrhages, dementia, ataxia, and psychosis.

Non-TTR amyloidoses are rarer than are ATTR variations and involve mutations in different genes that also have significant health impacts. These include proteins such as apolipoprotein AI, fibrinogen A alpha, lysozyme, apolipoprotein AII, gelsolin, and cystatin C. Each type contributes to a range of symptoms and requires individualized management approaches.
 

3. Heightened disease awareness has increased the recognized prevalence of hereditary amyloidosis.

hATTR amyloidosis has historically been recognized as a rare disease, with significant clusters in Portugal, Brazil, Sweden, and Japan and alongside smaller foci in regions such as Cyprus and Majorca. This disease›s variable incidence across Europe is now perceived to be on the rise. It is attributed to heightened disease awareness among healthcare providers and the broader availability of genetic testing, extending its recognized impact to at least 29 countries globally. The genetic landscape of hATTR amyloidosis is diverse, with over 140 mutations identified in the TTR gene. Among these, the Val50Met mutation is particularly notable for its association with large patient clusters in the endemic regions.

Morbidity and mortality associated with hATTR amyloidosis are significant, with an average lifespan of 7-11 years post diagnosis; however, survival rates can vary widely depending on the specific genetic variant and organ involvement. Early diagnosis can substantially improve outcomes; yet, for many, the prognosis remains poor, especially in cases dominated by cardiomyopathy. Genetics play a central role in the disease›s transmission, with autosomal-dominant inheritance patterns and high penetrance among carriers of pathogenic mutations. Research continues to uncover the broad spectrum of genetic variations contributing to hATTR amyloidosis, with ongoing studies poised to expand our understanding of its molecular underpinnings and potential treatment options.

4. The effect on quality of life is significant both in patients living with hATTR amyloidosis and their caregivers.

hATTR amyloidosis imposes a multifaceted burden on patients and their caregivers as the disease progresses. Symptoms range from sensorimotor impairment and gastrointestinal or autonomic dysfunction to heart failure, leading to significant health-related quality-of-life deficits. The systemic nature of hATTR amyloidosis significantly affects patients› lifestyles, daily activities, and general well-being, especially because it typically manifests in adulthood — a crucial time for occupational changes. The progression of hATTR amyloidosis exacerbates the challenges in maintaining employment and managing household chores, with symptomatic patients often unable to work and experiencing difficulties with absenteeism and presenteeism when they are able to work.

hATTR amyloidosis leads to physical, mental, occupational, and social limitations for patients, and it also places a considerable strain on their families and caregivers, who report poor mental health, work impairment, and a high time commitment (mean, 45.9 h/wk) to providing care.

5. There have been significant advancements in therapeutic options for early-stage hATTR amyloidosis.

After diagnosis, prompt initiation of treatment is recommended to delay the progression of hATTR amyloidosis; a multidisciplinary approach is essential, incorporating anti-amyloid therapy to inhibit further production and/or deposition of amyloid aggregates. Treatment strategies also include addressing symptomatic therapy and managing cardiac, renal, and ocular involvement. Although many therapies have been developed, especially for the early stages of hATTR amyloidosis, therapeutic benefits for patients with advanced disease remain limited.

Recent advancements in the treatment of hATTR amyloidosis have introduced RNA-targeted therapies including patisiranvutrisiran, and eplontersen, which have shown efficacy in reducing hepatic TTR synthesis and the aggregation of misfolded monomers into amyloid deposits. These therapies, ranging from small interfering RNA formulations to antisense oligonucleotides, offer benefits in managing both cardiomyopathy and neuropathy associated with hATTR amyloidosis , administered through various methods, including intravenous infusions and subcutaneous injections. In addition, the stabilization of TTR tetramers with the use of drugs such as tafamidis and diflunisal has effectively prevented the formation of amyloidogenic monomers. Moreover, other investigational agents, including TTR stabilizers like acoramidis and tolcapone, as well as novel compounds that inhibit amyloid formation and disrupt fibrils, are expanding the therapeutic landscape for hATTR amyloidosis , providing hope for improved management of this complex condition.

Dr. Gertz is a professor and consultant in the Department of Hematology, Mayo Clinic, Rochester, Minnesota. He has disclosed the following relevant financial relationships: Received income in an amount equal to or greater than $250 from AstraZeneca, Ionis, and Alnylym.

A version of this article appeared on Medscape.com.

Amyloidosis is a condition marked by the accumulation of insoluble beta-sheet fibrillar protein aggregates in tissues that can be acquired or hereditary. Hereditary amyloidogenic transthyretin (hATTR) amyloidosis is an autosomal-dominant disease caused by pathogenic variants in the TTR gene. The TTR protein is essential for transporting thyroxine and retinol-binding protein and is primarily synthesized in the liver, becoming unstable as a result of the pathogenic mutations. Inherited pathogenic variants lead to the protein’s misfolding, aggregation, and deposition as amyloid fibrils in different organs, resulting in progressive multisystem dysfunction. hATTR amyloidosis is a heterogenous disease, characterized by a wide range of clinical manifestations affecting the peripheral (both somatic and autonomic) nervous system, heart, kidneys, and central nervous system (CNS); however, the heart and peripheral nerves appear to be the main targets of the TTR-related pathologic process. Without treatment, the prognosis is poor, with an average life expectancy of 7-11 years; however, in recent years, the development of new therapeutics has brought new hope to patients.

Here are five things to know about hereditary amyloidosis.
 

