Improving prediction of sudden unexpected death in epilepsy: From SUDEP-7 to SUDEP-3

Influence of Risk Factor Combinations on Incidence Rates of SUDEP: A Population-Based Study

BACKGROUND AND OBJECTIVE

Information on absolute risks of sudden unexpected death in epilepsy (SUDEP) in individual patients with epilepsy is scarce. Our main objective was therefore to explore the range in incidence rates of SUDEP to provide a more solid basis for individualized counseling and to characterize patients with high and very high SUDEP incidence for future intervention studies aiming at prevention of SUDEP.

METHODS

We used data on everyone in Sweden diagnosed with epilepsy from 1998 to 2005 (n = 60,952), followed until 2011 and identified SUDEP cases through adjudication of deceased patients who had epilepsy. We conducted a nested case-control study and retrieved detailed information on clinical characteristics for the SUDEP cases and matched living epilepsy controls (5:1). Estimates of the strengths of associations from the case-control study were used to estimate the incidence rate of SUDEP (per 100,000 person-years) in the full cohort by SUDEP risk factors.

RESULTS

Two hundred fifty-five SUDEP cases (median age 48 years; 154 males) were identified. The lowest incidence, 8 (95% CI 3-17), was observed among patients without a history of tonic-clonic seizures (TCS), whereas patients with 1 or more TCS the preceding year had an incidence of 287 (95% CI 192-428). Incidence rates above 200 were also found among patients with a history of nocturnal TCS, substance abuse or alcohol dependence, and nonadherence with antiseizure medication (ASM) treatment. Considering combination of risk factors, the incidence rate was very low, 5 (95% CI 2-12), for patients who share bedroom and are free from TCS the preceding year as well as adherent with the prescribed ASM treatment. By contrast, patients living alone who are nonadherent have a history of nocturnal TCS and at least 1 TCS the preceding year have an incidence at 1808 (95% CI 594-5,504), more than 350 times higher than the low-risk patient.

DISCUSSION

In this analysis of Swedish population-based SUDEP data, we have identified a 350-fold difference in the SUDEP incidence depending on individual circumstances and epilepsy characteristics. Although somewhat old, our data should be useful for patient counseling about individual SUDEP risks amenable to modification and for case stratifications for intervention studies aiming at prevention of SUDEP.

Sudden Unexpected Death in Epilepsy: Central Respiratory Chemoreception

Sudden unexpected death in epilepsy (SUDEP) is a critical concern for individuals suffering from epilepsy, with respiratory dysfunction playing a significant role in its pathology. Fatal seizures are often characterized by central apnea and hypercapnia (elevated CO2 levels), indicating a failure in ventilatory control. Research has shown that both human epilepsy patients and animal models exhibit a reduced hypercapnic ventilatory response in the interictal (non-seizure) period, suggesting an impaired ability to regulate breathing in response to high CO2 levels. This review examines the role of central chemoreceptors-specifically the retrotrapezoid nucleus, raphe nuclei, nucleus tractus solitarius, locus coeruleus, and hypothalamus in this pathology. These structures are critical for sensing CO2 and maintaining respiratory homeostasis. Emerging evidence also implicates neuropeptidergic pathways within these chemoreceptive regions in SUDEP. Neuropeptides like galanin, pituitary adenylate cyclase-activating peptide (PACAP), orexin, somatostatin, and bombesin-like peptides may modulate chemosensitivity and respiratory function, potentially exacerbating respiratory failure during seizures. Understanding the mechanisms linking central chemoreception, respiratory control, and neuropeptidergic signaling is essential to developing targeted interventions to reduce the risk of SUDEP in epilepsy patients.

Sex-specific differences in mortality and neurocardiac interactions in the Kv1.1 knockout mouse model of sudden unexpected death in epilepsy (SUDEP)

