Underestimation of sudden deaths among patients with seizures and epilepsy

Development of an International Standard Set of Outcomes and Measurement Methods for Routine Practice for Infants, Children, and Adolescents with Epilepsy: The International Consortium for Health Outcomes Measurement Consensus Recommendations

At present, there is no internationally accepted set of core outcomes or measurement methods for epilepsy clinical practice. The International Consortium for Health Outcomes Measurement (ICHOM) convened an international working group of experts in epilepsy, people with epilepsy, and their representatives to develop minimum sets of standardized outcomes and outcome measurement methods for clinical practice. Using modified Delphi consensus methods with consecutive rounds of online voting over 12 months, a core set of outcomes and corresponding measurement tool packages to capture the outcomes were identified for infants, children, and adolescents with epilepsy. Consensus methods identified 20 core outcomes. In addition to the outcomes identified for the ICHOM Epilepsy adult standard set, behavioral, motor, and cognitive/language development outcomes were voted as essential for all infants and children with epilepsy. The proposed set of outcomes and measurement methods will facilitate the implementation of the use of patient-centered outcomes in daily practice.

Development of an International Standard Set of Outcomes and Measurement Methods for Routine Practice for Adults with Epilepsy: The International Consortium for Health Outcomes Measurement Consensus Recommendations

At present, there is no internationally accepted set of core outcomes or measurement methods for epilepsy clinical practice. Therefore, the International Consortium for Health Outcomes Measurement (ICHOM) convened an international working group of experts in epilepsy, people with epilepsy and their representatives to develop minimum sets of standardized outcomes and outcomes measurement methods for clinical practice that support patient-clinician decision-making and quality improvement. Consensus methods identified 20 core outcomes. Measurement tools were recommended based on their evidence of strong clinical measurement properties, feasibility, and cross-cultural applicability. The essential outcomes included many non-seizure outcomes: anxiety, depression, suicidality, memory and attention, sleep quality, functional status, and the social impact of epilepsy. The proposed set will facilitate the implementation of the use of patient-centered outcomes in daily practice, ensuring holistic care. They also encourage harmonization of outcome measurement, and if widely implemented should reduce the heterogeneity of outcome measurement, accelerate comparative research, and facilitate quality improvement efforts.

Cardiac arrhythmia and epilepsy genetic variants in sudden unexpected death in epilepsy

Introduction

Sudden Unexpected Death in Epilepsy (SUDEP) is the leading epilepsy-related cause of death, affecting approximately 1 per 1,000 individuals with epilepsy per year. Genetic variants that affect autonomic function, such as genes associated with cardiac arrhythmias, may predispose people with epilepsy to greater risk of both sudden cardiac death and SUDEP. Advances in next generation sequencing allow for the exploration of gene variants as potential biomarkers.

Methods

Genetic testing for the presence of cardiac arrhythmia and epilepsy gene variants was performed via genetic panels in 39 cases of SUDEP identified via autopsy by the Ontario Forensic Pathology Service. Variants were summarized by in-silico evidence for pathogenicity from 4 algorithms (SIFT, PolyPhen-2, PROVEAN, Mutation Taster) and allele frequencies in the general population (GnomAD). A maximum credible population allele frequency of 0.00004 was calculated based on epilepsy prevalence and SUDEP incidence to assess whether a variant was compatible with a pathogenic interpretation.

Results

Median age at the time of death was 33.3 years (range: 2, 60). Fifty-nine percent (n=23) were male. Gene panels detected 62 unique variants in 45 genes: 19 on the arrhythmia panel and 26 on the epilepsy panel. At least one variant was identified in 28 (72%) of decedents. Missense mutations comprised 57 (92%) of the observed variants. At least three in silico models predicted 12 (46%) cardiac arrhythmia panel missense variants and 20 (65%) epilepsy panel missense variants were pathogenic. Population allele frequencies were <0.00004 for 11 (42%) of the cardiac variants and 10 (32%) of the epilepsy variants. Together, these metrics identified 13 SUDEP variants of interest.

Discussion

Nearly three-quarters of decedents in this SUDEP cohort carried variants in comprehensive epilepsy or cardiac arrhythmia gene panels, with more than a third having variants in both panels. The proportion of decedents with cardiac variants aligns with recent studies of the disproportionate cardiac burden the epilepsy community faces compared to the general population and suggests a possible cardiac contribution to epilepsy mortality. These results identified 13 priority targets for future functional studies of these genes potential role in sudden death and demonstrates the necessity for further exploration of potential genetic contributions to SUDEP.

Video Analyses of Sudden Unexplained Deaths in Toddlers

BACKGROUND AND OBJECTIVES

More than 2,900 US children aged younger than 4 years die from unknown causes each year, accounting for more than 219,000 life years lost annually. They are mostly sleep-related and unwitnessed with unremarkable autopsies, limiting our understanding of death mechanisms. We sought to understand potential mechanisms of death by evaluating videos of sudden deaths in toddlers.

METHODS

In our registry of 301 sudden unexplained child deaths, a series of 7 consecutively enrolled cases with home video recordings of the child's last sleep period were independently assessed by 8 physicians for video quality, movement, and sound.

RESULTS

Four boys and 3 girls (13-27 months at death) with terminal videos shared similar demographic features to the 293 other registry cases without video recordings. Five video recordings were continuous and 2 were triggered by sound or motion. Two lacked audio. All continuous recordings included a terminal convulsive event lasting 8-50 seconds; 4 children survived for >2.5 minutes postconvulsion. Among discontinuous videos, time lapses limited review; 1 suggested a convulsive event. Six were prone with face down, and 1 had autopsy evidence of airway obstruction. Primary cardiac arrhythmias were not supported; all 7 children had normal cardiac pathology and whole-exome sequencing identified no known cardiac disease variants.

DISCUSSION

Audio-visual recordings in 7 toddlers with unexplained sudden deaths strongly implicate that deaths were related to convulsive seizures, suggesting that many unexplained sleep-related deaths may result from seizures.

Differentiation of Epileptic Brain Abnormalities among Neurological Patients at Taif Region Using MRI

This study was conducted to assess the prevalence of epilepsy among different age groups and gender of neurological patients in the Taif region and define the most common brain lesion, affecting epileptic patients living in the Taif city using MRI. Data from 150 patients who were clinically diagnosed with epilepsy and had brain MRIs were analyzed using SPSS. Statistical significance was considered when the p value is 0.05. The percentage of epilepsy was generally higher in males than in females in the Taif city, and seizures were different between the studied age groups. However, epilepsy was more pronounced in females than in males at certain age groups. Moreover, white matter lesions were most commonly found in the studied group (27.7%), followed by focal lesions, edema, and stroke with equal percentages (16.9%) and less commonly with congenital diseases (12%) and atrophic changes (9.6%). Epilepsy was more pronounced in females than in males at certain age groups. White matter lesions were identified as the most common lesion, presenting in epilepsy patients in the Taif city.

Derivation and validation of a new prediction model for sudden unexpected death in epilepsy based on a longitudinal prospective population-based cohort

OBJECTIVE

We conducted a population-based, prospective cohort study with a large sample size in Ningxia Province of the Northwest, a rural area in China, by developing a model to specifically assess risk factors of sudden unexpected death in epilepsy (SUDEP) in people with convulsive epilepsy by clinical variables.

