Neurology

The severity and duration of vaccine-proximate febrile seizures (VP-FSs) are no worse than non–vaccine proximate febrile seizures (NVP-FSs), according to a study in Pediatrics.

KatarzynaBialasiewicz/Thinkstock

Lucy Deng, MBBS, of the University of Sydney and her colleagues investigated 1,022 index febrile seizures in children aged 6 years or less, of which 6% (n = 67) were VP-FSs and 94% (n = 955) were NVP-FSs. Both univariate and multivariate analyses showed no increased risk of severe seizure associated with VP-FSs, compared with NVP-FS. Most of the febrile seizures of either type were brief (15 minutes or less) and had a length of stay of 1 day or less; there also were no differences in 24-hour recurrence. The most common symptom was respiratory, and the rates were similar in each group (62.7% with VP-FS vs. 62.8% with NVP-FS). In keeping with a known 100% increased risk associated with measles vaccination, 84% of VP-FSs were associated with measles-containing vaccines. The majority of the remaining VP-FSs occurred after combination vaccines.

One limitation is that, because these cases were documented in sentinel tertiary pediatric hospitals, the case ascertainment may not be representative. Also, the small proportion of VP-FSs and limited cohort size means the study may not have been powered to detect true differences in prolonged seizures between the groups, Dr. Deng and her colleagues wrote.

“This study confirms that VP-FSs are clinically not any different from NVP-FSs and should be managed the same way,” the researchers concluded.

The authors reported no relevant financial disclosures, although Dr. Deng is supported by the University of Sydney Training Program scholarship, and two other study authors are supported by Australian National Health and Medical Research Council Career Development Fellowships. The study was funded by a grant from the Australian Government Department of Health and the National Health and Medical Research Council.

[email protected]

SOURCE: Deng L et al. Pediatrics. 2019 Apr 19. doi: 10.1542/peds.2018-2120.

The severity and duration of vaccine-proximate febrile seizures (VP-FSs) are no worse than non–vaccine proximate febrile seizures (NVP-FSs), according to a study in Pediatrics.

KatarzynaBialasiewicz/Thinkstock

Lucy Deng, MBBS, of the University of Sydney and her colleagues investigated 1,022 index febrile seizures in children aged 6 years or less, of which 6% (n = 67) were VP-FSs and 94% (n = 955) were NVP-FSs. Both univariate and multivariate analyses showed no increased risk of severe seizure associated with VP-FSs, compared with NVP-FS. Most of the febrile seizures of either type were brief (15 minutes or less) and had a length of stay of 1 day or less; there also were no differences in 24-hour recurrence. The most common symptom was respiratory, and the rates were similar in each group (62.7% with VP-FS vs. 62.8% with NVP-FS). In keeping with a known 100% increased risk associated with measles vaccination, 84% of VP-FSs were associated with measles-containing vaccines. The majority of the remaining VP-FSs occurred after combination vaccines.

One limitation is that, because these cases were documented in sentinel tertiary pediatric hospitals, the case ascertainment may not be representative. Also, the small proportion of VP-FSs and limited cohort size means the study may not have been powered to detect true differences in prolonged seizures between the groups, Dr. Deng and her colleagues wrote.

“This study confirms that VP-FSs are clinically not any different from NVP-FSs and should be managed the same way,” the researchers concluded.

The authors reported no relevant financial disclosures, although Dr. Deng is supported by the University of Sydney Training Program scholarship, and two other study authors are supported by Australian National Health and Medical Research Council Career Development Fellowships. The study was funded by a grant from the Australian Government Department of Health and the National Health and Medical Research Council.

[email protected]

SOURCE: Deng L et al. Pediatrics. 2019 Apr 19. doi: 10.1542/peds.2018-2120.

The severity and duration of vaccine-proximate febrile seizures (VP-FSs) are no worse than non–vaccine proximate febrile seizures (NVP-FSs), according to a study in Pediatrics.

KatarzynaBialasiewicz/Thinkstock

Lucy Deng, MBBS, of the University of Sydney and her colleagues investigated 1,022 index febrile seizures in children aged 6 years or less, of which 6% (n = 67) were VP-FSs and 94% (n = 955) were NVP-FSs. Both univariate and multivariate analyses showed no increased risk of severe seizure associated with VP-FSs, compared with NVP-FS. Most of the febrile seizures of either type were brief (15 minutes or less) and had a length of stay of 1 day or less; there also were no differences in 24-hour recurrence. The most common symptom was respiratory, and the rates were similar in each group (62.7% with VP-FS vs. 62.8% with NVP-FS). In keeping with a known 100% increased risk associated with measles vaccination, 84% of VP-FSs were associated with measles-containing vaccines. The majority of the remaining VP-FSs occurred after combination vaccines.

One limitation is that, because these cases were documented in sentinel tertiary pediatric hospitals, the case ascertainment may not be representative. Also, the small proportion of VP-FSs and limited cohort size means the study may not have been powered to detect true differences in prolonged seizures between the groups, Dr. Deng and her colleagues wrote.

“This study confirms that VP-FSs are clinically not any different from NVP-FSs and should be managed the same way,” the researchers concluded.

The authors reported no relevant financial disclosures, although Dr. Deng is supported by the University of Sydney Training Program scholarship, and two other study authors are supported by Australian National Health and Medical Research Council Career Development Fellowships. The study was funded by a grant from the Australian Government Department of Health and the National Health and Medical Research Council.

[email protected]

SOURCE: Deng L et al. Pediatrics. 2019 Apr 19. doi: 10.1542/peds.2018-2120.

Treatment with pembrolizumab or nivolumab may benefit patients with progressive multifocal leukoencephalopathy (PML), investigators reported in the New England Journal of Medicine.

Three research teams described 10 cases in which patients with PML received pembrolizumab or nivolumab.

In one study, researchers administered pembrolizumab to eight adults with PML. Five patients had clinical improvement or stabilization, whereas 3 patients did not. Among the patients with clinical improvement, treatment led to reduced JC viral load in cerebrospinal fluid (CSF) and increased CD4+ and CD8+ anti–JC virus activity in vitro. Among patients without clinical improvement, treatment did not meaningfully change viral load or antiviral cellular immune response.

In a separate letter, researchers in Germany described an additional patient with PML who had clinical stabilization and no disease progression on MRI after treatment with pembrolizumab.

In another letter, researchers in France described a patient with PML whose condition improved after treatment with nivolumab.

“Do pembrolizumab and nivolumab fit the bill for treatment of PML? The current reports are encouraging but suggest that the presence of JC virus–specific T cells in the blood is a prerequisite for their use,” said Igor J. Koralnik, MD, of the department of neurological sciences at Rush University Medical Center in Chicago, in an accompanying editorial. “A controlled trial may be needed to determine whether immune checkpoint inhibitors are indeed able to keep JC virus in check in patients with PML.”


 

Reinvigorating T cells

Both monoclonal antibodies target programmed cell death protein 1 (PD-1), which inhibits T-cell proliferation and cytokine production when it binds its associated ligand, Dr. Koralnik said. Pembrolizumab and nivolumab block this inhibition and have been used to spur T-cell activity against tumors in patients with cancer.

PML, an often fatal brain infection caused by the JC virus in patients with immunosuppression, has no specific treatment. Management hinges on “recovery of the immune system, either by treating the underlying cause of immunosuppression or by discontinuing the use of immunosuppressive medications,” said Dr. Koralnik.
 

Pembrolizumab

Prior studies have found that PD-1 expression is elevated on T lymphocytes of patients with PML. To determine whether PD-1 blockade with pembrolizumab reinvigorates anti–JC virus immune activity in patients with PML, Irene Cortese, MD, of the National Institutes of Health’s Neuroimmunology Clinic and her research colleagues administered pembrolizumab at a dose of 2 mg/kg of body weight every 4-6 weeks to eight adults with PML. The patients received 1-3 doses, and each patient had a different underlying condition.

In all patients, treatment induced down-regulation of PD-1 expression on lymphocytes in CSF and peripheral blood, and five of the eight patients had clinical stabilization or improvement. Of the other three patients who did not improve, one had stabilized prior to treatment and remained stable. The other two patients died from PML.
 

Additional reports

Separately, Sebastian Rauer, MD, of Albert Ludwigs University in Freiburg, Germany, and his colleagues reported that a patient with PML whose symptoms culminated in mutism in February 2018 began speaking again after receiving five infusions of pembrolizumab over 10 weeks. “In addition, the size and number of lesions on MRI decreased, and JCV was no longer detectable in CSF,” Dr. Rauer and his colleagues wrote. “The patient has remained stable as of the end of March 2019, with persistent but abating psychomotor slowing, aphasia, and disorientation.”

Finally, Ondine Walter, of Toulouse (France) University Hospital and colleagues described the case of a 60-year-old woman with PML who received nivolumab on a compassionate-use basis. Two weeks after treatment, JC viral load in CSF and blood had decreased. “Starting 8 weeks after the initiation of nivolumab therapy, the patient’s neurologic symptoms and signs stabilized, and subsequently she showed improved alertness, and the ptosis and hemiplegia abated.”
 

Reason for caution

Prior studies, however, give reasons for caution when considering the potential use of immune checkpoint inhibitors to treat PML, Dr. Koralnik noted. In one case, a patient developed an inflammatory form of PML known as immune reconstitution inflammatory syndrome after receiving nivolumab (J Neurovirol. 2019 March 12. doi: 10.1007/s13365-019-00738-x). In addition, researchers have reported a case of PML that occurred after 1 year of nivolumab treatment, and four cases of PML related to nivolumab have been reported in pharmacovigilance databases (Emerg Infect Dis. 2018;24:1594-6). The cost and safety profiles of the medications also may be considerations, Dr. Koralnik said.

The study by Dr. Cortese and colleagues was funded by the National Institutes of Health, and the authors had no relevant disclosures. Some of the research letter authors disclosed grants and personal fees from pharmaceutical companies.

[email protected]

SOURCES: Cortese I et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMoa1815039; Rauer S et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMc1817193; Walter O et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMc1816198; Koralnik IJ. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMe1904140.

Treatment with pembrolizumab or nivolumab may benefit patients with progressive multifocal leukoencephalopathy (PML), investigators reported in the New England Journal of Medicine.

Three research teams described 10 cases in which patients with PML received pembrolizumab or nivolumab.

In one study, researchers administered pembrolizumab to eight adults with PML. Five patients had clinical improvement or stabilization, whereas 3 patients did not. Among the patients with clinical improvement, treatment led to reduced JC viral load in cerebrospinal fluid (CSF) and increased CD4+ and CD8+ anti–JC virus activity in vitro. Among patients without clinical improvement, treatment did not meaningfully change viral load or antiviral cellular immune response.

In a separate letter, researchers in Germany described an additional patient with PML who had clinical stabilization and no disease progression on MRI after treatment with pembrolizumab.

In another letter, researchers in France described a patient with PML whose condition improved after treatment with nivolumab.

“Do pembrolizumab and nivolumab fit the bill for treatment of PML? The current reports are encouraging but suggest that the presence of JC virus–specific T cells in the blood is a prerequisite for their use,” said Igor J. Koralnik, MD, of the department of neurological sciences at Rush University Medical Center in Chicago, in an accompanying editorial. “A controlled trial may be needed to determine whether immune checkpoint inhibitors are indeed able to keep JC virus in check in patients with PML.”


 

Reinvigorating T cells

Both monoclonal antibodies target programmed cell death protein 1 (PD-1), which inhibits T-cell proliferation and cytokine production when it binds its associated ligand, Dr. Koralnik said. Pembrolizumab and nivolumab block this inhibition and have been used to spur T-cell activity against tumors in patients with cancer.

PML, an often fatal brain infection caused by the JC virus in patients with immunosuppression, has no specific treatment. Management hinges on “recovery of the immune system, either by treating the underlying cause of immunosuppression or by discontinuing the use of immunosuppressive medications,” said Dr. Koralnik.
 

Pembrolizumab

Prior studies have found that PD-1 expression is elevated on T lymphocytes of patients with PML. To determine whether PD-1 blockade with pembrolizumab reinvigorates anti–JC virus immune activity in patients with PML, Irene Cortese, MD, of the National Institutes of Health’s Neuroimmunology Clinic and her research colleagues administered pembrolizumab at a dose of 2 mg/kg of body weight every 4-6 weeks to eight adults with PML. The patients received 1-3 doses, and each patient had a different underlying condition.

In all patients, treatment induced down-regulation of PD-1 expression on lymphocytes in CSF and peripheral blood, and five of the eight patients had clinical stabilization or improvement. Of the other three patients who did not improve, one had stabilized prior to treatment and remained stable. The other two patients died from PML.
 

Additional reports

Separately, Sebastian Rauer, MD, of Albert Ludwigs University in Freiburg, Germany, and his colleagues reported that a patient with PML whose symptoms culminated in mutism in February 2018 began speaking again after receiving five infusions of pembrolizumab over 10 weeks. “In addition, the size and number of lesions on MRI decreased, and JCV was no longer detectable in CSF,” Dr. Rauer and his colleagues wrote. “The patient has remained stable as of the end of March 2019, with persistent but abating psychomotor slowing, aphasia, and disorientation.”

Finally, Ondine Walter, of Toulouse (France) University Hospital and colleagues described the case of a 60-year-old woman with PML who received nivolumab on a compassionate-use basis. Two weeks after treatment, JC viral load in CSF and blood had decreased. “Starting 8 weeks after the initiation of nivolumab therapy, the patient’s neurologic symptoms and signs stabilized, and subsequently she showed improved alertness, and the ptosis and hemiplegia abated.”
 

Reason for caution

Prior studies, however, give reasons for caution when considering the potential use of immune checkpoint inhibitors to treat PML, Dr. Koralnik noted. In one case, a patient developed an inflammatory form of PML known as immune reconstitution inflammatory syndrome after receiving nivolumab (J Neurovirol. 2019 March 12. doi: 10.1007/s13365-019-00738-x). In addition, researchers have reported a case of PML that occurred after 1 year of nivolumab treatment, and four cases of PML related to nivolumab have been reported in pharmacovigilance databases (Emerg Infect Dis. 2018;24:1594-6). The cost and safety profiles of the medications also may be considerations, Dr. Koralnik said.

The study by Dr. Cortese and colleagues was funded by the National Institutes of Health, and the authors had no relevant disclosures. Some of the research letter authors disclosed grants and personal fees from pharmaceutical companies.

[email protected]

SOURCES: Cortese I et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMoa1815039; Rauer S et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMc1817193; Walter O et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMc1816198; Koralnik IJ. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMe1904140.

Treatment with pembrolizumab or nivolumab may benefit patients with progressive multifocal leukoencephalopathy (PML), investigators reported in the New England Journal of Medicine.

Three research teams described 10 cases in which patients with PML received pembrolizumab or nivolumab.

In one study, researchers administered pembrolizumab to eight adults with PML. Five patients had clinical improvement or stabilization, whereas 3 patients did not. Among the patients with clinical improvement, treatment led to reduced JC viral load in cerebrospinal fluid (CSF) and increased CD4+ and CD8+ anti–JC virus activity in vitro. Among patients without clinical improvement, treatment did not meaningfully change viral load or antiviral cellular immune response.

In a separate letter, researchers in Germany described an additional patient with PML who had clinical stabilization and no disease progression on MRI after treatment with pembrolizumab.

In another letter, researchers in France described a patient with PML whose condition improved after treatment with nivolumab.

“Do pembrolizumab and nivolumab fit the bill for treatment of PML? The current reports are encouraging but suggest that the presence of JC virus–specific T cells in the blood is a prerequisite for their use,” said Igor J. Koralnik, MD, of the department of neurological sciences at Rush University Medical Center in Chicago, in an accompanying editorial. “A controlled trial may be needed to determine whether immune checkpoint inhibitors are indeed able to keep JC virus in check in patients with PML.”


