Sudden unexpected death in epilepsy in lamotrigine randomized-controlled trials

Antiseizure medication and SUDEP - a need for unifying methodology in research

The risk of sudden unexpected death in epilepsy (SUDEP) increases with the frequency of generalized tonic-clonic seizures. Carbamazepine (CBZ) and lamotrigine (LTG) have been suggested to increase the risk. However, the prevailing viewpoint is that the choice of antiseizure medication (ASM) does not influence the occurrence. We have explored the approach to addressing this question in relevant studies to evaluate the validity of the conclusions reached. A systematic search was performed in PubMed to identify all controlled studies on SUDEP risk in individuals on CBZ or LTG. Studies were categorized according to whether idiopathic generalized epilepsy (IGE) or females were considered separately, and whether data were adjusted for seizure frequency. Eight studies on CBZ and six studies on LTG were identified. For CBZ, one study showed a significantly increased risk of SUDEP without adjustment for seizure frequency. Another study found significantly increased risk after statistical adjustment for seizure frequency and one study found increased risk with high blood levels. Five other studies found no increase in risk. For LTG, one study showed a significantly increased risk in patients with IGE as opposed to focal epilepsy, and another study showed a significantly increased risk in females. None of the subsequent studies on LTG and none of the studies on CBZ considered females with IGE separately. Taken together the available studies suggest that LTG, and possibly CBZ, may increase occurrence of SUDEP when used in females with IGE. Additional studies with sub-group analysis of females with IGE are needed.

Lamotrigine add-on therapy for drug-resistant focal epilepsy

BACKGROUND

This is an updated version of a Cochrane Review last updated in 2020. Epilepsy is a common neurological disorder, affecting 0.5% to 1% of the population. In nearly 30% of cases, epilepsy is resistant to currently available drugs. Pharmacological treatment remains the first choice to control epilepsy. Lamotrigine is a second-generation antiseizure medication. When used as an add-on (in combination with other antiseizure medications), lamotrigine can reduce seizures, but with some adverse effects.

OBJECTIVES

To evaluate the benefits and harms of add-on lamotrigine, compared with add-on placebo or no add-on treatment in people with drug-resistant focal epilepsy.

SEARCH METHODS

For this update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid) on 3 October 2022 with no language restrictions. CRS Web includes randomised and quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialised Registers of Cochrane Review Groups, including Epilepsy.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that investigated add-on lamotrigine versus add-on placebo or no add-on treatment in people of any age with drug-resistant focal epilepsy. We used data from the first period of eligible cross-over trials.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently selected trials and extracted data. Our primary outcome was 50% or greater reduction in seizure frequency. Our secondary outcomes were treatment withdrawal, adverse effects, cognitive effects, and quality of life. Primary analyses were by intention-to-treat. We performed sensitivity best- and worse-case analyses to account for missing outcome data. We calculated pooled risk ratios (RRs) with 95% confidence intervals (95% Cls) for dichotomous outcomes.

MAIN RESULTS

We identified no new studies for this update, so the results and conclusions of the review are unchanged. We included five parallel-group studies in adults or children, eight cross-over studies in adults or children, and one parallel study with a responder-enriched design in infants. In total, these 14 studies enroled 1806 eligible participants (38 infants, 199 children, 1569 adults). Baseline phases ranged from four to 12 weeks and treatment phases ranged from eight to 36 weeks. We rated 11 studies (1243 participants) at low overall risk of bias and three (697 participants) at unclear overall risk of bias due to lack of information on study design. Four studies (563 participants) reported effective blinding. Lamotrigine compared with placebo probably increases the likelihood of achieving 50% or greater reduction in seizure frequency (RR 1.80, 95% CI 1.45 to 2.23; 12 trials, 1322 participants (adults and children); moderate-certainty evidence). There is probably little or no difference in risk of treatment withdrawal for any reason among people treated with lamotrigine versus people treated with placebo (RR 1.11, 95% CI 0.91 to 1.37; 14 trials; 1806 participants; moderate-certainty evidence). Lamotrigine compared with placebo is probably associated with a greater risk of ataxia (RR 3.34, 99% Cl 2.01 to 5.55; 12 trials; 1525 participants; moderate-certainty evidence), dizziness (RR 1.76, 99% Cl 1.28 to 2.43; 13 trials; 1768 participants; moderate-certainty evidence), nausea (RR 1.81, 99% CI 1.22 to 2.68; 12 studies, 1486 participants; moderate-certainty evidence), and diplopia (RR 3.79, 99% Cl 2.15 to 6.68; 3 trials, 944 participants; moderate-certainty evidence). There is probably little or no difference in the risk of fatigue between lamotrigine and placebo (RR 0.82, 99% CI 0.55 to 1.22; 12 studies, 1552 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Lamotrigine as an add-on treatment for drug-resistant focal seizures is probably effective for reducing seizure frequency. Certain adverse effects (ataxia, dizziness, diplopia, and nausea) are probably more likely to occur with lamotrigine compared with placebo. There is probably little or no difference in the number of people who withdraw from treatment with lamotrigine versus placebo. The trials were of relatively short duration and provided no long-term evidence. In addition, some trials had few participants. Further trials are needed to assess the long-term effects of lamotrigine and to compare lamotrigine with other add-on drugs.

Sudden unexpected death in epilepsy during cenobamate clinical development

OBJECTIVE

We assessed mortality, sudden unexpected death in epilepsy (SUDEP), and standardized mortality ratio (SMR) among adults treated with cenobamate during the cenobamate clinical development program.

METHODS

We retrospectively analyzed deaths among all adults with uncontrolled focal (focal to bilateral tonic-clonic [FBTC], focal impaired awareness, focal aware) or primary generalized tonic-clonic (PGTC) seizures who received ≥1 dose of adjunctive cenobamate in completed and ongoing phase 2 and 3 clinical studies. In patients with focal seizures from completed studies, median baseline seizure frequencies ranged from 2.8 to 11 seizures per 28 days and median epilepsy duration ranged from 20 to 24 years. Total person-years included all days that a patient received cenobamate during completed studies or up to June 1, 2022, for ongoing studies. All deaths were evaluated by two epileptologists. All-cause mortality and SUDEP rates were expressed per 1000 person-years.

RESULTS

A total of 2132 patients (n = 2018 focal epilepsy; n = 114 idiopathic generalized epilepsy) were exposed to cenobamate for 5693 person-years. Approximately 60% of patients with focal seizures and all patients in the PGTC study had tonic-clonic seizures. A total of 23 deaths occurred (all in patients with focal epilepsy), for an all-cause mortality rate of 4.0 per 1000 person-years. Five cases of definite or probable SUDEP were identified, for a rate of .88 per 1000 person-years. Of the 23 overall deaths, 22 patients (96%) had FBTC seizures, and all 5 of the SUDEP patients had a history of FBTC seizures. The duration of exposure to cenobamate for patients with SUDEP ranged from 130 to 620 days. The SMR among cenobamate-treated patients in completed studies (5515 person-years of follow-up) was 1.32 (95% confidence interval [CI] .84-2.0), which was not significantly different from the general population.

SIGNIFICANCE

These data suggest that effective long-term medical treatment with cenobamate may reduce excess mortality associated with epilepsy.

Risk of sudden unexpected death in epilepsy (SUDEP) with lamotrigine and other sodium channel-modulating antiseizure medications

OBJECTIVE

In vitro data prompted U.S Food and Drug Administration warnings that lamotrigine, a common sodium channel modulating anti-seizure medication (NaM-ASM), could increase the risk of sudden death in patients with structural or ischaemic cardiac disease, however, its implications for Sudden Unexpected Death in Epilepsy (SUDEP) are unclear.