1. Diagnosis of hereditary amyloidosis requires a high level of suspicion.

The diagnosis of hATTR amyloidosis presents a significant challenge, particularly in nonendemic regions where a lack of family history and heterogeneity of clinical presentation can delay diagnosis by 4-5 years. A timely diagnosis requires clinicians to maintain a high index of suspicion, especially when evaluating patients with neuropathic symptoms. Early diagnosis is crucial to begin patients on recently available disease-modifying therapies that can slow the disease course. Failure to recognize is the major barrier to improved patient outcomes.

Confirming the diagnosis involves detecting amyloid deposits in tissue biopsy specimens from various possible sites, including the skin, nerves, myocardium, and others. However, the diagnosis can be challenging owing to the uneven distribution of amyloid fibrils, sometimes requiring multiple biopsies or alternative diagnostic approaches, such as TTR gene sequencing, to confirm the presence of an amyloidogenic pathogenic variant. Biopsy for hATTR amyloidosis is not required if imaging of the clinical phenotype and genetic testing are consistent.

Once diagnosed, the assessment of organ involvement is essential, using nerve conduction studies, cardiac investigations (eg, echocardiographyECG, scintigraphy), ophthalmologic assessments, and complete renal function evaluations to fully understand the extent of disease impact.
 

2. Hereditary amyloidosis diseases are classified into two primary categories.

Hereditary amyloidosis represents a group of diseases caused by inherited gene mutations and is classified into two main types: ATTR (transthyretin-related) and non-TTR. Most cases of hereditary amyloidosis are associated with the TTR gene. Mutations in this protein lead to different forms of ATTR amyloidosis, categorized on the basis of the specific mutation involved, such as hATTR50M (genotype Val50Met), which is the most prevalent form.

ATTR mutations result in a variety of health issues, manifesting in three primary forms:

  • Neuropathic ATTR (genotype Val50Met): Early symptoms include sensorimotor polyneuropathy of the legs, carpal tunnel syndrome, autonomic dysfunction, constipation/diarrhea, and impotence; late symptoms include cardiomyopathy, vitreous opacities, glaucoma, nephropathy, and CNS symptoms.
  • Cardiac ATTR (genotype Val142Ile): This type is characterized by cardiomegaly, conduction block, arrhythmia, anginal pain, congestive heart failure, and sudden death.
  • Leptomeningeal ATTR (genotype Asp38Gly): This is characterized by transient focal neurologic episodes, intracerebral and/or subarachnoid hemorrhages, dementia, ataxia, and psychosis.

Non-TTR amyloidoses are rarer than are ATTR variations and involve mutations in different genes that also have significant health impacts. These include proteins such as apolipoprotein AI, fibrinogen A alpha, lysozyme, apolipoprotein AII, gelsolin, and cystatin C. Each type contributes to a range of symptoms and requires individualized management approaches.
 

3. Heightened disease awareness has increased the recognized prevalence of hereditary amyloidosis.

hATTR amyloidosis has historically been recognized as a rare disease, with significant clusters in Portugal, Brazil, Sweden, and Japan and alongside smaller foci in regions such as Cyprus and Majorca. This disease›s variable incidence across Europe is now perceived to be on the rise. It is attributed to heightened disease awareness among healthcare providers and the broader availability of genetic testing, extending its recognized impact to at least 29 countries globally. The genetic landscape of hATTR amyloidosis is diverse, with over 140 mutations identified in the TTR gene. Among these, the Val50Met mutation is particularly notable for its association with large patient clusters in the endemic regions.

Morbidity and mortality associated with hATTR amyloidosis are significant, with an average lifespan of 7-11 years post diagnosis; however, survival rates can vary widely depending on the specific genetic variant and organ involvement. Early diagnosis can substantially improve outcomes; yet, for many, the prognosis remains poor, especially in cases dominated by cardiomyopathy. Genetics play a central role in the disease›s transmission, with autosomal-dominant inheritance patterns and high penetrance among carriers of pathogenic mutations. Research continues to uncover the broad spectrum of genetic variations contributing to hATTR amyloidosis, with ongoing studies poised to expand our understanding of its molecular underpinnings and potential treatment options.

4. The effect on quality of life is significant both in patients living with hATTR amyloidosis and their caregivers.

hATTR amyloidosis imposes a multifaceted burden on patients and their caregivers as the disease progresses. Symptoms range from sensorimotor impairment and gastrointestinal or autonomic dysfunction to heart failure, leading to significant health-related quality-of-life deficits. The systemic nature of hATTR amyloidosis significantly affects patients› lifestyles, daily activities, and general well-being, especially because it typically manifests in adulthood — a crucial time for occupational changes. The progression of hATTR amyloidosis exacerbates the challenges in maintaining employment and managing household chores, with symptomatic patients often unable to work and experiencing difficulties with absenteeism and presenteeism when they are able to work.

hATTR amyloidosis leads to physical, mental, occupational, and social limitations for patients, and it also places a considerable strain on their families and caregivers, who report poor mental health, work impairment, and a high time commitment (mean, 45.9 h/wk) to providing care.

5. There have been significant advancements in therapeutic options for early-stage hATTR amyloidosis.

After diagnosis, prompt initiation of treatment is recommended to delay the progression of hATTR amyloidosis; a multidisciplinary approach is essential, incorporating anti-amyloid therapy to inhibit further production and/or deposition of amyloid aggregates. Treatment strategies also include addressing symptomatic therapy and managing cardiac, renal, and ocular involvement. Although many therapies have been developed, especially for the early stages of hATTR amyloidosis, therapeutic benefits for patients with advanced disease remain limited.