METHODS

Participants with convulsive epilepsy were recruited from January 1, 2008, to April 28, 2022, in rural Northwest China. They received regular assessments and management of epilepsy at the primary healthcare level and were followed up monthly. Information on the cause of death and relevant clinical details was obtained from death certificates or neurologist-conducted verbal autopsies. Survival analysis was employed to identify potential risk factors associated with SUDEP.

RESULTS

Five variables were independently associated with SUDEP: generalized tonic-clonic seizures (GTCS) with ≥1 attack during the preceding month, GTCS with >3 attacks during the preceding year, body mass index (BMI) ≥24, age of onset ≤14 years, and duration >20 years. The area under receiver operator characteristic (ROC) curve (AUC) value (95% CI) of the model was 0.789 (0.735-0.843) in the derivation dataset and 0.830 (0.758-0.902) in the validation dataset. There was agreement between the observed and predicted probabilities of SUDEP.

CONCLUSIONS

This study establishes that high GTCS frequency, early age of onset, long duration of epilepsy, and being overweight are associated with an increased risk of SUDEP in individuals with convulsive epilepsy. The study also developed and validated a personalized prediction model to accurately assess the risk of SUDEP.

Electroencephalography characteristics related to risk of sudden unexpected death in epilepsy in patients with Dravet syndrome

Objective

To investigate the quantitative electroencephalography (EEG) features associated with a high risk of sudden unexpected death in epilepsy (SUDEP) in patients with Dravet syndrome (DS).

Methods

Patients with DS and healthy controls (HCs) who underwent EEG were included in the study. EEG signals were recorded using a 21 channel digital EEG system, and pre-processed data were analyzed to identify quantitative EEG features associated with a high SUDEP risk. To assess the risk of SUDEP, SUDEP-7 scores were used.

Results

A total of 64 patients with DS [38 males and 26 females, aged: 128.51 ± 75.50 months (range: 23-380 months)], and 13 HCs [7 males and 6 females, aged: 95.46 ± 86.48 months (range: 13-263 months)] were included. For the absolute band power, the theta power was significantly higher in the high-SUDEP group than in the low-SUDEP group in the central brain region. For the relative band power, the theta power was also significantly higher in the high-SUDEP group than in the low-SUDEP group in the central and occipital brain regions. The alpha power was significantly lower in the high-SUDEP group than in the low-SUDEP group in the central and parietal brain regions.

Conclusion

Patients with high SUDEP-7 scores have different EEG features from those with low SUDEP-7 scores, suggesting that EEG may be used as a biomarker of SUDEP in DS.

Significance

Early intervention in patients with DS at a high risk of SUDEP can reduce mortality and morbidity. Patients with high theta band powers warrant high-level supervision.

A unified hypothesis of SUDEP: Seizure-induced respiratory depression induced by adenosine may lead to SUDEP but can be prevented by autoresuscitation and other restorative respiratory response mechanisms mediated by the action of serotonin on the periaqueductal gray

Sudden unexpected death in epilepsy (SUDEP) is a major cause of death in people with epilepsy (PWE). Postictal apnea leading to cardiac arrest is the most common sequence of terminal events in witnessed cases of SUDEP, and postconvulsive central apnea has been proposed as a potential biomarker of SUDEP susceptibility. Research in SUDEP animal models has led to the serotonin and adenosine hypotheses of SUDEP. These neurotransmitters influence respiration, seizures, and lethality in animal models of SUDEP, and are implicated in human SUDEP cases. Adenosine released during seizures is proposed to be an important seizure termination mechanism. However, adenosine also depresses respiration, and this effect is mediated, in part, by inhibition of neuronal activity in subcortical structures that modulate respiration, including the periaqueductal gray (PAG). Drugs that enhance the action of adenosine increase postictal death in SUDEP models. Serotonin is also released during seizures, but enhances respiration in response to an elevated carbon dioxide level, which often occurs postictally. This effect of serotonin can potentially compensate, in part, for the adenosine-mediated respiratory depression, acting to facilitate autoresuscitation and other restorative respiratory response mechanisms. A number of drugs that enhance the action of serotonin prevent postictal death in several SUDEP models and reduce postictal respiratory depression in PWE. This effect of serotonergic drugs may be mediated, in part, by actions on brainstem sites that modulate respiration, including the PAG. Enhanced activity in the PAG increases respiration in response to hypoxia and other exigent conditions and can be activated by electrical stimulation. Thus, we propose the unifying hypothesis that seizure-induced adenosine release leads to respiratory depression. This can be reversed by serotonergic action on autoresuscitation and other restorative respiratory responses acting, in part, via the PAG. Therefore, we hypothesize that serotonergic or direct activation of this brainstem site may be a useful approach for SUDEP prevention.

Mortality after a first-ever unprovoked seizure

OBJECTIVE

Although increased mortality associated with epilepsy is well understood, data in patients after their first-ever seizure are limited. We aimed to assess mortality after a first-ever unprovoked seizure and identify causes of death (CODs) and risk factors.

METHODS

A prospective cohort study was undertaken of patients with first-ever unprovoked seizure between 1999 and 2015 in Western Australia. Two age-, gender-, and calendar year-matched local controls were obtained for each patient. Mortality data, including COD, based on International Statistical Classification of Diseases and Related Health Problems, 10th Revision codes, were obtained. Final analysis was performed in January 2022.

RESULTS

One thousand two hundred seventy-eight patients with a first-ever unprovoked seizure were compared to 2556 controls. Mean follow-up was 7.3 years (range = .1-20). Overall hazard ratio (HR) for death after a first unprovoked seizure compared to controls was 3.06 (95% confidence interval [CI] = 2.48-3.79), with HRs of 3.30 (95% CI = 2.26-4.82) for those without seizure recurrence and 3.21 (95% CI = 2.47-4.16) after a second seizure. Mortality was also increased in patients with normal imaging and no identified cause (HR = 2.50, 95% CI = 1.82-3.42). Multivariate predictors of mortality were increasing age, remote symptomatic causes, first seizure presentation with seizure cluster or status epilepticus, neurological disability, and antidepressant use at time of first seizure. Seizure recurrence did not influence mortality rate. The commonest CODs were neurological, most relating to the underlying cause of seizures rather than being seizure-related. Substance overdoses and suicide were more frequent CODs in patients compared to controls and were commoner than seizure-related deaths.

SIGNIFICANCE

Mortality is increased two- to threefold after a first-ever unprovoked seizure, independent of seizure recurrence, and is not only attributable to the underlying neurological etiology. The greater likelihood of deaths related to substance overdose and suicide highlights the importance of assessing psychiatric comorbidity and substance use in patients with first-ever unprovoked seizure.

Cardiac structural and functional abnormalities in epilepsy: A systematic review and meta-analysis

OBJECTIVE

Epilepsy is associated with an increased risk of cardiovascular disease and mortality. Whether cardiac structure and function are altered in epilepsy remains unclear. To address this, we conducted a systematic review and meta-analysis of studies evaluating cardiac structure and function in patients with epilepsy.

METHODS

We searched the electronic databases MEDLINE, PubMed, COCHRANE, and Web of Science from inception to 31 December 2021. Primary outcomes of interest included left ventricular ejection fraction (LVEF) for studies reporting echocardiogram findings and cardiac weight and fibrosis for postmortem investigations. Study quality was assessed using the National Heart, Lung, and Blood Institute (NHLBI) assessment tools.