METHODS

This retrospective, nested case-control study identified 101 sudden unexpected death in epilepsy (SUDEP) cases and 199 living epilepsy controls from Epilepsy Monitoring Units (EMUs) in Australia and the USA. Differences in proportions of lamotrigine and NaM-ASM use were compared between cases and controls at the time of admission, and survival analyses from the time of admission up to 16 years were conducted. Multivariable logistic regression and survival analyses compared each ASM subgroup adjusting for SUDEP risk factors.

RESULTS

Proportions of cases and controls prescribed lamotrigine (P = 0.166), one NaM-ASM (P = 0.80), or ≥2NaM-ASMs (P = 0.447) at EMU admission were not significantly different. Patients taking lamotrigine (adjusted hazard ratio [aHR] = 0.56; P = 0.054), one NaM-ASM (aHR = 0.8; P = 0.588) or ≥2 NaM-ASMs (aHR = 0.49; P = 0.139) at EMU admission were not at increased SUDEP risk up to 16 years following admission. Active tonic-clonic seizures at EMU admission associated with >2-fold SUDEP risk, irrespective of lamotrigine (aHR = 2.24; P = 0.031) or NaM-ASM use (aHR = 2.25; P = 0.029). Sensitivity analyses accounting for incomplete ASM data at follow-up suggest undetected changes to ASM use are unlikely to alter our results.

SIGNIFICANCE

This study provides additional evidence that lamotrigine and other NaM-ASMs are unlikely to be associated with an increased long-term risk of SUDEP, up to 16 years post-EMU admission.

Cardiac morbidity and mortality associated with the use of lamotrigine

OBJECTIVE

The US Food and Drug Administration recently issued a warning against the use of the antiseizure medication lamotrigine in people at risk of cardiac rhythm and conduction abnormalities. This study assessed the risk of cardiac morbidity and mortality in new users of lamotrigine.

METHODS

In a Danish population-based cohort study, we followed cohort members aged ≥15 years for the first 2 years after they initiated lamotrigine therapy. The main outcomes were cardiac conduction disorders in people without pre-existing cardiac morbidity and all-cause mortality in people with pre-existing cardiac morbidity. Cox proportional hazards models provided hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for comparison of the risk in current versus past users of lamotrigine.

RESULTS

There were 91 949 (36 618 males [39.8%]) new users of lamotrigine (median age = 45.7 years, interquartile range = 32.0-60.2 years). Among users without pre-existing cardiac disease (n = 86 769), 194 (.23%) developed a cardiac conduction disorder. Comparison of the risk in current and past lamotrigine treatment periods yielded an adjusted HR of new onset cardiac conduction disorder of 1.03 (95% CI = .76-1.40). Among users with pre-existing cardiac disease (n = 5180), 1150 (22.2%) died. Comparison of the risk in current and past lamotrigine treatment periods yielded an adjusted HR for all cause-mortality of 1.05 (95% CI = .93-1.19).

SIGNIFICANCE

In this large population-based study, lamotrigine use was associated neither with a risk of cardiac conduction disorders in people without pre-existing cardiac morbidity nor with all-cause mortality in people with pre-existing cardiac morbidity.

Sudden Death and Cardiac Arrythmia With Lamotrigine: A Rapid Systematic Review

BACKGROUND AND OBJECTIVES

A recent Food and Drug Administration warning concerning an arrhythmogenic potential of lamotrigine created concern in the neurologic community. This warning was based on in vitro studies, but no clinically relevant risk was considered. This rapid systematic review aims to elucidate the risk of lamotrigine on sudden death or ECG abnormalities.

METHODS

We conducted a systematic search of Ovid Medline and Ovid Embase, including randomized controlled trials and observational studies and studies of people with or without epilepsy, with the outcome measures sudden unexpected death in epilepsy (SUDEP) or sudden cardiac death as well as the development or worsening of ECG abnormalities. We evaluated the sudden death definitions used in all included studies, as some could have used unclear or overlapping definitions. We used the American Academy of Neurology risk of bias tool to evaluate the class of evidence and the GRADE approach to evaluate our confidence in the evidence.

RESULTS

We included 26 studies with 24,962 participants, of whom 2,326 used lamotrigine. Twelve studies showed no significant risk of SUDEP for lamotrigine users. One study reporting on sudden cardiac death and 3 studies with unclear sudden death definitions did not report an elevated risk of death in lamotrigine users compared to controls. In 10 studies reporting on ECG measures, there was no statistically significant increased risk among lamotrigine users except in 2 studies. These 2 studies reported either "slight increases" in PR interval or an increased PQ interval that the primary study authors believed to be related to structural cardiac differences rather than an effect of lamotrigine. One study was rated Class II; all others were Class III or IV. We had very low confidence in the evidence following the GRADE assessment. None of the studies examined the risk of lamotrigine in people with preexisting cardiac conditions.

DISCUSSION

There is insufficient evidence to support or refute that lamotrigine is associated with sudden death or ECG changes in people with or without epilepsy as compared to antiseizure medication or placebo, due to the high risk of bias in most studies and low precision and inconsistency in the reported results.

Sudden unexpected death in epilepsy

PURPOSE OF REVIEW

Sudden unexpected death in epilepsy (SUDEP) is a major contributor to premature mortality in people with epilepsy. This review provides an update on recent findings on the epidemiology of SUDEP, clinical risk factors and potential mechanisms.

RECENT FINDINGS

The overall risk rate of SUDEP is approximately 1 per 1000 patients per year in the general epilepsy population and that children and older adults have a similar incidence. Generalized convulsive seizures (GCS), perhaps through their effects on brainstem cardiopulmonary networks, can cause significant postictal respiratory and autonomic dysfunction though other mechanisms likely exist as well. Work in animal models of SUDEP has identified multiple neurotransmitter systems, which may be future targets for pharmacological intervention. There are also chronic functional and structural changes in autonomic function in patients who subsequently die from SUDEP suggesting that some SUDEP risk is dynamic. Modifiable risks for SUDEP include GCS seizure frequency, medication adherence and nighttime supervision.

SUMMARY

Current knowledge of SUDEP risk factors has identified multiple targets for SUDEP prevention today as we await more specific therapeutic targets that are emerging from translational research studies.

Reducing Sudden Unexpected Death in Epilepsy: Considering Risk Factors, Pathophysiology and Strategies

Purpose of Review

Sudden Unexpected Death in Epilepsy (SUDEP) is the commonest cause of epilepsy-related premature mortality in people with chronic epilepsy. It is the most devastating epilepsy outcome. We describe and discuss risk factors and possible pathophysiological mechanisms to elucidate possible preventative strategies to avert SUDEP.

Recent Findings

Sudden death accounts for a significant proportion of premature mortality in people with epilepsy compared to the general population. Unmodifiable risk factors include a history of neurologic insult, younger age of seizure-onset, longer epilepsy duration, a history of convulsions, symptomatic epilepsy, intellectual disability, and non-ambulatory status. Modifiable risk factors include the presence of convulsive seizures, increased seizure frequency, timely and appropriate use of antiseizure medications, polytherapy, alcoholism, and supervision while sleeping. Pathophysiology is unclear, but several possible mechanisms such as direct alteration of cardiorespiratory function, pulmonary impairment, electrocerebral shutdown, adenosine dysfunction, and genetic susceptibility suggested.

Summary

Methods to prevent SUDEP include increasing awareness of SUDEP, augmenting knowledge of unmodifiable risk factors, obtaining full seizure remission, addressing lifestyle factors such as supervision and prone positioning, and enacting protocols to increase the detection of and intervention for SUDEP. Further studies are required to characterize precisely and comprehensively SUDEP risk factors and pathophysiological drivers and develop evidence-based algorithms to minimize SUDEP in people with epilepsy.