Sudden unexpected death in epilepsy (SUDEP) is a devastating complication of epilepsy with possible sex-specific risk factors, although the exact relationship between sex and SUDEP remains unclear. To investigate this, we studied Kcna1 knockout (Kcna1-/-) mice, which lack voltage-gated Kv1.1 channel subunits and are widely used as a SUDEP model that mirrors key features in humans. To assess sex differences, we first performed survival analysis, EEG-ECG recordings, seizure threshold testing and retrospective analysis of previous intracardiac pacing data. We then applied a novel modelling approach across organs (organomics) to uncover potential sex-specific differences in brain-heart communication. Our findings revealed female Kcna1-/- mice have significantly longer lifespans than males, suggesting lower SUDEP rates. Although no sex differences were found in seizure frequency, duration, burden, susceptibility or interictal heart rate variability, females showed a higher incidence of bradycardia during spontaneous seizures than males, as well as resistance to inducible ventricular tachyarrhythmias in response to programmed electrical stimulation. Two captured SUDEP events, one per sex, displayed similar patterns of ictal bradycardia in both sexes, progressing to postictal cardiorespiratory failure. Going beyond traditional seizure and cardiac metrics, organomics analysis revealed that seizures affect brain-heart communication differently between sexes. Females exhibited more effective resetting of brain-heart interactions postictally than males. This finding may contribute to the lower SUDEP risk in females and underscores the complex interplay between sex, cardiac function and brain-heart communication in determining SUDEP susceptibility. Furthermore, seizure-resetting measures could represent a promising class of biomarkers for SUDEP risk stratification. KEY POINTS: Female Kcna1-/- mice live longer than males, suggesting lower sudden unexpected death in epilepsy (SUDEP) rates. There are no sex differences in seizure metrics or interictal heart rate variability. Females show more bradycardia during seizures and are resistant to inducible ventricular tachyarrhythmias. Seizures affect brain-heart communication differently between the sexes. Seizures in females reset brain-heart interactions more effectively postictally, potentially lowering SUDEP risk.

Obstructive sleep apnea is associated with risk for sudden unexpected death in epilepsy (SUDEP) using rSUDEP-7

BACKGROUND AND OBJECTIVE

Evaluate relationships between PSG-confirmed OSA and SUDEP risk using the revised SUDEP Risk Inventory (rSUDEP-7).

METHODS

Identified adults with epilepsy (AWE) who underwent PSG 2004-2016 at Cleveland Clinic. OSA was defined as apnea-hypopnea index (AHI)- ≥-5/h sleep; moderate/severe OSA as AHI≥15. SUDEP risk was assessed using rSUDEP-7: higher rSUDEP-7 score, greater SUDEP risk. Associations between rSUDEP-7 score and OSA groups (AHI≥15 vs. <15) were evaluated using Wilcoxon rank-sum tests and multivariable linear models adjusting for age, sex, BMI, and smoking status. Spearman correlations measured relationships between rSUDEP-7 score with AHI and oxygen desaturation indices (ODI).

RESULTS

OSA was present in 134 (62.6 %) of 214 AWE; moderate/severe in 75 (35 %). AWE with AHI≥15 were more likely to be male and older, had higher BMI, greater frequency of tonic-clonic seizures (TCS), longer epilepsy duration, and more likely to have drug-resistant epilepsy (DRE) and sleep-related seizures (all p< 0.05). The median rSUDEP-7 score was 1 (0,3) but 37.4 % had a score ≥3 (high SUDEP risk), and 11.7 % ≥5 (highest SUDEP risk). rSUDEP-7 scores were higher in those with AHI≥15 (3 vs. 1, p = 0.001). Higher AHI and ODI 3% positively correlated with rSUDEP-7 (p=0.002 and p=0.016) while SpO2 nadir negatively correlated with rSUDEP-7 (p=0.007). After adjustments, AWE with AHI≥15 had mean rSUDEP-7 score 1.14 points (95% CI 0.55-1.72, p<0.001) higher than those with AHI<15.

DISCUSSION

AWE with PSG-confirmed moderate/severe OSA especially those who are older and have GTC had higher rSUDEP-7 scores potentially increasing their risk for SUDEP. Our findings support routine screening for OSA in AWE. Further studies confirming the significance and impact of OSA on SUDEP risk are needed.