Recent advancements in the treatment of hATTR amyloidosis have introduced RNA-targeted therapies including patisiranvutrisiran, and eplontersen, which have shown efficacy in reducing hepatic TTR synthesis and the aggregation of misfolded monomers into amyloid deposits. These therapies, ranging from small interfering RNA formulations to antisense oligonucleotides, offer benefits in managing both cardiomyopathy and neuropathy associated with hATTR amyloidosis , administered through various methods, including intravenous infusions and subcutaneous injections. In addition, the stabilization of TTR tetramers with the use of drugs such as tafamidis and diflunisal has effectively prevented the formation of amyloidogenic monomers. Moreover, other investigational agents, including TTR stabilizers like acoramidis and tolcapone, as well as novel compounds that inhibit amyloid formation and disrupt fibrils, are expanding the therapeutic landscape for hATTR amyloidosis , providing hope for improved management of this complex condition.

Dr. Gertz is a professor and consultant in the Department of Hematology, Mayo Clinic, Rochester, Minnesota. He has disclosed the following relevant financial relationships: Received income in an amount equal to or greater than $250 from AstraZeneca, Ionis, and Alnylym.

A version of this article appeared on Medscape.com.

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Major Gaps in Care and Management of Neurologic Diseases

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DENVER – Real-world, US claims-based data show major gaps in the care and management of three major neurologic disorders: Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS).

Investigators led by Nikki Win, PhD, medical manager/team lead, OMNI Scientific Strategy and Collaborations, US Medical Affairs, Genentech/Roche, found that patients with Parkinson’s disease were referred to a specialist most often, followed by those with MS and those with AD. 

The findings were presented at the 2024 annual meeting of the American Academy of Neurology (AAN).
 

National Neurologist Shortage

The national neurologist shortage, coupled with the growing incidence of Alzheimer’s disease, Parkinson’s disease, MS, and other conditions has led the AAN and other organizations to call for expanding the role of primary care physicians in the diagnosis and management of neurologic disorders, the leading global cause of disability.

“These neurological conditions are increasing in prevalence and there’s a limited number of neurologists, so we wanted to understand what this looks like in the US,” Dr. Win said.

“There is a need to understand the patient journey from primary care to neurology care, from presentation of a suspected neurological disorder to diagnosis, referral to a specialist, and the time elapsed before the specialist visit for Alzheimer’s disease, MS, and Parkinson’s disease in the US,” Dr. Win added. 

Timely and accurate diagnoses of neurologic disorders can optimize treatment outcomes. Because many of these diseases are first detected during a visit with a primary care physician, it is important to understand the timeline from the initial visit to a specialist referral, the investigators noted. 
 

Analyzing Trends in Specialist Referrals

Using claims data from the Optum Normative Health Information database, researchers identified 48,525 adults with Alzheimer’s disease, 26,431 with Parkinson’s disease, and 8169 with MS who received a diagnosis from a primary care physician between 2016 and 2021.

They examined the proportion, timing, and demographic factors associated with referrals from primary care clinicians or other healthcare providers to specialists including neurologists, neurosurgeons, psychiatrists, and geriatric medicine specialists.

Results showed that patients with Parkinson’s disease were referred to a specialist most often (53%), followed by those with MS (42%) and those with Alzheimer’s disease (27%).

Individuals with Alzheimer’s disease waited the longest for a specialist referral, with a median of 10 months between the time of referral and the first specialist visit compared with 5.7 months for patients with Parkinson’s disease and 2.6 months for MS patients.

“Some patients with common conditions like Alzheimer’s disease, MS, and Parkinson’s disease don’t see a neurologist, and when they do, it can take as long as 10 months,” said Dr. Win.

Using zip code heatmaps, researchers found that the proportion of referrals for all neurologic disorders was higher in the Midwest and Northeast, whereas patients in the South and West were less likely to receive a referral. 

Referrals for Alzheimer’s disease were low nationwide, except for some areas of Michigan and New England. California had the lowest referral rate for MS, followed by regions in the South and Northeast. Patients with Parkinson’s disease living in the Midwest and Northeast were more likely than those in the West to receive a specialist referral. 

Previous studies have reported regional shortages of neurologists, said Dr. Win. “Our data seem to correlate that in terms of the areas with lower referral patterns, but as to whether that is causative or correlative, we don’t know.” 

Odds of referral were also influenced by demographic characteristics such as sex, age, race, and ethnicity, investigators found. 

For example, there were fewer referrals with increasing age across all three neurologic disorders, and men were more likely than women to be referred for Alzheimer’s disease and Parkinson’s disease. Compared with White patients, Parkinson’s disease referrals were less likely among African American, Asian, and Hispanic patients and Alzheimer’s disease referrals were less common among Asian and Hispanic patients.

Insurance status also affected referrals. People with MS and Parkinson’s disease who had commercial insurance were referred more often than were those with Medicare Advantage, said Dr. Win.

She also noted, “Additional research is needed to understand how being referred or not being referred to a neurologist actually impacts patient treatment, care and outcomes.”
 

 

 

Neurology Challenges

Commenting on the research, Thomas Vidic, MD, a community neurologist in Elkhart, Indiana, and clinical professor of neurology at Indiana University School of Medicine at South Bend, said that he was surprised by the variation in wait times for patients.

This, he said, could reflect a study limitation or a higher comfort level among primary care doctors in treating dementia.

With respect to MS, Dr. Vidic said that he believes primary care physicians may not be uncertain about prescribing the approved medications for the disease because there are so many of them.

In addition, patients with Alzheimer’s disease are older and perhaps less accepting of being referred to a specialist that may be hours away.

The bottom line for Dr. Vidic, though, is the lack of specialists. “It comes back to the fact we’re not doing a good job of having community neurologists available to take care of these problems,” he said.

The issue of community neurologist shortages was underlined by the study’s findings about geographic gaps in specialist referrals across the country, he said.