The effect of lamotrigine and other antiepileptic drugs on respiratory rhythm generation in the pre-Bötzinger complex

OBJECTIVE

Lamotrigine and other sodium-channel blocking agents are among the most commonly used antiepileptic drugs (AEDs). Because other sodium channel blockers, such as riluzole, can severely alter respiratory rhythm generation during hypoxia, we wanted to investigate if AEDs can have similar effects. This is especially important in the context of sudden unexpected death in epilepsy (SUDEP), the major cause of death in patients suffering from therapy-resistant epilepsy. Although the mechanism of action is not entirely understood, respiratory dysfunction after generalized tonic-clonic seizures seems to play a major role.

METHODS

We used transverse brainstem slice preparations from neonatal and juvenile mice containing the pre-Bötzinger complex (PreBötC) and measured population as well as intracellular activity of the rhythm-generating network under normoxia and hypoxia in the presence or absence of AEDs.

RESULTS

We found a substantial inhibition of the gasping response induced by the application of sodium channel blockers (lamotrigine and carbamazepine). In contrast, levetiracetam, an AED-modulating synaptic function, had a much smaller effect. The inhibition of gasping by lamotrigine was accompanied by a significant reduction of the persistent sodium current (INap) in PreBötC neurons. Surprisingly, the suppression of persistent sodium currents by lamotrigine did not affect the voltage-dependent bursting activity in PreBötC pacemaker neurons, but led to a hypoxia-dependent shift of the action potential rheobase in all measured PreBötC neurons.

SIGNIFICANCE

Our results contribute to the understanding of the effects of AEDs on the vital respiratory functions of the central nervous system. Moreover, our study adds further insight into sodium-dependent changes occurring during hypoxia and the contribution of cellular properties to the respiratory rhythm generation in the pre-Bötzinger complex. It raises the question of whether sodium channel blocking AEDs could, in conditions of extreme hypoxia, contribute to SUDEP, an important issue that warrants further studies.

The role of convulsive seizures in SUDEP

Convulsive seizures are the most consistently reported risk factor for SUDEP. However, the precise mechanisms by which convulsive seizures trigger fatal cardiopulmonary changes are still unclear. Additionally, it is not clear why some seizures cause death when most do not. This article reviews the physiologic changes that occur during and after convulsive seizures and how these may contribute to SUDEP. Seizures activate specific cortical and subcortical regions that can cause potentially lethal cardiorespiratory changes. Clinical factors, including sleep state, medication treatment and withdrawal, positioning and posturing during seizures, and underlying structural or genetic conditions may also affect specific aspects of seizures that may contribute to SUDEP. While seizure control, either through medication or surgical treatment, is the primary intervention that reduces SUDEP risk, unfortunately, seizures cannot be fully controlled despite maximal treatment in a significant proportion of people with epilepsy. Thus specific interventions to prevent adverse seizure-related cardiopulmonary consequences are needed. The potential roles of repositioning/stimulation after seizures, oxygen supplementation, cardiopulmonary resuscitation and clinical treatment options in reducing SUDEP risk are explored. Ultimately, understanding of these factors may lead to interventions that could reduce or prevent SUDEP.

Pharmacologic treatment and SUDEP risk: A nationwide, population-based, case-control study

Objective

We conducted a nationwide case–control study in Sweden to test the hypothesis that antiepileptic drugs (AEDs) mono- or polytherapy, adherence, antidepressants, neuroleptics, β-blockers, and statins are associated with sudden unexpected death in epilepsy (SUDEP) risk.

Methods

Included were 255 SUDEP cases and 1,148 matched controls. Information on clinical factors and medications came from medical records and the National Patient and Prescription Registers. The association between SUDEP and medications was assessed by odds ratios (ORs) with 95% confidence intervals (CIs) adjusted for potential risk factors including type of epilepsy, living conditions, comorbidity, and frequency of generalized tonic-clonic seizures (GTCS).

Results

Polytherapy, especially taking 3 or more AEDs, was associated with a substantially reduced risk of SUDEP (OR 0.31, 95% CI 0.14–0.67). Combinations including lamotrigine (OR 0.55, 95% CI 0.31–0.97), valproic acid (OR 0.53, 95% CI 0.29–0.98), and levetiracetam (OR 0.49, 95% CI 0.27–0.90) were associated with reduced risk. No specific AED was associated with increased risk. Regarding monotherapy, although numbers were limited, the lowest SUDEP risk was seen in users of levetiracetam (0.10, 95% CI 0.02–0.61). Having nonadherence mentioned in the medical record was associated with an OR of 2.75 (95% CI 1.58–4.78). Statin use was associated with a reduced SUDEP risk (OR 0.34, 95% CI 0.11–0.99) but selective serotonin reuptake inhibitor use was not.

Conclusion

These results provide support for the importance of medication adherence and intensified AED treatment for patients with poorly controlled GTCS in the effort to reduce SUDEP risk and suggest that comedication with statins may reduce risk.

Prevention of sudden unexpected death in epilepsy: current status and future perspectives

Introduction: Sudden unexpected death in epilepsy (SUDEP) affects about 1 in 1000 people with epilepsy, and even more in medically refractory epilepsy. As most people are between 20 and 40 years when dying suddenly, SUDEP leads to a considerable loss of potential life years. The most important risk factors are nocturnal and tonic-clonic seizures, underscoring that supervision and effective seizure control are key elements for SUDEP prevention. The question of whether specific antiepileptic drugs are linked to SUDEP is still controversially discussed. Knowledge and education about SUDEP among health-care professionals, patients, and relatives are of outstanding importance for preventive measures to be taken, but still poor and widely neglected.Areas covered: This article reviews epidemiology, pathophysiology, risk factors, assessment of individual SUDEP risk and available measures for SUDEP prevention. Literature search was done using Medline and Pubmed in October 2019.Expert opinion: Significant advances in the understanding of SUDEP were made in the last decade which allow testing of novel strategies to prevent SUDEP. Promising current strategies target neuronal mechanisms of brain stem dysfunction, cardiac susceptibility for fatal arrhythmias, and reliable detection of tonic-clonic seizures using mobile health technologies.Abbreviations: AED, antiepileptic drug; CBZ, carbamazepine; cLQTS, congenital long QT syndrome; EMU, epilepsy monitoring unit; FBTCS, focal to bilateral tonic-clonic seizures; GTCS, generalized tonic-clonic seizures; ICA, ictal central apnea; LTG, lamotrigine; PCCA, postconvulsive central apnea; PGES, postictal generalized EEG suppression; SRI, serotonin reuptake inhibitor; SUDEP, sudden unexpected death in epilepsy; TCS, tonic-clonic seizures.

Lamotrigine add-on therapy for drug-resistant focal epilepsy

BACKGROUND

This is an updated version of the Cochrane Review previously published in 2016. Epilepsy is a common neurological disorder, affecting 0.5% to 1% of the population. For nearly 30% of these people, their epilepsy is resistant to currently available drugs. Pharmacological treatment remains the first choice to control epilepsy. Lamotrigine is one of the newer antiepileptic drugs. Lamotrigine, in combination with other antiepileptic drugs (add-on), can reduce seizures, but with some adverse effects.

OBJECTIVES

To determine the effects of lamotrigine on (1) seizures, (2) adverse-effect profile, and (3) cognition and quality of life, compared to placebo, when used as an add-on treatment for people with drug-resistant focal epilepsy.

SEARCH METHODS

For the latest update of the review, we searched the following databases on 9 March 2020: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to March 06, 2020). CRS Web includes randomized or quasi-randomized, controlled trials from PubMed, EMBASE, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups including Epilepsy. No language restrictions were imposed.