RESULTS

Among the 10 case-control studies with epilepsy patients (n = 515) and healthy controls (n = 445), LVEF was significantly decreased in epilepsy group compared with controls (MD: -1.80; 95% confidence interval [CI]: -3.56 to -0.04; P = 0.045), whereas A-wave velocity (MD: 4.73; 95% CI: 1.87-7.60; P = 0.001), E/e' ratio (MD: 0.39; 95% CI: 0.06-0.71; P = 0.019), and isovolumic relaxation time (MD: 10.18; 95% CI: 2.05-18.32; P = 0.014) were increased in epilepsy, compared with controls. A pooled analysis was performed in sudden unexpected death in epilepsy (SUDEP) cases with autopsy data (n = 714). Among SUDEP cases, the prevalence of cardiac hypertrophy was 16% (95% CI: 9%-23%); cardiac fibrosis was 20% (95% CI: 15%-26%). We found no marked differences in cardiac hypertrophy, heart weight, or cardiac fibrosis between SUDEP cases and epilepsy controls.

SIGNIFICANCE

Our findings suggest that epilepsy is associated with altered diastolic and systolic echocardiogram parameters compared with healthy controls. Notably, SUDEP does not appear to be associated with a higher incidence of structural cardiac abnormalities, compared with non-SUDEP epilepsy controls. Longitudinal studies are needed to understand the prognostic significance of such changes. Echocardiography may be a useful noninvasive diagnostic test in epilepsy population.

Adherence patterns in antiseizure medications influencing risk of sudden unexplained death in epilepsy: A data linkage study using dispensed prescriptions

OBJECTIVE

Medication adherence is considered an important risk factor for sudden unexpected death in epilepsy (SUDEP), although measurement accuracy is difficult. Using prescription dispensations, this study aims to estimate antiseizure medication (ASM) adherence and identify adherence patterns that influence epilepsy mortality.

METHODS

This is a retrospective cohort study of tertiary epilepsy outpatients seen at St Vincent's Hospital Melbourne, Victoria, Australia, from January 1, 2012 until December 31, 2017. Privacy-preserving data linkage with the Australian national prescription, death, and coroner's databases was performed. We fitted a four-cluster longitudinal group-based trajectory model for ASM adherence from recurring 90-day windows of prescription dispensations during a 3-year "landmark period" from January 1, 2012 to December 31, 2014, using the AdhereR package. We estimated the risk of SUDEP and all-cause death for each adherence pattern during an "observation period" from January 1, 2015 to December 31, 2017. The Cox proportional hazards and logistic regression models were adjusted for age, sex, socioeconomic status, epilepsy duration, comorbidity, drug resistance, and inadequate seizure control.

RESULTS

One thousand one hundred eighty-seven participants were observed for a median of 3.2 years (interquartile range = 2.4-4.0 years). We observed 66 deaths with 10 SUDEP cases during the observation period. We identified four patterns of ASM adherence: good, 51%; declining, 24%; poor, 16%; and very poor, 9%. Declining adherence was associated with an increased risk for SUDEP, with hazard ratio (HR) = 8.43 (95% confidence interval [CI] = 1.10-64.45) at 1 year and HR = 9.17 (95% CI = 1.16-72.21) at 3 years. Compared to no ASM therapeutic change, the addition of a second to fourth ASM offered increased protection against SUDEP in patients with continuing drug-resistant epilepsy.

SIGNIFICANCE

ASM nonadherence was observed in half of outpatients with epilepsy. A declining pattern of adherence, observed in a quarter of patients, was associated with more than eight times increased risk of SUDEP. Any ongoing medication interventions must include strategies to maintain and improve ASM adherence if we are to reduce the risk of SUDEP.

Autonomic dysfunction in epilepsy mouse models with implications for SUDEP research

Epilepsy has a high prevalence and can severely impair quality of life and increase the risk of premature death. Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in drug-resistant epilepsy and most often results from respiratory and cardiac impairments due to brainstem dysfunction. Epileptic activity can spread widely, influencing neuronal activity in regions outside the epileptic network. The brainstem controls cardiorespiratory activity and arousal and reciprocally connects to cortical, diencephalic, and spinal cord areas. Epileptic activity can propagate trans-synaptically or via spreading depression (SD) to alter brainstem functions and cause cardiorespiratory dysfunction. The mechanisms by which seizures propagate to or otherwise impair brainstem function and trigger the cascading effects that cause SUDEP are poorly understood. We review insights from mouse models combined with new techniques to understand the pathophysiology of epilepsy and SUDEP. These techniques include in vivo, ex vivo, invasive and non-invasive methods in anesthetized and awake mice. Optogenetics combined with electrophysiological and optical manipulation and recording methods offer unique opportunities to study neuronal mechanisms under normal conditions, during and after non-fatal seizures, and in SUDEP. These combined approaches can advance our understanding of brainstem pathophysiology associated with seizures and SUDEP and may suggest strategies to prevent SUDEP.

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.

Impact of fenfluramine on the expected SUDEP mortality rates in patients with Dravet syndrome

PURPOSE

To assess the impact of fenfluramine (FFA) on the expected mortality incidence, including sudden unexpected death in epilepsy (SUDEP), in persons with Dravet syndrome (DS).

METHODS

In this pooled analysis, total time of exposure for persons with DS who were treated with FFA in phase 3 clinical trials, in United States and European Early Access Programs, and in two long-term open-label observational studies in Belgium was calculated. Literature was searched for reports of SUDEP mortality in DS, which were utilized as a comparison. Mortality rates were expressed per 1000 person-years.

RESULTS

A total of 732 persons with DS were treated with FFA, representing a total of 1185.3 person-years of exposure. Three deaths occurred, all in the phase 3 program: one during placebo treatment (probable SUDEP) and two during treatment with FFA (one probable SUDEP and one definite SUDEP). The all-cause and SUDEP mortality rates during treatment with FFA was 1.7 per 1000 person-years (95% CI, 0.4 to 6.7), a value lower than the all-cause estimate of 15.8 per 1000 person-years (95% CI, 9.9 to 25.4) and SUDEP estimate of 9.3 (95% CI, 5.0 to 17.3) reported by Cooper et al. (Epilepsy Res 2016;128:43-7) for persons with DS receiving standard-of-care.

CONCLUSION

All-cause and SUDEP mortality rates in DS patients treated with FFA were substantially lower than in literature reports. Further studies are warranted to confirm that FFA reduces SUDEP risk in DS patients and to better understand the potential mechanism(s) by which FFA lowers SUDEP risk.

CLINICAL TRIAL REGISTRATION

NCT02926898, NCT02682927, NCT02826863, NCT02823145, NCT03780127.

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.