 

Reinvigorating T cells

Both monoclonal antibodies target programmed cell death protein 1 (PD-1), which inhibits T-cell proliferation and cytokine production when it binds its associated ligand, Dr. Koralnik said. Pembrolizumab and nivolumab block this inhibition and have been used to spur T-cell activity against tumors in patients with cancer.

PML, an often fatal brain infection caused by the JC virus in patients with immunosuppression, has no specific treatment. Management hinges on “recovery of the immune system, either by treating the underlying cause of immunosuppression or by discontinuing the use of immunosuppressive medications,” said Dr. Koralnik.
 

Pembrolizumab

Prior studies have found that PD-1 expression is elevated on T lymphocytes of patients with PML. To determine whether PD-1 blockade with pembrolizumab reinvigorates anti–JC virus immune activity in patients with PML, Irene Cortese, MD, of the National Institutes of Health’s Neuroimmunology Clinic and her research colleagues administered pembrolizumab at a dose of 2 mg/kg of body weight every 4-6 weeks to eight adults with PML. The patients received 1-3 doses, and each patient had a different underlying condition.

In all patients, treatment induced down-regulation of PD-1 expression on lymphocytes in CSF and peripheral blood, and five of the eight patients had clinical stabilization or improvement. Of the other three patients who did not improve, one had stabilized prior to treatment and remained stable. The other two patients died from PML.
 

Additional reports

Separately, Sebastian Rauer, MD, of Albert Ludwigs University in Freiburg, Germany, and his colleagues reported that a patient with PML whose symptoms culminated in mutism in February 2018 began speaking again after receiving five infusions of pembrolizumab over 10 weeks. “In addition, the size and number of lesions on MRI decreased, and JCV was no longer detectable in CSF,” Dr. Rauer and his colleagues wrote. “The patient has remained stable as of the end of March 2019, with persistent but abating psychomotor slowing, aphasia, and disorientation.”

Finally, Ondine Walter, of Toulouse (France) University Hospital and colleagues described the case of a 60-year-old woman with PML who received nivolumab on a compassionate-use basis. Two weeks after treatment, JC viral load in CSF and blood had decreased. “Starting 8 weeks after the initiation of nivolumab therapy, the patient’s neurologic symptoms and signs stabilized, and subsequently she showed improved alertness, and the ptosis and hemiplegia abated.”
 

Reason for caution

Prior studies, however, give reasons for caution when considering the potential use of immune checkpoint inhibitors to treat PML, Dr. Koralnik noted. In one case, a patient developed an inflammatory form of PML known as immune reconstitution inflammatory syndrome after receiving nivolumab (J Neurovirol. 2019 March 12. doi: 10.1007/s13365-019-00738-x). In addition, researchers have reported a case of PML that occurred after 1 year of nivolumab treatment, and four cases of PML related to nivolumab have been reported in pharmacovigilance databases (Emerg Infect Dis. 2018;24:1594-6). The cost and safety profiles of the medications also may be considerations, Dr. Koralnik said.

The study by Dr. Cortese and colleagues was funded by the National Institutes of Health, and the authors had no relevant disclosures. Some of the research letter authors disclosed grants and personal fees from pharmaceutical companies.

[email protected]

SOURCES: Cortese I et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMoa1815039; Rauer S et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMc1817193; Walter O et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMc1816198; Koralnik IJ. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMe1904140.

Spinal cord injuries (SCI) are common in veteran populations.¹ Veterans with spinal cord injuries and disorders (SCI/D) also may have concurrent sleep disturbances. Spinal cord injury typically causes spasticity.^2,3 Hypersensitivity of the flexor reflex pathways is believed to cause painful muscle spasms in patients with SCI.⁴ Neuropathic pain at or below the level of the lesion also is common.

Restless legs syndrome (RLS) is a common sleep disorder that affects sleep quality and can occur concomitantly with spinal cord lesions.⁵ In about 80% of RLS cases, involuntary movements of legs across hip, knee, and ankle joints during sleep, known as periodic limb movement during sleep (PLMS), occurs.⁶ Several studies showed increased prevalence of PLMS in patients with SCI, and some case reports suggest an increased prevalence of RLS in this population.^7,8 One small study showed that 100% of patients with SCI had symptoms of RLS.⁶ Another study found that SCI could trigger PLMS.⁸

The pathophysiology of RLS and PLMS in patients with SCI is not fully understood, but case reports describing PLM in SCI patients points to a possible role of central pattern generators and the flexor reflex afferents in the pathophysiology of PLMS.^9,10 Changes of the tissue microstructure in the midbrain and upper cervical spinal cord have been described in patients with RLS.¹¹The objective of this study was to assess the prevalence of RLS in a veteran population with SCI/D and to determine possible neuroanatomical patterns involved in RLS and SCI/D.

Methods

The institutional review and ethical approval boards of the Minneapolis VA Health Care System approved the study. Within the VA system, 666 patients with SCI/D were identified using a national database. Of the 666 people, 316 were excluded, 199 were included, and 151 were deceased.

Patients aged between 18 and 65 years were included in the study. Charts of patients who had been discharged with the diagnosis of SCI from 2002 to 2008 were studied. All patients met the inclusion criteria of the International Restless Legs Syndrome Study Group diagnosis.

Exclusion criteria were as follows: Patients with evidence of brain pathology (eg, stroke), concurrent neurologic condition associated with RLS (Parkinson disease, spinocerebellar ataxia, peripheral neuropathy), concurrent psychiatric condition within the setting of treatment with dopamine antagonists, secondary causes of RLS (renal failure/uremia, iron deficiency, rheumatoid arthritis, and pregnancy) and a recent history of alcohol or drug misuse or current evidence of substance use of < 1 year.

A patient list was compiled that included the etiology of the SCI (vascular injury, multiple sclerosis [MS], trauma, unknown, and other), the level(s) and completeness of the SCI per radiology report, RLS pharmacotherapies, and pertinent medical history.

Axial T2-weighted images on magnetic resonance imaging (MRI) scans were retrospectively reviewed. Sagittal T1/T2-weighted and axial T2-weighted sequences were performed routinely on all patients with spinal cord lesions. The analysis included the extension of the lesion on both sagittal and axial distributions. The anatomic location of the cord lesion was categorized by the following: (1) pure gray matter (central cord); (2) white matter (dorsal [D], dorsolateral [DL], ventral [V], ventrolateral areas [VL]).

A questionnaire using standard diagnostic criteria for RLS was mailed to the 199 patients who met the inclusion criteria (Appendix A).

All analyses were carried out using StataCorp STATA 13 (College Station, TX). Descriptive statistics were used. The analyses were carried out using chi-square and Fisher exact tests. Differences between the groups were considered statistically significant at P < .05. The data were analyzed to obtain point prevalence among patients with SCI, and comparisons were made among the different subgroups.

Results

Of the 162 patients who chose to participate in the study, the sleep specialists confirmed 31 (19%) to have RLS, 112 (69%) were confirmed negative for RLS, and an additional 19 (12%) screened positive for RLS but were not confirmed to have RLS by the sleep specialists (Figure 1).

The etiology of SCI was subdivided into 4 groups: MS, trauma, vascular, and other/unknown. Within each group (– RLS vs + RLS), MS and trauma were the most common etiologies with 55% MS and 36% trauma in the + RLS group.

When comparing RLS among the spinal cord levels (cervical, thoracic, lumbar and cervical + thoracic), only the cervical + thoracic subgroup (18% + RLS vs 5% – RLS) showed a significant difference (Figure 2).

There was no significant difference found with the prevalence of RLS in the axial plane of the spinal cord lesions (ventral/ventro-lateral/central cord vs dorsal/dorsolateral) or by the completeness of spinal cord lesions, P = .76. There was a higher prevalence of incomplete cord injury, however, within each subgroup of RLS.

The Mann-Whitney test was used to analyze the burden of disease in both groups (+ RLS vs – RLS). Moderate level of burden was most frequently reported with a higher prevalence within the + RLS group. Of those receiving treatment for RLS, 71% were + RLS vs 46% – RLS with a P value of .01. Symptoms of RLS after cord injury were 89% + RLS vs 55% – RLS with a P value of .03.

Discussion

This study represents one of the first studies to determine the prevalence of RLS in veterans with spinal cord disease. Research in this area is important to raise awareness of RLS among the veteran population with and without SCI and disorders. Restless legs syndrome often escapes diagnosis because of difficulty understanding the patient’s descriptions of their sensations. In addition, RLS may cause debilitating symptoms of sleep deprivation, daytime sleepiness, discomfort, and fatigue, which often results in decreased quality of life (QOL). Proper screening and treatment may improve QOL.

A study by Kumru and colleagues showed a similar rate of RLS in patients with SCI and RLS symptoms presented in the first year after SCI as did this study (18% vs 19%, respectively).⁴ In that study, RLS was more common in patients with lesions in lumbosacral area. Kumru and colleagues also showed that a dopaminergic medication improved symptoms of RLS in this population, whereas this study did not explore treatment outcomes.⁴

The pathogenesis of RLS is not fully known, but hereditary factors, iron metabolism, and the brain dopaminergic system are thought to be involved.¹¹ It is hypothesized that spinal cord lesions allow the appearance of RLS symptoms and spinal leg movement generator by blocking descending inhibitory spinal pathways.¹² One hypothesis is that damage to A11 nuclei (the main source of dopamine in the spinal cord or its diencephalospinal tract in animals) causes hyperexcitability of the spinal cord and leads to PLM and RLS symptoms.¹³ As the axons of A11 nuclei are present along the whole span of the spinal cord, SCI/D in patients with RLS might interrupt this dopaminergic tract and produce the RLS symptoms.

Limitations

This study included only veterans, so the prevalence may not apply to the nonveteran SCI population. Also, the population mainly was male, and there was no accurate information on race. Ferritin levels of the patients were not checked and is a major factor in RLS. The reported onset of RLS after the SCI could be due to recall bias.

Conclusion

The prevalence of RLS in veterans with SCI is above that reported in the general population (19% vs 10%, respectively). Furthermore, those with RLS have symptoms that often started after the SCI (suggesting causality) and required therapy due to their level of RLS symptom burden. A spectrum of severity of symptoms is present among those with RLS, with 83% having moderate-to-severe RLS affecting their QOL.

Although there was not a statistically significant relationship between RLS and spinal cord lesion level, there was a slightly higher prevalence of RLS at the cervical and thoracic levels, which may be relevant for future studies. There was no difference found between the RLS subgroups with respect to the location of the lesion within the spinal cord; however, a larger sample size may be needed to determine whether this would reach statistical significance. Prompt search for symptoms of RLS in veterans with SCI is warranted to provide adequate treatment to improve sleep health and QOL in this population.

Spinal cord injuries (SCI) are common in veteran populations.¹ Veterans with spinal cord injuries and disorders (SCI/D) also may have concurrent sleep disturbances. Spinal cord injury typically causes spasticity.^2,3 Hypersensitivity of the flexor reflex pathways is believed to cause painful muscle spasms in patients with SCI.⁴ Neuropathic pain at or below the level of the lesion also is common.

Restless legs syndrome (RLS) is a common sleep disorder that affects sleep quality and can occur concomitantly with spinal cord lesions.⁵ In about 80% of RLS cases, involuntary movements of legs across hip, knee, and ankle joints during sleep, known as periodic limb movement during sleep (PLMS), occurs.⁶ Several studies showed increased prevalence of PLMS in patients with SCI, and some case reports suggest an increased prevalence of RLS in this population.^7,8 One small study showed that 100% of patients with SCI had symptoms of RLS.⁶ Another study found that SCI could trigger PLMS.⁸

The pathophysiology of RLS and PLMS in patients with SCI is not fully understood, but case reports describing PLM in SCI patients points to a possible role of central pattern generators and the flexor reflex afferents in the pathophysiology of PLMS.^9,10 Changes of the tissue microstructure in the midbrain and upper cervical spinal cord have been described in patients with RLS.¹¹The objective of this study was to assess the prevalence of RLS in a veteran population with SCI/D and to determine possible neuroanatomical patterns involved in RLS and SCI/D.

Methods

The institutional review and ethical approval boards of the Minneapolis VA Health Care System approved the study. Within the VA system, 666 patients with SCI/D were identified using a national database. Of the 666 people, 316 were excluded, 199 were included, and 151 were deceased.

Patients aged between 18 and 65 years were included in the study. Charts of patients who had been discharged with the diagnosis of SCI from 2002 to 2008 were studied. All patients met the inclusion criteria of the International Restless Legs Syndrome Study Group diagnosis.

Exclusion criteria were as follows: Patients with evidence of brain pathology (eg, stroke), concurrent neurologic condition associated with RLS (Parkinson disease, spinocerebellar ataxia, peripheral neuropathy), concurrent psychiatric condition within the setting of treatment with dopamine antagonists, secondary causes of RLS (renal failure/uremia, iron deficiency, rheumatoid arthritis, and pregnancy) and a recent history of alcohol or drug misuse or current evidence of substance use of < 1 year.

A patient list was compiled that included the etiology of the SCI (vascular injury, multiple sclerosis [MS], trauma, unknown, and other), the level(s) and completeness of the SCI per radiology report, RLS pharmacotherapies, and pertinent medical history.

Axial T2-weighted images on magnetic resonance imaging (MRI) scans were retrospectively reviewed. Sagittal T1/T2-weighted and axial T2-weighted sequences were performed routinely on all patients with spinal cord lesions. The analysis included the extension of the lesion on both sagittal and axial distributions. The anatomic location of the cord lesion was categorized by the following: (1) pure gray matter (central cord); (2) white matter (dorsal [D], dorsolateral [DL], ventral [V], ventrolateral areas [VL]).

A questionnaire using standard diagnostic criteria for RLS was mailed to the 199 patients who met the inclusion criteria (Appendix A).

All analyses were carried out using StataCorp STATA 13 (College Station, TX). Descriptive statistics were used. The analyses were carried out using chi-square and Fisher exact tests. Differences between the groups were considered statistically significant at P < .05. The data were analyzed to obtain point prevalence among patients with SCI, and comparisons were made among the different subgroups.

Results

Of the 162 patients who chose to participate in the study, the sleep specialists confirmed 31 (19%) to have RLS, 112 (69%) were confirmed negative for RLS, and an additional 19 (12%) screened positive for RLS but were not confirmed to have RLS by the sleep specialists (Figure 1).

The etiology of SCI was subdivided into 4 groups: MS, trauma, vascular, and other/unknown. Within each group (– RLS vs + RLS), MS and trauma were the most common etiologies with 55% MS and 36% trauma in the + RLS group.

When comparing RLS among the spinal cord levels (cervical, thoracic, lumbar and cervical + thoracic), only the cervical + thoracic subgroup (18% + RLS vs 5% – RLS) showed a significant difference (Figure 2).

There was no significant difference found with the prevalence of RLS in the axial plane of the spinal cord lesions (ventral/ventro-lateral/central cord vs dorsal/dorsolateral) or by the completeness of spinal cord lesions, P = .76. There was a higher prevalence of incomplete cord injury, however, within each subgroup of RLS.

The Mann-Whitney test was used to analyze the burden of disease in both groups (+ RLS vs – RLS). Moderate level of burden was most frequently reported with a higher prevalence within the + RLS group. Of those receiving treatment for RLS, 71% were + RLS vs 46% – RLS with a P value of .01. Symptoms of RLS after cord injury were 89% + RLS vs 55% – RLS with a P value of .03.

Discussion

This study represents one of the first studies to determine the prevalence of RLS in veterans with spinal cord disease. Research in this area is important to raise awareness of RLS among the veteran population with and without SCI and disorders. Restless legs syndrome often escapes diagnosis because of difficulty understanding the patient’s descriptions of their sensations. In addition, RLS may cause debilitating symptoms of sleep deprivation, daytime sleepiness, discomfort, and fatigue, which often results in decreased quality of life (QOL). Proper screening and treatment may improve QOL.