SELECTION CRITERIA

Randomised placebo-controlled trials of people with drug-resistant focal epilepsy of any age, in which an adequate method of concealment of randomisation was used. The studies were double-, single- or unblinded, placebo-controlled. For cross-over studies, the first treatment period was treated as a parallel trial. Eligible participants were adults or children with drug-resistant focal epilepsy.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently assessed the trials for inclusion, and extracted data. Outcomes included 50% or greater reduction in seizure frequency, treatment withdrawal (any reason), adverse effects, effects on cognition and quality of life. Primary analyses were by intention-to-treat. Sensitivity best- and worse-case analyses were undertaken to account for missing outcome data. Pooled risk ratios (RRs) with 95% confidence intervals (95% Cls) were estimated for the primary outcomes of seizure frequency and treatment withdrawal. For adverse effects, we calculated pooled RRs and 99% Cls.

MAIN RESULTS

We did not identify any new studies for this update, therefore, the results and conclusions are unchanged. In previous updates of this review, the authors found five parallel add-on studies, eight cross-over studies in adults or children with drug-resistant focal epilepsy, and one parallel add-on study with a responder-enriched design in infants. In total, these 14 studies included 1806 eligible participants (38 infants, 199 children, 1569 adults). Baseline phases ranged from four to 12 weeks; treatment phases from eight to 36 weeks. Overall, 11 studies (1243 participants) were rated as having low risk of bias, and three (697 participants) had unclear risk of bias due to lack of reported information around study design. Effective blinding of studies was reported in four studies (563 participants). The overall risk ratio (RR) for 50% or greater reduction in seizure frequency was 1.80 (95% CI 1.45 to 2.23; 12 trials, 1322 participants (adults and children); moderate-certainty evidence) indicating that lamotrigine was significantly more effective than placebo in reducing seizure frequency. The overall RR for treatment withdrawal (for any reason) was 1.11 (95% CI 0.91 to 1.37; 14 trials; 1806 participants; moderate-certainty evidence). The adverse events significantly associated with lamotrigine were: ataxia, dizziness, diplopia (double vision), and nausea. The RR of these adverse effects were as follows: ataxia 3.34 (99% Cl 2.01 to 5.55; 12 trials; 1525 participants; high-certainty evidence); dizziness 2.00 (99% Cl 1.52 to 2.64;13 trials; 1768 participants; moderate-certainty evidence); diplopia 3.79 (99% Cl 2.15 to 6.68; 3 trials, 944 participants; high-certainty evidence); nausea 1.81 (99% Cl 1.22 to 2.68; 12 studies,1486 participants; moderate-certainty evidence). The limited data available precluded any conclusions about effects on cognition and quality of life. No important heterogeneity between studies was found for any of the outcomes. Overall, we assessed the evidence as high to moderate certainty, due to incomplete data for some outcomes.

AUTHORS' CONCLUSIONS

Lamotrigine as an add-on treatment for drug-resistant focal seizures appears to be effective in reducing seizure frequency, and seems to be fairly well-tolerated. However, the trials were of relatively short duration and provided no evidence for the long term. Further trials are needed to assess the long-term effects of lamotrigine, and to compare lamotrigine with other add-on drugs.

SUDEP in the North American SUDEP Registry: The full spectrum of epilepsies

Objective

To obtain medical records, family interviews, and death-related reports of sudden unexpected death in epilepsy (SUDEP) cases to better understand SUDEP.

Methods

All cases referred to the North American SUDEP Registry (NASR) between October 2011 and June 2018 were reviewed; cause of death was determined by consensus review. Available medical records, death scene investigation reports, autopsy reports, and next-of-kin interviews were reviewed for all cases of SUDEP. Seizure type, EEG, MRI, and SUDEP classification were adjudicated by 2 epileptologists.

Results

There were 237 definite and probable cases of SUDEP among 530 NASR participants. SUDEP decedents had a median age of 26 (range 1–70) years at death, and 38% were female. In 143 with sufficient information, 40% had generalized and 60% had focal epilepsy. SUDEP affected the full spectrum of epilepsies, from benign epilepsy with centrotemporal spikes (n = 3, 1%) to intractable epileptic encephalopathies (n = 27, 11%). Most (93%) SUDEPs were unwitnessed; 70% occurred during apparent sleep; and 69% of patients were prone. Only 37% of cases of SUDEP took their last dose of antiseizure medications (ASMs). Reported lifetime generalized tonic-clonic seizures (GTCS) were <10 in 33% and 0 in 4%.

Conclusions

NASR participants commonly have clinical features that have been previously been associated with SUDEP risk such as young adult age, ASM nonadherence, and frequent GTCS. However, a sizeable minority of SUDEP occurred in patients thought to be treatment responsive or to have benign epilepsies. These results emphasize the importance of SUDEP education across the spectrum of epilepsy severities. We aim to make NASR data and biospecimens available for researchers to advance SUDEP understanding and prevention.

Treatment of Juvenile Myoclonic Epilepsy in Patients of Child-Bearing Potential

Juvenile myoclonic epilepsy (JME) is both a frequent and a very characteristic epileptic syndrome with female preponderance. Treatment of JME in women of childbearing potential must consider multiple factors such as desire for pregnancy, use of contraception, seizure control and previously used antiepileptic drugs (AEDs). Approximately 85% of cases are well controlled with valproate, which remains the reference AED in JME but is nowadays considered unsafe for the expecting mother and her fetus. The prescription of valproate is now severely restricted in women of childbearing potential but may still be considered, at the lowest possible dose and when pregnancies can be reliably planned, with temporary alternatives to valproate prescribed before fertilization. Alternatives have emerged, especially lamotrigine and levetiracetam, but also topiramate, zonisamide, and recently perampanel, but none of these AEDs can be considered fully safe in the context of pregnancy. In special settings, benzodiazepines and barbiturates may be useful. In some cases, combination therapy, especially lamotrigine and levetiracetam, may be useful or even required. However, lamotrigine may have the potential to aggravate JME, with promyoclonic effects. Carbamazepine, oxcarbazepine and phenytoin must be avoided. Valproate, levetiracetam, zonisamide, topiramate if the daily dose is ≤ 200 mg and perampanel if the daily dose is ≤ 10 mg do not affect combined hormonal contraception. Lamotrigine ≥ 300 mg/day has been shown to decrease levonorgestrel levels by 20% but does not compromise combined hormonal contraception. Patients with JME taking oral contraceptive should be counselled on the fact that the estrogenic component can reduce concentrations of lamotrigine by over 50%, putting patients at risk of increased seizures. Pregnancy is a therapeutic challenge, and the risk/benefit ratio for the mother and fetus must be considered when choosing the appropriate drug. Lamotrigine (< 325 mg daily in the European Registry of Antiepileptic Drugs in Pregnancy) and levetiracetam seem to be comparatively safer in pregnancy than other AEDs, especially topiramate and valproate. Plasma concentration of lamotrigine and levetiracetam decreases significantly during pregnancy, and dosage adjustments may be necessary. With persisting generalized tonic-clonic seizures, the combination of lamotrigine and levetiracetam offer the chance of seizure control and lesser risks of major congenital malformations. The risk of malformation increases when valproate or topiramate are included in the drug combination. In one study, the relative risk of autism and autism spectrum disorders (ASD) in children born to women with epilepsy (WWE) treated with valproate were, respectively, 5.2 for autism and 2.9 for ASD versus 2.12 for autism and 1.6 for ASD in WWE not treated with valproate. More studies are needed to assess the risk of autism with AEDs other than valproate. The current knowledge is that the risk appears to be double that in the general population. In patients with JME, valproate remains an essential and life-changing agent. The consequences of a lifetime of poorly controlled epilepsy need to be balanced against the teratogenic risks of valproate during limited times in a woman's life. The management of JME in WWE should include lifestyle interventions, with avoidance of sleep deprivation, and planned pregnancy.