Mortality among People with Epilepsy: A Retrospective Nationwide Analysis from 2016 to 2019

We estimated age-adjusted mortality and investigated the dominant causes of death as well as comorbidities among people with epilepsy (PWE) in Lithuania, a country with frequent deaths from external causes. From 2016 to 2019, the age-adjusted rate of death among PWE in Lithuania was compared with mortality data in the general population. Each year of analysis, individuals who were diagnosed with epilepsy comprised a retrospective cohort. The standardized mortality ratio (SMR) of PWE varied from 2.93 (95% CI 2.78 to 3.07) to 3.18 (95% CI 3.02 to 3.34). PWE died at least one decade earlier than expected in the general population. The dominant causes of death were cardiovascular diseases (their proportion ranged from 44.8% to 49.3%), cancer (16.7% to 21.3%) and external causes of death (8.5% to 10.9%). The proportion of the latter decreased over time (r = −0.99, p = 0.01), whereas the SMR for external causes of death remained relatively constant. Epilepsy was the underlying cause of death in 163 cases (2.6%), and noted as a condition contributing to death in 1010 cases (15.9%). Cerebrovascular and cardiological conditions and dementia were the most frequent comorbidities among PWE before their death. Epilepsy-unrelated causes of death are relevant contributors to mortality among PWE. There is a need for PWE-oriented societal interventions to reduce the frequency of external deaths beyond the trend in the general population.

Altered cardiac structure and function is related to seizure frequency in a rat model of chronic acquired temporal lobe epilepsy

OBJECTIVE

This study aimed to prospectively examine cardiac structure and function in the kainic acid-induced post-status epilepticus (post-KA SE) model of chronic acquired temporal lobe epilepsy (TLE), specifically to examine for changes between the pre-epileptic, early epileptogenesis and the chronic epilepsy stages. We also aimed to examine whether any changes related to the seizure frequency in individual animals.

METHODS

Four hours of SE was induced in 9 male Wistar rats at 10 weeks of age, with 8 saline treated matched control rats. Echocardiography was performed prior to the induction of SE, two- and 10-weeks post-SE. Two weeks of continuous video-EEG and simultaneous ECG recordings were acquired for two weeks from 11 weeks post-KA SE. The video-EEG recordings were analyzed blindly to quantify the number and severity of spontaneous seizures, and the ECG recordings analyzed for measures of heart rate variability (HRV). PicroSirius red histology was performed to assess cardiac fibrosis, and intracellular Ca²⁺ levels and cell contractility were measured by microfluorimetry.

RESULTS

All 9 post-KA SE rats were demonstrated to have spontaneous recurrent seizures on the two-week video-EEG recording acquired from 11 weeks SE (seizure frequency ranging from 0.3 to 10.6 seizures/day with the seizure durations from 11 to 62 s), and none of the 8 control rats. Left ventricular wall thickness was thinner, left ventricular internal dimension was shorter, and ejection fraction was significantly decreased in chronically epileptic rats, and was negatively correlated to seizure frequency in individual rats. Diastolic dysfunction was evident in chronically epileptic rats by a decrease in mitral valve deceleration time and an increase in E/E` ratio. Measures of HRV were reduced in the chronically epileptic rats, indicating abnormalities of cardiac autonomic function. Cardiac fibrosis was significantly increased in epileptic rats, positively correlated to seizure frequency, and negatively correlated to ejection fraction. The cardiac fibrosis was not a consequence of direct effect of KA toxicity, as it was not seen in the 6/10 rats from separate cohort that received similar doses of KA but did not go into SE. Cardiomyocyte length, width, volume, and rate of cell lengthening and shortening were significantly reduced in epileptic rats.

SIGNIFICANCE

The results from this study demonstrate that chronic epilepsy in the post-KA SE rat model of TLE is associated with a progressive deterioration in cardiac structure and function, with a restrictive cardiomyopathy associated with myocardial fibrosis. Positive correlations between seizure frequency and the severity of the cardiac changes were identified. These results provide new insights into the pathophysiology of cardiac disease in chronic epilepsy, and may have relevance for the heterogeneous mechanisms that place these people at risk of sudden unexplained death.

Pediatric epilepsy and psychoeducational interventions: A review of the literature

For many individuals, living with epilepsy is truly a family affair throughout the life span. When it comes to childhood epilepsy, the unpredictability of seizure patterns, comorbid conditions, the risk of sudden unexpected death in epilepsy (SUDEP), and societal stigma can be emotionally taxing on children and their primary caregivers. To this end, this article proposes to review psychoeducational interventions provided to primary caregivers of children with an epilepsy diagnosis and the impact of such interventions on general parental coping skills. There were three main themes identified (1) caregivers' knowledge and self-efficacy about seizure management; (2) parental epilepsy-related fears, anxiety, and stress; (3) parental sleep quality and SUDEP psychoeducation. Overall, considering research limitations, providing epilepsy-related psychoeducational interventions to primary caregivers of children with epilepsy seems to have promising evidence in the literature. After receiving such interventions, the studies show that caregivers' psychosocial outcomes improved; they become more empowered to manage their children's seizures and advocate for their children's psychosocial needs.

Sudden Unexpected Death in Epilepsy: A Personalized Prediction Tool

Objective

To develop and validate a tool for individualized prediction of sudden unexpected death in epilepsy (SUDEP) risk, we reanalyzed data from 1 cohort and 3 case–control studies undertaken from 1980 through 2005.

Methods

We entered 1,273 epilepsy cases (287 SUDEP, 986 controls) and 22 clinical predictor variables into a Bayesian logistic regression model.

Results

Cross-validated individualized model predictions were superior to baseline models developed from only average population risk or from generalized tonic-clonic seizure frequency (pairwise difference in leave-one-subject-out expected log posterior density = 35.9, SEM ± 12.5, and 22.9, SEM ± 11.0, respectively). The mean cross-validated (95% bootstrap confidence interval) area under the receiver operating curve was 0.71 (0.68–0.74) for our model vs 0.38 (0.33–0.42) and 0.63 (0.59–0.67) for the baseline average and generalized tonic-clonic seizure frequency models, respectively. Model performance was weaker when applied to nonrepresented populations. Prognostic factors included generalized tonic-clonic and focal-onset seizure frequency, alcohol excess, younger age at epilepsy onset, and family history of epilepsy. Antiseizure medication adherence was associated with lower risk.

Conclusions

Even when generalized to unseen data, model predictions are more accurate than population-based estimates of SUDEP. Our tool can enable risk-based stratification for biomarker discovery and interventional trials. With further validation in unrepresented populations, it may be suitable for routine individualized clinical decision-making. Clinicians should consider assessment of multiple risk factors, and not focus only on the frequency of convulsions.

Seizure-related deaths in children: The expanding spectrum

Although seizures are common in children, they are often overlooked as a potential cause of death. Febrile and nonfebrile seizures can be fatal in children with or without an epilepsy diagnosis and may go unrecognized by parents or physicians. Sudden unexpected infant deaths, sudden unexplained death in childhood, and sudden unexpected death in epilepsy share clinical, neuropathological, and genetic features, including male predominance, unwitnessed deaths, death during sleep, discovery in the prone position, hippocampal abnormalities, and variants in genes regulating cardiac and neuronal excitability. Additionally, epidemiological studies reveal that miscarriages are more common among individuals with a personal or family history of epilepsy, suggesting that some fetal losses may result from epileptic factors. The spectrum of seizure-related deaths in pediatrics is wide and underappreciated; accurately estimating this mortality and understanding its mechanism in children is critical to developing effective education and interventions to prevent these tragedies.

Autopsy-reported cause of death in a population-based cohort of sudden unexpected death in epilepsy

OBJECTIVE

Sudden unexpected death in epilepsy (SUDEP) is a diagnosis of exclusion; the definition includes individuals with epilepsy who die suddenly without an identifiable toxicological or anatomical cause of death. Limited data suggest underidentification of SUDEP as the cause of death on death certificates. Here, we evaluate the autopsy-reported cause of death in a population-based cohort of SUDEP cases.