A study by Kumru and colleagues showed a similar rate of RLS in patients with SCI and RLS symptoms presented in the first year after SCI as did this study (18% vs 19%, respectively).⁴ In that study, RLS was more common in patients with lesions in lumbosacral area. Kumru and colleagues also showed that a dopaminergic medication improved symptoms of RLS in this population, whereas this study did not explore treatment outcomes.⁴

The pathogenesis of RLS is not fully known, but hereditary factors, iron metabolism, and the brain dopaminergic system are thought to be involved.¹¹ It is hypothesized that spinal cord lesions allow the appearance of RLS symptoms and spinal leg movement generator by blocking descending inhibitory spinal pathways.¹² One hypothesis is that damage to A11 nuclei (the main source of dopamine in the spinal cord or its diencephalospinal tract in animals) causes hyperexcitability of the spinal cord and leads to PLM and RLS symptoms.¹³ As the axons of A11 nuclei are present along the whole span of the spinal cord, SCI/D in patients with RLS might interrupt this dopaminergic tract and produce the RLS symptoms.

Limitations

This study included only veterans, so the prevalence may not apply to the nonveteran SCI population. Also, the population mainly was male, and there was no accurate information on race. Ferritin levels of the patients were not checked and is a major factor in RLS. The reported onset of RLS after the SCI could be due to recall bias.

Conclusion

The prevalence of RLS in veterans with SCI is above that reported in the general population (19% vs 10%, respectively). Furthermore, those with RLS have symptoms that often started after the SCI (suggesting causality) and required therapy due to their level of RLS symptom burden. A spectrum of severity of symptoms is present among those with RLS, with 83% having moderate-to-severe RLS affecting their QOL.

Although there was not a statistically significant relationship between RLS and spinal cord lesion level, there was a slightly higher prevalence of RLS at the cervical and thoracic levels, which may be relevant for future studies. There was no difference found between the RLS subgroups with respect to the location of the lesion within the spinal cord; however, a larger sample size may be needed to determine whether this would reach statistical significance. Prompt search for symptoms of RLS in veterans with SCI is warranted to provide adequate treatment to improve sleep health and QOL in this population.

Spinal cord injuries (SCI) are common in veteran populations.¹ Veterans with spinal cord injuries and disorders (SCI/D) also may have concurrent sleep disturbances. Spinal cord injury typically causes spasticity.^2,3 Hypersensitivity of the flexor reflex pathways is believed to cause painful muscle spasms in patients with SCI.⁴ Neuropathic pain at or below the level of the lesion also is common.

Restless legs syndrome (RLS) is a common sleep disorder that affects sleep quality and can occur concomitantly with spinal cord lesions.⁵ In about 80% of RLS cases, involuntary movements of legs across hip, knee, and ankle joints during sleep, known as periodic limb movement during sleep (PLMS), occurs.⁶ Several studies showed increased prevalence of PLMS in patients with SCI, and some case reports suggest an increased prevalence of RLS in this population.^7,8 One small study showed that 100% of patients with SCI had symptoms of RLS.⁶ Another study found that SCI could trigger PLMS.⁸

The pathophysiology of RLS and PLMS in patients with SCI is not fully understood, but case reports describing PLM in SCI patients points to a possible role of central pattern generators and the flexor reflex afferents in the pathophysiology of PLMS.^9,10 Changes of the tissue microstructure in the midbrain and upper cervical spinal cord have been described in patients with RLS.¹¹The objective of this study was to assess the prevalence of RLS in a veteran population with SCI/D and to determine possible neuroanatomical patterns involved in RLS and SCI/D.

Methods

The institutional review and ethical approval boards of the Minneapolis VA Health Care System approved the study. Within the VA system, 666 patients with SCI/D were identified using a national database. Of the 666 people, 316 were excluded, 199 were included, and 151 were deceased.

Patients aged between 18 and 65 years were included in the study. Charts of patients who had been discharged with the diagnosis of SCI from 2002 to 2008 were studied. All patients met the inclusion criteria of the International Restless Legs Syndrome Study Group diagnosis.

Exclusion criteria were as follows: Patients with evidence of brain pathology (eg, stroke), concurrent neurologic condition associated with RLS (Parkinson disease, spinocerebellar ataxia, peripheral neuropathy), concurrent psychiatric condition within the setting of treatment with dopamine antagonists, secondary causes of RLS (renal failure/uremia, iron deficiency, rheumatoid arthritis, and pregnancy) and a recent history of alcohol or drug misuse or current evidence of substance use of < 1 year.

A patient list was compiled that included the etiology of the SCI (vascular injury, multiple sclerosis [MS], trauma, unknown, and other), the level(s) and completeness of the SCI per radiology report, RLS pharmacotherapies, and pertinent medical history.

Axial T2-weighted images on magnetic resonance imaging (MRI) scans were retrospectively reviewed. Sagittal T1/T2-weighted and axial T2-weighted sequences were performed routinely on all patients with spinal cord lesions. The analysis included the extension of the lesion on both sagittal and axial distributions. The anatomic location of the cord lesion was categorized by the following: (1) pure gray matter (central cord); (2) white matter (dorsal [D], dorsolateral [DL], ventral [V], ventrolateral areas [VL]).

A questionnaire using standard diagnostic criteria for RLS was mailed to the 199 patients who met the inclusion criteria (Appendix A).

All analyses were carried out using StataCorp STATA 13 (College Station, TX). Descriptive statistics were used. The analyses were carried out using chi-square and Fisher exact tests. Differences between the groups were considered statistically significant at P < .05. The data were analyzed to obtain point prevalence among patients with SCI, and comparisons were made among the different subgroups.

Results

Of the 162 patients who chose to participate in the study, the sleep specialists confirmed 31 (19%) to have RLS, 112 (69%) were confirmed negative for RLS, and an additional 19 (12%) screened positive for RLS but were not confirmed to have RLS by the sleep specialists (Figure 1).

The etiology of SCI was subdivided into 4 groups: MS, trauma, vascular, and other/unknown. Within each group (– RLS vs + RLS), MS and trauma were the most common etiologies with 55% MS and 36% trauma in the + RLS group.

When comparing RLS among the spinal cord levels (cervical, thoracic, lumbar and cervical + thoracic), only the cervical + thoracic subgroup (18% + RLS vs 5% – RLS) showed a significant difference (Figure 2).

There was no significant difference found with the prevalence of RLS in the axial plane of the spinal cord lesions (ventral/ventro-lateral/central cord vs dorsal/dorsolateral) or by the completeness of spinal cord lesions, P = .76. There was a higher prevalence of incomplete cord injury, however, within each subgroup of RLS.

The Mann-Whitney test was used to analyze the burden of disease in both groups (+ RLS vs – RLS). Moderate level of burden was most frequently reported with a higher prevalence within the + RLS group. Of those receiving treatment for RLS, 71% were + RLS vs 46% – RLS with a P value of .01. Symptoms of RLS after cord injury were 89% + RLS vs 55% – RLS with a P value of .03.

Discussion

This study represents one of the first studies to determine the prevalence of RLS in veterans with spinal cord disease. Research in this area is important to raise awareness of RLS among the veteran population with and without SCI and disorders. Restless legs syndrome often escapes diagnosis because of difficulty understanding the patient’s descriptions of their sensations. In addition, RLS may cause debilitating symptoms of sleep deprivation, daytime sleepiness, discomfort, and fatigue, which often results in decreased quality of life (QOL). Proper screening and treatment may improve QOL.

A study by Kumru and colleagues showed a similar rate of RLS in patients with SCI and RLS symptoms presented in the first year after SCI as did this study (18% vs 19%, respectively).⁴ In that study, RLS was more common in patients with lesions in lumbosacral area. Kumru and colleagues also showed that a dopaminergic medication improved symptoms of RLS in this population, whereas this study did not explore treatment outcomes.⁴

The pathogenesis of RLS is not fully known, but hereditary factors, iron metabolism, and the brain dopaminergic system are thought to be involved.¹¹ It is hypothesized that spinal cord lesions allow the appearance of RLS symptoms and spinal leg movement generator by blocking descending inhibitory spinal pathways.¹² One hypothesis is that damage to A11 nuclei (the main source of dopamine in the spinal cord or its diencephalospinal tract in animals) causes hyperexcitability of the spinal cord and leads to PLM and RLS symptoms.¹³ As the axons of A11 nuclei are present along the whole span of the spinal cord, SCI/D in patients with RLS might interrupt this dopaminergic tract and produce the RLS symptoms.

Limitations

This study included only veterans, so the prevalence may not apply to the nonveteran SCI population. Also, the population mainly was male, and there was no accurate information on race. Ferritin levels of the patients were not checked and is a major factor in RLS. The reported onset of RLS after the SCI could be due to recall bias.

Conclusion

The prevalence of RLS in veterans with SCI is above that reported in the general population (19% vs 10%, respectively). Furthermore, those with RLS have symptoms that often started after the SCI (suggesting causality) and required therapy due to their level of RLS symptom burden. A spectrum of severity of symptoms is present among those with RLS, with 83% having moderate-to-severe RLS affecting their QOL.

Although there was not a statistically significant relationship between RLS and spinal cord lesion level, there was a slightly higher prevalence of RLS at the cervical and thoracic levels, which may be relevant for future studies. There was no difference found between the RLS subgroups with respect to the location of the lesion within the spinal cord; however, a larger sample size may be needed to determine whether this would reach statistical significance. Prompt search for symptoms of RLS in veterans with SCI is warranted to provide adequate treatment to improve sleep health and QOL in this population.

More and better research is needed to guide primary care clinicians in screening asymptomatic young children and asymptomatic pregnant women for lead exposure, according to a recommendation from the U.S. Preventive Services Task Force.

KatarzynaBialasiewicz/Thinkstock

Elevated blood lead levels are associated with potentially irreversible neurologic problems in children and with organ system impairment and adverse perinatal effects in pregnant women, according to the statement.

“Thus, the primary benefit of screening may be in preventing future exposures or exposure of others to environmental sources,” the task force members wrote in JAMA Pediatrics.

However, the task force issued I statements, meaning that “the current evidence is insufficient to assess the balance of benefits and harms of screening for elevated blood lead levels” in asymptomatic children aged 5 years and younger and in asymptomatic pregnant women.

The task force cited evidence that questionnaires and other clinical prediction tools are inaccurate at identifying elevated blood lead levels in asymptomatic children and pregnant women. In addition, the task force found adequate evidence that capillary blood testing identified elevated blood lead levels in children, but found inadequate evidence that treating elevated blood lead levels was effective in asymptomatic children aged 5 years and younger or in pregnant women.

In the evidence report accompanying the recommendation statement in JAMA Pediatrics, Amy G. Cantor, MD, MPH, of Oregon Health & Science University, Portland, and her colleagues reviewed data from a total of 24 studies including 11,433 individuals.

None of the studies evaluated the risks or benefits of blood lead screening in children. However, in three of four studies, capillary blood lead testing showed sensitivities ranging from 87% to 91% and specificities from 92% to 99%, based on a blood lead level cutoff of 10 mcg/dL or less.

“Evidence indicates that capillary sampling is slightly less sensitive than venous sampling, with comparable specificity,” Dr. Cantor and her colleagues wrote. “Both methods require confirmation.”

There is only limited evidence on whether intervening when children present with elevated blood lead levels results in better neurodevelopmental outcomes. One trial showed beneficial effects of dimercaptosuccinic acid chelation of lowering elevated blood lead levels (20-44 mcg/dL) at 1 year versus placebo, but no clear effect on longer term blood lead levels or neurodevelopmental outcomes, they reported.

For residential interventions, again evidence is limited and blood lead concentrations were not clearly affected. Evidence on calcium and iron interventions was poor quality and insufficient to tell if there was an effect on blood lead levels or clinical outcomes, Dr. Cantor and her colleagues wrote.

No studies of screening for elevated lead levels in pregnant women were identified, nor were studies of health outcomes after interventions to reduce blood lead levels in asymptomatic pregnant women, they noted.

Studies involving pregnant women were limited, and included data on the diagnostic accuracy of a clinical questionnaire and the effects of nutritional intervention during pregnancy, Dr. Cantor and her colleagues wrote.

“This update confirms there are no clear effects of interventions for lowering elevated blood levels in affected children or to improve neurodevelopmental outcomes,” they concluded. “Evidence to determine benefits and harms of screening or treating elevated lead levels during pregnancy remains extremely limited.”

The recommendation updates the last version issued in 2006. The USPSTF is supported by the Agency for Healthcare Research and Quality. The researchers for both articles reported no relevant financial disclosures.

SOURCE: Curry SJ et al. JAMA Pediatr. 2019 Apr 16. doi: 10.1001/jama.2019.3326; Cantor AG et al. JAMA Pediatr. 2019 Apr 16. doi: 10.1001/jama.2019.1004.

More and better research is needed to guide primary care clinicians in screening asymptomatic young children and asymptomatic pregnant women for lead exposure, according to a recommendation from the U.S. Preventive Services Task Force.

KatarzynaBialasiewicz/Thinkstock

Elevated blood lead levels are associated with potentially irreversible neurologic problems in children and with organ system impairment and adverse perinatal effects in pregnant women, according to the statement.

“Thus, the primary benefit of screening may be in preventing future exposures or exposure of others to environmental sources,” the task force members wrote in JAMA Pediatrics.

However, the task force issued I statements, meaning that “the current evidence is insufficient to assess the balance of benefits and harms of screening for elevated blood lead levels” in asymptomatic children aged 5 years and younger and in asymptomatic pregnant women.

The task force cited evidence that questionnaires and other clinical prediction tools are inaccurate at identifying elevated blood lead levels in asymptomatic children and pregnant women. In addition, the task force found adequate evidence that capillary blood testing identified elevated blood lead levels in children, but found inadequate evidence that treating elevated blood lead levels was effective in asymptomatic children aged 5 years and younger or in pregnant women.

In the evidence report accompanying the recommendation statement in JAMA Pediatrics, Amy G. Cantor, MD, MPH, of Oregon Health & Science University, Portland, and her colleagues reviewed data from a total of 24 studies including 11,433 individuals.

None of the studies evaluated the risks or benefits of blood lead screening in children. However, in three of four studies, capillary blood lead testing showed sensitivities ranging from 87% to 91% and specificities from 92% to 99%, based on a blood lead level cutoff of 10 mcg/dL or less.

“Evidence indicates that capillary sampling is slightly less sensitive than venous sampling, with comparable specificity,” Dr. Cantor and her colleagues wrote. “Both methods require confirmation.”

There is only limited evidence on whether intervening when children present with elevated blood lead levels results in better neurodevelopmental outcomes. One trial showed beneficial effects of dimercaptosuccinic acid chelation of lowering elevated blood lead levels (20-44 mcg/dL) at 1 year versus placebo, but no clear effect on longer term blood lead levels or neurodevelopmental outcomes, they reported.

For residential interventions, again evidence is limited and blood lead concentrations were not clearly affected. Evidence on calcium and iron interventions was poor quality and insufficient to tell if there was an effect on blood lead levels or clinical outcomes, Dr. Cantor and her colleagues wrote.

No studies of screening for elevated lead levels in pregnant women were identified, nor were studies of health outcomes after interventions to reduce blood lead levels in asymptomatic pregnant women, they noted.

Studies involving pregnant women were limited, and included data on the diagnostic accuracy of a clinical questionnaire and the effects of nutritional intervention during pregnancy, Dr. Cantor and her colleagues wrote.

“This update confirms there are no clear effects of interventions for lowering elevated blood levels in affected children or to improve neurodevelopmental outcomes,” they concluded. “Evidence to determine benefits and harms of screening or treating elevated lead levels during pregnancy remains extremely limited.”

The recommendation updates the last version issued in 2006. The USPSTF is supported by the Agency for Healthcare Research and Quality. The researchers for both articles reported no relevant financial disclosures.

SOURCE: Curry SJ et al. JAMA Pediatr. 2019 Apr 16. doi: 10.1001/jama.2019.3326; Cantor AG et al. JAMA Pediatr. 2019 Apr 16. doi: 10.1001/jama.2019.1004.