Risk Factors for Sudden Unexpected Death in Epilepsy (SUDEP) and Their Mitigation

PURPOSE OF REVIEW

People with epilepsy have an increased risk of mortality when compared to the general population. Sudden unexpected death in epilepsy (SUDEP) is the most common cause of epilepsy-related death in children and adults. The purpose of this review is to discuss SUDEP, with an emphasis on SUDEP risk factors, their mitigation and prevention.

RECENT FINDINGS

SUDEP affects approximately 1 in 1000 people with epilepsy each year. Recent studies suggest that the incidence in children is similar to that of adults. The most important risk factor for SUDEP is the presence and frequency of generalized tonic-clonic seizures. The presence of nocturnal supervision may decrease risk along with the use of nocturnal listening devices. Underlying genetic influences, both cardiac and epilepsy-related may further alter risk. Risk mitigation strategies include reducing seizure frequency, optimizing therapy, and the use of nocturnal supervision/seizure detection devices. Risk factors for SUDEP are well established; however, pediatric specific risk factors have not been identified. Current prevention strategies are focused on reduction of risk factors and the possible role of seizure detection devices. More research is needed to better understand the varied underlying pathological mechanisms and develop targeted prevention strategies. Further understanding the genetic factors that influence SUDEP risk may potentially aid in understanding the underlying pathophysiology of SUDEP.

A prospective open-label trial of a CBD/THC cannabis oil in dravet syndrome

Introduction

Both Δ⁹ Tetrahydrocannabidiol (THC) and cannabidiol (CBD) components of cannabis, have been shown to have anticonvulsant effects. Cannabis oils are used to treat seizures in drug‐resistant epilepsy (DRE). Recent trials provide data on dosing, side effects, and efficacy of CBD, yet there is a paucity of information on THC in epilepsy. Primary objective was to establish dosing and tolerability of TIL‐TC150 ‐ a cannabis plant extract produced by Tilray^®, containing 100 mg/mL CBD and 2 mg/mL THC‐ in children with Dravet syndrome. Secondary objectives were to assess impact of therapy on seizures, electroencephalogram (EEG) and quality of life.

Methods

Twenty children received add‐on therapy with TIL‐TC150. The dose ranged from 2 to 16 mg/kg/day of CBD and 0.04 to 0.32 mg/kg/day of THC. Patients were monitored for tolerability and adverse events, and secondary objectives.

Results

Nineteen participants completed the 20‐week intervention. Mean dose achieved was 13.3 mg/kg/day of CBD (range 7–16 mg/kg/day) and 0.27 mg/kg/day of THC (range 0.14–0.32 mg/kg/day). Adverse events, common during titration included somnolence, anorexia, and diarrhea. Abnormalities of liver transaminases and platelets were observed with concomitant valproic acid therapy. There was a statistically significant improvement in quality of life, reduction in EEG spike activity, and median motor seizure reduction of 70.6%, with 50% responder rate of 63%.

Conclusions

TIL‐TC150 was safe and well tolerated in our subjects. TIL‐TC150 treatment resulted in a reduction in seizure counts, spike index on EEG, and improved quality of life measures. This study provides safety and dosing information for THC‐containing cannabinoid preparations.

Action Potential Recording and Pro-arrhythmia Risk Analysis in Human Ventricular Trabeculae

To assess drug-induced pro-arrhythmic risk, especially Torsades de Pointe (TdP), new models have been proposed, such as in-silico modeling of ventricular action potential (AP) and stem cell-derived cardiomyocytes (SC-CMs). Previously we evaluated the electrophysiological profile of 15 reference drugs in hESC-CMs and hiPSC-CMs for their effects on intracellular AP and extracellular field potential, respectively. Our findings indicated that SC-CMs exhibited immature phenotype and had the propensity to generate false positives in predicting TdP risk. To expand our knowledge with mature human cardiac tissues for drug-induced pro-arrhythmic risk assessment, human ventricular trabeculae (hVT) from ethically consented organ donors were used to evaluate the effects of the same 15 drugs (8 torsadogenic, 5 non-torsadogenic, and 2 discovery molecules) on AP parameters at 1 and 2 Hz. Each drug was tested blindly with 4 concentrations in duplicate trabeculae from 2 hearts. To identify the pro-arrhythmic risk of each drug, a pro-arrhythmic score was calculated as the weighted sum of percent drug-induced changes compared to baseline in various AP parameters, including AP duration and recognized pro-arrhythmia predictors such as triangulation, beat-to-beat variability and incidence of early-afterdepolarizations, at each concentration. In addition, to understand the translation of this preclinical hVT AP-based model to clinical studies, a ratio that relates each testing concentration to the human therapeutic unbound Cmax (Cmax) was calculated. At a ratio of 10, for the 8 torsadogenic drugs, 7 were correctly identified by the pro-arrhythmic score; 1 was mislabeled. For the 5 non-torsadogenic drugs, 4 were correctly identified as safe; 1 was mislabeled. Calculation of sensitivity, specificity, positive predictive value, and negative predictive value indicated excellent performance. For example, at a ratio of 10, scores for sensitivity, specificity, positive predictive value and negative predictive values were 0.88, 0.8, 0.88 and 0.8, respectively. Thus, the hVT AP-based model combined with the integrated analysis of pro-arrhythmic score can differentiate between torsadogenic and non-torsadogenic drugs, and has a greater predictive performance when compared to human SC-CM models.

Sudden unexpected death in epilepsy

People with epilepsy have increased risk of premature death, and their life expectancy may reduce by 2-10 yr. Population- and hospital-based studies have shown that the excess mortality in epilepsy is not entirely explained by deaths directly attributable to epilepsy such as accidents and drowning during a seizure. It is also significantly contributed by deaths from other causes such as cardiac deaths, deaths due to malignancies and other causes. It had recently been recognized that sudden unexpected deaths in epilepsy (SUDEP) contributed to a small yet important proportion of mortality in epilepsy. SUDEPs are deaths (witnessed or unwitnessed) unrelated to trauma, drowning or status epilepticus and not attributable to any specific medical conditions. Several factors related to epilepsy and drug therapy have been found to be associated with higher risk of SUDEP.

Ranking the Leading Risk Factors for Sudden Unexpected Death in Epilepsy

Background

Sudden unexpected death in epilepsy (SUDEP) is rare in well-controlled epilepsy. However, SUDEP is a common cause of death in drug-resistant epilepsy. Over the last 30 years, multiple cohort and population studies have identified clinical risk factors associated with an increased risk for SUDEP.

Objective

To identify and rank the leading SUDEP risk factors from major cohort and population-based studies. The incidence of SUDEP is also evaluated in special clinical situations, including antiepileptic drug treatment, epilepsy surgery, devices, and assignment to placebo in clinical trials.

Methods

A PubMed search for English language human cohort studies for the terms Sudden, Death, and Epilepsy was performed for the years 1987–2017. Risk factors for SUDEP were identified and ranked by the weighted log adjusted odds ratio (OR)/relative risk ratio (RR).

Findings

The top 10 leading risk factors ranked from highest to lowest log adjusted OR/RR are the following: ≥3 GTC seizures per year; ≥13 seizures in the last year; No Antiepileptic Drug (AED) treatment; ≥3 AEDs; ≥3 GTCs in the past year; 11–20 GTC seizures in the last 3 months; age of onset 0–15 years old; IQ < 70; 3–5 AED changes in the last year; ≥3 AEDs. Two risk factors from separate sources (≥3 GTC seizures and ≥3 AEDs) occur twice in the top 10 risk factors.

