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Epilepsy surgery outcome prediction seeks to gain ground
BANGKOK –
She and her colleagues have created and validated an online risk prediction tool that clinicians can use to predict a patient’s individualized likelihood of complete freedom from seizures 2 and 5 years after undergoing resective brain surgery for drug-resistant epilepsy. The risk predictor, known as the Epilepsy Surgery Nomogram, uses a handful of simple clinical characteristics – patient gender, pathologic cause of the seizures, the proposed type of epilepsy surgery, the presence or absence of generalized tonic-clonic seizures, epilepsy duration, and preoperative seizure frequency – and spits out the patient’s predicted seizure outcome, she explained at the congress, sponsored by the International League Against Epilepsy.
“The point here is that every patient is an individual. And to give people predictions based on 500- or 600-patient Kaplan-Meier-derived curves that just provide the average outcome for the whole cohort isn’t really going to give them what they need as far as their individualized chance of becoming seizure free,” said Dr. Jehi, a neurologist at the Cleveland Clinic.
Similarly, reliance solely upon clinical judgment is a minefield. Multiple biases prevent physicians from making objective medical predictions, she continued.
“We think of the process of medical decision-making and outcome prediction as being a process that is logical and rational, where the accumulation of knowledge improves the decisions that we make, and where past experience improves judgment, and where collective decisions are more reliable. This is what intuitively we all think. That’s why we think we are invincible as physicians. And to that I say, really? There is a wealth of literature that actually disproves each one of these points,” Dr. Jehi declared.
Outcomes of brain surgery for drug-resistant epilepsy have remained static for more than half a century: Ten years after surgery, roughly half of treated patients remain completely seizure free. The inability of clinicians to use advanced statistics to inform potential surgical candidates about their individualized chance of becoming seizure free has probably contributed to underutilization of epilepsy surgery, she added.
The Epilepsy Surgery Nomogram was developed through detailed analysis of the records of 846 patients who underwent epilepsy surgery at the Cleveland Clinic. The resultant nomogram was then validated in a cohort of 604 patients who had resective surgery at the Mayo Clinic and epilepsy surgery centers in Brazil, Italy, and France. In the development cohort, the rate of complete freedom from seizures was 57% at 2 years and 40% at 5 years. In the validation study, the nomogram had a concordance statistic of 0.60 for complete freedom from seizures, which is considered better than chance, but well below the 0.80 threshold defined as strong concordance (Lancet Neurol. 2015 Mar;14[3]:283-90).
However, in an era when personalized medicine has become a catch phrase, the Epilepsy Surgery Nomogram has captured the attention of officials at the National Institutes of Health. Indeed, Dr. Jehi and her coworkers have received a $3.4 million, 5-year grant from the NIH to improve their risk prediction model by incorporating additional variables, including EEG data, MRI findings, family history, and genetic information. The enhanced risk calculator also will include a predictor of the likelihood that an individual will experience clinically meaningful improvement in quality of life in response to epilepsy surgery, since that’s an important outcome even in the absence of 100% freedom from seizures.
Recently, Dr. Jehi and coworkers have developed and then externally validated nomograms to predict the individualized risk of clinically relevant postoperative naming decline after temporal lobe epilepsy surgery in adults. A model based upon five variables – side of surgery, sex, education, age at epilepsy onset, and age at epilepsy surgery – performed very well, with a concordance statistic of 0.81. Moreover, a second nomogram predicting moderate to severe postoperative naming decline on the basis of just three variables – side of surgery, age at epilepsy onset, and preoperative score on the Boston Naming Test – had a concordance statistic of 0.84 (Neurology. 2018 Dec 4;91[23]:e2144-e2152. doi: 10.1212/WNL.0000000000006629).
“Our future hopefully is one where there will always be room for gut feelings and intuition because we definitely need them. We want to honor them. But hopefully it is one where algorithms can help our guesses be more educated and where the science of algorithms and predictive modeling can help inform our outcome predictions and decision-making process,” she said.
The original Epilepsy Surgery Nomogram project was funded by the Cleveland Clinic Epilepsy Center. The postoperative naming decline nomograms project was funded by the NIH.
BANGKOK –
She and her colleagues have created and validated an online risk prediction tool that clinicians can use to predict a patient’s individualized likelihood of complete freedom from seizures 2 and 5 years after undergoing resective brain surgery for drug-resistant epilepsy. The risk predictor, known as the Epilepsy Surgery Nomogram, uses a handful of simple clinical characteristics – patient gender, pathologic cause of the seizures, the proposed type of epilepsy surgery, the presence or absence of generalized tonic-clonic seizures, epilepsy duration, and preoperative seizure frequency – and spits out the patient’s predicted seizure outcome, she explained at the congress, sponsored by the International League Against Epilepsy.
“The point here is that every patient is an individual. And to give people predictions based on 500- or 600-patient Kaplan-Meier-derived curves that just provide the average outcome for the whole cohort isn’t really going to give them what they need as far as their individualized chance of becoming seizure free,” said Dr. Jehi, a neurologist at the Cleveland Clinic.
Similarly, reliance solely upon clinical judgment is a minefield. Multiple biases prevent physicians from making objective medical predictions, she continued.
“We think of the process of medical decision-making and outcome prediction as being a process that is logical and rational, where the accumulation of knowledge improves the decisions that we make, and where past experience improves judgment, and where collective decisions are more reliable. This is what intuitively we all think. That’s why we think we are invincible as physicians. And to that I say, really? There is a wealth of literature that actually disproves each one of these points,” Dr. Jehi declared.
Outcomes of brain surgery for drug-resistant epilepsy have remained static for more than half a century: Ten years after surgery, roughly half of treated patients remain completely seizure free. The inability of clinicians to use advanced statistics to inform potential surgical candidates about their individualized chance of becoming seizure free has probably contributed to underutilization of epilepsy surgery, she added.
The Epilepsy Surgery Nomogram was developed through detailed analysis of the records of 846 patients who underwent epilepsy surgery at the Cleveland Clinic. The resultant nomogram was then validated in a cohort of 604 patients who had resective surgery at the Mayo Clinic and epilepsy surgery centers in Brazil, Italy, and France. In the development cohort, the rate of complete freedom from seizures was 57% at 2 years and 40% at 5 years. In the validation study, the nomogram had a concordance statistic of 0.60 for complete freedom from seizures, which is considered better than chance, but well below the 0.80 threshold defined as strong concordance (Lancet Neurol. 2015 Mar;14[3]:283-90).
However, in an era when personalized medicine has become a catch phrase, the Epilepsy Surgery Nomogram has captured the attention of officials at the National Institutes of Health. Indeed, Dr. Jehi and her coworkers have received a $3.4 million, 5-year grant from the NIH to improve their risk prediction model by incorporating additional variables, including EEG data, MRI findings, family history, and genetic information. The enhanced risk calculator also will include a predictor of the likelihood that an individual will experience clinically meaningful improvement in quality of life in response to epilepsy surgery, since that’s an important outcome even in the absence of 100% freedom from seizures.
Recently, Dr. Jehi and coworkers have developed and then externally validated nomograms to predict the individualized risk of clinically relevant postoperative naming decline after temporal lobe epilepsy surgery in adults. A model based upon five variables – side of surgery, sex, education, age at epilepsy onset, and age at epilepsy surgery – performed very well, with a concordance statistic of 0.81. Moreover, a second nomogram predicting moderate to severe postoperative naming decline on the basis of just three variables – side of surgery, age at epilepsy onset, and preoperative score on the Boston Naming Test – had a concordance statistic of 0.84 (Neurology. 2018 Dec 4;91[23]:e2144-e2152. doi: 10.1212/WNL.0000000000006629).
“Our future hopefully is one where there will always be room for gut feelings and intuition because we definitely need them. We want to honor them. But hopefully it is one where algorithms can help our guesses be more educated and where the science of algorithms and predictive modeling can help inform our outcome predictions and decision-making process,” she said.
The original Epilepsy Surgery Nomogram project was funded by the Cleveland Clinic Epilepsy Center. The postoperative naming decline nomograms project was funded by the NIH.
BANGKOK –
She and her colleagues have created and validated an online risk prediction tool that clinicians can use to predict a patient’s individualized likelihood of complete freedom from seizures 2 and 5 years after undergoing resective brain surgery for drug-resistant epilepsy. The risk predictor, known as the Epilepsy Surgery Nomogram, uses a handful of simple clinical characteristics – patient gender, pathologic cause of the seizures, the proposed type of epilepsy surgery, the presence or absence of generalized tonic-clonic seizures, epilepsy duration, and preoperative seizure frequency – and spits out the patient’s predicted seizure outcome, she explained at the congress, sponsored by the International League Against Epilepsy.
“The point here is that every patient is an individual. And to give people predictions based on 500- or 600-patient Kaplan-Meier-derived curves that just provide the average outcome for the whole cohort isn’t really going to give them what they need as far as their individualized chance of becoming seizure free,” said Dr. Jehi, a neurologist at the Cleveland Clinic.
Similarly, reliance solely upon clinical judgment is a minefield. Multiple biases prevent physicians from making objective medical predictions, she continued.
“We think of the process of medical decision-making and outcome prediction as being a process that is logical and rational, where the accumulation of knowledge improves the decisions that we make, and where past experience improves judgment, and where collective decisions are more reliable. This is what intuitively we all think. That’s why we think we are invincible as physicians. And to that I say, really? There is a wealth of literature that actually disproves each one of these points,” Dr. Jehi declared.
Outcomes of brain surgery for drug-resistant epilepsy have remained static for more than half a century: Ten years after surgery, roughly half of treated patients remain completely seizure free. The inability of clinicians to use advanced statistics to inform potential surgical candidates about their individualized chance of becoming seizure free has probably contributed to underutilization of epilepsy surgery, she added.