More and better research is needed to guide primary care clinicians in screening asymptomatic young children and asymptomatic pregnant women for lead exposure, according to a recommendation from the U.S. Preventive Services Task Force.

KatarzynaBialasiewicz/Thinkstock

Elevated blood lead levels are associated with potentially irreversible neurologic problems in children and with organ system impairment and adverse perinatal effects in pregnant women, according to the statement.

“Thus, the primary benefit of screening may be in preventing future exposures or exposure of others to environmental sources,” the task force members wrote in JAMA Pediatrics.

However, the task force issued I statements, meaning that “the current evidence is insufficient to assess the balance of benefits and harms of screening for elevated blood lead levels” in asymptomatic children aged 5 years and younger and in asymptomatic pregnant women.

The task force cited evidence that questionnaires and other clinical prediction tools are inaccurate at identifying elevated blood lead levels in asymptomatic children and pregnant women. In addition, the task force found adequate evidence that capillary blood testing identified elevated blood lead levels in children, but found inadequate evidence that treating elevated blood lead levels was effective in asymptomatic children aged 5 years and younger or in pregnant women.

In the evidence report accompanying the recommendation statement in JAMA Pediatrics, Amy G. Cantor, MD, MPH, of Oregon Health & Science University, Portland, and her colleagues reviewed data from a total of 24 studies including 11,433 individuals.

None of the studies evaluated the risks or benefits of blood lead screening in children. However, in three of four studies, capillary blood lead testing showed sensitivities ranging from 87% to 91% and specificities from 92% to 99%, based on a blood lead level cutoff of 10 mcg/dL or less.

“Evidence indicates that capillary sampling is slightly less sensitive than venous sampling, with comparable specificity,” Dr. Cantor and her colleagues wrote. “Both methods require confirmation.”

There is only limited evidence on whether intervening when children present with elevated blood lead levels results in better neurodevelopmental outcomes. One trial showed beneficial effects of dimercaptosuccinic acid chelation of lowering elevated blood lead levels (20-44 mcg/dL) at 1 year versus placebo, but no clear effect on longer term blood lead levels or neurodevelopmental outcomes, they reported.

For residential interventions, again evidence is limited and blood lead concentrations were not clearly affected. Evidence on calcium and iron interventions was poor quality and insufficient to tell if there was an effect on blood lead levels or clinical outcomes, Dr. Cantor and her colleagues wrote.

No studies of screening for elevated lead levels in pregnant women were identified, nor were studies of health outcomes after interventions to reduce blood lead levels in asymptomatic pregnant women, they noted.

Studies involving pregnant women were limited, and included data on the diagnostic accuracy of a clinical questionnaire and the effects of nutritional intervention during pregnancy, Dr. Cantor and her colleagues wrote.

“This update confirms there are no clear effects of interventions for lowering elevated blood levels in affected children or to improve neurodevelopmental outcomes,” they concluded. “Evidence to determine benefits and harms of screening or treating elevated lead levels during pregnancy remains extremely limited.”

The recommendation updates the last version issued in 2006. The USPSTF is supported by the Agency for Healthcare Research and Quality. The researchers for both articles reported no relevant financial disclosures.

SOURCE: Curry SJ et al. JAMA Pediatr. 2019 Apr 16. doi: 10.1001/jama.2019.3326; Cantor AG et al. JAMA Pediatr. 2019 Apr 16. doi: 10.1001/jama.2019.1004.

PHILADELPHIA – Nearly 7%-10% of the general population experiences neuropathic pain, but studies on treatments have not found a clear winner for reducing this “burning or electriclike pain,” explained Raymond Price, MD, during a presentation.

Andrew Bowser/MDedge News

“It isn’t that exciting,” said Dr. Price, associate professor of neurology at the University of Pennsylvania, Philadelphia, in reference to his review of level 1-2 evidence for treatment of neuropathic pain that was presented in a study published in JAMA (2015 Nov 24;314[20]:2172-81). a few years ago. “On a scale of 1 to 10, you can reduce their pain scale by 1-2 points more than placebo,” he told his audience at the annual meeting of the American College of Physicians.

“In general, you can use any of these medicines [for neuropathic pain]. There are very limited head-to-head data as to which one is actually better,” he explained.

Given the absence of robust head-to-head trial data, Dr. Price tends to start a lot of patients on old, cheap medications like nortriptyline.

While there aren’t many head-to-head trials to guide treatment choice, the results of one prospective, randomized, open-label study of 333 patients with cryptogenic sensory polyneuropathy was presented by Barohn and colleagues at the 2018 annual meeting of the American Academy of Neurology, he said. In that study, somewhat higher efficacy rates were seen with duloxetine, a serotonin-noradrenaline reuptake inhibitor, and nortriptyline, a tricyclic antidepressant, compared with pregabalin, Dr. Price noted. Duloxetine and nortriptyline also had slightly better tolerability, as evidenced by a lower quit rate, compared with pregabalin, he added.

There was also a systematic review and meta-analysis (Lancet Neurol. 2015 Feb; 14[2]:162-73) conducted that determined the number needed to treat for neuropathic pain treatments, Dr. Price noted. In that paper, tricyclic antidepressants had a number needed to treat of 3.6, comparing favorably to 7.7 for pregabalin, 7.2 for gabapentin, and 6.4 for serotonin-noradrenaline reuptake inhibitors, mainly including duloxetine, said Dr. Price.

Regardless of the cause of neuropathic pain, the same general approach to treatment is taken, though most of the evidence comes from studies of patients with painful diabetic peripheral neuropathy or postherpetic neuralgia, he added.

For these patients, an adequate trial of a neuropathic pain treatment should be 6-12 weeks, reflecting the length of the intervention needed to demonstrate the efficacy of these agents, he said.

If that first drug doesn’t work, another can be tried, or multiple drugs can be tried together to see if the patient’s condition improves, he said.

Dr. Price reported no conflicts of interest.
 

SOURCE: Price R Internal Medicine 2019, Presentation MSFM 002.

PHILADELPHIA – Nearly 7%-10% of the general population experiences neuropathic pain, but studies on treatments have not found a clear winner for reducing this “burning or electriclike pain,” explained Raymond Price, MD, during a presentation.

Andrew Bowser/MDedge News

“It isn’t that exciting,” said Dr. Price, associate professor of neurology at the University of Pennsylvania, Philadelphia, in reference to his review of level 1-2 evidence for treatment of neuropathic pain that was presented in a study published in JAMA (2015 Nov 24;314[20]:2172-81). a few years ago. “On a scale of 1 to 10, you can reduce their pain scale by 1-2 points more than placebo,” he told his audience at the annual meeting of the American College of Physicians.

“In general, you can use any of these medicines [for neuropathic pain]. There are very limited head-to-head data as to which one is actually better,” he explained.

Given the absence of robust head-to-head trial data, Dr. Price tends to start a lot of patients on old, cheap medications like nortriptyline.

While there aren’t many head-to-head trials to guide treatment choice, the results of one prospective, randomized, open-label study of 333 patients with cryptogenic sensory polyneuropathy was presented by Barohn and colleagues at the 2018 annual meeting of the American Academy of Neurology, he said. In that study, somewhat higher efficacy rates were seen with duloxetine, a serotonin-noradrenaline reuptake inhibitor, and nortriptyline, a tricyclic antidepressant, compared with pregabalin, Dr. Price noted. Duloxetine and nortriptyline also had slightly better tolerability, as evidenced by a lower quit rate, compared with pregabalin, he added.

There was also a systematic review and meta-analysis (Lancet Neurol. 2015 Feb; 14[2]:162-73) conducted that determined the number needed to treat for neuropathic pain treatments, Dr. Price noted. In that paper, tricyclic antidepressants had a number needed to treat of 3.6, comparing favorably to 7.7 for pregabalin, 7.2 for gabapentin, and 6.4 for serotonin-noradrenaline reuptake inhibitors, mainly including duloxetine, said Dr. Price.

Regardless of the cause of neuropathic pain, the same general approach to treatment is taken, though most of the evidence comes from studies of patients with painful diabetic peripheral neuropathy or postherpetic neuralgia, he added.

For these patients, an adequate trial of a neuropathic pain treatment should be 6-12 weeks, reflecting the length of the intervention needed to demonstrate the efficacy of these agents, he said.

If that first drug doesn’t work, another can be tried, or multiple drugs can be tried together to see if the patient’s condition improves, he said.

Dr. Price reported no conflicts of interest.
 

SOURCE: Price R Internal Medicine 2019, Presentation MSFM 002.

PHILADELPHIA – Nearly 7%-10% of the general population experiences neuropathic pain, but studies on treatments have not found a clear winner for reducing this “burning or electriclike pain,” explained Raymond Price, MD, during a presentation.

Andrew Bowser/MDedge News

“It isn’t that exciting,” said Dr. Price, associate professor of neurology at the University of Pennsylvania, Philadelphia, in reference to his review of level 1-2 evidence for treatment of neuropathic pain that was presented in a study published in JAMA (2015 Nov 24;314[20]:2172-81). a few years ago. “On a scale of 1 to 10, you can reduce their pain scale by 1-2 points more than placebo,” he told his audience at the annual meeting of the American College of Physicians.

“In general, you can use any of these medicines [for neuropathic pain]. There are very limited head-to-head data as to which one is actually better,” he explained.

Given the absence of robust head-to-head trial data, Dr. Price tends to start a lot of patients on old, cheap medications like nortriptyline.

While there aren’t many head-to-head trials to guide treatment choice, the results of one prospective, randomized, open-label study of 333 patients with cryptogenic sensory polyneuropathy was presented by Barohn and colleagues at the 2018 annual meeting of the American Academy of Neurology, he said. In that study, somewhat higher efficacy rates were seen with duloxetine, a serotonin-noradrenaline reuptake inhibitor, and nortriptyline, a tricyclic antidepressant, compared with pregabalin, Dr. Price noted. Duloxetine and nortriptyline also had slightly better tolerability, as evidenced by a lower quit rate, compared with pregabalin, he added.

There was also a systematic review and meta-analysis (Lancet Neurol. 2015 Feb; 14[2]:162-73) conducted that determined the number needed to treat for neuropathic pain treatments, Dr. Price noted. In that paper, tricyclic antidepressants had a number needed to treat of 3.6, comparing favorably to 7.7 for pregabalin, 7.2 for gabapentin, and 6.4 for serotonin-noradrenaline reuptake inhibitors, mainly including duloxetine, said Dr. Price.

Regardless of the cause of neuropathic pain, the same general approach to treatment is taken, though most of the evidence comes from studies of patients with painful diabetic peripheral neuropathy or postherpetic neuralgia, he added.

For these patients, an adequate trial of a neuropathic pain treatment should be 6-12 weeks, reflecting the length of the intervention needed to demonstrate the efficacy of these agents, he said.

If that first drug doesn’t work, another can be tried, or multiple drugs can be tried together to see if the patient’s condition improves, he said.

Dr. Price reported no conflicts of interest.
 

SOURCE: Price R Internal Medicine 2019, Presentation MSFM 002.

DALLAS – Neurologists soon may use a blood biomarker of axonal damage to monitor patients with multiple sclerosis (MS) and guide treatment decisions, according to a lecture delivered at ACTRIMS Forum 2019.

Physicians have lacked biomarkers to assess subclinical MS disease activity, but technological advances and recently published data suggest that blood levels of neurofilament light chain (NfL) will help fill that gap, said David Leppert, MD, senior research associate in the department of neurology at University Hopsital Basel (Switzerland).

Among patients with MS, blood NfL levels predict disability, brain volume loss, and spinal cord atrophy. In addition, studies have found that blood NfL decreases in response to disease-modifying therapy (DMT) and that second-line DMTs may decrease blood NfL more than first-line DMTs do.

The establishment of normative databases and reference biomarkers may allow neurologists to use NfL in their care of individual patients, Dr. Leppert predicted at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis. “I am very positive that we will make a breakthrough in the next 2 or 3 years for an individual use of neurofilaments,” he said.
 

Response to DMT

An analysis of blood NfL levels from patients with MS and from healthy controls in two phase 3 trials of fingolimod, FREEDOMS and TRANSFORMS, provides insights into NfL’s response to DMT (Neurology. 2019 Mar 5;92[10]:e1007-15). In FREEDOMS, which compared fingolimod with placebo, “fingolimod leads to a rapid decrease of neurofilament levels, close to normality, while placebo patients continue to have high levels,” said Dr. Leppert, a coauthor of the study.

TRANSFORMS compared interferon-beta and fingolimod. “The clinical experience that fingolimod is a more potent compound than interferon is actually reflected here by the NfL results,” Dr. Leppert said. “Both compounds lead to a decrease of neurofilaments – so, a decrease of neuronal damage – but one drug is more potent than the other one.”

Similarly, data from the observational EPIC study indicate that patients who do not receive DMT have a consistent increase in NfL levels, whereas those who receive platform therapies have a slight decrease in NfL and those who receive second-line therapies have a greater decrease, Dr. Leppert said.


 

Decades of research

For about 20 years, researchers have studied neurofilaments in cerebrospinal fluid (CSF) as a potential biomarker for MS and other diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, Parkinson’s disease, and head trauma.

“What prevented the emergence of NfL to clinical practice was the inability to measure it in blood because levels are 50-100 times lower [in blood] than in CSF,” Dr. Leppert said.

The development of single molecule array (SIMOA) technology enabled researchers to show a proper correlation between levels of NfL in CSF and those in blood, Dr. Leppert said. “That is now allowing repetitive testing in an accessible fluid compartment, meaning serum or plasma,” he said.

Compared with brain MRI, NfL may provide novel insights into MS disease activity. “MRI is measuring a structural deficit of the past,” Dr. Leppert said. “NfL is measuring online, real time what axonal damage is occurring.”
 

Correlation with outcomes

At the group level, patients with MS have higher levels of NfL, compared with controls, and levels are higher in patients with progressive forms of MS versus relapsing forms. “Levels increase dramatically in the wake of relapse,” he said.

Barro et al. found that patients with higher serum levels of NfL are more likely to experience Expanded Disability Status Scale (EDSS) worsening (Brain. 2018 Aug 1;141[8]:2382-91). Furthermore, MRI lesions are independently associated with serum NfL, and patients with higher levels of serum NfL have significantly greater average loss in brain volume and spinal cord volume over 5 years.
 

A treatment algorithm

NfL someday could be incorporated into MS treatment algorithms, Dr. Leppert suggested. For instance, if a patient has high levels of disease activity based on MRI or clinical grounds, then prescribe a high-efficacy therapy. If not, measure NfL. “If the levels are low, then you can be assured to use platform therapies or continue what the patient has. But if NfL levels are high, then you should choose high efficacious therapies or switch to high-efficacious therapies in the long run,” he said.

Limitations and next steps

Although NfL is a specific marker of neuronal damage, it is not specific for the cause of the damage. Further studies are needed to better understand NfL metabolism and confounding factors such as age. Reference biomarkers likely will be needed “to conceptualize whether the signal of NfL is due to acute disease or chronic disease,” Dr. Leppert said.

“We need to optimize the assay and come to a worldwide agreement on the platform. We need to have prospective studies, mainly to achieve regulatory acceptance. And we need to have a normative database” to determine which NfL values are pathologic at a particular age, he said.

Despite the biomarker’s potential, blood NfL levels will not replace clinical expertise. “Biomarkers cannot be of value without a clinical backing and a clinical evaluation,” Dr. Leppert said. “The idea that this will replace us or any other person who makes a clinical judgment is a big error. NfL will prevail as a biomarker. ... But interpretation of the clinical background is germane.”

Dr. Leppert has been an employee of pharmaceutical companies, most recently Novartis.

[email protected]

DALLAS – Neurologists soon may use a blood biomarker of axonal damage to monitor patients with multiple sclerosis (MS) and guide treatment decisions, according to a lecture delivered at ACTRIMS Forum 2019.

Physicians have lacked biomarkers to assess subclinical MS disease activity, but technological advances and recently published data suggest that blood levels of neurofilament light chain (NfL) will help fill that gap, said David Leppert, MD, senior research associate in the department of neurology at University Hopsital Basel (Switzerland).