Conclusion

The top 10 risk factors for SUDEP are identified and ranked. A ranking of the top risk factors could help clinicians identify patients at highest risk for SUDEP.

Reducing placebo exposure in trials: Considerations from the Research Roundtable in Epilepsy

The randomized controlled trial is the unequivocal gold standard for demonstrating clinical efficacy and safety of investigational therapies. Recently there have been concerns raised about prolonged exposure to placebo and ineffective therapy during the course of an add-on regulatory trial for new antiepileptic drug approval (typically ∼6 months in duration), due to the potential risks of continued uncontrolled epilepsy for that period. The first meeting of the Research Roundtable in Epilepsy on May 19-20, 2016, focused on "Reducing placebo exposure in epilepsy clinical trials," with a goal of considering new designs for epilepsy regulatory trials that may be added to the overall development plan to make it, as a whole, safer for participants while still providing rigorous evidence of effect. This topic was motivated in part by data from a meta-analysis showing a 3- to 5-fold increased rate of sudden unexpected death in epilepsy in participants randomized to placebo or ineffective doses of new antiepileptic drugs. The meeting agenda included rationale and discussion of different trial designs, including active-control add-on trials, placebo add-on to background therapy with adjustment, time to event designs, adaptive designs, platform trials with pooled placebo control, a pharmacokinetic/pharmacodynamic approach to reducing placebo exposure, and shorter trials when drug tolerance has been ruled out. The merits and limitations of each design were discussed and are reviewed here.

Practice guideline summary: Sudden unexpected death in epilepsy incidence rates and risk factors: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology and the American Epilepsy Society

OBJECTIVE

To determine the incidence rates of sudden unexpected death in epilepsy (SUDEP) in different epilepsy populations and address the question of whether risk factors for SUDEP have been identified.

METHODS

Systematic review of evidence; modified Grading Recommendations Assessment, Development, and Evaluation process for developing conclusions; recommendations developed by consensus.

RESULTS

Findings for incidence rates based on 12 Class I studies include the following: SUDEP risk in children with epilepsy (aged 0-17 years) is 0.22/1,000 patient-years (95% confidence interval [CI] 0.16-0.31) (moderate confidence in evidence). SUDEP risk increases in adults to 1.2/1,000 patient-years (95% CI 0.64-2.32) (low confidence in evidence). The major risk factor for SUDEP is the occurrence of generalized tonic-clonic seizures (GTCS); the SUDEP risk increases in association with increasing frequency of GTCS occurrence (high confidence in evidence).

RECOMMENDATIONS

Level B: Clinicians caring for young children with epilepsy should inform parents/guardians that in 1 year, SUDEP typically affects 1 in 4,500 children; therefore, 4,499 of 4,500 children will not be affected. Clinicians should inform adult patients with epilepsy that SUDEP typically affects 1 in 1,000 adults with epilepsy per year; therefore, annually 999 of 1,000 adults will not be affected. For persons with epilepsy who continue to experience GTCS, clinicians should continue to actively manage epilepsy therapies to reduce seizures and SUDEP risk while incorporating patient preferences and weighing the risks and benefits of any new approach. Clinicians should inform persons with epilepsy that seizure freedom, particularly freedom from GTCS, is strongly associated with decreased SUDEP risk.

Terminal seizure frequency and its relation to SUDEP

BACKGROUND

Sudden unexpected death in epilepsy (SUDEP) is a major cause of death in patients with epilepsy. Several risk factors have been implicated, including early age of onset, tonic-clonic seizures and antiepileptic drugs. However, whether patients who die from SUDEP have a greater frequency of seizures in the few months before death is unclear. We investigated the terminal seizure frequency and its relation to SUDEP among a large group of patients with tonic-clonic seizures in rural West China.

METHODS

We used the database from the Convulsive Epilepsy Control and Management Program in West China, which routinely provides phenobarbital (PB) as a treatment for convulsive epilepsy. Patients with probable SUDEP were included according to pre-set criteria. A verbal autopsy was undertaken for each case. By matching each patient's age, sex, date of joining the program, time in follow-up, and baseline seizure frequency, we set up a 1:5 ratio control group. SPSS 21.0 statistics were applied to compare the differences in seizure frequency 3months prior to SUDEP between patients with probable SUDEP and controls. Furthermore, the dynamic changes of terminal seizure frequency 6-9months, 3-6months, and 3months prior to SUDEP was also analyzed.

RESULTS

A total of 41 patients who died from probable SUDEP were identified out of 7844 patients during 10years of follow-up. The SUDEP group had a significantly higher tonic-clonic seizure frequency 3months before their deaths than the control group (p=0.023). At the same time, their seizure-free rate was lower than the control group (p=0.025). Patients with probable SUDEP who were followed up over 12months were further studied as a subgroup. They had more tonic-clonic seizures 3months prior to death compared to the control group (p=0.010). They also had an increase in seizure frequency in their terminal phase (3months prior) compared to an earlier stage (3-6months prior) (p=0.029). Furthermore, the terminal PB dose in the SUDEP group was higher than the control group (p=0.002).

CONCLUSION

Patients who died from SUDEP had more frequent tonic-clonic seizures 3months before their deaths. Higher seizure frequency increases the exposure to peri-ictal pathophysiological events, which possibly relate to SUDEP. This phenomenon may be due to the drug resistance potential of these patients or the high dose of PB. Further research is required to ascertain the underlying mechanisms of SUDEP.

Practice Guideline Summary: Sudden Unexpected Death in Epilepsy Incidence Rates and Risk Factors: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology and the American Epilepsy Society

OBJECTIVE

To determine the incidence rates of sudden unexpected death in epilepsy (SUDEP) in different epilepsy populations and address the question of whether risk factors for SUDEP have been identified.

METHODS

Systematic review of evidence; modified Grading Recommendations Assessment, Development and Evaluation process for developing conclusions; recommendations developed by consensus.

RESULTS

Findings for incidence rates based on 12 Class I studies include the following: SUDEP risk in children with epilepsy (aged 0-17 years) is 0.22/1,000 patient-years (95% CI 0.16-0.31) (high confidence in evidence). SUDEP risk increases in adults to 1.2/1,000 patient-years (95% CI 0.64-2.32) (low confidence in evidence). The major risk factor for SUDEP is the occurrence of generalized tonic-clonic seizures (GTCS); the SUDEP risk increases in association with increasing frequency of GTCS occurrence (high confidence in evidence).

RECOMMENDATIONS

Level B: Clinicians caring for young children with epilepsy should inform parents/guardians that in 1 year, SUDEP typically affects 1 in 4,500 children; therefore, 4,499 of 4,500 children will not be affected. Clinicians should inform adult patients with epilepsy that SUDEP typically affects 1 in 1,000 adults with epilepsy per year; therefore, annually 999 of 1,000 adults will not be affected. For persons with epilepsy who continue to experience GTCS, clinicians should continue to actively manage epilepsy therapies to reduce seizures and SUDEP risk while incorporating patient preferences and weighing the risks and benefits of any new approach. Clinicians should inform persons with epilepsy that seizure freedom, particularly freedom from GTCS, is strongly associated with decreased SUDEP risk.