Neurologists make up about 2% of the medical workforce and this has remained static for some time, Dr. Vidic noted. Meanwhile, people are living longer and developing more neurologic diseases.

Dr. Vidic also pointed to the lack of neurology training programs. “There has not been a significant change in the number of programs in the last 10-15 years,” he said.

Study funding was not disclosed. Dr. Win reports receiving personal compensation for serving as an employee of Genentech and has stock in Genentech. Dr. Vidic reports no relevant financial disclosures.

A version of this article appeared on Medscape.com.

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DENVER – Real-world, US claims-based data show major gaps in the care and management of three major neurologic disorders: Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS).

Investigators led by Nikki Win, PhD, medical manager/team lead, OMNI Scientific Strategy and Collaborations, US Medical Affairs, Genentech/Roche, found that patients with Parkinson’s disease were referred to a specialist most often, followed by those with MS and those with AD. 

The findings were presented at the 2024 annual meeting of the American Academy of Neurology (AAN).
 

National Neurologist Shortage

The national neurologist shortage, coupled with the growing incidence of Alzheimer’s disease, Parkinson’s disease, MS, and other conditions has led the AAN and other organizations to call for expanding the role of primary care physicians in the diagnosis and management of neurologic disorders, the leading global cause of disability.

“These neurological conditions are increasing in prevalence and there’s a limited number of neurologists, so we wanted to understand what this looks like in the US,” Dr. Win said.

“There is a need to understand the patient journey from primary care to neurology care, from presentation of a suspected neurological disorder to diagnosis, referral to a specialist, and the time elapsed before the specialist visit for Alzheimer’s disease, MS, and Parkinson’s disease in the US,” Dr. Win added. 

Timely and accurate diagnoses of neurologic disorders can optimize treatment outcomes. Because many of these diseases are first detected during a visit with a primary care physician, it is important to understand the timeline from the initial visit to a specialist referral, the investigators noted. 
 

Analyzing Trends in Specialist Referrals

Using claims data from the Optum Normative Health Information database, researchers identified 48,525 adults with Alzheimer’s disease, 26,431 with Parkinson’s disease, and 8169 with MS who received a diagnosis from a primary care physician between 2016 and 2021.

They examined the proportion, timing, and demographic factors associated with referrals from primary care clinicians or other healthcare providers to specialists including neurologists, neurosurgeons, psychiatrists, and geriatric medicine specialists.

Results showed that patients with Parkinson’s disease were referred to a specialist most often (53%), followed by those with MS (42%) and those with Alzheimer’s disease (27%).

Individuals with Alzheimer’s disease waited the longest for a specialist referral, with a median of 10 months between the time of referral and the first specialist visit compared with 5.7 months for patients with Parkinson’s disease and 2.6 months for MS patients.

“Some patients with common conditions like Alzheimer’s disease, MS, and Parkinson’s disease don’t see a neurologist, and when they do, it can take as long as 10 months,” said Dr. Win.

Using zip code heatmaps, researchers found that the proportion of referrals for all neurologic disorders was higher in the Midwest and Northeast, whereas patients in the South and West were less likely to receive a referral. 

Referrals for Alzheimer’s disease were low nationwide, except for some areas of Michigan and New England. California had the lowest referral rate for MS, followed by regions in the South and Northeast. Patients with Parkinson’s disease living in the Midwest and Northeast were more likely than those in the West to receive a specialist referral. 

Previous studies have reported regional shortages of neurologists, said Dr. Win. “Our data seem to correlate that in terms of the areas with lower referral patterns, but as to whether that is causative or correlative, we don’t know.” 

Odds of referral were also influenced by demographic characteristics such as sex, age, race, and ethnicity, investigators found. 

For example, there were fewer referrals with increasing age across all three neurologic disorders, and men were more likely than women to be referred for Alzheimer’s disease and Parkinson’s disease. Compared with White patients, Parkinson’s disease referrals were less likely among African American, Asian, and Hispanic patients and Alzheimer’s disease referrals were less common among Asian and Hispanic patients.

Insurance status also affected referrals. People with MS and Parkinson’s disease who had commercial insurance were referred more often than were those with Medicare Advantage, said Dr. Win.

She also noted, “Additional research is needed to understand how being referred or not being referred to a neurologist actually impacts patient treatment, care and outcomes.”
 

 

 

Neurology Challenges

Commenting on the research, Thomas Vidic, MD, a community neurologist in Elkhart, Indiana, and clinical professor of neurology at Indiana University School of Medicine at South Bend, said that he was surprised by the variation in wait times for patients.

This, he said, could reflect a study limitation or a higher comfort level among primary care doctors in treating dementia.

With respect to MS, Dr. Vidic said that he believes primary care physicians may not be uncertain about prescribing the approved medications for the disease because there are so many of them.

In addition, patients with Alzheimer’s disease are older and perhaps less accepting of being referred to a specialist that may be hours away.

The bottom line for Dr. Vidic, though, is the lack of specialists. “It comes back to the fact we’re not doing a good job of having community neurologists available to take care of these problems,” he said.

The issue of community neurologist shortages was underlined by the study’s findings about geographic gaps in specialist referrals across the country, he said.

Neurologists make up about 2% of the medical workforce and this has remained static for some time, Dr. Vidic noted. Meanwhile, people are living longer and developing more neurologic diseases.

Dr. Vidic also pointed to the lack of neurology training programs. “There has not been a significant change in the number of programs in the last 10-15 years,” he said.

Study funding was not disclosed. Dr. Win reports receiving personal compensation for serving as an employee of Genentech and has stock in Genentech. Dr. Vidic reports no relevant financial disclosures.