Among patients with MS, blood NfL levels predict disability, brain volume loss, and spinal cord atrophy. In addition, studies have found that blood NfL decreases in response to disease-modifying therapy (DMT) and that second-line DMTs may decrease blood NfL more than first-line DMTs do.

The establishment of normative databases and reference biomarkers may allow neurologists to use NfL in their care of individual patients, Dr. Leppert predicted at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis. “I am very positive that we will make a breakthrough in the next 2 or 3 years for an individual use of neurofilaments,” he said.
 

Response to DMT

An analysis of blood NfL levels from patients with MS and from healthy controls in two phase 3 trials of fingolimod, FREEDOMS and TRANSFORMS, provides insights into NfL’s response to DMT (Neurology. 2019 Mar 5;92[10]:e1007-15). In FREEDOMS, which compared fingolimod with placebo, “fingolimod leads to a rapid decrease of neurofilament levels, close to normality, while placebo patients continue to have high levels,” said Dr. Leppert, a coauthor of the study.

TRANSFORMS compared interferon-beta and fingolimod. “The clinical experience that fingolimod is a more potent compound than interferon is actually reflected here by the NfL results,” Dr. Leppert said. “Both compounds lead to a decrease of neurofilaments – so, a decrease of neuronal damage – but one drug is more potent than the other one.”

Similarly, data from the observational EPIC study indicate that patients who do not receive DMT have a consistent increase in NfL levels, whereas those who receive platform therapies have a slight decrease in NfL and those who receive second-line therapies have a greater decrease, Dr. Leppert said.


 

Decades of research

For about 20 years, researchers have studied neurofilaments in cerebrospinal fluid (CSF) as a potential biomarker for MS and other diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, Parkinson’s disease, and head trauma.

“What prevented the emergence of NfL to clinical practice was the inability to measure it in blood because levels are 50-100 times lower [in blood] than in CSF,” Dr. Leppert said.

The development of single molecule array (SIMOA) technology enabled researchers to show a proper correlation between levels of NfL in CSF and those in blood, Dr. Leppert said. “That is now allowing repetitive testing in an accessible fluid compartment, meaning serum or plasma,” he said.

Compared with brain MRI, NfL may provide novel insights into MS disease activity. “MRI is measuring a structural deficit of the past,” Dr. Leppert said. “NfL is measuring online, real time what axonal damage is occurring.”
 

Correlation with outcomes

At the group level, patients with MS have higher levels of NfL, compared with controls, and levels are higher in patients with progressive forms of MS versus relapsing forms. “Levels increase dramatically in the wake of relapse,” he said.

Barro et al. found that patients with higher serum levels of NfL are more likely to experience Expanded Disability Status Scale (EDSS) worsening (Brain. 2018 Aug 1;141[8]:2382-91). Furthermore, MRI lesions are independently associated with serum NfL, and patients with higher levels of serum NfL have significantly greater average loss in brain volume and spinal cord volume over 5 years.
 

A treatment algorithm

NfL someday could be incorporated into MS treatment algorithms, Dr. Leppert suggested. For instance, if a patient has high levels of disease activity based on MRI or clinical grounds, then prescribe a high-efficacy therapy. If not, measure NfL. “If the levels are low, then you can be assured to use platform therapies or continue what the patient has. But if NfL levels are high, then you should choose high efficacious therapies or switch to high-efficacious therapies in the long run,” he said.

Limitations and next steps

Although NfL is a specific marker of neuronal damage, it is not specific for the cause of the damage. Further studies are needed to better understand NfL metabolism and confounding factors such as age. Reference biomarkers likely will be needed “to conceptualize whether the signal of NfL is due to acute disease or chronic disease,” Dr. Leppert said.

“We need to optimize the assay and come to a worldwide agreement on the platform. We need to have prospective studies, mainly to achieve regulatory acceptance. And we need to have a normative database” to determine which NfL values are pathologic at a particular age, he said.

Despite the biomarker’s potential, blood NfL levels will not replace clinical expertise. “Biomarkers cannot be of value without a clinical backing and a clinical evaluation,” Dr. Leppert said. “The idea that this will replace us or any other person who makes a clinical judgment is a big error. NfL will prevail as a biomarker. ... But interpretation of the clinical background is germane.”

Dr. Leppert has been an employee of pharmaceutical companies, most recently Novartis.

[email protected]

DALLAS – Neurologists soon may use a blood biomarker of axonal damage to monitor patients with multiple sclerosis (MS) and guide treatment decisions, according to a lecture delivered at ACTRIMS Forum 2019.

Physicians have lacked biomarkers to assess subclinical MS disease activity, but technological advances and recently published data suggest that blood levels of neurofilament light chain (NfL) will help fill that gap, said David Leppert, MD, senior research associate in the department of neurology at University Hopsital Basel (Switzerland).

Among patients with MS, blood NfL levels predict disability, brain volume loss, and spinal cord atrophy. In addition, studies have found that blood NfL decreases in response to disease-modifying therapy (DMT) and that second-line DMTs may decrease blood NfL more than first-line DMTs do.

The establishment of normative databases and reference biomarkers may allow neurologists to use NfL in their care of individual patients, Dr. Leppert predicted at the meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis. “I am very positive that we will make a breakthrough in the next 2 or 3 years for an individual use of neurofilaments,” he said.
 

Response to DMT

An analysis of blood NfL levels from patients with MS and from healthy controls in two phase 3 trials of fingolimod, FREEDOMS and TRANSFORMS, provides insights into NfL’s response to DMT (Neurology. 2019 Mar 5;92[10]:e1007-15). In FREEDOMS, which compared fingolimod with placebo, “fingolimod leads to a rapid decrease of neurofilament levels, close to normality, while placebo patients continue to have high levels,” said Dr. Leppert, a coauthor of the study.

TRANSFORMS compared interferon-beta and fingolimod. “The clinical experience that fingolimod is a more potent compound than interferon is actually reflected here by the NfL results,” Dr. Leppert said. “Both compounds lead to a decrease of neurofilaments – so, a decrease of neuronal damage – but one drug is more potent than the other one.”

Similarly, data from the observational EPIC study indicate that patients who do not receive DMT have a consistent increase in NfL levels, whereas those who receive platform therapies have a slight decrease in NfL and those who receive second-line therapies have a greater decrease, Dr. Leppert said.


 

Decades of research

For about 20 years, researchers have studied neurofilaments in cerebrospinal fluid (CSF) as a potential biomarker for MS and other diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, Parkinson’s disease, and head trauma.

“What prevented the emergence of NfL to clinical practice was the inability to measure it in blood because levels are 50-100 times lower [in blood] than in CSF,” Dr. Leppert said.

The development of single molecule array (SIMOA) technology enabled researchers to show a proper correlation between levels of NfL in CSF and those in blood, Dr. Leppert said. “That is now allowing repetitive testing in an accessible fluid compartment, meaning serum or plasma,” he said.

Compared with brain MRI, NfL may provide novel insights into MS disease activity. “MRI is measuring a structural deficit of the past,” Dr. Leppert said. “NfL is measuring online, real time what axonal damage is occurring.”
 

Correlation with outcomes

At the group level, patients with MS have higher levels of NfL, compared with controls, and levels are higher in patients with progressive forms of MS versus relapsing forms. “Levels increase dramatically in the wake of relapse,” he said.

Barro et al. found that patients with higher serum levels of NfL are more likely to experience Expanded Disability Status Scale (EDSS) worsening (Brain. 2018 Aug 1;141[8]:2382-91). Furthermore, MRI lesions are independently associated with serum NfL, and patients with higher levels of serum NfL have significantly greater average loss in brain volume and spinal cord volume over 5 years.
 

A treatment algorithm

NfL someday could be incorporated into MS treatment algorithms, Dr. Leppert suggested. For instance, if a patient has high levels of disease activity based on MRI or clinical grounds, then prescribe a high-efficacy therapy. If not, measure NfL. “If the levels are low, then you can be assured to use platform therapies or continue what the patient has. But if NfL levels are high, then you should choose high efficacious therapies or switch to high-efficacious therapies in the long run,” he said.

Limitations and next steps

Although NfL is a specific marker of neuronal damage, it is not specific for the cause of the damage. Further studies are needed to better understand NfL metabolism and confounding factors such as age. Reference biomarkers likely will be needed “to conceptualize whether the signal of NfL is due to acute disease or chronic disease,” Dr. Leppert said.

“We need to optimize the assay and come to a worldwide agreement on the platform. We need to have prospective studies, mainly to achieve regulatory acceptance. And we need to have a normative database” to determine which NfL values are pathologic at a particular age, he said.

Despite the biomarker’s potential, blood NfL levels will not replace clinical expertise. “Biomarkers cannot be of value without a clinical backing and a clinical evaluation,” Dr. Leppert said. “The idea that this will replace us or any other person who makes a clinical judgment is a big error. NfL will prevail as a biomarker. ... But interpretation of the clinical background is germane.”

Dr. Leppert has been an employee of pharmaceutical companies, most recently Novartis.

[email protected]

More bad news for Alzheimer’s research. Two more BACE inhibitors fall far short of the finish line.

Not only did both verubecestat and atabecestat fail to improve cognition and function patients with prodromal Alzheimer’s disease, they also made things worse. Declining cognitive scores, falls, suicidal ideation, and liver enzyme abnormalities were all seen in clinical trials.

The news doesn’t bode well for the therapeutic target of BACE (beta-site APP cleaving enzyme) inhibition. BACE is one of the enzymes that trims the amyloid precursor protein (APP). Inhibiting it does reduce the amount of toxic amyloid-beta in cerebrospinal fluid, and amyloid plaque in the brain. But none of these molecules has shown clinical benefit in dementia patients, whether their disease is mild, or moderate or – now – prodromal. And it is now apparent that inhibiting BACE also produces serious off-target problems.

“BACE-1 inhibition certainly seemed to have a sound rationale assuming the basis for amyloid’s role in Alzheimer’s disease pathogenesis is a gain of toxicity,” Richard J. Caselli, MD, of the Mayo Clinic, Rochester, Minn., said in an interview. “That APP is important for Alzheimer’s pathogenesis still seems clear but whether amyloid-beta toxicity is the driving force is no longer clear. Further, interruption of the APP system disrupts more than amyloid-beta peptide, possibly explaining the adverse cognitive effects of BACE-1 inhibition shown exhibited now by three different BACE-1 inhibitors.”
 

Verubecestat

Researchers got their first dose of bad news regarding verubecestat at the 2017 Clinical Trials in Alzheimer’s Disease meeting. There, Michael F. Egan, MD, Merck’s associate vice president of clinical neuroscience, discussed the molecule’s failure to slow cognitive decline in patients with mild to moderate Alzheimer’s disease. There was plenty of biomarker evidence that the drug did block amyloid-beta production, but there also was a plethora of concerning adverse events, Dr. Egan said in an interview.

However, verubecestat still was being pursued in patients with prodromal Alzheimer’s disease. In February, Merck stopped the trial after a futility analysis and announced that the company was terminating studies of verubecestat in that population as well. In the April 11 issue of the New England Journal of Medicine, Dr. Egan and his colleagues report the full extent of verubecestat’s failure in prodromal patients, and the accompanying adverse events.

At the time of termination, 1,454 patients had been enrolled. Of these, 485 received 12 mg/day, 484 received 40 mg/day, and 485 received placebo. About half of each group completed 104 weeks of treatment in the study, which was designed to extend up to 5 years.

The primary outcome was change in the Clinical Dementia Rating Scale–Sum of Boxes score (CDR-SB). Seven secondary outcomes examined other cognitive and functional end points, along with changes in hippocampal volume on MRI and amyloid burden as determined in PET imaging.

Not only did verubecestat fail to slow cognitive decline, it appeared to exacerbate it. The mean change on the CDR-SB was 1.65 in the 12-mg group, 2.02 in the 40-mg group, and 1.58 in the placebo group, favoring placebo.

“In an exploratory analysis according to time point, scores on the CDR-SB were also higher [signifying more impairment of cognition and daily functioning] in the 40-mg group than in the placebo group at 13, 26, and 52 weeks ... suggesting but not confirming the possibility of worse performance at these earlier time points in the high-dose verubecestat group,” the investigators said.

Verubecestat also was associated with more conversions to Alzheimer’s disease. Per 100 patient-years, the Alzheimer’s disease event rates were 24.5 in the 12-mg group, 25.5 in the 40-mg group, and 19.3 in the placebo group. Compared with placebo, those taking 12-mg doses were 30% more likely to develop Alzheimer’s disease and those taking 40-mg doses were 38% more likely. The findings suggest that “verubecestat may have accelerated the progression to diagnosis of dementia due to Alzheimer’s disease,” the investigators said.

The negative impact of verubecestat was apparent quite early in the study. “In exploratory analyses, both dose levels of verubecestat were associated with poorer outcomes on the [Composite Cognition Score-3 Domain] and the ADAS-Cog [Alzheimer’s Disease Assessment Scale–Cognitive Subscale] measures of cognition that, relative to placebo, appeared worse at week 13 and did not appear to progress thereafter.”

Results of the secondary end points, including the ADAS-Cog and the Mini-Mental State Exam, also indicated that verubecestat may have worsened cognitive performance.

Imaging outcomes were positive, however. Hippocampal volume was 6,448 mL in the 12-mg group, 6,469 mL in the 40-mg group, and 6,435 mL in the placebo group. Brain amyloid increased in the placebo group, as expected, and decreased in the active groups. The small group of patients who underwent cerebrospinal fluid sampling showed reductions of more than 60% in amyloid-beta and soluble APP-beta associated with verubecestat. These results show that the molecule was indeed hitting its intended target, but that doing so was not clinically beneficial.

Adverse events were more common in the verubecestat groups. These included rash, dermatitis, urticaria, sleep disturbance, weight loss, and cough. Hair coloring changed in 2.5% of patients in the 12-mg group and 5% of the 40-mg group, but in none of the subjects taking placebo.

Patients taking verubecestat were more likely to sustain falls and injuries and to express suicidal ideation.

The results of this trial differ from the study of verubecestat in mild to moderate Alzheimer’s disease, the investigators noted. Those patients did not decline cognitively as did those with prodromal disease.

“Patients at an earlier stage of the disease may be more sensitive to the effects of substantial BACE-1 inhibition, perhaps because of a role of BACE-1 in normal synaptic function. It is also possible that the effects of verubecestat are due to inhibition of BACE-2,” they said.

Atabecestat

In a research letter in the same issue of the New England Journal of Medicine (2019 Apr 11;380:1483-5), David Henley, MD, senior director of Janssen’s Alzheimer’s clinical development core, released similarly negative results from an interim analysis of EARLY (Efficacy and Safety Study of Atabecestat in Participants Who Are Asymptomatic at Risk for Developing Alzheimer’s Dementia) trial, a randomized study of the BACE-1 inhibitor candidate, atabecestat.

The phase 2 trial enrolled 557 patients with prodromal Alzheimer’s disease. The primary cognitive end point was change from baseline in the Preclinical Alzheimer’s Cognitive Composite (PACC) score.

This trial was discontinued in May 2018 because of liver-related adverse events, although safety follow-up continues. The research letter did not disclose details of the hepatic events, but a company press release from May 2018 referred to them in a general sense.

“Elevations of liver enzymes, which were serious in nature, have been observed in some study participants who received the Janssen BACE inhibitor, atabecestat. After a thorough evaluation of all available liver safety data from our studies, Janssen has concluded that the benefit-risk ratio is no longer favorable to continue development of atabecestat for people who have late-onset preclinical stage Alzheimer’s disease.”

Patients in EARLY were randomized to 5 mg, 25 mg, or placebo. As in the verubecestat trial, those randomized to placebo did better. The mean changes from baseline in the PACC score were −1.44 in the 25-mg group, −0.58 in the 5-mg group, and −0.32 in the placebo group.