Antiepileptic Drugs Impair Shortening of Isolated Cardiomyocytes

Background

Most antiepileptic drugs (AEDs) inhibit seizure generation by acting on voltage-dependent ion channels. Voltage-dependent sodium and calcium channels are commonly expressed in brain and heart, suggesting that AEDs may have considerable cardiodepressive effects, thereby facilitating sudden cardiac death as a potential cause of sudden unexpected death in epilepsy. Here, we investigated the effects of carbamazepine (CBZ), lamotrigine (LTG), and levetiracetam (LEV) alone and in combination on the shortening properties of isolated ventricular cardiomyocytes of wild-type mice.

Methods

Properties of murine cardiomyocytes were determined by recording the sarcomere shortening with a video imaging system before, during, and after administration of AEDs in different concentrations and combinations. We assessed (i) the number of successful shortenings during continuous electrical stimulation (electromechanical coupling) and (ii) the shortening amplitude as well as other shortening-related properties upon repetitive electrical stimulation at 4 Hz. Data are given as mean ± SEM.

Results

At 100 μM, CBZ (10 cells), LTG (11 cells), and LEV (11 cells) alone had no effect on the electromechanical coupling but reversibly reduced shortening amplitudes by 15 ± 4, 24 ± 3, and 11 ± 3%, respectively. Increasing the LTG concentration to 250 (21 cells) and 500 μM (4 cells) reversibly inhibited the electromechanical coupling in 62 and 100% of the experiments. Importantly, simultaneous application of CBZ, LTG, and LEV at 100 μM also impaired the electromechanical coupling in 8 of 19 cardiomyocytes (42%) and reduced the shortening amplitude by 21 ± 4%.

Conclusion

Our data show that AEDs reversibly impair cardiac excitation and contraction. Importantly, the blocking effect on electromechanical coupling appears to be additive when different AEDs are simultaneously applied. The translational value of these experimental findings into clinical practice is limited. Our results, however, suggest that rationale AED therapy may be important with respect to cardiac side effects and potential facilitation of serious cardiac dysfunction especially when AEDs are used in combination or at very high doses.

SUDEP: The First Case Series in Turkey

INTRODUCTION

Sudden unexpected death in epilepsy (SUDEP) is defined as the sudden, unexpected, witnessed or unwitnessed, non-traumatic, and non-drowning death of patients with epilepsy with or without evidence of a seizure, excluding documented status epilepticus, and in whom postmortem examinations do not reveal a toxicological or anatomic cause for death. In this study, data on patients who passed away under observation in the epilepsy clinic due to sudden, unexpected death have been compiled, and we also aim to emphasize the importance of SUDEP in Turkey.

METHODS

This study was performed with a total of nine cases. Data were obtained from hospital records, information given by the families of patients, the database of the General Directorate for Civil Services of the Ministry of Internal Affairs of Turkey, and from the Ankara Metropolitan Municipality Cemetery Information System. As the basis of classification and definition, the proposals suggested by Nashef et al., which were made to the International League Against Epilepsy (ILAE) in 2011, were taken into consideration.

RESULTS

Eight of the patients were classified as probable SUDEP and one of them as possible SUDEP; the mean age at SUDEP was 33 years, and the average follow-up period was 19.7 years. In these cases, except for known risk factors (generalized tonic-clonic seizures, nocturnal seizures, severe epilepsy, more frequent seizures, younger age at the onset of epilepsy, unwitnessed seizures, polytherapy, and mental handicap), a different risk factor was not identified.

CONCLUSION

This study is the first case series on SUDEP in Turkey. Postmortem studies are the most important shortcoming of the study. However, the importance of the topic is highlighted by presenting the available data. SUDEP deserves more attention during the daily practice of neurologists, pediatric neurologists, forensic physicians, and family physicians. If death is sudden and unexpected in a patient with epilepsy, SUDEP should be considered, regardless of the clear causes of death.

The role of antiepileptic drugs in sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) primarily affects young adults and is the leading cause of death related directly to seizures. High frequency of generalized tonic-clonic seizures is the most important risk factor, and effective seizure protection is probably the most important measure to prevent these tragic deaths. For several years a potential role of antiepileptic drugs (AEDs) has been discussed, but at present there is wide agreement that choice of AED therapy does not influence the risk. However, although it is well known that the efficacy and safety profiles of AEDs may differ significantly when used in the treatment of genetic epilepsy compared to symptomatic or cryptogenic epilepsy, this has generally been overlooked in epidemiologic studies of possible relationships between AEDs and SUDEP. Consequently important information about drug safety may have been lost. This review challenges the current view that no AED can increase the risk of SUDEP.

Lamotrigine add-on for drug-resistant partial epilepsy

BACKGROUND

This is an updated version of the Cochrane review published in The Cochrane Library 2010, Issue 1.Epilepsy is a common neurological disorder, affecting almost 0.5% to 1% of the population. For nearly 30% of these people, their epilepsy is refractory to currently available drugs. Pharmacological treatment remains the first choice to control epilepsy. Lamotrigine is one of the newer antiepileptic drugs and is the topic of this review. Lamotrigine in combination with other antiepileptic drugs (add-on) can reduce seizures, but with some adverse effects. The aim of this systematic review was to overview the current evidence for the efficacy and tolerability of lamotrigine when used as an adjunctive treatment for people with refractory partial epilepsy.

OBJECTIVES

To determine the effects of lamotrigine on (1) seizures, (2) adverse effect profile, and (3) cognition and quality of life, compared to placebo controls, when used as an add-on treatment for people with refractory partial epilepsy.

SEARCH METHODS

For the previous version of the review, the authors searched the Cochrane Epilepsy Group Specialized Register (January 2010), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2010, Issue 1), MEDLINE (1950 to January 2010), and reference lists of articles.For this update, we searched the Cochrane Epilepsy Group Specialized Register (28 May 2015), CENTRAL (The Cochrane Library 2015, Issue 4), MEDLINE (Ovid, 1946 to May 2015), and reference lists of articles. We also contacted the manufacturers of lamotrigine (GlaxoSmithKline). No language restrictions were imposed.

SELECTION CRITERIA

Randomised placebo-controlled trials of people with drug-resistant partial epilepsy of any age, in which an adequate method of concealment of randomisation was used. The studies were double-, single- or unblinded. For cross-over studies, the first treatment period was treated as a parallel trial. Eligible participants were adults or children with drug-resistant partial epilepsy.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently assessed the trials for inclusion, and extracted data. Outcomes included 50% or greater reduction in seizure frequency, treatment withdrawal (any reason), adverse effects, effects on cognition and quality of life. Primary analyses were by intention-to-treat. Sensitivity best and worse case analyses were undertaken to account for missing outcome data. Pooled Risk Ratios (RR) with 95% confidence intervals (95% Cl) were estimated for the primary outcomes of seizure frequency and treatment withdrawal. For adverse effects, pooled RRs and 99% Cls were calculated.

MAIN RESULTS

We did not identify any new studies for this update, therefore, the results are unchanged.For the previous version of the review, the authors found five parallel add-on studies and eight cross-over studies in adults or children with refractory focal epilepsy, and one parallel add-on study with a responder-enriched design in infants. In total, these 14 studies included 1958 participants (38 infants, 199 children, and 1721 adults). Baseline phases ranged from 4 to 12 weeks; treatment phases from 8 to 36 weeks. Overall, eleven studies (n = 1243 participants) were rated as having a low risk of bias, and three (n = 715 participants) had un unclear risk of bias due to lack of reported information around study design. Effective blinding of studies was reported in three studies (n = 504 participants). The overall risk ratio (RR) for 50% or greater reduction in seizure frequency was 1.80 (95% CI 1.45 to 2.23; 12 RCTs) for twelve studies (n = 1322 participants, adults and children) indicating that lamotrigine was significantly more effective than placebo in reducing seizure frequency. The overall RR for treatment withdrawal (for any reason) was 1.11 (95% CI 0.90 to 1.36; 14 RCTs) for fourteen studies (n = 1958 participants). The adverse events significantly associated with lamotrigine were: ataxia, dizziness, diplopia, and nausea. The RR of these adverse effects were as follows: ataxia 3.34 (99% Cl 2.01 to 5.55; 12 RCTs; n = 1524); dizziness 2.00 (99% Cl 1.51 to 2.64;13 RCTs; n = 1767); diplopia 3.79 (99% Cl 2.15 to 6.68; 3 RCTs; n = 943); nausea 1.81 (99% Cl 1.22 to 2.68; 12 RCTs; n = 1486). The limited data available precluded any conclusions about effects on cognition and quality of life. No important heterogeneity between studies was found for any of the outcomes. Overall, we assessed the evidence as high to moderate quality, due to incomplete data for some outcomes.