A version of this article appeared on Medscape.com.

DENVER – Real-world, US claims-based data show major gaps in the care and management of three major neurologic disorders: Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS).

Investigators led by Nikki Win, PhD, medical manager/team lead, OMNI Scientific Strategy and Collaborations, US Medical Affairs, Genentech/Roche, found that patients with Parkinson’s disease were referred to a specialist most often, followed by those with MS and those with AD. 

The findings were presented at the 2024 annual meeting of the American Academy of Neurology (AAN).
 

National Neurologist Shortage

The national neurologist shortage, coupled with the growing incidence of Alzheimer’s disease, Parkinson’s disease, MS, and other conditions has led the AAN and other organizations to call for expanding the role of primary care physicians in the diagnosis and management of neurologic disorders, the leading global cause of disability.

“These neurological conditions are increasing in prevalence and there’s a limited number of neurologists, so we wanted to understand what this looks like in the US,” Dr. Win said.

“There is a need to understand the patient journey from primary care to neurology care, from presentation of a suspected neurological disorder to diagnosis, referral to a specialist, and the time elapsed before the specialist visit for Alzheimer’s disease, MS, and Parkinson’s disease in the US,” Dr. Win added. 

Timely and accurate diagnoses of neurologic disorders can optimize treatment outcomes. Because many of these diseases are first detected during a visit with a primary care physician, it is important to understand the timeline from the initial visit to a specialist referral, the investigators noted. 
 

Analyzing Trends in Specialist Referrals

Using claims data from the Optum Normative Health Information database, researchers identified 48,525 adults with Alzheimer’s disease, 26,431 with Parkinson’s disease, and 8169 with MS who received a diagnosis from a primary care physician between 2016 and 2021.

They examined the proportion, timing, and demographic factors associated with referrals from primary care clinicians or other healthcare providers to specialists including neurologists, neurosurgeons, psychiatrists, and geriatric medicine specialists.

Results showed that patients with Parkinson’s disease were referred to a specialist most often (53%), followed by those with MS (42%) and those with Alzheimer’s disease (27%).

Individuals with Alzheimer’s disease waited the longest for a specialist referral, with a median of 10 months between the time of referral and the first specialist visit compared with 5.7 months for patients with Parkinson’s disease and 2.6 months for MS patients.

“Some patients with common conditions like Alzheimer’s disease, MS, and Parkinson’s disease don’t see a neurologist, and when they do, it can take as long as 10 months,” said Dr. Win.

Using zip code heatmaps, researchers found that the proportion of referrals for all neurologic disorders was higher in the Midwest and Northeast, whereas patients in the South and West were less likely to receive a referral. 

Referrals for Alzheimer’s disease were low nationwide, except for some areas of Michigan and New England. California had the lowest referral rate for MS, followed by regions in the South and Northeast. Patients with Parkinson’s disease living in the Midwest and Northeast were more likely than those in the West to receive a specialist referral. 

Previous studies have reported regional shortages of neurologists, said Dr. Win. “Our data seem to correlate that in terms of the areas with lower referral patterns, but as to whether that is causative or correlative, we don’t know.” 

Odds of referral were also influenced by demographic characteristics such as sex, age, race, and ethnicity, investigators found. 

For example, there were fewer referrals with increasing age across all three neurologic disorders, and men were more likely than women to be referred for Alzheimer’s disease and Parkinson’s disease. Compared with White patients, Parkinson’s disease referrals were less likely among African American, Asian, and Hispanic patients and Alzheimer’s disease referrals were less common among Asian and Hispanic patients.

Insurance status also affected referrals. People with MS and Parkinson’s disease who had commercial insurance were referred more often than were those with Medicare Advantage, said Dr. Win.

She also noted, “Additional research is needed to understand how being referred or not being referred to a neurologist actually impacts patient treatment, care and outcomes.”
 

 

 

Neurology Challenges

Commenting on the research, Thomas Vidic, MD, a community neurologist in Elkhart, Indiana, and clinical professor of neurology at Indiana University School of Medicine at South Bend, said that he was surprised by the variation in wait times for patients.

This, he said, could reflect a study limitation or a higher comfort level among primary care doctors in treating dementia.

With respect to MS, Dr. Vidic said that he believes primary care physicians may not be uncertain about prescribing the approved medications for the disease because there are so many of them.

In addition, patients with Alzheimer’s disease are older and perhaps less accepting of being referred to a specialist that may be hours away.

The bottom line for Dr. Vidic, though, is the lack of specialists. “It comes back to the fact we’re not doing a good job of having community neurologists available to take care of these problems,” he said.

The issue of community neurologist shortages was underlined by the study’s findings about geographic gaps in specialist referrals across the country, he said.

Neurologists make up about 2% of the medical workforce and this has remained static for some time, Dr. Vidic noted. Meanwhile, people are living longer and developing more neurologic diseases.

Dr. Vidic also pointed to the lack of neurology training programs. “There has not been a significant change in the number of programs in the last 10-15 years,” he said.

Study funding was not disclosed. Dr. Win reports receiving personal compensation for serving as an employee of Genentech and has stock in Genentech. Dr. Vidic reports no relevant financial disclosures.

A version of this article appeared on Medscape.com.

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Three Conditions for Which Cannabis Appears to Help

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The utility of cannabinoids to treat most medical conditions remains uncertain at best, but for at least three indications the data lean in favor of effectiveness, Ellie Grossman, MD, MPH, told attendees recently at the 2024 American College of Physicians Internal Medicine meeting.

Those are neuropathic pain, chemotherapy-induced nausea or vomiting, and spasticity in people with multiple sclerosis, said Dr. Grossman, an instructor at Harvard Medical School in Boston and medical director for primary care/behavioral health integration at Cambridge Health Alliance in Somerville, Massachusetts.