The Epilepsy Surgery Nomogram was developed through detailed analysis of the records of 846 patients who underwent epilepsy surgery at the Cleveland Clinic. The resultant nomogram was then validated in a cohort of 604 patients who had resective surgery at the Mayo Clinic and epilepsy surgery centers in Brazil, Italy, and France. In the development cohort, the rate of complete freedom from seizures was 57% at 2 years and 40% at 5 years. In the validation study, the nomogram had a concordance statistic of 0.60 for complete freedom from seizures, which is considered better than chance, but well below the 0.80 threshold defined as strong concordance (Lancet Neurol. 2015 Mar;14[3]:283-90).
However, in an era when personalized medicine has become a catch phrase, the Epilepsy Surgery Nomogram has captured the attention of officials at the National Institutes of Health. Indeed, Dr. Jehi and her coworkers have received a $3.4 million, 5-year grant from the NIH to improve their risk prediction model by incorporating additional variables, including EEG data, MRI findings, family history, and genetic information. The enhanced risk calculator also will include a predictor of the likelihood that an individual will experience clinically meaningful improvement in quality of life in response to epilepsy surgery, since that’s an important outcome even in the absence of 100% freedom from seizures.
Recently, Dr. Jehi and coworkers have developed and then externally validated nomograms to predict the individualized risk of clinically relevant postoperative naming decline after temporal lobe epilepsy surgery in adults. A model based upon five variables – side of surgery, sex, education, age at epilepsy onset, and age at epilepsy surgery – performed very well, with a concordance statistic of 0.81. Moreover, a second nomogram predicting moderate to severe postoperative naming decline on the basis of just three variables – side of surgery, age at epilepsy onset, and preoperative score on the Boston Naming Test – had a concordance statistic of 0.84 (Neurology. 2018 Dec 4;91[23]:e2144-e2152. doi: 10.1212/WNL.0000000000006629).
“Our future hopefully is one where there will always be room for gut feelings and intuition because we definitely need them. We want to honor them. But hopefully it is one where algorithms can help our guesses be more educated and where the science of algorithms and predictive modeling can help inform our outcome predictions and decision-making process,” she said.
The original Epilepsy Surgery Nomogram project was funded by the Cleveland Clinic Epilepsy Center. The postoperative naming decline nomograms project was funded by the NIH.
REPORTING FROM IEC 2019
Antiepileptic drug outcomes have remained flat for 3 decades
BANGKOK – Since founding the Epilepsy Unit at Glasgow’s Western Infirmary 37 years ago, Martin J. Brodie, MD, has seen many changes in the field, including the introduction of more than a dozen new antiepileptic drugs (AEDs) in the past 2 decades.
And based upon this vast clinical experience coupled with his leadership of landmark studies, he has a message for his physician colleagues and their epilepsy patients. And it’s not pretty.
“Has the probability of achieving seizure freedom increased significantly in the last 3 decades? Regrettably, the answer is no,” he declared at the International Epilepsy Congress.
“Over all these years, in terms of seizure freedom there has been no real difference in outcome. There’s really quite a long way to go before we can say that we are doing all that well for people,” he said at the congress sponsored by the International League Against Epilepsy.
In the year 2000, he and his coinvestigators published a prospective, longitudinal, observational cohort study of 470 newly diagnosed patients with epilepsy treated at the Western Infirmary during 1982-1997, all with a minimum of 2 years’ follow-up. Sixty-one percent achieved complete freedom from seizures for at least 1 year on monotherapy, and another 3% did so on polytherapy, for a total rate of 64% (N Engl J Med. 2000 Feb 3;342[5]:314-19).
But these were patients who by and large were treated with older AEDs such as carbamazepine, which has since fallen by the wayside because of toxicities. Scottish neurologists now generally turn to lamotrigine (Lamictal), levetiracetam (Spritam), and other, newer AEDs. So Dr. Brodie and his coworkers recently published a follow-up study, this one featuring 30 years of longitudinal follow-up of 1,795 patients newly treated for epilepsy with AEDs, new and old, during 1982-2012. The investigators demonstrated that the seizure-free survival curves over time were virtually superimposable. In the larger, more recent study, remission was achieved in 55% of patients with AED monotherapy and in another 9% with polytherapy, for a total rate of 64%, identical to the rate in the 2000 study, and as was the case in the earlier study, 36% of patients remained uncontrolled (JAMA Neurol. 2018 Mar 1;75[3]:279-86).
“Overall, the way this population behaves, there’s no difference in efficacy and no difference in tolerability whether you’re using old drugs used properly or new drugs used properly,” said Dr. Brodie, professor of neurology at the University of Glasgow (Scotland).
It’s noteworthy that Sir William R. Gowers, the Londoner who has been called the greatest neurologist of all time, reported a 70% seizure-free rate in 1881, while Dr. Brodie and workers achieved a 64% rate in their 30-year study. “It’s interesting that the numbers are so bad, really, I suppose,” Dr. Brodie commented.
How about outcomes in pediatric epilepsy?
Dr. Brodie and coworkers recently published a 30-year prospective cohort study of 332 adolescent epilepsy patients newly diagnosed and treated at the Western Infirmary during 1982-2012. At the end of the study, 67% were seizure-free for at least the past year, a feat accomplished via monotherapy in 83% of cases. The seizure-free rate was 72% in those with generalized epilepsy, significantly better than the 60% figure in those with focal epilepsy. The efficacy rate was 74% with newer AED monotherapy and similar at 77% with monotherapy older drugs. Adverse event rates ranged from a low of 12% with lamotrigine to 56% with topiramate (Topamax), according to the findings published in Epilepsia (2019 Jun;60[6]:1083-90).
Roughly similar outcomes have been reported from Norway in a study of 600 children with epilepsy, median age 7 years, with a median follow-up of 5.8 years that is considerably shorter than that in the Glasgow pediatric study. Overall, 59% of the Norwegian children remained seizure free for at least 1 year, 30% developed drug-resistant epilepsy, and 11% followed an intermediate remitting/relapsing course (Pediatrics. 2018 Jun. doi: 10.1542/peds.2017-4016).
Why the decades of flat pharmacologic outcomes?
The consistently suboptimal seizure-free outcomes obtained over the past 30 years shouldn’t really be surprising, according to Dr. Brodie.
“Although we think we have lots of mechanisms of action and lots of differences between the drugs, they’re arguably all antiseizure drugs and not antiepilepsy drugs. We don’t treat the whale; we treat the spout. We don’t treat what we cannot see; we treat what we can see, which is the seizures, but we’re not influencing the long-term outcome,” the neurologist explained.
The compelling case for early epilepsy surgery
Epilepsy surgery remains underutilized, according to Dr. Brodie and other experts.
The International League Against Epilepsy defines drug-resistant epilepsy as failure to achieve sustained seizure freedom after adequate trials of two tolerated and appropriately chosen and used AED schedules. Dr. Brodie’s work was influential in creating that definition because his data demonstrated the sharply diminishing returns of additional drug trials.
“When do we consider epilepsy surgery? Arguably, the earlier, the better. After two drugs have failed appropriately, I don’t think anybody in this room would argue about that, although people in some of the other rooms might,” he said at the congress.
Influential in his thinking on this score were the impressive results of an early study, the first-ever randomized trial of surgery for epilepsy. In 80 patients with a 21-year history of drug-refractory temporal lobe epilepsy who were randomized to surgery or 1 year of AED therapy, at 1 year of follow-up blinded epileptologists rated 58% of surgically treated patients as free from seizures that impair awareness of self and surroundings, compared with just 8% in the AED group (N Engl J Med. 2001 Aug 2;345[5]:311-8).
“That’s a big outcome, and I’m very keen to ensure that my data continue to drive the push for early surgery,” according to the neurologist.
A Cochrane review of 177 studies totaling more than 16,000 patients concluded that 65% of epilepsy patients had good outcomes following surgery. Prognostic factors associated with better surgical outcomes included complete surgical resection of the epileptogenic focus, the presence of mesial temporal sclerosis, concordance of MRI and EEG findings, and an absence of cortical dysplasia (Cochrane Database Syst Rev. 2019;6:CD010541. doi: 10.1002/14651858.CD010541.pub3).
In addition, a systematic review and meta-analysis by Canadian investigators found that 72% of adults with lesional epilepsy identified by MRI or histopathology were seizure-free after surgery, compared with 36% of those with nonlesional epilepsy. The disparity in outcomes was similar in pediatric epilepsy patients, with seizure freedom after surgery in 74% of those with lesional disease versus 45% with nonlesional epilepsy (Epilepsy Res. 2010 May;89[2-3]:310-8).
Whither are neurostimulatory device therapies headed?
Dr. Brodie was quick to admit that as a pharmacologic researcher, device modalities including vagus nerve stimulation, responsive neurostimulation, and deep brain stimulation are outside his area of expertise. But he’s been following developments in the field with interest.
“These device therapies have shown efficacy in short-term randomized trials, but very few patients attain long-term seizure freedom. I think these are largely palliative techniques. I gave up on these techniques a long time ago because I felt it was a very costly way of reducing seizures by a relatively small margin, and really we need to go a little bit further than that. But I know there’s a lot of work going on at the moment,” he said.
Dr. Brodie reported serving on the scientific advisory boards of more than a half dozen pharmaceutical companies.
BANGKOK – Since founding the Epilepsy Unit at Glasgow’s Western Infirmary 37 years ago, Martin J. Brodie, MD, has seen many changes in the field, including the introduction of more than a dozen new antiepileptic drugs (AEDs) in the past 2 decades.
And based upon this vast clinical experience coupled with his leadership of landmark studies, he has a message for his physician colleagues and their epilepsy patients. And it’s not pretty.
“Has the probability of achieving seizure freedom increased significantly in the last 3 decades? Regrettably, the answer is no,” he declared at the International Epilepsy Congress.
“Over all these years, in terms of seizure freedom there has been no real difference in outcome. There’s really quite a long way to go before we can say that we are doing all that well for people,” he said at the congress sponsored by the International League Against Epilepsy.