METHODS

Case summaries of forensic autopsies conducted in Ontario, Canada between January 2014 and June 2016 were retrospectively screened using a language processing script for decedents with a history of epilepsy or seizures. After manual review for potential SUDEP cases, two neurologists independently examined the autopsy reports and classified deaths by Nashef criteria. Demographic characteristics and consideration by the forensic pathologist of the role of epilepsy, seizure, and SUDEP in death were summarized.

RESULTS

One hundred and eight Definite, 34 Definite Plus, and 22 Possible SUDEP cases were identified. Seventy-five percent of Definite/Definite Plus SUDEP cases identified by the neurologists were attributed to SUDEP, epilepsy, or seizure disorder in the autopsy report. There was a significant association between the proportion of cases listed in the autopsy report as SUDEP, epilepsy, or seizure disorder and neurologists' SUDEP classification (86% of Definite, 38% of Definite Plus, 0% of Possible). Age was significantly associated with SUDEP classification; Definite cases were younger than Definite Plus, which were younger than Possible SUDEP cases.

SIGNIFICANCE

Most SUDEP cases identified by neurologists were classified concordantly by forensic pathologists in Ontario, Canada; however, concordance decreased with increased case complexity. Although the role of epilepsy/seizures was considered in most Definite/Definite Plus cases, this study highlights the need for autopsy report review of potential SUDEP cases in research studies and assessments of the public health burden of SUDEP. The relationship between age and SUDEP classification has important public health implications; SUDEP incidence may be underappreciated in older adults.

SUDEP classification: Discordances between forensic investigators and epileptologists

We compared sudden unexpected death in epilepsy (SUDEP) diagnosis rates between North American SUDEP Registry (NASR) epileptologists and original death investigators, to determine degree and causes of discordance. In 220 SUDEP cases with post-mortem examination, we recorded the epileptologist adjudications and medical examiner- and coroner- (ME/C) listed causes of death (CODs). COD diagnosis concordance decreased with NASR's uncertainty in the SUDEP diagnosis: highest for Definite SUDEP (84%, n = 158), lower in Definite Plus (50%, n = 36), and lowest in Possible (0%, n = 18). Rates of psychiatric comorbidity, substance abuse, and toxicology findings for drugs of abuse were all higher in discordant cases than concordant cases. Possible SUDEP cases, an understudied group, were significantly older, and had higher rates of cardiac, drug, or toxicology findings than more certain SUDEP cases. With a potentially contributing or competing COD, ME/Cs favored non-epilepsy-related diagnoses, suggesting a bias toward listing CODs with structural or toxicological findings; SUDEP has no pathognomonic features. A history of epilepsy should always be listed on death certificates and autopsy reports. Even without an alternate COD, ME/Cs infrequently classified COD as "SUDEP." Improved collaboration and communication between epilepsy and ME/C communities improve diagnostic accuracy, as well as bereavement and research opportunities.

Temporal trends and autopsy findings of SUDEP based on medico-legal investigations in the United States

OBJECTIVE

To determine time trends and distinguishing autopsy findings of sudden unexpected death in epilepsy (SUDEP) in the United States.

METHODS

We identified decedents where epilepsy/seizure was listed as cause/contributor to death or comorbid condition on the death certificate among all decedents who underwent medico-legal investigation at 3 medical examiner (ME) offices across the country: New York City (2009-2016), San Diego County (2008-2016), and Maryland (2000-2016). After reviewing all available reports, deaths classified as definite/probable/near SUDEP or SUDEP plus were included for analysis. Mann-Kendall trend test was used to analyze temporal trends in SUDEP rate for 2009-2016. Definite SUDEPs were compared to sex- and age ±2 years-matched non-SUDEP deaths with a history of epilepsy regarding autopsy findings, circumstances, and comorbidities.

RESULTS

A total of 1,086 SUDEP cases were identified. There was a decreasing trend in ME-investigated SUDEP incidence between 2009 and 2016 (z = -2.2, S = -42, p = 0.028) among 3 regions. There was a 28% reduction in ME-investigated SUDEP incidence from 2009 to 2012 to 2013-2016 (confidence interval, 17%-38%, p < 0.0001). We found no correlation between SUDEP rates and the month of year or day of week. There was no difference between SUDEP and non-SUDEP deaths regarding neurodevelopmental abnormalities, pulmonary congestion/edema, and myocardial fibrosis.

CONCLUSIONS

There was a decreasing monotonic trend in ME-investigated SUDEP incidence over 8 years, with a 28% reduction in incidence from 2009-2012 to 2013-2016. Unlike SIDS and sudden cardiac death, we found no correlation between SUDEP and the season of year or day of week. No autopsy findings distinguished SUDEP from non-SUDEP deaths.

Socioeconomic disparities in SUDEP in the US

OBJECTIVE

To determine the impact of socioeconomic status (SES) on sudden unexpected death in epilepsy (SUDEP) rates.

METHODS

We queried all decedents presented for medico-legal investigation at 3 medical examiner (ME) offices across the country (New York City, Maryland, San Diego County) in 2009 to 2010 and 2014 to 2015. We identified all decedents for whom epilepsy/seizure was listed as cause/contributor to death or comorbid condition on the death certificate. We then reviewed all available reports. Decedents determined to have SUDEP were included for analysis. We used median income in the ZIP code of residence as a surrogate for SES. For each region, zip code regions were ranked by median household income and divided into quartiles based on total population for 2 time periods. Region-, age-, and income-adjusted epilepsy prevalence was estimated in each zip code. SUDEP rates in the highest and lowest SES quartiles were evaluated to determine disparity. Examined SUDEP rates in 2 time periods were also compared.

RESULTS

There were 159 and 43 SUDEP cases in the lowest and highest SES quartiles. ME-investigated SUDEP rate ratio between the lowest and highest SES quartiles was 2.6 (95% confidence interval [CI] 1.7-4.1, p < 0.0001) in 2009 to 2010 and 3.3 (95% CI 1.9-6.0, p < 0.0001) in 2014 to 2015. There was a significant decline in overall SUDEP rate between the 2 study periods (36% decrease, 95% CI 22%-48%, p < 0.0001).

CONCLUSION

ME-investigated SUDEP incidence was significantly higher in people with the lowest SES compared to the highest SES. The difference persisted over a 5-year period despite decreased overall SUDEP rates.

Review on post-mortem diagnosis in suspected SUDEP: Currently still a difficult task for Forensic Pathologists

Sudden and unexpected death in epilepsy (SUDEP) represents the predominant cause of premature deaths in young adults with epilepsy and is more common with patients with poorly controlled and generalized convulsive seizures. It is reported that there are 1,16 cases for every 1000 subjects affected with epilepsy. This review takes stock of the current problems and issues in the autopsy of cases of sudden death with epileptic people. For this purpose, all the possible findings of post-mortem examinations reported in the literature were analyzed and summarized, which can currently be considered useful for autopsy diagnoses as well as in the comprehension of the physiopathology of SUDEP. The enormous limitation of forensic pathology studies is the complete lack of a specific SUDEP diagnostic marker. Only in a few cases was it possible to find pathological signs of the brain that would clarify epilepsy-related deaths. Genetic research has tracked down variants of neurocardiac genes of ion channels in a restricted percentage of suspected SUDEP cases. The actual pathogenicity test requires an in-depth statistical analysis in order to prove there is a real excess of variants and evidence that the mutation alters the function. Despite scientific efforts, it is often difficult to distinguish SUDEP from other causes of sudden death. For these reasons, it will be necessary to create an international standard SUDEP death scene investigation and postmortem examination protocols. Further future studies of immunohistochemistry or genetics may help and may facilitate post-mortem diagnosis in cases of presumed SUDEP.