Dearth of Research Persists

Research is sorely lacking and of low quality in the field for many reasons, Dr. Grossman said. Most of the products tested come from outside the United States and often are synthetic and taken orally — which does not match the real-world use when patients go to dispensaries for cannabis derived directly from plants (or the plant product itself). And studies often rely on self-report.

Chronic pain is by far the top reason patients say they use medical cannabis, Dr. Grossman said. A Cochrane review of 16 studies found only that the potential benefits of cannabis may outweigh the potential harms for chronic neuropathic pain.
 

No Evidence in OUD

Dr. Grossman said she is frequently asked if cannabis can help people quit taking opioids. The answer seems to be no. A study published earlier this year in states with legalized medical or recreational cannabis found no difference between rates of opioid overdose compared with states with no such laws. “It seems like it doesn’t do anything to help us with our opioid problem,” she said.

Nor does high-quality evidence exist showing use of cannabis can improve sleep, she said. A 2022 systematic review found fewer than half of studies showed the substance useful for sleep outcomes. “Where studies were positives, it was in people who had chronic pain,” Dr. Grossman noted. Research indicates cannabis may have substantial benefit for chronic pain compared with placebo.
 

Potential Harms

If the medical benefits of cannabis are murky, the evidence for its potential harms, at least in the short term, are clearer, according to Dr. Grossman. A simplified guideline for prescribing medical cannabinoids in primary care includes sedation, feeling high, dizziness, speech disorders, muscle twitching, hypotension, and several other conditions among the potential hazards of the drug. 

But the potential for long-term harm is uncertain. “All the evidence comes from people who have been using it for recreational reasons,” where there may be co-use of tobacco, self-reported outcomes, and recall bias, she said. The characteristics of people using cannabis recreationally often differ from those using it medicinally.
 

Use With Other Controlled Substances

Dr. Grossman said clinicians should consider whether the co-use of cannabis and other controlled substances, such as benzodiazepines, opioids, or Adderall, raises the potential risks associated with those drugs. “Ultimately it comes down to talking to your patients,” she said. If a toxicity screen shows the presence of controlled substances, ask about their experience with the drugs they are using and let them know your main concern is their safety.

Dr. Grossman reported no relevant financial conflicts of interest.

A version of this article appeared on Medscape.com.

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The utility of cannabinoids to treat most medical conditions remains uncertain at best, but for at least three indications the data lean in favor of effectiveness, Ellie Grossman, MD, MPH, told attendees recently at the 2024 American College of Physicians Internal Medicine meeting.

Those are neuropathic pain, chemotherapy-induced nausea or vomiting, and spasticity in people with multiple sclerosis, said Dr. Grossman, an instructor at Harvard Medical School in Boston and medical director for primary care/behavioral health integration at Cambridge Health Alliance in Somerville, Massachusetts.

Dearth of Research Persists

Research is sorely lacking and of low quality in the field for many reasons, Dr. Grossman said. Most of the products tested come from outside the United States and often are synthetic and taken orally — which does not match the real-world use when patients go to dispensaries for cannabis derived directly from plants (or the plant product itself). And studies often rely on self-report.

Chronic pain is by far the top reason patients say they use medical cannabis, Dr. Grossman said. A Cochrane review of 16 studies found only that the potential benefits of cannabis may outweigh the potential harms for chronic neuropathic pain.
 

No Evidence in OUD

Dr. Grossman said she is frequently asked if cannabis can help people quit taking opioids. The answer seems to be no. A study published earlier this year in states with legalized medical or recreational cannabis found no difference between rates of opioid overdose compared with states with no such laws. “It seems like it doesn’t do anything to help us with our opioid problem,” she said.

Nor does high-quality evidence exist showing use of cannabis can improve sleep, she said. A 2022 systematic review found fewer than half of studies showed the substance useful for sleep outcomes. “Where studies were positives, it was in people who had chronic pain,” Dr. Grossman noted. Research indicates cannabis may have substantial benefit for chronic pain compared with placebo.
 

Potential Harms

If the medical benefits of cannabis are murky, the evidence for its potential harms, at least in the short term, are clearer, according to Dr. Grossman. A simplified guideline for prescribing medical cannabinoids in primary care includes sedation, feeling high, dizziness, speech disorders, muscle twitching, hypotension, and several other conditions among the potential hazards of the drug. 

But the potential for long-term harm is uncertain. “All the evidence comes from people who have been using it for recreational reasons,” where there may be co-use of tobacco, self-reported outcomes, and recall bias, she said. The characteristics of people using cannabis recreationally often differ from those using it medicinally.
 

Use With Other Controlled Substances

Dr. Grossman said clinicians should consider whether the co-use of cannabis and other controlled substances, such as benzodiazepines, opioids, or Adderall, raises the potential risks associated with those drugs. “Ultimately it comes down to talking to your patients,” she said. If a toxicity screen shows the presence of controlled substances, ask about their experience with the drugs they are using and let them know your main concern is their safety.

Dr. Grossman reported no relevant financial conflicts of interest.

A version of this article appeared on Medscape.com.

The utility of cannabinoids to treat most medical conditions remains uncertain at best, but for at least three indications the data lean in favor of effectiveness, Ellie Grossman, MD, MPH, told attendees recently at the 2024 American College of Physicians Internal Medicine meeting.

Those are neuropathic pain, chemotherapy-induced nausea or vomiting, and spasticity in people with multiple sclerosis, said Dr. Grossman, an instructor at Harvard Medical School in Boston and medical director for primary care/behavioral health integration at Cambridge Health Alliance in Somerville, Massachusetts.