In the year 2000, he and his coinvestigators published a prospective, longitudinal, observational cohort study of 470 newly diagnosed patients with epilepsy treated at the Western Infirmary during 1982-1997, all with a minimum of 2 years’ follow-up. Sixty-one percent achieved complete freedom from seizures for at least 1 year on monotherapy, and another 3% did so on polytherapy, for a total rate of 64% (N Engl J Med. 2000 Feb 3;342[5]:314-19).
But these were patients who by and large were treated with older AEDs such as carbamazepine, which has since fallen by the wayside because of toxicities. Scottish neurologists now generally turn to lamotrigine (Lamictal), levetiracetam (Spritam), and other, newer AEDs. So Dr. Brodie and his coworkers recently published a follow-up study, this one featuring 30 years of longitudinal follow-up of 1,795 patients newly treated for epilepsy with AEDs, new and old, during 1982-2012. The investigators demonstrated that the seizure-free survival curves over time were virtually superimposable. In the larger, more recent study, remission was achieved in 55% of patients with AED monotherapy and in another 9% with polytherapy, for a total rate of 64%, identical to the rate in the 2000 study, and as was the case in the earlier study, 36% of patients remained uncontrolled (JAMA Neurol. 2018 Mar 1;75[3]:279-86).
“Overall, the way this population behaves, there’s no difference in efficacy and no difference in tolerability whether you’re using old drugs used properly or new drugs used properly,” said Dr. Brodie, professor of neurology at the University of Glasgow (Scotland).
It’s noteworthy that Sir William R. Gowers, the Londoner who has been called the greatest neurologist of all time, reported a 70% seizure-free rate in 1881, while Dr. Brodie and workers achieved a 64% rate in their 30-year study. “It’s interesting that the numbers are so bad, really, I suppose,” Dr. Brodie commented.
How about outcomes in pediatric epilepsy?
Dr. Brodie and coworkers recently published a 30-year prospective cohort study of 332 adolescent epilepsy patients newly diagnosed and treated at the Western Infirmary during 1982-2012. At the end of the study, 67% were seizure-free for at least the past year, a feat accomplished via monotherapy in 83% of cases. The seizure-free rate was 72% in those with generalized epilepsy, significantly better than the 60% figure in those with focal epilepsy. The efficacy rate was 74% with newer AED monotherapy and similar at 77% with monotherapy older drugs. Adverse event rates ranged from a low of 12% with lamotrigine to 56% with topiramate (Topamax), according to the findings published in Epilepsia (2019 Jun;60[6]:1083-90).
Roughly similar outcomes have been reported from Norway in a study of 600 children with epilepsy, median age 7 years, with a median follow-up of 5.8 years that is considerably shorter than that in the Glasgow pediatric study. Overall, 59% of the Norwegian children remained seizure free for at least 1 year, 30% developed drug-resistant epilepsy, and 11% followed an intermediate remitting/relapsing course (Pediatrics. 2018 Jun. doi: 10.1542/peds.2017-4016).
Why the decades of flat pharmacologic outcomes?
The consistently suboptimal seizure-free outcomes obtained over the past 30 years shouldn’t really be surprising, according to Dr. Brodie.
“Although we think we have lots of mechanisms of action and lots of differences between the drugs, they’re arguably all antiseizure drugs and not antiepilepsy drugs. We don’t treat the whale; we treat the spout. We don’t treat what we cannot see; we treat what we can see, which is the seizures, but we’re not influencing the long-term outcome,” the neurologist explained.
The compelling case for early epilepsy surgery
Epilepsy surgery remains underutilized, according to Dr. Brodie and other experts.
The International League Against Epilepsy defines drug-resistant epilepsy as failure to achieve sustained seizure freedom after adequate trials of two tolerated and appropriately chosen and used AED schedules. Dr. Brodie’s work was influential in creating that definition because his data demonstrated the sharply diminishing returns of additional drug trials.
“When do we consider epilepsy surgery? Arguably, the earlier, the better. After two drugs have failed appropriately, I don’t think anybody in this room would argue about that, although people in some of the other rooms might,” he said at the congress.
Influential in his thinking on this score were the impressive results of an early study, the first-ever randomized trial of surgery for epilepsy. In 80 patients with a 21-year history of drug-refractory temporal lobe epilepsy who were randomized to surgery or 1 year of AED therapy, at 1 year of follow-up blinded epileptologists rated 58% of surgically treated patients as free from seizures that impair awareness of self and surroundings, compared with just 8% in the AED group (N Engl J Med. 2001 Aug 2;345[5]:311-8).
“That’s a big outcome, and I’m very keen to ensure that my data continue to drive the push for early surgery,” according to the neurologist.
A Cochrane review of 177 studies totaling more than 16,000 patients concluded that 65% of epilepsy patients had good outcomes following surgery. Prognostic factors associated with better surgical outcomes included complete surgical resection of the epileptogenic focus, the presence of mesial temporal sclerosis, concordance of MRI and EEG findings, and an absence of cortical dysplasia (Cochrane Database Syst Rev. 2019;6:CD010541. doi: 10.1002/14651858.CD010541.pub3).
In addition, a systematic review and meta-analysis by Canadian investigators found that 72% of adults with lesional epilepsy identified by MRI or histopathology were seizure-free after surgery, compared with 36% of those with nonlesional epilepsy. The disparity in outcomes was similar in pediatric epilepsy patients, with seizure freedom after surgery in 74% of those with lesional disease versus 45% with nonlesional epilepsy (Epilepsy Res. 2010 May;89[2-3]:310-8).
Whither are neurostimulatory device therapies headed?
Dr. Brodie was quick to admit that as a pharmacologic researcher, device modalities including vagus nerve stimulation, responsive neurostimulation, and deep brain stimulation are outside his area of expertise. But he’s been following developments in the field with interest.
“These device therapies have shown efficacy in short-term randomized trials, but very few patients attain long-term seizure freedom. I think these are largely palliative techniques. I gave up on these techniques a long time ago because I felt it was a very costly way of reducing seizures by a relatively small margin, and really we need to go a little bit further than that. But I know there’s a lot of work going on at the moment,” he said.
Dr. Brodie reported serving on the scientific advisory boards of more than a half dozen pharmaceutical companies.
BANGKOK – Since founding the Epilepsy Unit at Glasgow’s Western Infirmary 37 years ago, Martin J. Brodie, MD, has seen many changes in the field, including the introduction of more than a dozen new antiepileptic drugs (AEDs) in the past 2 decades.
And based upon this vast clinical experience coupled with his leadership of landmark studies, he has a message for his physician colleagues and their epilepsy patients. And it’s not pretty.
“Has the probability of achieving seizure freedom increased significantly in the last 3 decades? Regrettably, the answer is no,” he declared at the International Epilepsy Congress.
“Over all these years, in terms of seizure freedom there has been no real difference in outcome. There’s really quite a long way to go before we can say that we are doing all that well for people,” he said at the congress sponsored by the International League Against Epilepsy.
In the year 2000, he and his coinvestigators published a prospective, longitudinal, observational cohort study of 470 newly diagnosed patients with epilepsy treated at the Western Infirmary during 1982-1997, all with a minimum of 2 years’ follow-up. Sixty-one percent achieved complete freedom from seizures for at least 1 year on monotherapy, and another 3% did so on polytherapy, for a total rate of 64% (N Engl J Med. 2000 Feb 3;342[5]:314-19).
But these were patients who by and large were treated with older AEDs such as carbamazepine, which has since fallen by the wayside because of toxicities. Scottish neurologists now generally turn to lamotrigine (Lamictal), levetiracetam (Spritam), and other, newer AEDs. So Dr. Brodie and his coworkers recently published a follow-up study, this one featuring 30 years of longitudinal follow-up of 1,795 patients newly treated for epilepsy with AEDs, new and old, during 1982-2012. The investigators demonstrated that the seizure-free survival curves over time were virtually superimposable. In the larger, more recent study, remission was achieved in 55% of patients with AED monotherapy and in another 9% with polytherapy, for a total rate of 64%, identical to the rate in the 2000 study, and as was the case in the earlier study, 36% of patients remained uncontrolled (JAMA Neurol. 2018 Mar 1;75[3]:279-86).
“Overall, the way this population behaves, there’s no difference in efficacy and no difference in tolerability whether you’re using old drugs used properly or new drugs used properly,” said Dr. Brodie, professor of neurology at the University of Glasgow (Scotland).
It’s noteworthy that Sir William R. Gowers, the Londoner who has been called the greatest neurologist of all time, reported a 70% seizure-free rate in 1881, while Dr. Brodie and workers achieved a 64% rate in their 30-year study. “It’s interesting that the numbers are so bad, really, I suppose,” Dr. Brodie commented.
How about outcomes in pediatric epilepsy?
Dr. Brodie and coworkers recently published a 30-year prospective cohort study of 332 adolescent epilepsy patients newly diagnosed and treated at the Western Infirmary during 1982-2012. At the end of the study, 67% were seizure-free for at least the past year, a feat accomplished via monotherapy in 83% of cases. The seizure-free rate was 72% in those with generalized epilepsy, significantly better than the 60% figure in those with focal epilepsy. The efficacy rate was 74% with newer AED monotherapy and similar at 77% with monotherapy older drugs. Adverse event rates ranged from a low of 12% with lamotrigine to 56% with topiramate (Topamax), according to the findings published in Epilepsia (2019 Jun;60[6]:1083-90).
Roughly similar outcomes have been reported from Norway in a study of 600 children with epilepsy, median age 7 years, with a median follow-up of 5.8 years that is considerably shorter than that in the Glasgow pediatric study. Overall, 59% of the Norwegian children remained seizure free for at least 1 year, 30% developed drug-resistant epilepsy, and 11% followed an intermediate remitting/relapsing course (Pediatrics. 2018 Jun. doi: 10.1542/peds.2017-4016).
Why the decades of flat pharmacologic outcomes?
The consistently suboptimal seizure-free outcomes obtained over the past 30 years shouldn’t really be surprising, according to Dr. Brodie.