“At month 6, the difference between the 25-mg group and the placebo group was −1.12 and the difference between the 5-mg group and the placebo group was −0.26, favoring placebo over the higher dose,” the authors said.

This theme reemerged in a secondary end point, the Repeatable Battery for the Assessment of Neuropsychological Status. The 25-mg group declined 3.58 points more than placebo, and the 5-mg group, 1.43 points more.

Adverse events were more common in the active groups and included depression, effects on sleep and dreams, and anxiety.

“The differences in cognitive performance between the groups are of uncertain clinical significance; however, given similar findings favoring placebo over BACE-1 inhibitors in other trial, we are communicating this potential signal of worsening cognitive function in the treated groups,” Dr. Henley said.

[email protected]

SOURCE: Egan MF et al. N Engl J Med. 2019 Apr 11;380:1408-20.

More bad news for Alzheimer’s research. Two more BACE inhibitors fall far short of the finish line.

Not only did both verubecestat and atabecestat fail to improve cognition and function patients with prodromal Alzheimer’s disease, they also made things worse. Declining cognitive scores, falls, suicidal ideation, and liver enzyme abnormalities were all seen in clinical trials.

The news doesn’t bode well for the therapeutic target of BACE (beta-site APP cleaving enzyme) inhibition. BACE is one of the enzymes that trims the amyloid precursor protein (APP). Inhibiting it does reduce the amount of toxic amyloid-beta in cerebrospinal fluid, and amyloid plaque in the brain. But none of these molecules has shown clinical benefit in dementia patients, whether their disease is mild, or moderate or – now – prodromal. And it is now apparent that inhibiting BACE also produces serious off-target problems.

“BACE-1 inhibition certainly seemed to have a sound rationale assuming the basis for amyloid’s role in Alzheimer’s disease pathogenesis is a gain of toxicity,” Richard J. Caselli, MD, of the Mayo Clinic, Rochester, Minn., said in an interview. “That APP is important for Alzheimer’s pathogenesis still seems clear but whether amyloid-beta toxicity is the driving force is no longer clear. Further, interruption of the APP system disrupts more than amyloid-beta peptide, possibly explaining the adverse cognitive effects of BACE-1 inhibition shown exhibited now by three different BACE-1 inhibitors.”
 

Verubecestat

Researchers got their first dose of bad news regarding verubecestat at the 2017 Clinical Trials in Alzheimer’s Disease meeting. There, Michael F. Egan, MD, Merck’s associate vice president of clinical neuroscience, discussed the molecule’s failure to slow cognitive decline in patients with mild to moderate Alzheimer’s disease. There was plenty of biomarker evidence that the drug did block amyloid-beta production, but there also was a plethora of concerning adverse events, Dr. Egan said in an interview.

However, verubecestat still was being pursued in patients with prodromal Alzheimer’s disease. In February, Merck stopped the trial after a futility analysis and announced that the company was terminating studies of verubecestat in that population as well. In the April 11 issue of the New England Journal of Medicine, Dr. Egan and his colleagues report the full extent of verubecestat’s failure in prodromal patients, and the accompanying adverse events.

At the time of termination, 1,454 patients had been enrolled. Of these, 485 received 12 mg/day, 484 received 40 mg/day, and 485 received placebo. About half of each group completed 104 weeks of treatment in the study, which was designed to extend up to 5 years.

The primary outcome was change in the Clinical Dementia Rating Scale–Sum of Boxes score (CDR-SB). Seven secondary outcomes examined other cognitive and functional end points, along with changes in hippocampal volume on MRI and amyloid burden as determined in PET imaging.

Not only did verubecestat fail to slow cognitive decline, it appeared to exacerbate it. The mean change on the CDR-SB was 1.65 in the 12-mg group, 2.02 in the 40-mg group, and 1.58 in the placebo group, favoring placebo.

“In an exploratory analysis according to time point, scores on the CDR-SB were also higher [signifying more impairment of cognition and daily functioning] in the 40-mg group than in the placebo group at 13, 26, and 52 weeks ... suggesting but not confirming the possibility of worse performance at these earlier time points in the high-dose verubecestat group,” the investigators said.

Verubecestat also was associated with more conversions to Alzheimer’s disease. Per 100 patient-years, the Alzheimer’s disease event rates were 24.5 in the 12-mg group, 25.5 in the 40-mg group, and 19.3 in the placebo group. Compared with placebo, those taking 12-mg doses were 30% more likely to develop Alzheimer’s disease and those taking 40-mg doses were 38% more likely. The findings suggest that “verubecestat may have accelerated the progression to diagnosis of dementia due to Alzheimer’s disease,” the investigators said.

The negative impact of verubecestat was apparent quite early in the study. “In exploratory analyses, both dose levels of verubecestat were associated with poorer outcomes on the [Composite Cognition Score-3 Domain] and the ADAS-Cog [Alzheimer’s Disease Assessment Scale–Cognitive Subscale] measures of cognition that, relative to placebo, appeared worse at week 13 and did not appear to progress thereafter.”

Results of the secondary end points, including the ADAS-Cog and the Mini-Mental State Exam, also indicated that verubecestat may have worsened cognitive performance.

Imaging outcomes were positive, however. Hippocampal volume was 6,448 mL in the 12-mg group, 6,469 mL in the 40-mg group, and 6,435 mL in the placebo group. Brain amyloid increased in the placebo group, as expected, and decreased in the active groups. The small group of patients who underwent cerebrospinal fluid sampling showed reductions of more than 60% in amyloid-beta and soluble APP-beta associated with verubecestat. These results show that the molecule was indeed hitting its intended target, but that doing so was not clinically beneficial.

Adverse events were more common in the verubecestat groups. These included rash, dermatitis, urticaria, sleep disturbance, weight loss, and cough. Hair coloring changed in 2.5% of patients in the 12-mg group and 5% of the 40-mg group, but in none of the subjects taking placebo.

Patients taking verubecestat were more likely to sustain falls and injuries and to express suicidal ideation.

The results of this trial differ from the study of verubecestat in mild to moderate Alzheimer’s disease, the investigators noted. Those patients did not decline cognitively as did those with prodromal disease.

“Patients at an earlier stage of the disease may be more sensitive to the effects of substantial BACE-1 inhibition, perhaps because of a role of BACE-1 in normal synaptic function. It is also possible that the effects of verubecestat are due to inhibition of BACE-2,” they said.

Atabecestat

In a research letter in the same issue of the New England Journal of Medicine (2019 Apr 11;380:1483-5), David Henley, MD, senior director of Janssen’s Alzheimer’s clinical development core, released similarly negative results from an interim analysis of EARLY (Efficacy and Safety Study of Atabecestat in Participants Who Are Asymptomatic at Risk for Developing Alzheimer’s Dementia) trial, a randomized study of the BACE-1 inhibitor candidate, atabecestat.

The phase 2 trial enrolled 557 patients with prodromal Alzheimer’s disease. The primary cognitive end point was change from baseline in the Preclinical Alzheimer’s Cognitive Composite (PACC) score.

This trial was discontinued in May 2018 because of liver-related adverse events, although safety follow-up continues. The research letter did not disclose details of the hepatic events, but a company press release from May 2018 referred to them in a general sense.

“Elevations of liver enzymes, which were serious in nature, have been observed in some study participants who received the Janssen BACE inhibitor, atabecestat. After a thorough evaluation of all available liver safety data from our studies, Janssen has concluded that the benefit-risk ratio is no longer favorable to continue development of atabecestat for people who have late-onset preclinical stage Alzheimer’s disease.”

Patients in EARLY were randomized to 5 mg, 25 mg, or placebo. As in the verubecestat trial, those randomized to placebo did better. The mean changes from baseline in the PACC score were −1.44 in the 25-mg group, −0.58 in the 5-mg group, and −0.32 in the placebo group.

“At month 6, the difference between the 25-mg group and the placebo group was −1.12 and the difference between the 5-mg group and the placebo group was −0.26, favoring placebo over the higher dose,” the authors said.

This theme reemerged in a secondary end point, the Repeatable Battery for the Assessment of Neuropsychological Status. The 25-mg group declined 3.58 points more than placebo, and the 5-mg group, 1.43 points more.

Adverse events were more common in the active groups and included depression, effects on sleep and dreams, and anxiety.

“The differences in cognitive performance between the groups are of uncertain clinical significance; however, given similar findings favoring placebo over BACE-1 inhibitors in other trial, we are communicating this potential signal of worsening cognitive function in the treated groups,” Dr. Henley said.

[email protected]

SOURCE: Egan MF et al. N Engl J Med. 2019 Apr 11;380:1408-20.

More bad news for Alzheimer’s research. Two more BACE inhibitors fall far short of the finish line.

Not only did both verubecestat and atabecestat fail to improve cognition and function patients with prodromal Alzheimer’s disease, they also made things worse. Declining cognitive scores, falls, suicidal ideation, and liver enzyme abnormalities were all seen in clinical trials.

The news doesn’t bode well for the therapeutic target of BACE (beta-site APP cleaving enzyme) inhibition. BACE is one of the enzymes that trims the amyloid precursor protein (APP). Inhibiting it does reduce the amount of toxic amyloid-beta in cerebrospinal fluid, and amyloid plaque in the brain. But none of these molecules has shown clinical benefit in dementia patients, whether their disease is mild, or moderate or – now – prodromal. And it is now apparent that inhibiting BACE also produces serious off-target problems.

“BACE-1 inhibition certainly seemed to have a sound rationale assuming the basis for amyloid’s role in Alzheimer’s disease pathogenesis is a gain of toxicity,” Richard J. Caselli, MD, of the Mayo Clinic, Rochester, Minn., said in an interview. “That APP is important for Alzheimer’s pathogenesis still seems clear but whether amyloid-beta toxicity is the driving force is no longer clear. Further, interruption of the APP system disrupts more than amyloid-beta peptide, possibly explaining the adverse cognitive effects of BACE-1 inhibition shown exhibited now by three different BACE-1 inhibitors.”
 

Verubecestat

Researchers got their first dose of bad news regarding verubecestat at the 2017 Clinical Trials in Alzheimer’s Disease meeting. There, Michael F. Egan, MD, Merck’s associate vice president of clinical neuroscience, discussed the molecule’s failure to slow cognitive decline in patients with mild to moderate Alzheimer’s disease. There was plenty of biomarker evidence that the drug did block amyloid-beta production, but there also was a plethora of concerning adverse events, Dr. Egan said in an interview.

However, verubecestat still was being pursued in patients with prodromal Alzheimer’s disease. In February, Merck stopped the trial after a futility analysis and announced that the company was terminating studies of verubecestat in that population as well. In the April 11 issue of the New England Journal of Medicine, Dr. Egan and his colleagues report the full extent of verubecestat’s failure in prodromal patients, and the accompanying adverse events.

At the time of termination, 1,454 patients had been enrolled. Of these, 485 received 12 mg/day, 484 received 40 mg/day, and 485 received placebo. About half of each group completed 104 weeks of treatment in the study, which was designed to extend up to 5 years.

The primary outcome was change in the Clinical Dementia Rating Scale–Sum of Boxes score (CDR-SB). Seven secondary outcomes examined other cognitive and functional end points, along with changes in hippocampal volume on MRI and amyloid burden as determined in PET imaging.

Not only did verubecestat fail to slow cognitive decline, it appeared to exacerbate it. The mean change on the CDR-SB was 1.65 in the 12-mg group, 2.02 in the 40-mg group, and 1.58 in the placebo group, favoring placebo.

“In an exploratory analysis according to time point, scores on the CDR-SB were also higher [signifying more impairment of cognition and daily functioning] in the 40-mg group than in the placebo group at 13, 26, and 52 weeks ... suggesting but not confirming the possibility of worse performance at these earlier time points in the high-dose verubecestat group,” the investigators said.

Verubecestat also was associated with more conversions to Alzheimer’s disease. Per 100 patient-years, the Alzheimer’s disease event rates were 24.5 in the 12-mg group, 25.5 in the 40-mg group, and 19.3 in the placebo group. Compared with placebo, those taking 12-mg doses were 30% more likely to develop Alzheimer’s disease and those taking 40-mg doses were 38% more likely. The findings suggest that “verubecestat may have accelerated the progression to diagnosis of dementia due to Alzheimer’s disease,” the investigators said.

The negative impact of verubecestat was apparent quite early in the study. “In exploratory analyses, both dose levels of verubecestat were associated with poorer outcomes on the [Composite Cognition Score-3 Domain] and the ADAS-Cog [Alzheimer’s Disease Assessment Scale–Cognitive Subscale] measures of cognition that, relative to placebo, appeared worse at week 13 and did not appear to progress thereafter.”

Results of the secondary end points, including the ADAS-Cog and the Mini-Mental State Exam, also indicated that verubecestat may have worsened cognitive performance.

Imaging outcomes were positive, however. Hippocampal volume was 6,448 mL in the 12-mg group, 6,469 mL in the 40-mg group, and 6,435 mL in the placebo group. Brain amyloid increased in the placebo group, as expected, and decreased in the active groups. The small group of patients who underwent cerebrospinal fluid sampling showed reductions of more than 60% in amyloid-beta and soluble APP-beta associated with verubecestat. These results show that the molecule was indeed hitting its intended target, but that doing so was not clinically beneficial.

Adverse events were more common in the verubecestat groups. These included rash, dermatitis, urticaria, sleep disturbance, weight loss, and cough. Hair coloring changed in 2.5% of patients in the 12-mg group and 5% of the 40-mg group, but in none of the subjects taking placebo.

Patients taking verubecestat were more likely to sustain falls and injuries and to express suicidal ideation.

The results of this trial differ from the study of verubecestat in mild to moderate Alzheimer’s disease, the investigators noted. Those patients did not decline cognitively as did those with prodromal disease.

“Patients at an earlier stage of the disease may be more sensitive to the effects of substantial BACE-1 inhibition, perhaps because of a role of BACE-1 in normal synaptic function. It is also possible that the effects of verubecestat are due to inhibition of BACE-2,” they said.

Atabecestat

In a research letter in the same issue of the New England Journal of Medicine (2019 Apr 11;380:1483-5), David Henley, MD, senior director of Janssen’s Alzheimer’s clinical development core, released similarly negative results from an interim analysis of EARLY (Efficacy and Safety Study of Atabecestat in Participants Who Are Asymptomatic at Risk for Developing Alzheimer’s Dementia) trial, a randomized study of the BACE-1 inhibitor candidate, atabecestat.

The phase 2 trial enrolled 557 patients with prodromal Alzheimer’s disease. The primary cognitive end point was change from baseline in the Preclinical Alzheimer’s Cognitive Composite (PACC) score.

This trial was discontinued in May 2018 because of liver-related adverse events, although safety follow-up continues. The research letter did not disclose details of the hepatic events, but a company press release from May 2018 referred to them in a general sense.

“Elevations of liver enzymes, which were serious in nature, have been observed in some study participants who received the Janssen BACE inhibitor, atabecestat. After a thorough evaluation of all available liver safety data from our studies, Janssen has concluded that the benefit-risk ratio is no longer favorable to continue development of atabecestat for people who have late-onset preclinical stage Alzheimer’s disease.”

Patients in EARLY were randomized to 5 mg, 25 mg, or placebo. As in the verubecestat trial, those randomized to placebo did better. The mean changes from baseline in the PACC score were −1.44 in the 25-mg group, −0.58 in the 5-mg group, and −0.32 in the placebo group.

“At month 6, the difference between the 25-mg group and the placebo group was −1.12 and the difference between the 5-mg group and the placebo group was −0.26, favoring placebo over the higher dose,” the authors said.

This theme reemerged in a secondary end point, the Repeatable Battery for the Assessment of Neuropsychological Status. The 25-mg group declined 3.58 points more than placebo, and the 5-mg group, 1.43 points more.

Adverse events were more common in the active groups and included depression, effects on sleep and dreams, and anxiety.

“The differences in cognitive performance between the groups are of uncertain clinical significance; however, given similar findings favoring placebo over BACE-1 inhibitors in other trial, we are communicating this potential signal of worsening cognitive function in the treated groups,” Dr. Henley said.