Dearth of Research Persists

Research is sorely lacking and of low quality in the field for many reasons, Dr. Grossman said. Most of the products tested come from outside the United States and often are synthetic and taken orally — which does not match the real-world use when patients go to dispensaries for cannabis derived directly from plants (or the plant product itself). And studies often rely on self-report.

Chronic pain is by far the top reason patients say they use medical cannabis, Dr. Grossman said. A Cochrane review of 16 studies found only that the potential benefits of cannabis may outweigh the potential harms for chronic neuropathic pain.
 

No Evidence in OUD

Dr. Grossman said she is frequently asked if cannabis can help people quit taking opioids. The answer seems to be no. A study published earlier this year in states with legalized medical or recreational cannabis found no difference between rates of opioid overdose compared with states with no such laws. “It seems like it doesn’t do anything to help us with our opioid problem,” she said.

Nor does high-quality evidence exist showing use of cannabis can improve sleep, she said. A 2022 systematic review found fewer than half of studies showed the substance useful for sleep outcomes. “Where studies were positives, it was in people who had chronic pain,” Dr. Grossman noted. Research indicates cannabis may have substantial benefit for chronic pain compared with placebo.
 

Potential Harms

If the medical benefits of cannabis are murky, the evidence for its potential harms, at least in the short term, are clearer, according to Dr. Grossman. A simplified guideline for prescribing medical cannabinoids in primary care includes sedation, feeling high, dizziness, speech disorders, muscle twitching, hypotension, and several other conditions among the potential hazards of the drug. 

But the potential for long-term harm is uncertain. “All the evidence comes from people who have been using it for recreational reasons,” where there may be co-use of tobacco, self-reported outcomes, and recall bias, she said. The characteristics of people using cannabis recreationally often differ from those using it medicinally.
 

Use With Other Controlled Substances

Dr. Grossman said clinicians should consider whether the co-use of cannabis and other controlled substances, such as benzodiazepines, opioids, or Adderall, raises the potential risks associated with those drugs. “Ultimately it comes down to talking to your patients,” she said. If a toxicity screen shows the presence of controlled substances, ask about their experience with the drugs they are using and let them know your main concern is their safety.

Dr. Grossman reported no relevant financial conflicts of interest.

A version of this article appeared on Medscape.com.

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Antidepressants and Dementia Risk: Reassuring Data

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Mon, 05/06/2024 - 17:07

 

TOPLINE:

Antidepressants are not associated with an increased risk for dementia, accelerated cognitive decline, or atrophy of white and gray matter in adults with no signs of cognitive impairment, new research suggests.

METHODOLOGY:

  • Investigators studied 5511 individuals (58% women; mean age, 71 years) from the Rotterdam study, an ongoing prospective population-based cohort study.
  • Participants were free from dementia at baseline, and incident dementia was monitored from baseline until 2018 with repeated cognitive assessments using the Mini-Mental Status Examination (MMSE) and the Geriatric Mental Schedule, as well as MRIs.
  • Information on participants’ antidepressant use was extracted from pharmacy records from 1992 until baseline (2002-2008).
  • During a mean follow-up of 10 years, 12% of participants developed dementia.

TAKEAWAY:

  • Overall, 17% of participants had used antidepressants during the roughly 10-year period prior to baseline, and 4.1% were still using antidepressants at baseline.
  • Medication use at baseline was more common in women than in men (21% vs 18%), and use increased with age: From 2.1% in participants aged between 45 and 50 years to 4.5% in those older than 80 years.
  • After adjustment for confounders, there was no association between antidepressant use and dementia risk (hazard ratio [HR], 1.14; 95% CI, 0.92-1.41), accelerated cognitive decline, or atrophy of white and gray matter.
  • However, tricyclic antidepressant use was associated with increased dementia risk (HR, 1.36; 95% CI, 1.01-1.83) compared with the use of selective serotonin reuptake inhibitors (HR, 1.12; 95% CI, 0.81-1.54).

IN PRACTICE:

“Although prescription of antidepressant medication in older individuals, in particular those with some cognitive impairment, may have acute symptomatic anticholinergic effects that warrant consideration in clinical practice, our results show that long-term antidepressant use does not have lasting effects on cognition or brain health in older adults without indication of cognitive impairment,” the authors wrote.

SOURCE:

Frank J. Wolters, MD, of the Department of Epidemiology and the Department of Radiology and Nuclear Medicine and Alzheimer Center, Erasmus University Medical Center, Rotterdam, the Netherlands, was the senior author on this study that was published online in Alzheimer’s and Dementia.

LIMITATIONS:

Limitations included the concern that although exclusion of participants with MMSE < 26 at baseline prevented reversed causation (ie, antidepressant use in response to depression during the prodromal phase of dementia), it may have introduced selection bias by disregarding the effects of antidepressant use prior to baseline and excluding participants with lower education.

DISCLOSURES:

This study was conducted as part of the Netherlands Consortium of Dementia Cohorts, which receives funding in the context of Deltaplan Dementie from ZonMW Memorabel and Alzheimer Nederland. Further funding was also obtained from the Stichting Erasmus Trustfonds. This study was further supported by a 2020 NARSAD Young Investigator Grant from the Brain & Behavior Research Foundation. The authors reported no conflicts of interest or relevant financial relationships.

A version of this article appeared on Medscape.com.

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TOPLINE:

Antidepressants are not associated with an increased risk for dementia, accelerated cognitive decline, or atrophy of white and gray matter in adults with no signs of cognitive impairment, new research suggests.