Update review on SUDEP: Risk assessment, background & seizure detection devices

This review focusses on sudden unexpected death in epilepsy patients (SUDEP) and incorporates risk stratification (through SUDEP risk factors and SUDEP risk scores), hypotheses on the mechanism of SUDEP and eligible seizure detection devices (SDDs) for further SUDEP prevention studies. The main risk factors for SUDEP are the presence and the frequency of generalized tonic-clonic seizures (GTC). In Swedish population-based case control study, the Odds ratio of the presence of GTC in the absence of bedroom sharing is 67. SUDEP risk scoring systems express a score that represents the cumulative presence of SUDEP risk factors, but not the exact effect of their combination. We describe 4 of the available scoring systems: SUDEP-7 inventory, SUDEP-3 inventory, SUDEP-ClinicAl Risk scorE (SUDEP-CARE score) and Kempenhaeghe SUDEP risk score. Although they all include GTC, their design is often different. Three of 4 scoring systems were validated (SUDEP-7 inventory, SUDEP-3 inventory and SUDEP-CARE score). None of the available scoring systems has been sufficiently validated for the use in a general epilepsy population. Plausible mechanisms of SUDEP are discussed. In the MORTEMUS-study (Mortality in Epilepsy Monitoring Unit Study), SUDEP was a postictal cardiorespiratory arrest after a GTC. The parallel respiratory and cardiac dysfunction in SUDEP suggests a central dysfunction of the brainstem centers that are involved in the control of respiration and heart rhythm. In the (consequent) adenosine serotonin hypotheses SUDEP occurs when a postictal adenosine-mediated respiratory depression is not compensated by the effect of serotonin. Other (adjuvant) mechanisms and factors are discussed. Seizure detection devices (SDDs) may help to improve nocturnal supervision. Five SDDs have been validated in phase 3 studies for the detection of TC: Seizure Link®, Epi-Care®, NightWatch, Empatica, Nelli®. They have demonstrated a sensitivity of at least 90 % combined with an acceptable false positive alarm rate. It has not yet been proven that the use will actually lead to SUDEP prevention, but clinical experience supports their effectiveness.

Status Epilepticus a risk factor for Sudden Unexpected Death in Epilepsy (SUDEP): A scoping review and narrative synthesis

BACKGROUND

Sudden Unexpected Death in Epilepsy (SUDEP) is a leading cause of mortality among people with epilepsy (PWE). Risk factors such as increased seizure frequency, drug-resistant epilepsy, and early epilepsy onset are well recognised. However, little evidence of the role of seizure severity, specifically Status Epilepticus (SE) on SUDEP risk exists.

OBJECTIVE

To identify mechanisms, risk factors and clinical characteristics overlap between SE and SUDEP.

METHODS

A scoping review using the PRISMA-ScR model was performed by two reviewers using suitable search terms. The PubMed Advanced Search tool along with the ancestry method was utilised to identify suitable articles published between 06/1992 and 05/2023. Quantitative, qualitative and mixed method studies were included. A narrative synthesis was undertaken and is presented as themes and subthemes.

RESULTS

Of 5453 papers identified in the preliminary search, 50 studies were suitable for final analysis. Key themes include overlap between SE complications and SUDEP risk factors (pharmaco-resistant generalised tonic-clonic epilepsy, intellectual disability), overlap of shared risk factors (alcohol abuse, developmental epileptic encephalopathies) and clinical characteristics (cardiac and respiratory). SE's role in development of drug-resistant epilepsy was the strongest potential mechanism for SE's contribution to SUDEP risk. SE's contribution to recurrent ictal hypoxaemia episodes and lowered heart rate variability suggests a relationship with SUDEP needing further study.

CONCLUSIONS

This review identifies research areas of influence of SE on SUDEP risk. Such research could inform counselling for patients concerned about seizure severity in relation to their SUDEP risk and optimise surveillance and subsequent management of post-SE epileptogenic outcomes.

Concentration of IL-1β, IL-7, IL-12, IL-17, CX3CL1, ITAC and relation with the seizure severity and sudden unexpected death in epilepsy patient

OBJECTIVE

Inflammation plays an important role in epilepsy. There is evidence for the relationship between proinflammatory cytokines and epilepsy. We aimed to detect the serum levels of multiple cytokines in epilepsy patients, looking for biological indicators, and providing a theoretical basis for the clinical diagnosis, treatment, and prognosis of epilepsy.

MATERIALS AND METHODS

In this study, 30 patients with drug-resistant epilepsy (DRE), 30 patients with well-controlled epilepsy (WCE), and 29 healthy controls (HC) were enrolled. Multi-proinflammatory cytokines were measured by LUMINX multi-factor detection.