[Sudden unexpected death in epilepsy (SUDEP) : Epidemiology, cardiac and other risk factors]

Sudden unexpected death in epilepsy (SUDEP) is one of the most frequent epilepsy-related causes of death. The incidence of SUDEP is estimated to be approximately 1.2/1000 person-years (PY); however, it varies considerably depending on disease-specific and demographic factors. The estimated incidence of SUDEP in children seems to be significantly lower (0.22/1000 PY) than in adults but recent studies in children (>12 years) indicated a similar incidence to that of adults. Based on these estimations, approximately 700 SUDEP cases would be expected in Germany annually but no reliable data or epidemiological studies on SUDEP are available. Various risk factors and predictors for SUDEP have been investigated, e.g. age, seizure frequency, number of antiepileptic drugs, non-compliance and comorbidities, with sometimes contradictory results. This is understandable given that the exact mechanisms of SUDEP are unclear; however, it is very likely that the frequency of (nocturnal) generalized tonic-clonic seizures is the most important risk factor. Nocturnal monitoring of seizures (using devices) or the presence of another person at night may represent important factors to reduce the risk of SUDEP. Thus, seizure control and seizure monitoring are, according to current knowledge, the most important factors to avoid SUDEP. Some recent studies have contributed to a better understanding of possible pathomechanisms of SUDEP; however, further research is needed to identify predictive clinical factors and biomarkers and in particular to prevent SUDEP.

Let's talk SUDEP

Sudden unexplained death in epilepsy (SUDEP) is a devastating complication of epilepsy which was under-recognized in the recent past despite its clear importance. In this review, we examine the definition of SUDEP, revise current pathophysiological theories, discuss risk factors and preventative measures, disclose tools for appraising the SUDEP risk, and last but not least dwell upon announcing and explaining the SUDEP risk to the patients and their caretakers. We aim to aid the clinicians in their responsibility of knowing SUDEP, explaining the SUDEP risk to their patients in a reasonable and sensible way and whenever possible, preventing SUDEP. Future studies are definitely needed to increase scientific knowledge and awareness related to this prioritized topic with malign consequences.

Epilepsy and seizure-related deaths: Mortality statistics do not tell the complete story

INTRODUCTION

The objective of the study was to identify where epilepsy or seizures may be the underlying cause of death but not identified by the death certification process in the Australian coronial system and to better characterize such deaths.

METHODS

Australian National Coronial Information System (NCIS) closed cases for the Australian Capital Territory (ACT) (population average 348,000) over 13 years were searched using cause of death, and a text search of police and autopsy reports, to identify all deaths where epilepsy or seizures were mentioned. Deaths where the underlying cause of death was not seizures or epilepsy were excluded (including suicide). The remaining cases (75) were categorized by the circumstances of death. Suspected sudden unexpected death in epilepsy (SUDEP) cases were further classified using the unified definition of SUDEP of Nashef and colleagues (2012).

RESULTS

Of the final 75 cases, only 44 were found by the cause of death search. Key word document searches found another 31. Cases were classified as Definite SUDEP (37), Definite SUDEP Plus (10), Probable SUDEP (1), Possible SUDEP (3), Near SUDEP (4), Near SUDEP Plus (1), Asphyxia (3), Treatment-related (1), Head injury (2), Drowning (2), motor vehicle accident (MVA) (1), deaths related to a single convulsive seizure (6), and status epilepticus (SE) (4). Cases were 80% male.

CONCLUSIONS

Epilepsy and seizure-related deaths are underreported in the Australian Coronial system. Enhanced documentation of the causal chain of events leading to deaths would increase recognition. Using the unified SUDEP definition would expand SUDEP identification.

Comparison of kainate-induced seizures, cognitive impairment and hippocampal damage in male and female mice

Kainate (KA) mouse model induced by intraperitoneal injection has been widely used for epilepsy and neurodegeneration studies. KA elicits sustained epileptic activity in mouse brain revealed by recurrent behavioral seizures, deteriorative neurodegeneration and various neurological deficits. However, to date, the vast majority of the studies used male mice only, and few studies on the comparison of brain injury between male and female mice in this model were reported. Epidemiological studies indicate that sex may affect the susceptibility to seizure response and neurodegeneration process. Therefore, this study focused on the effect of sex difference on KA-induced recurrent seizures and mortality, locomotor activity and cognitive impairment, and hippocampal neurodegeneration and reactive gliosis in mice. Our results showed that, compared to females, adult male mice exhibited worse performance in mortality rate, severity of epileptic seizures, and cognitive impairment indicated by novel object recognition task. Unexpectedly, post-KA male and female mice underwent similar decline and recovery of locomotor activity. KA-induced neurodegeneration in the whole hippocampus, particularly in CA1 and CA3 subregions, along with the deteriorative reactive gliosis in astrocytes and microglia, was more severe in males than that in females. These data provided the direct in vivo evidence that indicates the key role of sex difference in studies with KA mouse model, and this could be beneficial for optimizing the design of future studies.

Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study

Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen’s d = −0.24 to −0.73; P < 1.49 × 10⁻⁴), and lower thickness in the precentral gyri bilaterally (d = −0.34 to −0.52; P < 4.31 × 10⁻⁶). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = −1.73 to −1.91, P < 1.4 × 10⁻¹⁹), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = −0.36 to −0.52; P < 1.49 × 10⁻⁴). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = −0.29 to −0.54; P < 1.49 × 10⁻⁴). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = −0.27 to −0.51; P < 1.49 × 10⁻⁴). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < −0.0018; P < 1.49 × 10⁻⁴). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed.

Automated detection of sudden unexpected death in epilepsy risk factors in electronic medical records using natural language processing

OBJECTIVE

Sudden unexpected death in epilepsy (SUDEP) is an important cause of mortality in epilepsy. However, there is a gap in how often providers counsel patients about SUDEP. One potential solution is to electronically prompt clinicians to provide counseling via automated detection of risk factors in electronic medical records (EMRs). We evaluated (1) the feasibility and generalizability of using regular expressions to identify risk factors in EMRs and (2) barriers to generalizability.

METHODS

Data included physician notes for 3000 patients from one medical center (home) and 1000 from five additional centers (away). Through chart review, we identified three SUDEP risk factors: (1) generalized tonic-clonic seizures, (2) refractory epilepsy, and (3) epilepsy surgery candidacy. Regular expressions of risk factors were manually created with home training data, and performance was evaluated with home test and away test data. Performance was evaluated by sensitivity, positive predictive value, and F-measure. Generalizability was defined as an absolute decrease in performance by <0.10 for away versus home test data. To evaluate underlying barriers to generalizability, we identified causes of errors seen more often in away data than home data. To demonstrate how small revisions can improve generalizability, we removed three "boilerplate" standard text phrases from away notes and repeated performance.

RESULTS

We observed high performance in home test data (F-measure range = 0.86-0.90), and low to high performance in away test data (F-measure range = 0.53-0.81). After removing three boilerplate phrases, away performance improved (F-measure range = 0.79-0.89) and generalizability was achieved for nearly all measures. The only significant barrier to generalizability was use of boilerplate phrases, causing 104 of 171 errors (61%) in away data.