“Although we think we have lots of mechanisms of action and lots of differences between the drugs, they’re arguably all antiseizure drugs and not antiepilepsy drugs. We don’t treat the whale; we treat the spout. We don’t treat what we cannot see; we treat what we can see, which is the seizures, but we’re not influencing the long-term outcome,” the neurologist explained.
The compelling case for early epilepsy surgery
Epilepsy surgery remains underutilized, according to Dr. Brodie and other experts.
The International League Against Epilepsy defines drug-resistant epilepsy as failure to achieve sustained seizure freedom after adequate trials of two tolerated and appropriately chosen and used AED schedules. Dr. Brodie’s work was influential in creating that definition because his data demonstrated the sharply diminishing returns of additional drug trials.
“When do we consider epilepsy surgery? Arguably, the earlier, the better. After two drugs have failed appropriately, I don’t think anybody in this room would argue about that, although people in some of the other rooms might,” he said at the congress.
Influential in his thinking on this score were the impressive results of an early study, the first-ever randomized trial of surgery for epilepsy. In 80 patients with a 21-year history of drug-refractory temporal lobe epilepsy who were randomized to surgery or 1 year of AED therapy, at 1 year of follow-up blinded epileptologists rated 58% of surgically treated patients as free from seizures that impair awareness of self and surroundings, compared with just 8% in the AED group (N Engl J Med. 2001 Aug 2;345[5]:311-8).
“That’s a big outcome, and I’m very keen to ensure that my data continue to drive the push for early surgery,” according to the neurologist.
A Cochrane review of 177 studies totaling more than 16,000 patients concluded that 65% of epilepsy patients had good outcomes following surgery. Prognostic factors associated with better surgical outcomes included complete surgical resection of the epileptogenic focus, the presence of mesial temporal sclerosis, concordance of MRI and EEG findings, and an absence of cortical dysplasia (Cochrane Database Syst Rev. 2019;6:CD010541. doi: 10.1002/14651858.CD010541.pub3).
In addition, a systematic review and meta-analysis by Canadian investigators found that 72% of adults with lesional epilepsy identified by MRI or histopathology were seizure-free after surgery, compared with 36% of those with nonlesional epilepsy. The disparity in outcomes was similar in pediatric epilepsy patients, with seizure freedom after surgery in 74% of those with lesional disease versus 45% with nonlesional epilepsy (Epilepsy Res. 2010 May;89[2-3]:310-8).
Whither are neurostimulatory device therapies headed?
Dr. Brodie was quick to admit that as a pharmacologic researcher, device modalities including vagus nerve stimulation, responsive neurostimulation, and deep brain stimulation are outside his area of expertise. But he’s been following developments in the field with interest.
“These device therapies have shown efficacy in short-term randomized trials, but very few patients attain long-term seizure freedom. I think these are largely palliative techniques. I gave up on these techniques a long time ago because I felt it was a very costly way of reducing seizures by a relatively small margin, and really we need to go a little bit further than that. But I know there’s a lot of work going on at the moment,” he said.
Dr. Brodie reported serving on the scientific advisory boards of more than a half dozen pharmaceutical companies.
EXPERT ANALYSIS FROM IEC 2019
Liberalized low–glycemic-index diet effective for seizure reduction
BANGKOK – in a randomized, double-blind, 24-week, noninferiority study.
The low–glycemic-index diet (LGID) was introduced as a kinder, gentler, variant of the classic ketogenic diet for seizure frequency reduction. The ketogenic diet’s efficacy for this purpose is well established, but compliance is a problem and discontinuation rates are high. Yet even though the LGID was designed to be less onerous than the ketogenic diet, many children and parents also find the 7-days-a-week LGID to be excessively burdensome. This was the impetus for pitting the daily LGID against an intermittent version – 5 days on, 2 days off – in a randomized trial, Prateek K. Panda, MD, explained at the International Epilepsy Congress.
The hypothesis of this noninferiority trial was that adherence to the liberalized LGID would be similar to or better than that with the daily LGID regimen, with resultant similar reductions in seizure frequency. And further, that patients on the intermittent LGID would feel better because it would help improve depleted glycogen stores important for daily activity and that the liberalized diet would also be rated more favorably by caregivers, Dr. Panda said at the congress sponsored by the International League Against Epilepsy.
The 24-week, single-center trial included 122 children ages 1-15 years with drug-resistant epilepsy. At baseline they averaged 99 seizures per week by parental diary despite being on a median of four antiepileptic drugs. A total of 88% of participants had some form of structural epilepsy; the rest had a probable or confirmed genetic cause for their seizure disorder, according to Dr. Panda of the All-India Institute of Medical Sciences in New Delhi.
The standard daily LGID was comprised of 10% carbohydrate, 30% protein, and 60% fat, with only low–glycemic-index foods permitted. The cohort randomized to the liberalized diet ate that way on weekdays; however, on Saturdays and Sundays their diet was 20% carbohydrate, 30% protein, and 50% fat, with both medium- and low–glycemic-index foods allowed.
The primary outcome was the mean reduction in seizures per week by caregiver records at 24 weeks. The reduction from baseline was 54% in the strict LGID group and not significantly different at 49% in the intermittent LGID patients. Overall, 54% of patients in the strict LGID arm experienced a greater than 50% reduction in weekly seizure frequency, as did 50% on the liberalized diet, a nonsignificant difference.
There were five study dropouts in the strict LGID group and three in the liberalized LGID cohort. The two groups showed similar improvements over baseline in measures of social function, behavior, and cognition. Parents of children in the liberalized LGID group rated that diet as significantly less difficult to administer than those randomized to the strict LGID therapy.
Mean hemoglobin A1c improved in the strict LGID patients from 5.7% at baseline to 5.1% at both 12 and 24 weeks. The intermittent LGID group went from 5.6% to 5.0% and then to 5.2%. There was no correlation between HbA1c and reduction in seizure frequency. In contrast, serum beta-hydroxybutyrate levels showed a moderate correlation with seizure frequency, a novel finding which if confirmed might render beta-hydroxybutyrate useful as a biomarker, according to Dr. Panda.
Adverse events – mostly dyslipidemia and GI complaints such as vomiting or constipation – occurred in 25% of the strict LGID group and 13% with the intermittent LGID. All adverse events were mild.
Dr. Panda reported having no financial conflicts regarding the study, sponsored by the All-India Institute of Medical Sciences.
SOURCE: Panda PK et al. IEC 2019, Abstract P056.
BANGKOK – in a randomized, double-blind, 24-week, noninferiority study.
The low–glycemic-index diet (LGID) was introduced as a kinder, gentler, variant of the classic ketogenic diet for seizure frequency reduction. The ketogenic diet’s efficacy for this purpose is well established, but compliance is a problem and discontinuation rates are high. Yet even though the LGID was designed to be less onerous than the ketogenic diet, many children and parents also find the 7-days-a-week LGID to be excessively burdensome. This was the impetus for pitting the daily LGID against an intermittent version – 5 days on, 2 days off – in a randomized trial, Prateek K. Panda, MD, explained at the International Epilepsy Congress.
The hypothesis of this noninferiority trial was that adherence to the liberalized LGID would be similar to or better than that with the daily LGID regimen, with resultant similar reductions in seizure frequency. And further, that patients on the intermittent LGID would feel better because it would help improve depleted glycogen stores important for daily activity and that the liberalized diet would also be rated more favorably by caregivers, Dr. Panda said at the congress sponsored by the International League Against Epilepsy.
The 24-week, single-center trial included 122 children ages 1-15 years with drug-resistant epilepsy. At baseline they averaged 99 seizures per week by parental diary despite being on a median of four antiepileptic drugs. A total of 88% of participants had some form of structural epilepsy; the rest had a probable or confirmed genetic cause for their seizure disorder, according to Dr. Panda of the All-India Institute of Medical Sciences in New Delhi.
The standard daily LGID was comprised of 10% carbohydrate, 30% protein, and 60% fat, with only low–glycemic-index foods permitted. The cohort randomized to the liberalized diet ate that way on weekdays; however, on Saturdays and Sundays their diet was 20% carbohydrate, 30% protein, and 50% fat, with both medium- and low–glycemic-index foods allowed.
The primary outcome was the mean reduction in seizures per week by caregiver records at 24 weeks. The reduction from baseline was 54% in the strict LGID group and not significantly different at 49% in the intermittent LGID patients. Overall, 54% of patients in the strict LGID arm experienced a greater than 50% reduction in weekly seizure frequency, as did 50% on the liberalized diet, a nonsignificant difference.
There were five study dropouts in the strict LGID group and three in the liberalized LGID cohort. The two groups showed similar improvements over baseline in measures of social function, behavior, and cognition. Parents of children in the liberalized LGID group rated that diet as significantly less difficult to administer than those randomized to the strict LGID therapy.
Mean hemoglobin A1c improved in the strict LGID patients from 5.7% at baseline to 5.1% at both 12 and 24 weeks. The intermittent LGID group went from 5.6% to 5.0% and then to 5.2%. There was no correlation between HbA1c and reduction in seizure frequency. In contrast, serum beta-hydroxybutyrate levels showed a moderate correlation with seizure frequency, a novel finding which if confirmed might render beta-hydroxybutyrate useful as a biomarker, according to Dr. Panda.
Adverse events – mostly dyslipidemia and GI complaints such as vomiting or constipation – occurred in 25% of the strict LGID group and 13% with the intermittent LGID. All adverse events were mild.
Dr. Panda reported having no financial conflicts regarding the study, sponsored by the All-India Institute of Medical Sciences.
SOURCE: Panda PK et al. IEC 2019, Abstract P056.
BANGKOK – in a randomized, double-blind, 24-week, noninferiority study.
The low–glycemic-index diet (LGID) was introduced as a kinder, gentler, variant of the classic ketogenic diet for seizure frequency reduction. The ketogenic diet’s efficacy for this purpose is well established, but compliance is a problem and discontinuation rates are high. Yet even though the LGID was designed to be less onerous than the ketogenic diet, many children and parents also find the 7-days-a-week LGID to be excessively burdensome. This was the impetus for pitting the daily LGID against an intermittent version – 5 days on, 2 days off – in a randomized trial, Prateek K. Panda, MD, explained at the International Epilepsy Congress.