METHODOLOGY:

  • Investigators studied 5511 individuals (58% women; mean age, 71 years) from the Rotterdam study, an ongoing prospective population-based cohort study.
  • Participants were free from dementia at baseline, and incident dementia was monitored from baseline until 2018 with repeated cognitive assessments using the Mini-Mental Status Examination (MMSE) and the Geriatric Mental Schedule, as well as MRIs.
  • Information on participants’ antidepressant use was extracted from pharmacy records from 1992 until baseline (2002-2008).
  • During a mean follow-up of 10 years, 12% of participants developed dementia.

TAKEAWAY:

  • Overall, 17% of participants had used antidepressants during the roughly 10-year period prior to baseline, and 4.1% were still using antidepressants at baseline.
  • Medication use at baseline was more common in women than in men (21% vs 18%), and use increased with age: From 2.1% in participants aged between 45 and 50 years to 4.5% in those older than 80 years.
  • After adjustment for confounders, there was no association between antidepressant use and dementia risk (hazard ratio [HR], 1.14; 95% CI, 0.92-1.41), accelerated cognitive decline, or atrophy of white and gray matter.
  • However, tricyclic antidepressant use was associated with increased dementia risk (HR, 1.36; 95% CI, 1.01-1.83) compared with the use of selective serotonin reuptake inhibitors (HR, 1.12; 95% CI, 0.81-1.54).

IN PRACTICE:

“Although prescription of antidepressant medication in older individuals, in particular those with some cognitive impairment, may have acute symptomatic anticholinergic effects that warrant consideration in clinical practice, our results show that long-term antidepressant use does not have lasting effects on cognition or brain health in older adults without indication of cognitive impairment,” the authors wrote.

SOURCE:

Frank J. Wolters, MD, of the Department of Epidemiology and the Department of Radiology and Nuclear Medicine and Alzheimer Center, Erasmus University Medical Center, Rotterdam, the Netherlands, was the senior author on this study that was published online in Alzheimer’s and Dementia.

LIMITATIONS:

Limitations included the concern that although exclusion of participants with MMSE < 26 at baseline prevented reversed causation (ie, antidepressant use in response to depression during the prodromal phase of dementia), it may have introduced selection bias by disregarding the effects of antidepressant use prior to baseline and excluding participants with lower education.

DISCLOSURES:

This study was conducted as part of the Netherlands Consortium of Dementia Cohorts, which receives funding in the context of Deltaplan Dementie from ZonMW Memorabel and Alzheimer Nederland. Further funding was also obtained from the Stichting Erasmus Trustfonds. This study was further supported by a 2020 NARSAD Young Investigator Grant from the Brain & Behavior Research Foundation. The authors reported no conflicts of interest or relevant financial relationships.

A version of this article appeared on Medscape.com.

 

TOPLINE:

Antidepressants are not associated with an increased risk for dementia, accelerated cognitive decline, or atrophy of white and gray matter in adults with no signs of cognitive impairment, new research suggests.

METHODOLOGY:

  • Investigators studied 5511 individuals (58% women; mean age, 71 years) from the Rotterdam study, an ongoing prospective population-based cohort study.
  • Participants were free from dementia at baseline, and incident dementia was monitored from baseline until 2018 with repeated cognitive assessments using the Mini-Mental Status Examination (MMSE) and the Geriatric Mental Schedule, as well as MRIs.
  • Information on participants’ antidepressant use was extracted from pharmacy records from 1992 until baseline (2002-2008).
  • During a mean follow-up of 10 years, 12% of participants developed dementia.

TAKEAWAY:

  • Overall, 17% of participants had used antidepressants during the roughly 10-year period prior to baseline, and 4.1% were still using antidepressants at baseline.
  • Medication use at baseline was more common in women than in men (21% vs 18%), and use increased with age: From 2.1% in participants aged between 45 and 50 years to 4.5% in those older than 80 years.
  • After adjustment for confounders, there was no association between antidepressant use and dementia risk (hazard ratio [HR], 1.14; 95% CI, 0.92-1.41), accelerated cognitive decline, or atrophy of white and gray matter.
  • However, tricyclic antidepressant use was associated with increased dementia risk (HR, 1.36; 95% CI, 1.01-1.83) compared with the use of selective serotonin reuptake inhibitors (HR, 1.12; 95% CI, 0.81-1.54).

IN PRACTICE:

“Although prescription of antidepressant medication in older individuals, in particular those with some cognitive impairment, may have acute symptomatic anticholinergic effects that warrant consideration in clinical practice, our results show that long-term antidepressant use does not have lasting effects on cognition or brain health in older adults without indication of cognitive impairment,” the authors wrote.

SOURCE:

Frank J. Wolters, MD, of the Department of Epidemiology and the Department of Radiology and Nuclear Medicine and Alzheimer Center, Erasmus University Medical Center, Rotterdam, the Netherlands, was the senior author on this study that was published online in Alzheimer’s and Dementia.

LIMITATIONS:

Limitations included the concern that although exclusion of participants with MMSE < 26 at baseline prevented reversed causation (ie, antidepressant use in response to depression during the prodromal phase of dementia), it may have introduced selection bias by disregarding the effects of antidepressant use prior to baseline and excluding participants with lower education.

DISCLOSURES:

This study was conducted as part of the Netherlands Consortium of Dementia Cohorts, which receives funding in the context of Deltaplan Dementie from ZonMW Memorabel and Alzheimer Nederland. Further funding was also obtained from the Stichting Erasmus Trustfonds. This study was further supported by a 2020 NARSAD Young Investigator Grant from the Brain & Behavior Research Foundation. The authors reported no conflicts of interest or relevant financial relationships.

A version of this article appeared on Medscape.com.

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