SIGNIFICANCE

Regular expressions are a feasible and probably a generalizable method to identify variables related to SUDEP risk. Our methods may be implemented to create large patient cohorts for research and to generate electronic prompts for SUDEP counseling.

Neural activity in the periaqueductal gray and other specific subcortical structures is enhanced when a selective serotonin reuptake inhibitor selectively prevents seizure-induced sudden death in the DBA/1 mouse model of sudden unexpected death in epilepsy

OBJECTIVE

Sudden unexpected death in epilepsy (SUDEP) is a critical issue in epilepsy, and DBA/1 mice are a useful animal model of this devastating epilepsy sequela. The serotonin hypothesis for SUDEP proposes that modifying serotonergic function significantly alters susceptibility to seizure-induced respiratory arrest (S-IRA). Agents that enhance serotonergic function, including a selective serotonin reuptake inhibitor, fluoxetine, selectively prevent S-IRA in DBA/1 mice. This study examined fluoxetine-induced changes in brain activity using manganese-enhanced magnetic resonance imaging (MEMRI) to reveal sites in the DBA/1 mouse brain where fluoxetine acts to prevent S-IRA.

METHODS

DBA/1 mice were subjected to audiogenic seizures (Sz) after saline or fluoxetine (45 mg/kg, intraperitoneal) administration. Control DBA/1 mice received fluoxetine or saline, but Sz were not evoked. A previous MEMRI study established the regions of interest (ROIs) for Sz in the DBA/1 mouse brain, and the present study examined MEMRI differences in the ROIs of these mouse groups.

RESULTS

The neural activity in several ROIs was significantly increased in fluoxetine-treated DBA/1 mice that exhibited Sz but not S-IRA when compared to the saline-treated mice that exhibited both Sz and respiratory arrest. These structures included the periaqueductal gray (PAG), amygdala, reticular formation (sensorimotor-limbic network), Kölliker-Fuse nucleus, facial-parafacial group (respiratory network), and pontine raphe. Of these ROIs, only the PAG showed significantly decreased neural activity with saline pretreatment when seizure-induced respiratory arrest occurred as compared to saline treatment without seizure.

SIGNIFICANCE

The PAG is known to play an important compensatory role for respiratory distress caused by numerous exigent situations in normal animals. The pattern of fluoxetine-induced activity changes in the present study suggests that PAG may be the most critical target for fluoxetine's action to prevent seizure-induced sudden death. These findings have potential clinical importance, because there is evidence of anomalous serotonergic function and PAG imaging abnormalities in human SUDEP.

Investigative practice into sudden death in epilepsy: A global survey

OBJECTIVES

Sudden death is a recognized consequence of epilepsy. Little is known about the practice of confirming the cause of sudden death from most nations. We sought to determine how often autopsy is undertaken, clinician confidence in cause of death and identify the factors which may influence autopsy utilization.

MATERIALS & METHODS

An online questionnaire survey was sent to all International League Against Epilepsy (ILAE) chapters chairpersons, asking them to complete the survey based on their perceptions in their country. Questions included: confidence in cause of death in people with epilepsy, frequency of autopsy uptake, and perceived barriers to an accurate diagnosis and ongoing research work. Data were analyzed by chi-squared, Kruskal-Wallis and Spearman rank analysis.

RESULTS

Responses were obtained from 77 of 114 individual chapter leaders (68%). Legal, coronial, family attitudes, including cultural and religious factors, to autopsy were considered the major barriers to obtaining an accurate diagnosis. Only 13% had a high level of confidence in the accuracy of the cause of death. There was greater confidence in the diagnosis of the causes of sudden death in epilepsy in the countries with higher autopsy rates. Sixty-six percent of responders were not aware of published or unpublished research or audits on sudden death in epilepsy in their country in the last decade.

CONCLUSIONS

Significant disparities exist in the investigation of sudden death in epilepsy across countries and identified factors in this study provide an opportunity to formulate a global public health strategy to help overcome this gap.

Potential Role of Febrile Seizures and Other Risk Factors Associated With Sudden Deaths in Children

IMPORTANCE

Sudden unexplained death in childhood (SUDC) is the fifth leading category of death among toddlers but remains underrecognized and inadequately studied.

OBJECTIVE

To assess the potential role of febrile seizures (FS) and other risk factors associated with SUDC and describe the epidemiology, mechanisms, and prevention of SUDC.

DESIGN, SETTING, AND PARTICIPANTS

This case series study reviewed 622 consecutive sudden child death cases aged 1 to 17 years from 2001 to 2017 from 18 countries. Data were collected from family members of children who died suddenly; these families voluntarily registered with the SUDC Foundation. Data analysis was conducted from November 2017 to February 2019.

MAIN OUTCOME MEASURES

Certified manner of death characterized as accident, natural, or undetermined.

RESULTS

A total of 391 families with decedents aged 1 to 6 years completed a comprehensive interview on medical and social histories, and circumstances of death with forensic evaluations revealing a cause of death (sudden explained death in childhood [SEDC]) or no cause of death (SUDC). Of these children, 231 (59.1%) were male, the mean (SD) age at death was 24.9 (12.8) months, and 104 (26.6%) had a history of FS. Compared with the general population FS prevalence (2%-5%), FS prevalence among SUDC (28.8%; 95% CI, 23.3%-34.2%) and SEDC (22.1%; 95% CI, 14.8%-29.3%) were elevated. The odds of death during sleep was 4.6-fold higher in SUDC than in SEDC cases (odds ratio, 4.61; 95% CI, 1.92-11.09; adjusted P = .008). The siblings of SUDC cases were followed up for 3144 life-years, and none died prematurely from SUDC.

CONCLUSIONS AND RELEVANCE

This analysis of the largest SUDC cohort confirmed an increased FS rate and found significantly increased rates of FS among SEDC. This study suggests that seizures may contribute to some SUDC and SEDC deaths. The risk of sudden death in a sibling was low. To develop and assess preventive strategies, population-based studies are needed to define the epidemiology and spectrum of risk factors and identify biomarkers of patients with FS at high risk of sudden death.

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.

Review: The past, present and future challenges in epilepsy-related and sudden deaths and biobanking

Awareness and research on epilepsy-related deaths (ERD), in particular Sudden Unexpected Death in Epilepsy (SUDEP), have exponentially increased over the last two decades. Most publications have focused on guidelines that inform clinicians dealing with these deaths, educating patients, potential risk factors and mechanisms. There is a relative paucity of information available for pathologists who conduct these autopsies regarding appropriate post mortem practice and investigations. As we move from recognizing SUDEP as the most common form of ERD toward in-depth investigations into its causes and prevention, health professionals involved with these autopsies and post mortem procedure must remain fully informed. Systematizing a more comprehensive and consistent practice of examining these cases will facilitate (i) more precise determination of cause of death, (ii) identification of SUDEP for improved epidemiological surveillance (the first step for an intervention study), and (iii) biobanking and cell-based research. This article reviews how pathologists and healthcare professionals have approached ERD, current practices, logistical problems and areas to improve and harmonize. The main neuropathology, cardiac and genetic findings in SUDEP are outlined, providing a framework for best practices, integration of clinical, pathological and molecular genetic investigations in SUDEP, and ultimately prevention.