The hypothesis of this noninferiority trial was that adherence to the liberalized LGID would be similar to or better than that with the daily LGID regimen, with resultant similar reductions in seizure frequency. And further, that patients on the intermittent LGID would feel better because it would help improve depleted glycogen stores important for daily activity and that the liberalized diet would also be rated more favorably by caregivers, Dr. Panda said at the congress sponsored by the International League Against Epilepsy.
The 24-week, single-center trial included 122 children ages 1-15 years with drug-resistant epilepsy. At baseline they averaged 99 seizures per week by parental diary despite being on a median of four antiepileptic drugs. A total of 88% of participants had some form of structural epilepsy; the rest had a probable or confirmed genetic cause for their seizure disorder, according to Dr. Panda of the All-India Institute of Medical Sciences in New Delhi.
The standard daily LGID was comprised of 10% carbohydrate, 30% protein, and 60% fat, with only low–glycemic-index foods permitted. The cohort randomized to the liberalized diet ate that way on weekdays; however, on Saturdays and Sundays their diet was 20% carbohydrate, 30% protein, and 50% fat, with both medium- and low–glycemic-index foods allowed.
The primary outcome was the mean reduction in seizures per week by caregiver records at 24 weeks. The reduction from baseline was 54% in the strict LGID group and not significantly different at 49% in the intermittent LGID patients. Overall, 54% of patients in the strict LGID arm experienced a greater than 50% reduction in weekly seizure frequency, as did 50% on the liberalized diet, a nonsignificant difference.
There were five study dropouts in the strict LGID group and three in the liberalized LGID cohort. The two groups showed similar improvements over baseline in measures of social function, behavior, and cognition. Parents of children in the liberalized LGID group rated that diet as significantly less difficult to administer than those randomized to the strict LGID therapy.
Mean hemoglobin A1c improved in the strict LGID patients from 5.7% at baseline to 5.1% at both 12 and 24 weeks. The intermittent LGID group went from 5.6% to 5.0% and then to 5.2%. There was no correlation between HbA1c and reduction in seizure frequency. In contrast, serum beta-hydroxybutyrate levels showed a moderate correlation with seizure frequency, a novel finding which if confirmed might render beta-hydroxybutyrate useful as a biomarker, according to Dr. Panda.
Adverse events – mostly dyslipidemia and GI complaints such as vomiting or constipation – occurred in 25% of the strict LGID group and 13% with the intermittent LGID. All adverse events were mild.
Dr. Panda reported having no financial conflicts regarding the study, sponsored by the All-India Institute of Medical Sciences.
SOURCE: Panda PK et al. IEC 2019, Abstract P056.
REPORTING FROM IEC 2019
Statins crush early seizure risk poststroke
BANGKOK – Statin therapy, even when initiated only upon hospitalization for acute ischemic stroke, was associated with a striking reduction in the risk of early poststroke symptomatic seizure in a large observational study.
Using propensity-score matching to control for potential confounders, use of a statin during acute stroke management was associated with a “robust” 77% reduction in the risk of developing a symptomatic seizure within 7 days after hospital admission, Soichiro Matsubara, MD, reported at the International Epilepsy Congress.
This is an important finding because early symptomatic seizure (ESS) occurs in 2%-7% of patients following an acute ischemic stroke. Moreover, an Italian meta-analysis concluded that ESS was associated with a 4.4-fold increased risk of developing poststroke epilepsy (Epilepsia. 2016 Aug;57[8]:1205-14), noted Dr. Matsubara, a neurologist at the National Cerebral and Cardiovascular Center in Suita, Japan, as well as at Kumamoto (Japan) University.
He presented a study of 2,969 consecutive acute ischemic stroke patients with no history of epilepsy who were admitted to the Japanese comprehensive stroke center, of whom 2.2% experienced ESS. At physician discretion, 19% of the ESS cohort were on a statin during their acute stroke management, as were 55% of the no-ESS group. Four-fifths of patients on a statin initiated the drug only upon hospital admission.
Strokes tended to be more severe in the ESS group, with a median initial National Institutes of Health Stroke Scale score of 12.5, compared with 4 in the seizure-free patients. A cortical stroke lesion was evident upon imaging in 89% of the ESS group and 55% of no-ESS patients. Among ESS patients, 46% had a cardiometabolic stroke, compared with 34% of the no-ESS cohort. Mean C-reactive protein levels and white blood cell counts were significantly higher in the ESS cohort as well. Their median hospital length of stay was 25.5 days, versus 18 days in the no-ESS group, Dr. Matsubara said at the congress sponsored by the International League Against Epilepsy.
Of the 76 ESSs that occurred in 66 patients, 37% were focal awareness seizures, 35% were focal to bilateral tonic-clonic seizures, and 28% were focal impaired awareness seizures.
In a multivariate analysis adjusted for age, sex, body mass index, stroke subtype, and other potential confounders, statin therapy during acute management of stroke was independently associated with a 56% reduction in the relative risk of ESS. In contrast, a cortical stroke lesion was associated with a 2.83-fold increased risk.
Since this wasn’t a randomized trial of statin therapy, Dr. Matsubara and his coinvestigators felt the need to go further in analyzing the data. After extensive propensity score matching for atrial fibrillation, current smoking, systolic blood pressure, the presence or absence of a cortical stroke lesion, large vessel stenosis, and other possible confounders, they were left with two closely comparable groups: 886 statin-treated stroke patients and an equal number who were not on statin therapy during their acute stroke management. The key finding: The risk of ESS was reduced by a whopping 77% in the patients on statin therapy.
The neurologist observed that these new findings in acute ischemic stroke patients are consistent with an earlier study in a U.S. Veterans Affairs population, which demonstrated that statin therapy was associated with a significantly lower risk of new-onset geriatric epilepsy (J Am Geriatr Soc. 2009 Feb;57[2]:237-42).
As to the possible mechanism by which statins may protect against ESS, Dr. Matsubara noted that acute ischemic stroke causes toxic neuronal excitation because of blood-brain barrier disruption, ion channel dysfunction, altered gene expression, and increased release of neurotransmitters. In animal models, statins provide a neuroprotective effect by reducing glutamate levels, activating endothelial nitric oxide synthase, and inhibiting production of interleukin-6, tumor necrosis factor-alpha, and other inflammatory cytokines.
Asked about the intensity of the statin therapy, Dr. Matsubara replied that the target was typically an LDL cholesterol below 100 mg/dL.
He reported having no financial conflicts regarding the study, conducted free of commercial support.
SOURCE: Matsubara S et al. IEC 219, Abstract P002.
BANGKOK – Statin therapy, even when initiated only upon hospitalization for acute ischemic stroke, was associated with a striking reduction in the risk of early poststroke symptomatic seizure in a large observational study.
Using propensity-score matching to control for potential confounders, use of a statin during acute stroke management was associated with a “robust” 77% reduction in the risk of developing a symptomatic seizure within 7 days after hospital admission, Soichiro Matsubara, MD, reported at the International Epilepsy Congress.
This is an important finding because early symptomatic seizure (ESS) occurs in 2%-7% of patients following an acute ischemic stroke. Moreover, an Italian meta-analysis concluded that ESS was associated with a 4.4-fold increased risk of developing poststroke epilepsy (Epilepsia. 2016 Aug;57[8]:1205-14), noted Dr. Matsubara, a neurologist at the National Cerebral and Cardiovascular Center in Suita, Japan, as well as at Kumamoto (Japan) University.
He presented a study of 2,969 consecutive acute ischemic stroke patients with no history of epilepsy who were admitted to the Japanese comprehensive stroke center, of whom 2.2% experienced ESS. At physician discretion, 19% of the ESS cohort were on a statin during their acute stroke management, as were 55% of the no-ESS group. Four-fifths of patients on a statin initiated the drug only upon hospital admission.
Strokes tended to be more severe in the ESS group, with a median initial National Institutes of Health Stroke Scale score of 12.5, compared with 4 in the seizure-free patients. A cortical stroke lesion was evident upon imaging in 89% of the ESS group and 55% of no-ESS patients. Among ESS patients, 46% had a cardiometabolic stroke, compared with 34% of the no-ESS cohort. Mean C-reactive protein levels and white blood cell counts were significantly higher in the ESS cohort as well. Their median hospital length of stay was 25.5 days, versus 18 days in the no-ESS group, Dr. Matsubara said at the congress sponsored by the International League Against Epilepsy.
Of the 76 ESSs that occurred in 66 patients, 37% were focal awareness seizures, 35% were focal to bilateral tonic-clonic seizures, and 28% were focal impaired awareness seizures.
In a multivariate analysis adjusted for age, sex, body mass index, stroke subtype, and other potential confounders, statin therapy during acute management of stroke was independently associated with a 56% reduction in the relative risk of ESS. In contrast, a cortical stroke lesion was associated with a 2.83-fold increased risk.
Since this wasn’t a randomized trial of statin therapy, Dr. Matsubara and his coinvestigators felt the need to go further in analyzing the data. After extensive propensity score matching for atrial fibrillation, current smoking, systolic blood pressure, the presence or absence of a cortical stroke lesion, large vessel stenosis, and other possible confounders, they were left with two closely comparable groups: 886 statin-treated stroke patients and an equal number who were not on statin therapy during their acute stroke management. The key finding: The risk of ESS was reduced by a whopping 77% in the patients on statin therapy.
The neurologist observed that these new findings in acute ischemic stroke patients are consistent with an earlier study in a U.S. Veterans Affairs population, which demonstrated that statin therapy was associated with a significantly lower risk of new-onset geriatric epilepsy (J Am Geriatr Soc. 2009 Feb;57[2]:237-42).