RESULTS

The levels of IL-1β, IL-7, IL-12, and IL-17 were significantly elevated, and the levels of CX3CL1 and ITAC were significantly decreased in epilepsy patients compared with healthy controls. Furthermore, the level of IL-17 was significantly higher in the DRE group compared to WCE. We also found the ratio of IL-7/CX3CL discriminates accurately between patients and controls, with a ROC Area Under the Curve (AUC) of 0.963 (P<0.001). The levels of IL-1β, IL-7, IL-12, and IL-17 in the DRE group were positively correlated with the National Hospital Seizure Severity Scale (NHS3) scores (IL-1β, P = 0.029; IL-12, P = 0.039; IL-17, P = 0.004). IL-17 was positively correlated with seizure frequency (P = 0.050), while ITAC was negatively correlated with seizure frequency (P = 0.012) and Sudden Unexpected Death in Epilepsy-3 (SUDEP-3) scores (P = 0.023).

CONCLUSIONS

IL-1β, IL-12, and IL-17 may be used to predict seizure severity and the IL-7/CX3CL1 ratio may be a candidate biomarker for predicting epileptic seizures. While CX3CL1 and ITAC play anti-epileptic effects, ITAC may be used to assess the risk of SUDEP.

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.

Case-control study developing Scottish Epilepsy Deaths Study Score to predict epilepsy-related death

This study aimed to develop a risk prediction model for epilepsy-related death in adults. In this age- and sex-matched case-control study, we compared adults (aged ≥16 years) who had epilepsy-related death between 2009 and 2016 to living adults with epilepsy in Scotland. Cases were identified from validated administrative national datasets linked to mortality records. ICD-10 cause-of-death coding was used to define epilepsy-related death. Controls were recruited from a research database and epilepsy clinics. Clinical data from medical records were abstracted and used to undertake univariable and multivariable conditional logistic regression to develop a risk prediction model consisting of four variables chosen a priori. A weighted sum of the factors present was taken to create a risk index-the Scottish Epilepsy Deaths Study Score. Odds ratios were estimated with 95% confidence intervals (CIs). Here, 224 deceased cases (mean age 48 years, 114 male) and 224 matched living controls were compared. In univariable analysis, predictors of epilepsy-related death were recent epilepsy-related accident and emergency attendance (odds ratio 5.1, 95% CI 3.2-8.3), living in deprived areas (odds ratio 2.5, 95% CI 1.6-4.0), developmental epilepsy (odds ratio 3.1, 95% CI 1.7-5.7), raised Charlson Comorbidity Index score (odds ratio 2.5, 95% CI 1.2-5.2), alcohol abuse (odds ratio 4.4, 95% CI 2.2-9.2), absent recent neurology review (odds ratio 3.8, 95% CI 2.4-6.1) and generalized epilepsy (odds ratio 1.9, 95% CI 1.2-3.0). Scottish Epilepsy Deaths Study Score model variables were derived from the first four listed before, with Charlson Comorbidity Index ≥2 given 1 point, living in the two most deprived areas given 2 points, having an inherited or congenital aetiology or risk factor for developing epilepsy given 2 points and recent epilepsy-related accident and emergency attendance given 3 points. Compared to having a Scottish Epilepsy Deaths Study Score of 0, those with a Scottish Epilepsy Deaths Study Score of 1 remained low risk, with odds ratio 1.6 (95% CI 0.5-4.8). Those with a Scottish Epilepsy Deaths Study Score of 2-3 had moderate risk, with odds ratio 2.8 (95% CI 1.3-6.2). Those with a Scottish Epilepsy Deaths Study Score of 4-5 and 6-8 were high risk, with odds ratio 14.4 (95% CI 5.9-35.2) and 24.0 (95% CI 8.1-71.2), respectively. The Scottish Epilepsy Deaths Study Score may be a helpful tool for identifying adults at high risk of epilepsy-related death and requires external validation.

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.

Seizure-related complication rate in a residential population with epilepsy and intellectual disability (ECOMRAID-trial)

INTRODUCTION

The aim of the ECOMRAID trial (Epileptic seizure related Complication RAte in residential population of persons with epilepsy and Intellectual Disability) was to study seizure-related complications (status epilepticus, respiratory complications, or other severe complications) in people with epilepsy and intellectual disability living in a residential setting. The results of the present study are a prerequisite for performing a prospective study into the effectiveness of nocturnal surveillance patients with high risk for Sudden unexpected death in epilepsy (SUDEP).