[email protected]

SOURCE: Egan MF et al. N Engl J Med. 2019 Apr 11;380:1408-20.

The Food and Drug Administration is making changes to opioid analgesic labeling to give better information to clinicians on how to properly taper patients dependent on opioid use, according to Douglas Throckmorton, MD, deputy director for regulatory programs in the FDA’s Center for Drug Evaluation and Research.

Wikimedia Commons/FitzColinGerald/Creative Commons License

The FDA has recently received reports that patients physically dependent on opioid pain medicines who are taken off their medication too quickly have experienced serious adverse events, such as withdrawal symptoms, uncontrolled pain, and suicide. Both the FDA and the Centers for Disease Control and Prevention offer guidelines on how to properly taper opioids, Dr. Throckmorton said, but more needs to be done to ensure that patients are being provided with the correct advice and care.

The changes to the labels will include expanded information to health care clinicians and are intended to be used when both the clinician and patient have agreed to reduce the opioid dosage. When this is discussed, factors that should be considered include the dose of the drug, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient.

Other actions the FDA is pursuing to combat opioid use disorder include working with the National Academies of Sciences, Engineering, and Medicine on guidelines for the proper opioid analgesic prescribing for acute pain resulting from specific conditions or procedures, and advancing policies that make immediate-release opioid formulations available in fixed-quantity packaging for 1 or 2 days.

“The FDA remains committed to addressing the opioid crisis on all fronts, with a significant focus on decreasing unnecessary exposure to opioids and preventing new addiction; supporting the treatment of those with opioid use disorder; fostering the development of novel pain treatment therapies and opioids more resistant to abuse and misuse; and taking action against those involved in the illegal importation and sale of opioids,” Dr. Throckmorton said.

Find the full statement by Dr. Throckmorton on the FDA website.

[email protected]

The Food and Drug Administration is making changes to opioid analgesic labeling to give better information to clinicians on how to properly taper patients dependent on opioid use, according to Douglas Throckmorton, MD, deputy director for regulatory programs in the FDA’s Center for Drug Evaluation and Research.

Wikimedia Commons/FitzColinGerald/Creative Commons License

The FDA has recently received reports that patients physically dependent on opioid pain medicines who are taken off their medication too quickly have experienced serious adverse events, such as withdrawal symptoms, uncontrolled pain, and suicide. Both the FDA and the Centers for Disease Control and Prevention offer guidelines on how to properly taper opioids, Dr. Throckmorton said, but more needs to be done to ensure that patients are being provided with the correct advice and care.

The changes to the labels will include expanded information to health care clinicians and are intended to be used when both the clinician and patient have agreed to reduce the opioid dosage. When this is discussed, factors that should be considered include the dose of the drug, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient.

Other actions the FDA is pursuing to combat opioid use disorder include working with the National Academies of Sciences, Engineering, and Medicine on guidelines for the proper opioid analgesic prescribing for acute pain resulting from specific conditions or procedures, and advancing policies that make immediate-release opioid formulations available in fixed-quantity packaging for 1 or 2 days.

“The FDA remains committed to addressing the opioid crisis on all fronts, with a significant focus on decreasing unnecessary exposure to opioids and preventing new addiction; supporting the treatment of those with opioid use disorder; fostering the development of novel pain treatment therapies and opioids more resistant to abuse and misuse; and taking action against those involved in the illegal importation and sale of opioids,” Dr. Throckmorton said.

Find the full statement by Dr. Throckmorton on the FDA website.

[email protected]

The Food and Drug Administration is making changes to opioid analgesic labeling to give better information to clinicians on how to properly taper patients dependent on opioid use, according to Douglas Throckmorton, MD, deputy director for regulatory programs in the FDA’s Center for Drug Evaluation and Research.

Wikimedia Commons/FitzColinGerald/Creative Commons License

The FDA has recently received reports that patients physically dependent on opioid pain medicines who are taken off their medication too quickly have experienced serious adverse events, such as withdrawal symptoms, uncontrolled pain, and suicide. Both the FDA and the Centers for Disease Control and Prevention offer guidelines on how to properly taper opioids, Dr. Throckmorton said, but more needs to be done to ensure that patients are being provided with the correct advice and care.

The changes to the labels will include expanded information to health care clinicians and are intended to be used when both the clinician and patient have agreed to reduce the opioid dosage. When this is discussed, factors that should be considered include the dose of the drug, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient.

Other actions the FDA is pursuing to combat opioid use disorder include working with the National Academies of Sciences, Engineering, and Medicine on guidelines for the proper opioid analgesic prescribing for acute pain resulting from specific conditions or procedures, and advancing policies that make immediate-release opioid formulations available in fixed-quantity packaging for 1 or 2 days.

“The FDA remains committed to addressing the opioid crisis on all fronts, with a significant focus on decreasing unnecessary exposure to opioids and preventing new addiction; supporting the treatment of those with opioid use disorder; fostering the development of novel pain treatment therapies and opioids more resistant to abuse and misuse; and taking action against those involved in the illegal importation and sale of opioids,” Dr. Throckmorton said.

Find the full statement by Dr. Throckmorton on the FDA website.

[email protected]

Altered mental status (AMS) is a common presentation to the emergency department (ED) for older patients and is often due to underlying drug-associated adverse effects (AEs), medical or psychiatric illness, or neurologic disease. EDs often have protocols for diagnosing and managing AMS to assess the underlying etiology. A formal assessment with a full history and physical examination is paramount to diagnosing the cause of AMS.

Oral metronidazole is a commonly used antibiotic for anaerobic bacterial infections and Clostridium difficile-associated diarrhea and colitis.¹Metronidazole produces cytotoxic intermediates that cause DNA strand breakage and destabilization, resulting in bactericidal activity in host cells.²Common AEs include gastrointestinal symptoms such as nausea, vomiting, and diarrhea; less common AEs can involve the nervous system and include seizures, peripheral neuropathy, dizziness, ataxia, and encephalopathy.^3,4A pattern of magnetic resonance image (MRI) abnormalities typically located at the cerebellar dentate nucleus midbrain, dorsal pons, medulla, and splenium of the corpus callosum have been associated with metronidazole usage.⁵

Hyperbaric oxygen therapy (HBOT) is a treatment modality used as the primary therapy for decompression sickness, arterial gas embolism, and carbon monoxide poisoning. HBOT is used as adjuvant therapy for osteonecrosis caused by radiation or bisphosphonate use.^6,7 HBOT increases the partial pressure of oxygen in plasma and increases the amount of oxygen delivered to tissues throughout the body.⁸Hyperoxia, defined as an elevated partial pressure of oxygen leading to excess oxygenation to tissues and organs, increases production of reactive oxygen and nitrogen species, which are signaling factors in a variety of pathways that stimulate angiogenesis.⁸ AEs of HBOT include barotrauma-related injuries and oxygen toxicity, such as respiratory distress or central nervous system (CNS) symptoms.⁹ Severe CNS AEs occur in 1% to 2% of patients undergoing therapy and manifest as generalized tonic-clonic seizures, typically in patients with preexisting neurologic disorders, brain injury, or lowered seizure threshold.^7,8,10 There have been no documented incidences of HBOT inducing acute encephalopathy.

Case Presentation

A 63-year-old male smoker with no history of alcohol use presented to the ED with an acute onset of lightheadedness, confusion, and poor coordination following his second HBOT for radiation-induced osteonecrosis of the mandible. The patient reported chronic, slowly progressive pain and numbness of the feet that began 4 years earlier. He noted marked worsening of pain and difficulty standing and walking 3 to 4 months prior to presentation.

Ten years prior, the patient was diagnosed with cancer of the right tonsil. A tonsillectomy with wide margins was performed, followed by 35 rounds of radiation treatment and 2 rounds of chemotherapy with cisplatin.

In May 2017, the patient presented with a lump in the right cheek that was diagnosed as osteonecrosis of the mandible. An oral surgeon prescribed metronidazole 500 mg qid and amoxicillin 500 mg tid. The patient was adherent until presentation in November 2017. Following lack of improvement of the osteonecrosis from antibiotic therapy, oral surgery was planned, and the patient was referred for HBOT with a planned 20 HBOT preoperative treatments and 10 postoperative treatments.

Following his first 2-hour HBOT treatment on November 13, 2017, the patient complained of light-headedness, confusion, and incoordination. While driving on a familiar route to his home, he collided with a tree that was 6 feet from the curb. The patient attempted to drive another vehicle later that day, resulting in a second motor vehicle accident. There was no significant injury reported in either accident.

His partner described the patient’s episode of disorientation lasting 6 to 8 hours, during which he “looked drunk” and was unable to sit in a chair without falling. The following morning, the patient had improved mental status but had not returned to baseline. His second HBOT treatment took place that day, and again, the patient acutely experienced light-headedness and confusion following completion. Therapy was suspended, and the patient was referred to the ED for further evaluation. Mild facial asymmetry without weakness, decreased sensation from toes to knees bilaterally, and absent Achilles reflexes bilaterally were found on neurologic examination. He exhibited past-pointing on finger-to-nose testing bilaterally. He was able to ambulate independently, but he could not perform tandem gait.

An MRI of the brain showed abnormal T2 hyperintensity found bilaterally at the dentate nuclei and inferior colliculi. The splenium of the corpus callosum also showed mild involvement with hyperintense lesions. Laboratory tests of the patient’s complete blood count; comprehensive metabolic panel; vitamins B₁, B₆, B₁₂; and folic acid levels had no notable abnormalities and were within normal limits.

Metronidazole and HBOT therapy were discontinued, and all of the patient’s symptoms resolved within 2 weeks. A repeat examination and MRI performed 1 month later showed resolution of all the patient’s clinical findings and MRI abnormalities. HBOT was resumed without the recurrence of previously described symptoms.

Discussion

This patient’s encephalopathic symptoms correlate temporally with the onset of HBOT. There is no medical literature suggesting a relationship between HBOT and encephalopathic symptoms with MRI abnormalities, and in fact, some studies suggest HBOT as a treatment for hypoxic-ischemic encephalopathy in neonates.¹¹ This led us to believe that the HBOT may have exacerbated some underlying condition, evidenced by the specific MRI findings of T2 fluid-attenuated inversion recovery (FLAIR) hyperintensities in the dentate nuclei and inferior colliculi (Figures 1 and 2). 

Differential diagnoses for T2 hyperintense lesions in the dentate nuclei include metronidazole toxicity, acute Wernicke encephalopathy (WE), and methyl bromide intoxication. Diseases that would have presented in infancy with similar MRI findings (Canavan disease, maple-syrup urine disease, and glutaric aciduria type 1) were not considered plausible.^12-14 

Despite his denial of alcohol use, the patient was at risk for malnutrition secondary to his mandibular lesion and difficulty eating. Clinically, he presented with episodes of confusion and ataxia, consistent with 2 of the classic triad of symptoms of WE (no ocular abnormalities noted on exam). Typical MRI findings in WE include signal intensity alterations (including T2 hyperintensities) in the medial thalami, mammillary bodies, collicular bodies, and periaqueductal and periventricular regions.^14,15 Atypical MRI findings in WE include symmetric signal intensity changes in the cerebellum, dentate nuclei, caudate nuclei, red nuclei, cranial nerve nuclei, and splenium.¹⁴ Of note, atypical MRI findings were more common in patients without alcohol use disorders and WE, and typical MRI findings were more common in patients with alcohol use disorders.¹⁴ However, this patient’s report of no alcohol use and the serum thiamine level being within normal limits (173 nmol/L; range 78-185 nmol/L) made acute WE less likely than metronidonazale-induced encephalopathy (MIE).

The most common neurologic AE of metronidazole is distal symmetric sensory polyneuropathy, which also can have motor or autonomic features.^16,17 While our patient had a history of peripheral neuropathy, he noted marked worsening of foot pain 3 months after initiating metronidazole therapy. A potential mechanism involves metronidazole or its cytotoxic intermediates binding neuronal ribonucleic acids, thus inhibiting protein synthesis and resulting in degenerative neuronal changes and reversible axonal swelling (as opposed to the DNA interference attributed to the drug’s mechanism of bactericidal action).¹⁸ Neuropathies may result from prolonged high-dose metronidazole therapy (cumulative dose > 42 g),³ but they also have been seen in short-term use of high dosages.¹⁷

CNS AEs are much rarer and are thought to be associated with metronidazole’s ability to cross the blood-brain barrier. These patients present as a toxic encephalopathy with cerebellar dysfunction (dysarthria, ataxia) as the most common presentation, followed by AMS and seizures.⁴ Our patient presented with acute confusion and ataxia. Animal studies suggest that γ-aminobutyric acid (GABA) receptor modulation in the cerebellar and vestibular systems may contribute to this neurotoxicity, but no definitive mechanism of injury has been found.¹⁹

On MRI, MIE most commonly presents with hyperintense lesions in the bilateral cerebellar dentate nucleus on T2-weighted and FLAIR images.^5,20 The midbrain, dorsal pons, medulla, and corpus callosum also can show increased signal intensity.⁵ This AE does not seem to be dose- or duration-dependent, and most cases report complete or partial resolution of symptoms following discontinuation of the drug, though this is not absolute.^4,13,21 The patient’s MRI findings were highly consistent with MIE (Figure 2).

Conclusion

This patient’s highly specific MRI findings, neurologic examination consistent with confusion, ataxia, length-dependent sensory neuropathy, and 360-g cumulative dose of metronidazole over the previous 6 months suggest he experienced MIE. The mechanism of how HBOT precipitated the patient’s altered mental status, incoordination, and worsening of peripheral neuropathy is unknown. Although encephalopathy with MRI abnormalities as described is not a reported AE of HBOT, it may be unrecognized. It is possible that without HBOT the patient would have remained asymptomatic apart from his peripheral neuropathy.

We propose HBOT may exacerbate or increase the risk of a patient developing MIE. Our patient was able to safely resume HBOT after metronidazole was discontinued, suggesting that the combination was the causation for the development of encephalopathy. We do not believe any similar cases have been reported.

Altered mental status (AMS) is a common presentation to the emergency department (ED) for older patients and is often due to underlying drug-associated adverse effects (AEs), medical or psychiatric illness, or neurologic disease. EDs often have protocols for diagnosing and managing AMS to assess the underlying etiology. A formal assessment with a full history and physical examination is paramount to diagnosing the cause of AMS.

Oral metronidazole is a commonly used antibiotic for anaerobic bacterial infections and Clostridium difficile-associated diarrhea and colitis.¹Metronidazole produces cytotoxic intermediates that cause DNA strand breakage and destabilization, resulting in bactericidal activity in host cells.²Common AEs include gastrointestinal symptoms such as nausea, vomiting, and diarrhea; less common AEs can involve the nervous system and include seizures, peripheral neuropathy, dizziness, ataxia, and encephalopathy.^3,4A pattern of magnetic resonance image (MRI) abnormalities typically located at the cerebellar dentate nucleus midbrain, dorsal pons, medulla, and splenium of the corpus callosum have been associated with metronidazole usage.⁵

Hyperbaric oxygen therapy (HBOT) is a treatment modality used as the primary therapy for decompression sickness, arterial gas embolism, and carbon monoxide poisoning. HBOT is used as adjuvant therapy for osteonecrosis caused by radiation or bisphosphonate use.^6,7 HBOT increases the partial pressure of oxygen in plasma and increases the amount of oxygen delivered to tissues throughout the body.⁸Hyperoxia, defined as an elevated partial pressure of oxygen leading to excess oxygenation to tissues and organs, increases production of reactive oxygen and nitrogen species, which are signaling factors in a variety of pathways that stimulate angiogenesis.⁸ AEs of HBOT include barotrauma-related injuries and oxygen toxicity, such as respiratory distress or central nervous system (CNS) symptoms.⁹ Severe CNS AEs occur in 1% to 2% of patients undergoing therapy and manifest as generalized tonic-clonic seizures, typically in patients with preexisting neurologic disorders, brain injury, or lowered seizure threshold.^7,8,10 There have been no documented incidences of HBOT inducing acute encephalopathy.