As to the possible mechanism by which statins may protect against ESS, Dr. Matsubara noted that acute ischemic stroke causes toxic neuronal excitation because of blood-brain barrier disruption, ion channel dysfunction, altered gene expression, and increased release of neurotransmitters. In animal models, statins provide a neuroprotective effect by reducing glutamate levels, activating endothelial nitric oxide synthase, and inhibiting production of interleukin-6, tumor necrosis factor-alpha, and other inflammatory cytokines.
Asked about the intensity of the statin therapy, Dr. Matsubara replied that the target was typically an LDL cholesterol below 100 mg/dL.
He reported having no financial conflicts regarding the study, conducted free of commercial support.
SOURCE: Matsubara S et al. IEC 219, Abstract P002.
BANGKOK – Statin therapy, even when initiated only upon hospitalization for acute ischemic stroke, was associated with a striking reduction in the risk of early poststroke symptomatic seizure in a large observational study.
Using propensity-score matching to control for potential confounders, use of a statin during acute stroke management was associated with a “robust” 77% reduction in the risk of developing a symptomatic seizure within 7 days after hospital admission, Soichiro Matsubara, MD, reported at the International Epilepsy Congress.
This is an important finding because early symptomatic seizure (ESS) occurs in 2%-7% of patients following an acute ischemic stroke. Moreover, an Italian meta-analysis concluded that ESS was associated with a 4.4-fold increased risk of developing poststroke epilepsy (Epilepsia. 2016 Aug;57[8]:1205-14), noted Dr. Matsubara, a neurologist at the National Cerebral and Cardiovascular Center in Suita, Japan, as well as at Kumamoto (Japan) University.
He presented a study of 2,969 consecutive acute ischemic stroke patients with no history of epilepsy who were admitted to the Japanese comprehensive stroke center, of whom 2.2% experienced ESS. At physician discretion, 19% of the ESS cohort were on a statin during their acute stroke management, as were 55% of the no-ESS group. Four-fifths of patients on a statin initiated the drug only upon hospital admission.
Strokes tended to be more severe in the ESS group, with a median initial National Institutes of Health Stroke Scale score of 12.5, compared with 4 in the seizure-free patients. A cortical stroke lesion was evident upon imaging in 89% of the ESS group and 55% of no-ESS patients. Among ESS patients, 46% had a cardiometabolic stroke, compared with 34% of the no-ESS cohort. Mean C-reactive protein levels and white blood cell counts were significantly higher in the ESS cohort as well. Their median hospital length of stay was 25.5 days, versus 18 days in the no-ESS group, Dr. Matsubara said at the congress sponsored by the International League Against Epilepsy.
Of the 76 ESSs that occurred in 66 patients, 37% were focal awareness seizures, 35% were focal to bilateral tonic-clonic seizures, and 28% were focal impaired awareness seizures.
In a multivariate analysis adjusted for age, sex, body mass index, stroke subtype, and other potential confounders, statin therapy during acute management of stroke was independently associated with a 56% reduction in the relative risk of ESS. In contrast, a cortical stroke lesion was associated with a 2.83-fold increased risk.
Since this wasn’t a randomized trial of statin therapy, Dr. Matsubara and his coinvestigators felt the need to go further in analyzing the data. After extensive propensity score matching for atrial fibrillation, current smoking, systolic blood pressure, the presence or absence of a cortical stroke lesion, large vessel stenosis, and other possible confounders, they were left with two closely comparable groups: 886 statin-treated stroke patients and an equal number who were not on statin therapy during their acute stroke management. The key finding: The risk of ESS was reduced by a whopping 77% in the patients on statin therapy.
The neurologist observed that these new findings in acute ischemic stroke patients are consistent with an earlier study in a U.S. Veterans Affairs population, which demonstrated that statin therapy was associated with a significantly lower risk of new-onset geriatric epilepsy (J Am Geriatr Soc. 2009 Feb;57[2]:237-42).
As to the possible mechanism by which statins may protect against ESS, Dr. Matsubara noted that acute ischemic stroke causes toxic neuronal excitation because of blood-brain barrier disruption, ion channel dysfunction, altered gene expression, and increased release of neurotransmitters. In animal models, statins provide a neuroprotective effect by reducing glutamate levels, activating endothelial nitric oxide synthase, and inhibiting production of interleukin-6, tumor necrosis factor-alpha, and other inflammatory cytokines.
Asked about the intensity of the statin therapy, Dr. Matsubara replied that the target was typically an LDL cholesterol below 100 mg/dL.
He reported having no financial conflicts regarding the study, conducted free of commercial support.
SOURCE: Matsubara S et al. IEC 219, Abstract P002.
REPORTING FROM IEC 2019
Noninvasive EEG may speed diagnosis of West syndrome
BANGKOK – , Hiroki Nariai, MD, reported at the International Epilepsy Congress.
Among the most promising of these potential EEG biomarkers for development of epilepsy are ictal or interictal high-frequency oscillations (HFOs) at 80 Hz or more, along with cross-frequency coupling of HFOs and delta wave activity, according to Dr. Nariai, a pediatric neurologist at the University of California, Los Angeles.
West syndrome, the most common epileptic encephalopathy during the first 2 years of life, has diverse etiologies. For example, in 250 infants with West syndrome enrolled in the United Kingdom National Infantile Spasms Consortium, a cause was identified in 64%. The etiology was genetic in 14% of subjects, a structural-congenital anomaly in 11%, tuberous sclerosis – a genetic-structural abnormality – in 10%, stroke in 22%, a metabolic defect in 5%, and infection in 2% (Epilepsia. 2015 Apr;56[4]:617-25).
West syndrome is rare, with an estimated prevalence of roughly 1 per 6,000 live births, but the associated mortality is high: 31% on average. And West syndrome often brings severe neurodevelopmental morbidity, with normal or near-normal intelligence present in only 25% of survivors.
An intensive search is on for an objective, reliable diagnostic biomarker – be it electroencephalographic, biochemical, or perhaps a neuroimaging finding – because the clinical diagnosis of West syndrome is highly subjective. It relies upon the triad of epileptic spasms, developmental regression or psychomotor delay, and hypsarrhythmia, which is a chaotic, disorganized, patternless form of brain electrical activity. And while that description makes hypsarrhythmia sound as if it should be easily recognizable, in fact that’s often not the case: Interrater reliability was poor in a study of six pediatric EEG experts at four centers who viewed 5-minute-long EEG samples obtained from 22 patients with infantile spasms (Epilepsia. 2015 Jan;56[1]:77-81), Dr. Nariai noted at the congress, sponsored by the International League Against Epilepsy.
“The clinical trial is maybe not so useful,” he observed.
The hunt for a reliable biomarker is further fueled by evidence that early diagnosis and treatment of West syndrome and other etiologies of infantile spasms makes a real difference. Indeed, investigators found in the United Kingdom Infantile Spasms Study that increasing lag time from onset of spasms to initiation of treatment was associated in stepwise fashion with significantly lower IQ at 4 years of age. While infants who started treatment within 7 days of onset of the seizure disorder had a mean IQ of 76.2 at age 4 years, those with an 8- to 14-day lag time between symptom onset and treatment averaged an additional 3.9-point decrement in IQ. A 15- to 30-day delay was associated with a 7.8-point reduction in IQ, compared with the reference group, while the decrease in IQ averaged 11.7 points in infants with a 1- to 2-month lag time and 15.6 points in those with a lag time of more than 2 months (Epilepsia. 2011 Jul;52[7]:1359-64).
At the start of the decade, Dr. Nariai and other investigators demonstrated that pathologic HFOs recorded during invasive EEG monitoring in conjunction with epilepsy surgery served as a reliable biomarker of epilepsy. While this was an important observation, a biomarker obtained through invasive monitoring during brain surgery clearly has very limited clinical applicability. But more recently, Dr. Nariai and his coinvestigators in the Tuberous Sclerosis Complex Autism Center of Excellence Network reported that noninvasive detection of interictal HFO fast ripples in the 250-500 Hz range via scalp EEG showed promise as a biomarker of epilepsy. Sensitivity of this far more practical approach to the detection of fast ripples was excellent, whether analyzed visually or by automatic detector (Clin Neurophysiol. 2018 Jul;129[7]:1458-66).
Moreover, in a recent, not-yet published study that Dr. Nariai and coworkers conducted in 24 infants with active epileptic spasms and 6 controls, noninvasive objective measurement of HFO rate using scalp EEG had an 83% sensitivity and 100% specificity for active epileptic spasms, while the modulation index of HFO and delta coupling in the 3-4 Hz range showed 74% sensitivity and 86% specificity.
If future studies validate the utility of detection of HFOs above a defined threshold or another noninvasively obtained EEG biomarker for diagnosis of epilepsy, the same strategy would presumably also be applicable for monitoring response to antiepileptic therapies, thereby eliminating the traditional trial-and-error approach to treatment. This would be a particularly important application in patients with West syndrome, where it’s believed that the electrical activity itself is contributing to the progressive – and often rapid – loss of cognitive function and behavioral disturbances. Thus, unlike in most other forms of epilepsy, the treatment goal isn’t merely to suppress the seizures, but also to achieve disease modification by eliminating the underlying subclinical EEG abnormalities, he explained.
A reliable biomarker would also be a boon in selecting the best participants for clinical trials of new antiseizure therapies.
Dr. Nariai reported having no financial conflicts regarding his presentation. His work is funded by research foundations and the National Institutes of Health.
BANGKOK – , Hiroki Nariai, MD, reported at the International Epilepsy Congress.
Among the most promising of these potential EEG biomarkers for development of epilepsy are ictal or interictal high-frequency oscillations (HFOs) at 80 Hz or more, along with cross-frequency coupling of HFOs and delta wave activity, according to Dr. Nariai, a pediatric neurologist at the University of California, Los Angeles.