MATERIAL AND METHODS

A retrospective study was conducted in three general residential care institutions and one residential specialized epilepsy clinic. In this 5-year cohort, we collected the following data: age (at inclusion and in case of death), sex, type of residential care, different types of complications, rescue/emergency medication administration, transfers to another department (internal midcare / monitoring unit or general hospital) and a self-designed SUDEP risk score. Our primary research questions were to assess the number of patients who experienced seizure-related complications and their individual complication rates. The secondary research questions were to document the relationship of these complications with the SUDEP risk score, with the type of residential living, and with the frequency of interventions by caregivers.

RESULTS

We included 370 patients (1790 patient-years) and in 135 of them, we found 717 seizure-related complications. The following complication rates were found: all complications: at 36%, status epilepticus: at 13%, respiratory complications: at 5%, and other complications at 26%. In residential care institutions, we found fewer patients with complications compared to the specialized epilepsy clinic (all complications 24% vs 42%, OR 0.44, p < 0.01; status epilepticus 5% vs 17%, OR 0.27, p < 0.01; other: complications 19% vs 30%, OR 0.56, p < 0.05). In residential care institutions, we found more "other complications" than in the specialized epilepsy clinic (89% vs 71%, OR 3.13, p < 0.0001). The annual frequency of all complications together was higher in residential care institutions (range 0 to 21 vs 0 to 10, p < 0.05). Rescue medication was given to 75% of the patients, but more often in the specialized epilepsy clinic (median 2.6 vs 0.5 times/patient/year, p < 0.001). In the specialized epilepsy clinic, more patients were transferred to a midcare / monitoring unit or general hospital (56% vs 9%, OR 13.44, p < 0.0001) with higher yearly frequencies (median 0.2 vs 0.0, p < 0.001). There were no reported cases of SUDEP. The median SUDEP risk score was higher in the specialized epilepsy clinic (5 vs 4, p < 0.05) and was weakly correlated with the status epilepticus (ρ = 0.20, p < 0.001) and (total) complication rate (ρ = 0.18, p < 0.001).

CONCLUSION

We found seizure-related complications in more than one-third of the patients with epilepsy and intellectual disability living in a residential setting over a period of 5 years. The data also quantify seizure-related complications in patients with epilepsy and intellectual disability.

Sudden unexpected death in epilepsy in children

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related mortality in children and adults living with epilepsy. The incidence of SUDEP is comparable in both children and adults; it is approximately 1.2 per 1000 person years. The pathophysiology of SUDEP is not well understood but may involve mechanisms such as cerebral shutdown, autonomic dysfunction, altered brainstem function, and cardiorespiratory demise. Risk factors for SUDEP include the presence of generalized tonic-clonic seizures, nocturnal seizures, possible genetic predisposition, and non-adherence to antiseizure medications. Pediatric-specific risk factors are not fully elucidated. Despite recommendations from consensus guidelines, many clinicians still do not follow the practice of counseling their patients about SUDEP. SUDEP prevention has been an area of important research focus and includes several strategies, such as obtaining seizure control, optimizing treatment regimens, nocturnal supervision, and seizure detection devices. This review discusses what is currently known about SUDEP risk factors and reviews current and future preventive strategies for SUDEP.

Prospective, longitudinal, multicenter study on the provision of information regarding sudden unexpected death in epilepsy to adults with epilepsy

OBJECTIVE

Despite increased awareness of the serious epilepsy complication sudden unexpected death in epilepsy (SUDEP), a substantial population of people with epilepsy (PWE) remain poorly informed. Physicians indicate concern that SUDEP information may adversely affect patients' health and quality of life. We examined SUDEP awareness and the immediate and long-term effects of providing SUDEP information to PWE.

METHODS

Baseline knowledge and behaviors among PWE and behavioral adjustments following the provision of SUDEP information were evaluated in a prospective, multicenter survey using the following validated scales: Neurological Disorders Depression Inventory for Epilepsy for depression symptoms, the EuroQoL five-dimension scale for health-related quality of life (HRQoL), a visual analog scale for overall health, the revised Epilepsy Stigma Scale for perceived stigma, and the Seizure Worry Scale for seizure-related worries. The prospective study collected data through semiquantitative interviews before (baseline), immediately after, and 3 months after the provision of SUDEP information.