Dead in the water: Epilepsy-related drowning or sudden unexpected death in epilepsy?

OBJECTIVE

Both drowning and sudden unexpected death in epilepsy (SUDEP) are diagnoses of exclusion with predominantly nonspecific autopsy findings. We hypothesized that people with epilepsy found dead in water with no clear sign of submersion could be misdiagnosed as SUDEP.

METHODS

All reported seizure-related deaths undergoing medicolegal investigation in three medical examiner's offices (New York City, Maryland, San Diego County) over different time periods were reviewed to identify epilepsy-related drownings and SUDEPs. Drowning cases that fulfilled inclusion criteria were divided into two groups according to the circumstances of death: definite drowning and possible drowning. The SUDEP group included two sex- and age (±2 years)-matched definite SUDEP/definite SUDEP plus cases for each drowning case.

RESULTS

Of 1346 deaths reviewed, we identified 36 definite (76.6%) and 11 possible drowning deaths (23.4%), most of which occurred in a bathtub (72.3%). There were drowning-related findings, including fluid within the sphenoid sinuses, foam in the airways, clear fluid in the stomach content, and lung hyperinflation in 58.3% (21/36) of the definite drowning group, 45.5% (5/11) of the possible drowning group, and 4.3% of the SUDEP group (4/92). There was no difference in the presence of pulmonary edema/congestion between the definite drowning group, possible drowning group, and SUDEP group. The definite drowning group had a higher mean combined lung weight than the SUDEP group, but there was no difference in mean lung weights between the possible drowning and SUDEP groups or between the possible drowning and definite drowning groups.

SIGNIFICANCE

No distinguishable autopsy finding could be found between SUDEPs and epilepsy-related drownings when there were no drowning-related signs and no clear evidence of submersion. SUDEP could be the cause of death in such possible drowning cases. As most drowning cases occurred in the bathtub, supervision and specific bathing precautions could be effective prevention strategies.

Ictal Mammalian Dive Response: A Likely Cause of Sudden Unexpected Death in Epilepsy

Even though sudden unexpected death in epilepsy (SUDEP) takes the lives of thousands of otherwise healthy epilepsy patients every year, the physiopathology associated with this condition remains unexplained. This article explores important parallels, which exist between the clinical observations and pathological responses associated with SUDEP, and the pathological responses that can develop when a set of autonomic reflexes known as the mammalian dive response (MDR) is deployed. Mostly unknown to physicians, this evolutionarily conserved physiological response to prolonged apnea economizes oxygen for preferential use by the brain. However, the drastic cardiovascular adjustments required for its execution, which include severe bradycardia and the sequestration of a significant portion of the total blood volume inside the cardiopulmonary vasculature, can result in many of the same pathological responses associated with SUDEP. Thus, this article advances the hypothesis that prolonged apneic generalized tonic clonic seizures induce augmented forms of the MDR, which, in the most severe cases, cause SUDEP.

Second-hit mosaic mutation in mTORC1 repressor DEPDC5 causes focal cortical dysplasia-associated epilepsy

DEP domain-containing 5 protein (DEPDC5) is a repressor of the recently recognized amino acid-sensing branch of the mTORC1 pathway. So far, its function in the brain remains largely unknown. Germline loss-of-function mutations in DEPDC5 have emerged as a major cause of familial refractory focal epilepsies, with case reports of sudden unexpected death in epilepsy (SUDEP). Remarkably, a fraction of patients also develop focal cortical dysplasia (FCD), a neurodevelopmental cortical malformation. We therefore hypothesized that a somatic second-hit mutation arising during brain development may support the focal nature of the dysplasia. Here, using postoperative human tissue, we provide the proof of concept that a biallelic 2-hit - brain somatic and germline - mutational mechanism in DEPDC5 causes focal epilepsy with FCD. We discovered a mutation gradient with a higher rate of mosaicism in the seizure-onset zone than in the surrounding epileptogenic zone. Furthermore, we demonstrate the causality of a Depdc5 brain mosaic inactivation using CRISPR-Cas9 editing and in utero electroporation in a mouse model recapitulating focal epilepsy with FCD and SUDEP-like events. We further unveil a key role of Depdc5 in shaping dendrite and spine morphology of excitatory neurons. This study reveals promising therapeutic avenues for treating drug-resistant focal epilepsies with mTORC1-targeting molecules.

Incidence of cardiac fibrosis in SUDEP and control cases

OBJECTIVE

Since cardic fibrosis was previously found more frequently in patients with sudden unexpected death in epilepsy (SUDEP) than control cases, we compared blinded and quantitative reviews of cardiac pathology in SUDEP to multiple control groups.

METHODS

We adjudicated causes of death in epilepsy patients as part of consecutive out-of-hospital sudden cardiac deaths (SCDs) from the Postmortem Systematic Investigation of Sudden Cardiac Death (POSTSCD) study. Blinded cardiac gross and microscopic examinations were performed by forensic and cardiac pathologists.

RESULTS

Of 541 SCDs over 37 months (mean age 62.8 years, 69% male), 525 (97%) were autopsied; 25/525 (4.8%) had epilepsy (mean age 56.4 years ± 15.4, range 27-92; 67% male). The 25 epilepsy patients died of definite SUDEP/definite SUDEP-plus (n = 8), possible SUDEP (n = 10), or other causes (n = 7). Comparison groups included autopsy-defined sudden arrhythmic death (SAD; n = 285) and trauma (n = 104) and we adjusted for age, sex, HIV, coronary artery disease, congestive heart failure, and cardiomyopathy in the analyses. Compared to SAD cases, SUDEP cases had less gross and histologic evidence of cardiac pathology; significant for cardiac mass (p < 0.0011), coronary artery disease (p < 0.0024), total cardiac fibrosis (CF) (p = 0.022), and interstitial CF (p = 0.013). Compared to trauma cases, SUDEP cases had similar cardiac pathology including CF.

CONCLUSION

Among SUDEP cases, cardiac pathology was less severe than in SAD cases but similar to trauma and epilepsy controls. Our data do not support prior studies finding elevated rates of CF among SUDEP cases compared to controls. Larger studies including molecular analyses would further our understanding of cardiac changes associated with SUDEP.

Epilepsy

Epilepsy affects all age groups and is one of the most common and most disabling neurological disorders. The accurate diagnosis of seizures is essential as some patients will be misdiagnosed with epilepsy, whereas others will receive an incorrect diagnosis. Indeed, errors in diagnosis are common, and many patients fail to receive the correct treatment, which often has severe consequences. Although many patients have seizure control using a single medication, others require multiple medications, resective surgery, neuromodulation devices or dietary therapies. In addition, one-third of patients will continue to have uncontrolled seizures. Epilepsy can substantially impair quality of life owing to seizures, comorbid mood and psychiatric disorders, cognitive deficits and adverse effects of medications. In addition, seizures can be fatal owing to direct effects on autonomic and arousal functions or owing to indirect effects such as drowning and other accidents. Deciphering the pathophysiology of epilepsy has advanced the understanding of the cellular and molecular events initiated by pathogenetic insults that transform normal circuits into epileptic circuits (epileptogenesis) and the mechanisms that generate seizures (ictogenesis). The discovery of >500 genes associated with epilepsy has led to new animal models, more precise diagnoses and, in some cases, targeted therapies.