West syndrome, the most common epileptic encephalopathy during the first 2 years of life, has diverse etiologies. For example, in 250 infants with West syndrome enrolled in the United Kingdom National Infantile Spasms Consortium, a cause was identified in 64%. The etiology was genetic in 14% of subjects, a structural-congenital anomaly in 11%, tuberous sclerosis – a genetic-structural abnormality – in 10%, stroke in 22%, a metabolic defect in 5%, and infection in 2% (Epilepsia. 2015 Apr;56[4]:617-25).
West syndrome is rare, with an estimated prevalence of roughly 1 per 6,000 live births, but the associated mortality is high: 31% on average. And West syndrome often brings severe neurodevelopmental morbidity, with normal or near-normal intelligence present in only 25% of survivors.
An intensive search is on for an objective, reliable diagnostic biomarker – be it electroencephalographic, biochemical, or perhaps a neuroimaging finding – because the clinical diagnosis of West syndrome is highly subjective. It relies upon the triad of epileptic spasms, developmental regression or psychomotor delay, and hypsarrhythmia, which is a chaotic, disorganized, patternless form of brain electrical activity. And while that description makes hypsarrhythmia sound as if it should be easily recognizable, in fact that’s often not the case: Interrater reliability was poor in a study of six pediatric EEG experts at four centers who viewed 5-minute-long EEG samples obtained from 22 patients with infantile spasms (Epilepsia. 2015 Jan;56[1]:77-81), Dr. Nariai noted at the congress, sponsored by the International League Against Epilepsy.
“The clinical trial is maybe not so useful,” he observed.
The hunt for a reliable biomarker is further fueled by evidence that early diagnosis and treatment of West syndrome and other etiologies of infantile spasms makes a real difference. Indeed, investigators found in the United Kingdom Infantile Spasms Study that increasing lag time from onset of spasms to initiation of treatment was associated in stepwise fashion with significantly lower IQ at 4 years of age. While infants who started treatment within 7 days of onset of the seizure disorder had a mean IQ of 76.2 at age 4 years, those with an 8- to 14-day lag time between symptom onset and treatment averaged an additional 3.9-point decrement in IQ. A 15- to 30-day delay was associated with a 7.8-point reduction in IQ, compared with the reference group, while the decrease in IQ averaged 11.7 points in infants with a 1- to 2-month lag time and 15.6 points in those with a lag time of more than 2 months (Epilepsia. 2011 Jul;52[7]:1359-64).
At the start of the decade, Dr. Nariai and other investigators demonstrated that pathologic HFOs recorded during invasive EEG monitoring in conjunction with epilepsy surgery served as a reliable biomarker of epilepsy. While this was an important observation, a biomarker obtained through invasive monitoring during brain surgery clearly has very limited clinical applicability. But more recently, Dr. Nariai and his coinvestigators in the Tuberous Sclerosis Complex Autism Center of Excellence Network reported that noninvasive detection of interictal HFO fast ripples in the 250-500 Hz range via scalp EEG showed promise as a biomarker of epilepsy. Sensitivity of this far more practical approach to the detection of fast ripples was excellent, whether analyzed visually or by automatic detector (Clin Neurophysiol. 2018 Jul;129[7]:1458-66).
Moreover, in a recent, not-yet published study that Dr. Nariai and coworkers conducted in 24 infants with active epileptic spasms and 6 controls, noninvasive objective measurement of HFO rate using scalp EEG had an 83% sensitivity and 100% specificity for active epileptic spasms, while the modulation index of HFO and delta coupling in the 3-4 Hz range showed 74% sensitivity and 86% specificity.
If future studies validate the utility of detection of HFOs above a defined threshold or another noninvasively obtained EEG biomarker for diagnosis of epilepsy, the same strategy would presumably also be applicable for monitoring response to antiepileptic therapies, thereby eliminating the traditional trial-and-error approach to treatment. This would be a particularly important application in patients with West syndrome, where it’s believed that the electrical activity itself is contributing to the progressive – and often rapid – loss of cognitive function and behavioral disturbances. Thus, unlike in most other forms of epilepsy, the treatment goal isn’t merely to suppress the seizures, but also to achieve disease modification by eliminating the underlying subclinical EEG abnormalities, he explained.
A reliable biomarker would also be a boon in selecting the best participants for clinical trials of new antiseizure therapies.
Dr. Nariai reported having no financial conflicts regarding his presentation. His work is funded by research foundations and the National Institutes of Health.
BANGKOK – , Hiroki Nariai, MD, reported at the International Epilepsy Congress.
Among the most promising of these potential EEG biomarkers for development of epilepsy are ictal or interictal high-frequency oscillations (HFOs) at 80 Hz or more, along with cross-frequency coupling of HFOs and delta wave activity, according to Dr. Nariai, a pediatric neurologist at the University of California, Los Angeles.
West syndrome, the most common epileptic encephalopathy during the first 2 years of life, has diverse etiologies. For example, in 250 infants with West syndrome enrolled in the United Kingdom National Infantile Spasms Consortium, a cause was identified in 64%. The etiology was genetic in 14% of subjects, a structural-congenital anomaly in 11%, tuberous sclerosis – a genetic-structural abnormality – in 10%, stroke in 22%, a metabolic defect in 5%, and infection in 2% (Epilepsia. 2015 Apr;56[4]:617-25).
West syndrome is rare, with an estimated prevalence of roughly 1 per 6,000 live births, but the associated mortality is high: 31% on average. And West syndrome often brings severe neurodevelopmental morbidity, with normal or near-normal intelligence present in only 25% of survivors.
An intensive search is on for an objective, reliable diagnostic biomarker – be it electroencephalographic, biochemical, or perhaps a neuroimaging finding – because the clinical diagnosis of West syndrome is highly subjective. It relies upon the triad of epileptic spasms, developmental regression or psychomotor delay, and hypsarrhythmia, which is a chaotic, disorganized, patternless form of brain electrical activity. And while that description makes hypsarrhythmia sound as if it should be easily recognizable, in fact that’s often not the case: Interrater reliability was poor in a study of six pediatric EEG experts at four centers who viewed 5-minute-long EEG samples obtained from 22 patients with infantile spasms (Epilepsia. 2015 Jan;56[1]:77-81), Dr. Nariai noted at the congress, sponsored by the International League Against Epilepsy.
“The clinical trial is maybe not so useful,” he observed.
The hunt for a reliable biomarker is further fueled by evidence that early diagnosis and treatment of West syndrome and other etiologies of infantile spasms makes a real difference. Indeed, investigators found in the United Kingdom Infantile Spasms Study that increasing lag time from onset of spasms to initiation of treatment was associated in stepwise fashion with significantly lower IQ at 4 years of age. While infants who started treatment within 7 days of onset of the seizure disorder had a mean IQ of 76.2 at age 4 years, those with an 8- to 14-day lag time between symptom onset and treatment averaged an additional 3.9-point decrement in IQ. A 15- to 30-day delay was associated with a 7.8-point reduction in IQ, compared with the reference group, while the decrease in IQ averaged 11.7 points in infants with a 1- to 2-month lag time and 15.6 points in those with a lag time of more than 2 months (Epilepsia. 2011 Jul;52[7]:1359-64).
At the start of the decade, Dr. Nariai and other investigators demonstrated that pathologic HFOs recorded during invasive EEG monitoring in conjunction with epilepsy surgery served as a reliable biomarker of epilepsy. While this was an important observation, a biomarker obtained through invasive monitoring during brain surgery clearly has very limited clinical applicability. But more recently, Dr. Nariai and his coinvestigators in the Tuberous Sclerosis Complex Autism Center of Excellence Network reported that noninvasive detection of interictal HFO fast ripples in the 250-500 Hz range via scalp EEG showed promise as a biomarker of epilepsy. Sensitivity of this far more practical approach to the detection of fast ripples was excellent, whether analyzed visually or by automatic detector (Clin Neurophysiol. 2018 Jul;129[7]:1458-66).
Moreover, in a recent, not-yet published study that Dr. Nariai and coworkers conducted in 24 infants with active epileptic spasms and 6 controls, noninvasive objective measurement of HFO rate using scalp EEG had an 83% sensitivity and 100% specificity for active epileptic spasms, while the modulation index of HFO and delta coupling in the 3-4 Hz range showed 74% sensitivity and 86% specificity.
If future studies validate the utility of detection of HFOs above a defined threshold or another noninvasively obtained EEG biomarker for diagnosis of epilepsy, the same strategy would presumably also be applicable for monitoring response to antiepileptic therapies, thereby eliminating the traditional trial-and-error approach to treatment. This would be a particularly important application in patients with West syndrome, where it’s believed that the electrical activity itself is contributing to the progressive – and often rapid – loss of cognitive function and behavioral disturbances. Thus, unlike in most other forms of epilepsy, the treatment goal isn’t merely to suppress the seizures, but also to achieve disease modification by eliminating the underlying subclinical EEG abnormalities, he explained.
A reliable biomarker would also be a boon in selecting the best participants for clinical trials of new antiseizure therapies.
Dr. Nariai reported having no financial conflicts regarding his presentation. His work is funded by research foundations and the National Institutes of Health.
REPORTING FROM IEC 2019
Cutaneous reaction to AEDs? Think autoimmune epilepsy
BANGKOK – Cutaneous reactions to antiepileptic drugs in patients with chronic epilepsy suggest increased likelihood of an autoimmune element to their seizure disorder, Fernando Cendes, MD, PhD, reported at the International Epilepsy Congress.
“My recommendation based on our findings is that if you have a patient who has a history of skin reactions to AEDs [antiepileptic drugs], or who has psychosis, or who has a very strange response to antiepileptic medication – meaning that at some points they are refractory and at other points they are very well controlled – I think those patients are probably at risk for having an autoantibody,” he said at the congress sponsored by the International League Against Epilepsy.
Screening for autoantibodies in such patients is appropriate. However, there’s a caveat: “The thing is, we don’t have evidence that treating these autoantibodies with immunotherapy will have any benefit on seizure control in these patients. We don’t have that data yet, but we are looking into it,” according to Dr. Cendes, professor of neurology at the State University of Campinas (Brazil).