RESULTS

In total, 236 participants (mean age = 39.3 years, range = 18-77 years, 51.7% women) were enrolled, and 205 (86.9%) completed long-term, 3-month follow-up. One patient died from SUDEP before follow-up. No worsening symptoms from baseline to 3-month follow-up were observed on any scale. At baseline, 27.5% of participants were aware of SUDEP. More than 85% of participants were satisfied with receiving SUDEP information. Three quarters of participants were not concerned by the information, and >80% of participants recommended the provision of SUDEP information to all PWE. Although most patients reported no behavioral adjustments, 24.8% reported strong behavioral adjustments at 3-month follow-up.

SIGNIFICANCE

The provision of SUDEP information has no adverse effects on overall health, HRQoL, depressive symptoms, stigma, or seizure worry among PWE, who appreciate receiving information. SUDEP information provision might improve compliance among PWE and reduce but not eliminate the increased mortality risk.

Stratifying sudden death risk in adults with drug-resistant focal epilepsy: The SUDEP-CARE score

BACKGROUND AND PURPOSE

A clinical risk score for sudden unexpected death in epilepsy (SUDEP) in patients with drug-resistant focal epilepsy could help improve prevention.

METHODS

A case-control study was conducted including (i) definite or probable SUDEP cases collected by the French National Sentinel Mortality Epilepsy Network and (ii) control patients from the French national research database of epilepsy monitoring units. Patients with drug-resistant focal epilepsy were eligible. Multiple logistic regressions were performed. After sensitivity analysis and internal validation, a simplified risk score was developed from the selected variables.

RESULTS

Sixty-two SUDEP cases and 620 controls were included. Of 21 potential predictors explored, seven were ultimately selected, including generalized seizure frequency (>1/month vs. <1/year: adjusted odds ratio [AOR] 2.6, 95% confidence interval [CI] 1.25-5.41), nocturnal or sleep-related seizures (AOR 4.49, 95% CI 2.68-7.53), current or past depression (AOR 2.0, 95% CI 1.19-3.34) or the ability to alert someone of an oncoming seizure (AOR 0.57, 95% CI 0.33-0.98). After internal validation, a clinically usable score ranging from -1 to 8 was developed, with high discrimination capabilities (area under the receiver operating curve 0.85, 95% CI 0.80-0.90). The threshold of 3 has good sensitivity (82.3%, 95% CI 72.7-91.8), whilst keeping a good specificity (82.7%, 95% CI 79.8-85.7).

CONCLUSIONS

These results outline the importance of generalized and nocturnal seizures on the occurrence of SUDEP, and show a protective role in the ability to alert someone of an oncoming seizure. The SUDEP-CARE score is promising and will need external validation. Further work, including paraclinical explorations, could improve this risk score.

Sudden Unexpected Death in Epilepsy: Pathogenesis, Risk Factors, and Prevention

Sudden unexpected death in epilepsy (SUDEP) is a tragic and unexpected cause of death in patients with a known diagnosis of epilepsy. It occurs in up to 6.3 to 9.3/1,000 patients with drug-resistant epilepsy. The main three risk factors associated with SUDEP are the presence of generalized tonic-clonic seizures, the presence of a seizure in the past year, and an intellectual disability. There are several mechanisms that can result in SUDEP. The most likely sequence of events appears to be a convulsive seizure, overactivation of the autonomic nervous system, cardiorespiratory dysfunction, and death. While the risk of SUDEP is relatively high in patients with drug-resistant epilepsy, studies indicate that more than 50% of patients and caregivers are unaware of the diagnosis. Counseling about the diagnosis and preventative measures at the time of diagnosis is important. There are numerous interventions that may reduce the risk of SUDEP, including conservative measures such as nocturnal surveillance with a bed partner (where applicable) and automated devices. Optimizing seizure control with antiseizure medications and surgical interventions can result in a reduced risk of SUDEP.