AUTHORS' CONCLUSIONS

Lamotrigine as an add-on treatment for partial seizures appears to be effective in reducing seizure frequency, and seems to be fairly well tolerated. However, the trials were of relatively short duration and provided no evidence for the long-term. Further trials are needed to assess the long-term effects of lamotrigine, and to compare it with other add-on drugs.Since we did not find any new studies, our conclusions remain unchanged.

Etiology of Sudden Cardiac Arrest in Patients with Epilepsy: Experience of Tertiary Referral Hospital in Sapporo City, Japan

It has been reported that epilepsy patients had higher risk of sudden death than that of the general population. However, in Japan, there is very little literature on the observational research conducted on sudden fatal events in epilepsy. We performed a single-center, retrospective study on all the out-of-hospital cardiac arrest (OHCA) patients treated in our emergency department between 2007 and 2013. Among the OHCA patients, we extracted those with a history of epilepsy and then analyzed the characteristics of the fatal events and the background of epilepsy. From 1,823 OHCA patients, a total of 10 cases were enrolled in our study. The median age was 34 years at the time of the incident [9–52 years; interquartile range (IQR), 24–45]. We determined that half of our cases resulted from external causes of death such as drowning and suffocation and the other half were classified as sudden unexpected death in epilepsy (SUDEP). In addition, asphyxia was implicated as the cause in eight cases. Only the two near-drowning patients were immediately resuscitated, but the remaining eight patients died. The median age of first onset of epilepsy was 12 years (0.5–30; IQR, 3–21), and the median disease duration was 25 years (4–38; IQR, 6–32). Patients with active epilepsy accounted for half of our series and they were undergoing poly anti-epileptic drug therapy. The fatal events related to epilepsy tended to occur in the younger adult by external causes. An appropriate therapeutic intervention and a thorough observation were needed for its prevention.

Who to target in sudden unexpected death in epilepsy prevention and how? Risk factors, biomarkers, and intervention study designs

The risk of dying suddenly and unexpectedly is increased 24- to 28-fold among young people with epilepsy compared to the general population, but the incidence of sudden unexpected death in epilepsy (SUDEP) varies markedly depending on the epilepsy population. This article first reviews risk factors and biomarkers for SUDEP with the overall aim of enabling identification of epilepsy populations with different risk levels as a background for a discussion of possible intervention strategies. The by far most important clinical risk factor is frequency of generalized tonic-clonic seizures (GTCS), but nocturnal seizures, early age at onset, and long duration of epilepsy have been identified as additional risk factors. Lack of antiepileptic drug (AED) treatment or, in the context of clinical trials, adjunctive placebo versus active treatment is associated with increased risks. Despite considerable research, reliable electrophysiologic (electrocardiography [ECG] or electroencephalography [EEG]) biomarkers of SUDEP risk remain to be established. This is an important limitation for prevention strategies and intervention studies. There is a lack of biomarkers for SUDEP, and until validated biomarkers are found, the endpoint of interventions to prevent SUDEP must be SUDEP itself. These interventions, be they pharmacologic, seizure-detection devices, or nocturnal supervision, require large numbers. Possible methods for assessing prevention measures include public health community interventions, self-management, and more traditional (and much more expensive) randomized clinical trials.

Sudden unexpected death in epilepsy: basic mechanisms and clinical implications for prevention

Sudden unexpected death in epilepsy (SUDEP) is the most common cause of death in patients with intractable epilepsy. The substantial lifetime risk of SUDEP and the lack of a clear pathophysiological connection between epilepsy itself and sudden death have fuelled increased attention to this phenomenon. Understanding the mechanisms underlying SUDEP is paramount to developing preventative strategies. In this review, we discuss SUDEP population studies, case-control studies, witnessed and monitored cases, as well as human seizure cardiorespiratory findings related to SUDEP, and SUDEP animal models. We integrate these data to suggest the most probable mechanisms underlying SUDEP. Understanding the modifiable risk factors and pathophysiology allows us to discuss potential preventative strategies.

[New aspects in the field of epilepsy]

Regarding epilepsy several new developments can be reported. The International League Against Epilepsy (ILAE) has suggested a new definition of epilepsy, for the first time including a definition of epilepsy resolution. Progress in the diagnosis relates to new genetic findings, improvements in magnetic resonance imaging (MRI) and the increasing use of stereo electroencephalograms (sEEG). Regarding treatment there are new clinically relevant data on the pathophysiology and prevention of sudden unexpected death in epilepsy (SUDEP). Zonisamide has been approved by the European Medicines Agency (EMA) for monotherapy in adults with focal seizures and combination therapy in children aged ≥ 6 years. Retigabin and perampanel have been approved but are currently taken off the market in Germany (only) because the Gemeinsamer Bundesausschuss (GBA, Joint Federal Committee) did not find any additional therapeutic value as compared to lamotrigine due to a lack of data. A decision regarding a new application for perampanel is pending. Regarding surgical treatment novel ablation techniques (e.g. stereotactic radiofrequency and laser ablation as well as focussed ultrasound ablation) and brain stimulation paradigms are under investigation. Experimental studies, generously supported by the European Union (EU) and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) are focusing on (opto-)genetic (e.g. using lentoviral transfection), epigenetic (e.g. micro-RNA-related) approaches and on the investigation of neuronal micronetworks.

The long-term safety of antiepileptic drugs

Antiepileptic drugs (AEDs) are used by millions of people worldwide for the treatment of epilepsy, as well as in many other neurological and psychiatric conditions. They are frequently associated with adverse effects (AEs), which have an impact on the tolerability and success of treatment. Half the people who develop intolerable AEs discontinue treatment early on after initiation, while the majority of people will continue to be exposed to their effects for long periods of time. The long-term safety of AEDs reflects their potential for chronic, cumulative dose effects; rare, but potentially serious late idiosyncratic effects; late, dose-related effects; and delayed, teratogenic or neurodevelopmental effects. These AEs can affect every body system and are usually insidious. With the exception of delayed effects, most other late or chronic AEs are reversible. To date, there is no clear evidence of a carcinogenic effect of AEDs in humans. While physicians are aware of the long-term AEs of old AEDs (the traditional liver enzyme-inducing AEDs and valproate), information about AEs of new AEDs (such as lamotrigine, levetiracetam, oxcarbazepine, topiramate or zonisamide), particularly of their teratogenic effects, has emerged over the years. Sporadic publications have raised issues about AEs of the newer AEDs eslicarbazepine, retigabine, rufinamide, lacosamide and perampanel but their long-term safety profiles may take years to be fully appreciated. Physicians should not only be aware of the late and chronic AEs of AEDs but should systematically enquire and screen for these according to the individual AED AE profile. Care should be taken for individuals with comorbid conditions that may render them more susceptible to specific AEs. Prevention and appropriate management of long-term AED AEs is expected to improve adherence to treatment, quality of life and control of epilepsy.