He presented a study of 221 consecutive adults with severe chronic refractory epilepsy as evidenced by a mean disease duration of nearly 29 years, with an average of 5.93 seizures per month. A total of 77% had a structural etiology for their epilepsy, in most cases hippocampal sclerosis. In 19% of patients, the etiology was unknown. Overall, 95% of subjects had focal epilepsy, and the remainder had generalized epilepsy. All underwent serum testing for a variety of antibodies against neuronal surface antigens that have been implicated in encephalitis, seizures, and/or psychosis. Those who tested positive then underwent confirmatory testing of their cerebrospinal fluid.
The impetus for this study, the neurologist explained, is that although it’s now well established that seizures are a common clinical expression of acute- and subacute-phase autoimmune encephalitis marked by neuronal autoantibodies, little is known about the relationship between chronic epilepsy and such antibodies.
Only five Brazilian patients with chronic epilepsy, or 2.2%, tested positive for autoantibodies, all of whom had mesial temporal lobe epilepsy with hippocampal sclerosis. This suggests a possible autoimmune etiology for hippocampal sclerosis. Three of the five patients had anti-N-methyl-D-aspartate receptor antibodies (anti-NMDA) and two had antiglutamic acid decarboxylate antibodies (anti-GAD). No one was positive for anti–leucine-rich glioma-inactivated 1 antibodies (anti-LGI1), anti–contactin-associated proteinlike 2 (anti-caspr2), anti-glutamate receptor antibodies (anti-AMPAr), or anti–gamma-aminobutyric acid receptor antibodies (anti-GABAr).
The autoantibody-negative and the much smaller autoantibody-positive groups didn’t differ significantly in terms of demographics, seizure frequency, disease duration, drug resistance, cognitive impairment, comorbid autoimmune conditions, or history of status epilepticus. Indeed, only two between-group differences were found: fluctuation in seizure control was an issue in 10.6% of autoantibody-negative and 40% of autoantibody-positive patients, and cutaneous adverse reactions to antiepileptic drugs were noted in 10.6% of antibody-negative and 60% of antibody-positive patients. Psychiatric comorbidities were present in 49.5% of autoantibody-negative patients as compared with 80% – that is, four of five – who were autoantibody-positive, a trend that didn’t achieve statistical significance.
Asked if he thinks the autoantibodies found in a small subset of patients with chronic epilepsy were a cause or an effect of repeated seizures for so long, Dr. Cendes replied, “That’s a very interesting question, and I don’t have an answer, actually. But if seizures trigger development of these antibodies – and remember, this population we’re talking about had many, many seizures over the years – I would expect antibodies to be more frequent than the figure we found.”
He reported having no financial conflicts regarding his study.
SOURCE: Watanabe N et al. IEC 2019, Abstract P004.
BANGKOK – Cutaneous reactions to antiepileptic drugs in patients with chronic epilepsy suggest increased likelihood of an autoimmune element to their seizure disorder, Fernando Cendes, MD, PhD, reported at the International Epilepsy Congress.
“My recommendation based on our findings is that if you have a patient who has a history of skin reactions to AEDs [antiepileptic drugs], or who has psychosis, or who has a very strange response to antiepileptic medication – meaning that at some points they are refractory and at other points they are very well controlled – I think those patients are probably at risk for having an autoantibody,” he said at the congress sponsored by the International League Against Epilepsy.
Screening for autoantibodies in such patients is appropriate. However, there’s a caveat: “The thing is, we don’t have evidence that treating these autoantibodies with immunotherapy will have any benefit on seizure control in these patients. We don’t have that data yet, but we are looking into it,” according to Dr. Cendes, professor of neurology at the State University of Campinas (Brazil).
He presented a study of 221 consecutive adults with severe chronic refractory epilepsy as evidenced by a mean disease duration of nearly 29 years, with an average of 5.93 seizures per month. A total of 77% had a structural etiology for their epilepsy, in most cases hippocampal sclerosis. In 19% of patients, the etiology was unknown. Overall, 95% of subjects had focal epilepsy, and the remainder had generalized epilepsy. All underwent serum testing for a variety of antibodies against neuronal surface antigens that have been implicated in encephalitis, seizures, and/or psychosis. Those who tested positive then underwent confirmatory testing of their cerebrospinal fluid.
The impetus for this study, the neurologist explained, is that although it’s now well established that seizures are a common clinical expression of acute- and subacute-phase autoimmune encephalitis marked by neuronal autoantibodies, little is known about the relationship between chronic epilepsy and such antibodies.
Only five Brazilian patients with chronic epilepsy, or 2.2%, tested positive for autoantibodies, all of whom had mesial temporal lobe epilepsy with hippocampal sclerosis. This suggests a possible autoimmune etiology for hippocampal sclerosis. Three of the five patients had anti-N-methyl-D-aspartate receptor antibodies (anti-NMDA) and two had antiglutamic acid decarboxylate antibodies (anti-GAD). No one was positive for anti–leucine-rich glioma-inactivated 1 antibodies (anti-LGI1), anti–contactin-associated proteinlike 2 (anti-caspr2), anti-glutamate receptor antibodies (anti-AMPAr), or anti–gamma-aminobutyric acid receptor antibodies (anti-GABAr).
The autoantibody-negative and the much smaller autoantibody-positive groups didn’t differ significantly in terms of demographics, seizure frequency, disease duration, drug resistance, cognitive impairment, comorbid autoimmune conditions, or history of status epilepticus. Indeed, only two between-group differences were found: fluctuation in seizure control was an issue in 10.6% of autoantibody-negative and 40% of autoantibody-positive patients, and cutaneous adverse reactions to antiepileptic drugs were noted in 10.6% of antibody-negative and 60% of antibody-positive patients. Psychiatric comorbidities were present in 49.5% of autoantibody-negative patients as compared with 80% – that is, four of five – who were autoantibody-positive, a trend that didn’t achieve statistical significance.
Asked if he thinks the autoantibodies found in a small subset of patients with chronic epilepsy were a cause or an effect of repeated seizures for so long, Dr. Cendes replied, “That’s a very interesting question, and I don’t have an answer, actually. But if seizures trigger development of these antibodies – and remember, this population we’re talking about had many, many seizures over the years – I would expect antibodies to be more frequent than the figure we found.”
He reported having no financial conflicts regarding his study.
SOURCE: Watanabe N et al. IEC 2019, Abstract P004.
BANGKOK – Cutaneous reactions to antiepileptic drugs in patients with chronic epilepsy suggest increased likelihood of an autoimmune element to their seizure disorder, Fernando Cendes, MD, PhD, reported at the International Epilepsy Congress.
“My recommendation based on our findings is that if you have a patient who has a history of skin reactions to AEDs [antiepileptic drugs], or who has psychosis, or who has a very strange response to antiepileptic medication – meaning that at some points they are refractory and at other points they are very well controlled – I think those patients are probably at risk for having an autoantibody,” he said at the congress sponsored by the International League Against Epilepsy.
Screening for autoantibodies in such patients is appropriate. However, there’s a caveat: “The thing is, we don’t have evidence that treating these autoantibodies with immunotherapy will have any benefit on seizure control in these patients. We don’t have that data yet, but we are looking into it,” according to Dr. Cendes, professor of neurology at the State University of Campinas (Brazil).
He presented a study of 221 consecutive adults with severe chronic refractory epilepsy as evidenced by a mean disease duration of nearly 29 years, with an average of 5.93 seizures per month. A total of 77% had a structural etiology for their epilepsy, in most cases hippocampal sclerosis. In 19% of patients, the etiology was unknown. Overall, 95% of subjects had focal epilepsy, and the remainder had generalized epilepsy. All underwent serum testing for a variety of antibodies against neuronal surface antigens that have been implicated in encephalitis, seizures, and/or psychosis. Those who tested positive then underwent confirmatory testing of their cerebrospinal fluid.
The impetus for this study, the neurologist explained, is that although it’s now well established that seizures are a common clinical expression of acute- and subacute-phase autoimmune encephalitis marked by neuronal autoantibodies, little is known about the relationship between chronic epilepsy and such antibodies.
Only five Brazilian patients with chronic epilepsy, or 2.2%, tested positive for autoantibodies, all of whom had mesial temporal lobe epilepsy with hippocampal sclerosis. This suggests a possible autoimmune etiology for hippocampal sclerosis. Three of the five patients had anti-N-methyl-D-aspartate receptor antibodies (anti-NMDA) and two had antiglutamic acid decarboxylate antibodies (anti-GAD). No one was positive for anti–leucine-rich glioma-inactivated 1 antibodies (anti-LGI1), anti–contactin-associated proteinlike 2 (anti-caspr2), anti-glutamate receptor antibodies (anti-AMPAr), or anti–gamma-aminobutyric acid receptor antibodies (anti-GABAr).
The autoantibody-negative and the much smaller autoantibody-positive groups didn’t differ significantly in terms of demographics, seizure frequency, disease duration, drug resistance, cognitive impairment, comorbid autoimmune conditions, or history of status epilepticus. Indeed, only two between-group differences were found: fluctuation in seizure control was an issue in 10.6% of autoantibody-negative and 40% of autoantibody-positive patients, and cutaneous adverse reactions to antiepileptic drugs were noted in 10.6% of antibody-negative and 60% of antibody-positive patients. Psychiatric comorbidities were present in 49.5% of autoantibody-negative patients as compared with 80% – that is, four of five – who were autoantibody-positive, a trend that didn’t achieve statistical significance.
Asked if he thinks the autoantibodies found in a small subset of patients with chronic epilepsy were a cause or an effect of repeated seizures for so long, Dr. Cendes replied, “That’s a very interesting question, and I don’t have an answer, actually. But if seizures trigger development of these antibodies – and remember, this population we’re talking about had many, many seizures over the years – I would expect antibodies to be more frequent than the figure we found.”
He reported having no financial conflicts regarding his study.
SOURCE: Watanabe N et al. IEC 2019, Abstract P004.
REPORTING FROM IEC 2019