Case Presentation

A 63-year-old male smoker with no history of alcohol use presented to the ED with an acute onset of lightheadedness, confusion, and poor coordination following his second HBOT for radiation-induced osteonecrosis of the mandible. The patient reported chronic, slowly progressive pain and numbness of the feet that began 4 years earlier. He noted marked worsening of pain and difficulty standing and walking 3 to 4 months prior to presentation.

Ten years prior, the patient was diagnosed with cancer of the right tonsil. A tonsillectomy with wide margins was performed, followed by 35 rounds of radiation treatment and 2 rounds of chemotherapy with cisplatin.

In May 2017, the patient presented with a lump in the right cheek that was diagnosed as osteonecrosis of the mandible. An oral surgeon prescribed metronidazole 500 mg qid and amoxicillin 500 mg tid. The patient was adherent until presentation in November 2017. Following lack of improvement of the osteonecrosis from antibiotic therapy, oral surgery was planned, and the patient was referred for HBOT with a planned 20 HBOT preoperative treatments and 10 postoperative treatments.

Following his first 2-hour HBOT treatment on November 13, 2017, the patient complained of light-headedness, confusion, and incoordination. While driving on a familiar route to his home, he collided with a tree that was 6 feet from the curb. The patient attempted to drive another vehicle later that day, resulting in a second motor vehicle accident. There was no significant injury reported in either accident.

His partner described the patient’s episode of disorientation lasting 6 to 8 hours, during which he “looked drunk” and was unable to sit in a chair without falling. The following morning, the patient had improved mental status but had not returned to baseline. His second HBOT treatment took place that day, and again, the patient acutely experienced light-headedness and confusion following completion. Therapy was suspended, and the patient was referred to the ED for further evaluation. Mild facial asymmetry without weakness, decreased sensation from toes to knees bilaterally, and absent Achilles reflexes bilaterally were found on neurologic examination. He exhibited past-pointing on finger-to-nose testing bilaterally. He was able to ambulate independently, but he could not perform tandem gait.

An MRI of the brain showed abnormal T2 hyperintensity found bilaterally at the dentate nuclei and inferior colliculi. The splenium of the corpus callosum also showed mild involvement with hyperintense lesions. Laboratory tests of the patient’s complete blood count; comprehensive metabolic panel; vitamins B₁, B₆, B₁₂; and folic acid levels had no notable abnormalities and were within normal limits.

Metronidazole and HBOT therapy were discontinued, and all of the patient’s symptoms resolved within 2 weeks. A repeat examination and MRI performed 1 month later showed resolution of all the patient’s clinical findings and MRI abnormalities. HBOT was resumed without the recurrence of previously described symptoms.

Discussion

This patient’s encephalopathic symptoms correlate temporally with the onset of HBOT. There is no medical literature suggesting a relationship between HBOT and encephalopathic symptoms with MRI abnormalities, and in fact, some studies suggest HBOT as a treatment for hypoxic-ischemic encephalopathy in neonates.¹¹ This led us to believe that the HBOT may have exacerbated some underlying condition, evidenced by the specific MRI findings of T2 fluid-attenuated inversion recovery (FLAIR) hyperintensities in the dentate nuclei and inferior colliculi (Figures 1 and 2). 

Differential diagnoses for T2 hyperintense lesions in the dentate nuclei include metronidazole toxicity, acute Wernicke encephalopathy (WE), and methyl bromide intoxication. Diseases that would have presented in infancy with similar MRI findings (Canavan disease, maple-syrup urine disease, and glutaric aciduria type 1) were not considered plausible.^12-14 

Despite his denial of alcohol use, the patient was at risk for malnutrition secondary to his mandibular lesion and difficulty eating. Clinically, he presented with episodes of confusion and ataxia, consistent with 2 of the classic triad of symptoms of WE (no ocular abnormalities noted on exam). Typical MRI findings in WE include signal intensity alterations (including T2 hyperintensities) in the medial thalami, mammillary bodies, collicular bodies, and periaqueductal and periventricular regions.^14,15 Atypical MRI findings in WE include symmetric signal intensity changes in the cerebellum, dentate nuclei, caudate nuclei, red nuclei, cranial nerve nuclei, and splenium.¹⁴ Of note, atypical MRI findings were more common in patients without alcohol use disorders and WE, and typical MRI findings were more common in patients with alcohol use disorders.¹⁴ However, this patient’s report of no alcohol use and the serum thiamine level being within normal limits (173 nmol/L; range 78-185 nmol/L) made acute WE less likely than metronidonazale-induced encephalopathy (MIE).

The most common neurologic AE of metronidazole is distal symmetric sensory polyneuropathy, which also can have motor or autonomic features.^16,17 While our patient had a history of peripheral neuropathy, he noted marked worsening of foot pain 3 months after initiating metronidazole therapy. A potential mechanism involves metronidazole or its cytotoxic intermediates binding neuronal ribonucleic acids, thus inhibiting protein synthesis and resulting in degenerative neuronal changes and reversible axonal swelling (as opposed to the DNA interference attributed to the drug’s mechanism of bactericidal action).¹⁸ Neuropathies may result from prolonged high-dose metronidazole therapy (cumulative dose > 42 g),³ but they also have been seen in short-term use of high dosages.¹⁷

CNS AEs are much rarer and are thought to be associated with metronidazole’s ability to cross the blood-brain barrier. These patients present as a toxic encephalopathy with cerebellar dysfunction (dysarthria, ataxia) as the most common presentation, followed by AMS and seizures.⁴ Our patient presented with acute confusion and ataxia. Animal studies suggest that γ-aminobutyric acid (GABA) receptor modulation in the cerebellar and vestibular systems may contribute to this neurotoxicity, but no definitive mechanism of injury has been found.¹⁹

On MRI, MIE most commonly presents with hyperintense lesions in the bilateral cerebellar dentate nucleus on T2-weighted and FLAIR images.^5,20 The midbrain, dorsal pons, medulla, and corpus callosum also can show increased signal intensity.⁵ This AE does not seem to be dose- or duration-dependent, and most cases report complete or partial resolution of symptoms following discontinuation of the drug, though this is not absolute.^4,13,21 The patient’s MRI findings were highly consistent with MIE (Figure 2).

Conclusion

This patient’s highly specific MRI findings, neurologic examination consistent with confusion, ataxia, length-dependent sensory neuropathy, and 360-g cumulative dose of metronidazole over the previous 6 months suggest he experienced MIE. The mechanism of how HBOT precipitated the patient’s altered mental status, incoordination, and worsening of peripheral neuropathy is unknown. Although encephalopathy with MRI abnormalities as described is not a reported AE of HBOT, it may be unrecognized. It is possible that without HBOT the patient would have remained asymptomatic apart from his peripheral neuropathy.

We propose HBOT may exacerbate or increase the risk of a patient developing MIE. Our patient was able to safely resume HBOT after metronidazole was discontinued, suggesting that the combination was the causation for the development of encephalopathy. We do not believe any similar cases have been reported.

Altered mental status (AMS) is a common presentation to the emergency department (ED) for older patients and is often due to underlying drug-associated adverse effects (AEs), medical or psychiatric illness, or neurologic disease. EDs often have protocols for diagnosing and managing AMS to assess the underlying etiology. A formal assessment with a full history and physical examination is paramount to diagnosing the cause of AMS.

Oral metronidazole is a commonly used antibiotic for anaerobic bacterial infections and Clostridium difficile-associated diarrhea and colitis.¹Metronidazole produces cytotoxic intermediates that cause DNA strand breakage and destabilization, resulting in bactericidal activity in host cells.²Common AEs include gastrointestinal symptoms such as nausea, vomiting, and diarrhea; less common AEs can involve the nervous system and include seizures, peripheral neuropathy, dizziness, ataxia, and encephalopathy.^3,4A pattern of magnetic resonance image (MRI) abnormalities typically located at the cerebellar dentate nucleus midbrain, dorsal pons, medulla, and splenium of the corpus callosum have been associated with metronidazole usage.⁵

Hyperbaric oxygen therapy (HBOT) is a treatment modality used as the primary therapy for decompression sickness, arterial gas embolism, and carbon monoxide poisoning. HBOT is used as adjuvant therapy for osteonecrosis caused by radiation or bisphosphonate use.^6,7 HBOT increases the partial pressure of oxygen in plasma and increases the amount of oxygen delivered to tissues throughout the body.⁸Hyperoxia, defined as an elevated partial pressure of oxygen leading to excess oxygenation to tissues and organs, increases production of reactive oxygen and nitrogen species, which are signaling factors in a variety of pathways that stimulate angiogenesis.⁸ AEs of HBOT include barotrauma-related injuries and oxygen toxicity, such as respiratory distress or central nervous system (CNS) symptoms.⁹ Severe CNS AEs occur in 1% to 2% of patients undergoing therapy and manifest as generalized tonic-clonic seizures, typically in patients with preexisting neurologic disorders, brain injury, or lowered seizure threshold.^7,8,10 There have been no documented incidences of HBOT inducing acute encephalopathy.

Case Presentation

A 63-year-old male smoker with no history of alcohol use presented to the ED with an acute onset of lightheadedness, confusion, and poor coordination following his second HBOT for radiation-induced osteonecrosis of the mandible. The patient reported chronic, slowly progressive pain and numbness of the feet that began 4 years earlier. He noted marked worsening of pain and difficulty standing and walking 3 to 4 months prior to presentation.

Ten years prior, the patient was diagnosed with cancer of the right tonsil. A tonsillectomy with wide margins was performed, followed by 35 rounds of radiation treatment and 2 rounds of chemotherapy with cisplatin.

In May 2017, the patient presented with a lump in the right cheek that was diagnosed as osteonecrosis of the mandible. An oral surgeon prescribed metronidazole 500 mg qid and amoxicillin 500 mg tid. The patient was adherent until presentation in November 2017. Following lack of improvement of the osteonecrosis from antibiotic therapy, oral surgery was planned, and the patient was referred for HBOT with a planned 20 HBOT preoperative treatments and 10 postoperative treatments.

Following his first 2-hour HBOT treatment on November 13, 2017, the patient complained of light-headedness, confusion, and incoordination. While driving on a familiar route to his home, he collided with a tree that was 6 feet from the curb. The patient attempted to drive another vehicle later that day, resulting in a second motor vehicle accident. There was no significant injury reported in either accident.

His partner described the patient’s episode of disorientation lasting 6 to 8 hours, during which he “looked drunk” and was unable to sit in a chair without falling. The following morning, the patient had improved mental status but had not returned to baseline. His second HBOT treatment took place that day, and again, the patient acutely experienced light-headedness and confusion following completion. Therapy was suspended, and the patient was referred to the ED for further evaluation. Mild facial asymmetry without weakness, decreased sensation from toes to knees bilaterally, and absent Achilles reflexes bilaterally were found on neurologic examination. He exhibited past-pointing on finger-to-nose testing bilaterally. He was able to ambulate independently, but he could not perform tandem gait.

An MRI of the brain showed abnormal T2 hyperintensity found bilaterally at the dentate nuclei and inferior colliculi. The splenium of the corpus callosum also showed mild involvement with hyperintense lesions. Laboratory tests of the patient’s complete blood count; comprehensive metabolic panel; vitamins B₁, B₆, B₁₂; and folic acid levels had no notable abnormalities and were within normal limits.

Metronidazole and HBOT therapy were discontinued, and all of the patient’s symptoms resolved within 2 weeks. A repeat examination and MRI performed 1 month later showed resolution of all the patient’s clinical findings and MRI abnormalities. HBOT was resumed without the recurrence of previously described symptoms.

Discussion

This patient’s encephalopathic symptoms correlate temporally with the onset of HBOT. There is no medical literature suggesting a relationship between HBOT and encephalopathic symptoms with MRI abnormalities, and in fact, some studies suggest HBOT as a treatment for hypoxic-ischemic encephalopathy in neonates.¹¹ This led us to believe that the HBOT may have exacerbated some underlying condition, evidenced by the specific MRI findings of T2 fluid-attenuated inversion recovery (FLAIR) hyperintensities in the dentate nuclei and inferior colliculi (Figures 1 and 2). 

Differential diagnoses for T2 hyperintense lesions in the dentate nuclei include metronidazole toxicity, acute Wernicke encephalopathy (WE), and methyl bromide intoxication. Diseases that would have presented in infancy with similar MRI findings (Canavan disease, maple-syrup urine disease, and glutaric aciduria type 1) were not considered plausible.^12-14 

Despite his denial of alcohol use, the patient was at risk for malnutrition secondary to his mandibular lesion and difficulty eating. Clinically, he presented with episodes of confusion and ataxia, consistent with 2 of the classic triad of symptoms of WE (no ocular abnormalities noted on exam). Typical MRI findings in WE include signal intensity alterations (including T2 hyperintensities) in the medial thalami, mammillary bodies, collicular bodies, and periaqueductal and periventricular regions.^14,15 Atypical MRI findings in WE include symmetric signal intensity changes in the cerebellum, dentate nuclei, caudate nuclei, red nuclei, cranial nerve nuclei, and splenium.¹⁴ Of note, atypical MRI findings were more common in patients without alcohol use disorders and WE, and typical MRI findings were more common in patients with alcohol use disorders.¹⁴ However, this patient’s report of no alcohol use and the serum thiamine level being within normal limits (173 nmol/L; range 78-185 nmol/L) made acute WE less likely than metronidonazale-induced encephalopathy (MIE).

The most common neurologic AE of metronidazole is distal symmetric sensory polyneuropathy, which also can have motor or autonomic features.^16,17 While our patient had a history of peripheral neuropathy, he noted marked worsening of foot pain 3 months after initiating metronidazole therapy. A potential mechanism involves metronidazole or its cytotoxic intermediates binding neuronal ribonucleic acids, thus inhibiting protein synthesis and resulting in degenerative neuronal changes and reversible axonal swelling (as opposed to the DNA interference attributed to the drug’s mechanism of bactericidal action).¹⁸ Neuropathies may result from prolonged high-dose metronidazole therapy (cumulative dose > 42 g),³ but they also have been seen in short-term use of high dosages.¹⁷

CNS AEs are much rarer and are thought to be associated with metronidazole’s ability to cross the blood-brain barrier. These patients present as a toxic encephalopathy with cerebellar dysfunction (dysarthria, ataxia) as the most common presentation, followed by AMS and seizures.⁴ Our patient presented with acute confusion and ataxia. Animal studies suggest that γ-aminobutyric acid (GABA) receptor modulation in the cerebellar and vestibular systems may contribute to this neurotoxicity, but no definitive mechanism of injury has been found.¹⁹

On MRI, MIE most commonly presents with hyperintense lesions in the bilateral cerebellar dentate nucleus on T2-weighted and FLAIR images.^5,20 The midbrain, dorsal pons, medulla, and corpus callosum also can show increased signal intensity.⁵ This AE does not seem to be dose- or duration-dependent, and most cases report complete or partial resolution of symptoms following discontinuation of the drug, though this is not absolute.^4,13,21 The patient’s MRI findings were highly consistent with MIE (Figure 2).

Conclusion

This patient’s highly specific MRI findings, neurologic examination consistent with confusion, ataxia, length-dependent sensory neuropathy, and 360-g cumulative dose of metronidazole over the previous 6 months suggest he experienced MIE. The mechanism of how HBOT precipitated the patient’s altered mental status, incoordination, and worsening of peripheral neuropathy is unknown. Although encephalopathy with MRI abnormalities as described is not a reported AE of HBOT, it may be unrecognized. It is possible that without HBOT the patient would have remained asymptomatic apart from his peripheral neuropathy.

We propose HBOT may exacerbate or increase the risk of a patient developing MIE. Our patient was able to safely resume HBOT after metronidazole was discontinued, suggesting that the combination was the causation for the development of encephalopathy. We do not believe any similar cases have been reported.