Epilepsy-associated death in the Southwestern Ontario: A clinicopathological correlation study

Patients with epilepsy are at elevated risk for premature mortality, of which sudden unexpected death in epilepsy (SUDEP) is one of the leading causes. SUDEP incidence varies significantly depending on the population and the methods used to document the cause of death. We performed retrospective case review at the London Health Sciences Centre for the period of 2000 to 2018. Clinical information, scene investigations, general pathology findings, toxicology, and neuropathology findings were obtained, examined, and confirmed by two neuropathologists and one epileptologist. The characteristics were compared and summarized. We also evaluated the impact of 2010 revision of Ontario Coroner Act Regulation, which significantly limited whole brain examination. Among the 12,206 cases reviewed, we identified 152 cases with a known history of epilepsy. Ninety-seven cases (64%) were classified as SUDEP. There were significantly more SUDEP decedents found dead unwitnessed at night in prone position, than non-SUDEP. Generalized seizures were strongly associated with SUDEP. A male predominance was observed in SUDEP group between 15 and 35 years old. Near half of the brains examined were "unremarkable." There was no difference in neuropathology findings between SUDEP and non-SUDEP groups. After implementation of the 2010 revision of Ontario Coroner Act Regulation, fixed whole brain examination was reduced from 88% to 7% of the epilepsy-related death investigation. Except a lower diagnosis rate of "inflammatory/infectious changes," there were no significant differences in neuropathology findings. This is the first detailed clinical-pathological study on epilepsy-related death based on a Canadian cohort. This study reinforces the previously reported findings in SUDEP and highlights the importance of clinicopathological correlation for accurate classification of epilepsy-related death.

Sudden Unexpected Death in Epilepsy

Epilepsy is a complex neurological condition with numerous etiologies and treatment options. In a subset of these patients, sudden unexpected death can occur, and to date, there are numerous explanations as to the pathophysiological mechanisms and how to mitigate these catastrophic outcomes. Approximately 2.3 million Americans have epilepsy, and nearly 150,000 people develop the condition each year. Sudden unexpected death in epilepsy (SUDEP) accounts for 2–18% of all epilepsy-related deaths and this is equivalent to one death in 1000 person-years of diagnosed epilepsy. It is more common in young adults aged 20–45. Seizures in the past year; the absence of terminal remission in the last five years; increased seizure frequency, particularly GTCS; and nocturnal seizures are the most potent modifiable risk factors for SUDEP. Patients not receiving any antiepileptic drug therapy are at higher risk of SUDEP. Patient education on medication compliance; care plans for seizure clusters (rescue medicines); epilepsy self-management programs; and lifestyle changes to avoid seizure-triggering factors, including avoiding excessive alcohol use and sleep deprivation, should be provided by health care providers. Continued research into SUDEP will hopefully lead to effective interventions to minimize occurrences. At present, aggressive control of epilepsy and enhanced education for individuals and the public are the most effective weapons for combating SUDEP. This narrative review focuses on updated information related to SUDEP epidemiology; pathophysiology; risk factor treatment options; and finally, a discussion of important clinical studies. We seek to encourage clinicians who care for patients with epilepsy to be aggressive in controlling seizure activity and diligent in their review of risk factors and education of patients and their families about SUDEP.

Ictal neural oscillatory alterations precede sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy is the most catastrophic outcome of epilepsy. Each year there are as many as 1.65 cases of such death for every 1000 individuals with epilepsy. Currently, there are no methods to predict or prevent this tragic event, due in part to a poor understanding of the pathologic cascade that leads to death following seizures. We recently identified enhanced seizure-induced mortality in four inbred strains from the genetically diverse Collaborative Cross mouse population. These mouse models of sudden unexpected death in epilepsy provide a unique tool to systematically examine the physiological alterations during fatal seizures, which can be studied in a controlled environment and with consideration of genetic complexity. Here, we monitored the brain oscillations and heart functions before, during, and after non-fatal and fatal seizures using a flurothyl-induced seizure model in freely moving mice. Compared with mice that survived seizures, non-survivors exhibited significant suppression of brainstem neural oscillations that coincided with cortical epileptic activities and tachycardia during the ictal phase of a fatal seizure. Non-survivors also exhibited suppressed delta (0.5-4 Hz)/gamma (30-200 Hz) phase-amplitude coupling in cortex but not in brainstem. A connectivity analysis revealed elevated synchronization of cortex and brainstem oscillations in the delta band during fatal seizures compared with non-fatal seizures. The dynamic ictal oscillatory and connectivity features of fatal seizures provide insights into sudden unexpected death in epilepsy and may suggest biomarkers and eventual therapeutic targets.