Sudden Unexpected Death In Epilepsy Patients Research Articles

Association of hyperventilation-induced heart rate variability and sudden unexpected death in epilepsy in drug-resistant epilepsy.

Within the general epilepsy population, the incidence of Sudden Unexpected Death in Epilepsy (SUDEP) ranges from approximately 0.35 to 2.3 per 1,000 individuals per year. We aimed to evaluate the relationship between SUDEP risk factors and heart rate variability (HRV) parameters as a potential biomarker of SUDEP in patients with drug-resistant epilepsy (DRE). There were 52 patients diagnosed with DRE and under follow-up, and controls including 45 healthy subjects, included in the study. Hyperventilation-induced HRV (HRVHV) parameters, including the standard deviation of all RR intervals (SDRR), mean heart rate (HR), root mean squares of successive differences (RMSSD), SD of mean NN intervals recordings (SDANN), and HRV triangular index, were assessed during resting. To predict the risk of SUDEP, the relationship between HRV parameters and SUDEP risks was evaluated using the Risk Assessment for Sudden Death in Epilepsy (SUDEP-7) Risk Inventory. No statistically significant difference was found in sympathetic skin response (SSR) latency and amplitudes between the patient and control groups. In comparing healthy control subjects with patients experiencing DRE, we observed significant decreases in SDRRHV and hyperventilation-induced RMSSD (RMSSDHV) values, specifically within HRVHV. Notably, a significant correlation emerged concerning the RMSSDHV values (p < 0.01), when examining the correlation between the SUDEP-7 inventory and HRVHV parameters. This correlation between RMSSDHV and the SUDEP-7 Risk Inventory in patients with DRE represents a novel and consequential finding, suggesting its potential as an indicator of SUDEP risk.

Characteristics of Cardiorespiratory Failure Preceding Seizure-Induced Mortality in SSKcnj16−/− Rats

Epilepsy is a common, chronic neurological condition characterized by repeated, uncontrolled seizures. These patients are at high risk for cardiorespiratory failure (CRF) and Sudden Unexpected Death in Epilepsy (SUDEP) — the mechanisms of which remain unknown. Most SUDEP events are unwitnessed at night suggesting a circadian influence on seizure-induced mortality. Here we studied cardiorespiratory (CR) function continuously (24/7) in a rat model of audiogenic seizures (SSKcnj16−/− rats) in which repeated seizures have been shown to cause progressive respiratory suppression and mortality. We hypothesized repeated seizures in SSKcnj16−/− rats also lead to 1) progressive dysfunction of post-ictal heart rate (HR) and blood pressure (BP) responses, and 2) cause death via cardiorespiratory failure most frequently when seizures occur after the onset of the inactive period (8am) or prior to the onset of the active phase (4pm). Age matched male and female SSKcnj16−/− rats were implanted with a carotid pressure telemeter and housed in a chronic monitoring plethysmograph with HD video to continuously measure breathing, BP, and HR. Audiogenic seizures (1/day (d) for up to 10d) were induced at a specific time of day and the physiologic data analyzed. Consistent with previous findings, repeated generalized tonic-clonic seizures (GTCSs) caused acute ictal/post-ictal apnea and transient respiratory rate suppression for ~5 minutes post-ictal which was exacerbated with additional seizures (n=6). In addition, GTCSs induced progressively greater transient post-ictal HR suppression and increased BP (n=3; p&lt;0.05 on days 8-10 compared to days 1-3). When seizures occurred at either 8am or 4pm, female SSKcnj16−/− rats had a 10% survival probability (18/20 died) and males had a 40% survival probability (12/20 died). These data combined with previous studies in which seizures were induced throughout the light period showed a higher percentage of deaths at specific times of day: &lt;10am (14%; n=81), 10am-2pm (3%; n=225), 2pm-7pm (8%; n=338). On average seizure-related mortality occurred 2-3 hours after seizures (20 of 30 events) and occurred throughout the 10-day protocol resulting from either moderate (score 2; 53%) or severe (score 3-4; 47%) seizures (Modified Racine Scale). Specific characteristics of death events (n=11-19) included transiently increased BP (+20mmHg) and tidal volume (+0.5 mL/100g; VT) but decreased HR (-50 beats/min), breathing frequency (-50 breaths/min; FB) and ventilation (-20 mL/min/100g; VE). These CR measures then returned to baseline until ~60 minutes post-seizure when there was a secondary decline in BP (-80 mmHg), elevated HR (+100 beats/min), and a concomitant progressive decline in VT and VE prior to terminal apnea/asystole. These data show acute progressive CR suppression with repeated seizures and seizure-induced CRF (tidal volume-mediated decreased ventilation and severe hypotension) leading to death, where time of day for seizure induction contributed to higher mortality rates. This model provides useful insight into the effects of seizures on CR function and understanding the mechanisms of SUDEP, with the ultimate goal of reducing the risk of SUDEP in patients with epilepsy. Supported by NIH HL122358 (MRH). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ketogenic Diet in the Treatment of Epilepsy.

Epilepsy is one of the most disabling neurological diseases. Despite proper pharmacotherapy and the availability of 2nd and 3rd generation antiepileptic drugs, deep brain stimulation, and surgery, up to 30-40% of epilepsy patients remain drug-resistant. Consequences of this phenomenon include not only decreased a quality of life, and cognitive, behavioral, and personal disorders, but also an increased risk of death, i.e., in the mechanism of sudden unexpected death in epilepsy patients (SUDEP). The main goals of epilepsy treatment include three basic issues: achieving the best possible seizure control, avoiding the undesired effects of treatment, and maintaining/improving the quality of patients' lives. Therefore, numerous attempts are made to offer alternative treatments for drug-resistant seizures, an example of which is the ketogenic diet. It is a long-known but rarely used dietary therapy for intractable seizures. One of the reasons for this is the unpalatability of the classic ketogenic diet, which reduces patient compliance and adherence rates. However, its antiseizure effects are often considered to be worth the effort. Until recently, the diet was considered the last-resort treatment. Currently, it is believed that a ketogenic diet should be used much earlier in patients with well-defined indications. In correctly qualified patients, seizure activity may be reduced by over 90% or even abolished for long periods after the diet is stopped. A ketogenic diet can be used in all age groups, although most of the available literature addresses pediatric epilepsy. In this article, we focus on the mechanisms of action, effectiveness, and adverse effects of different variants of the ketogenic diet, including its classic version, a medium-chain triglyceride diet, a modified Atkins diet, and a low glycemic index treatment.

Wavelet phase coherence of ictal scalp EEG-extracted muscle activity (SMA) as a biomarker for sudden unexpected death in epilepsy (SUDEP).

Approximately 50 million people worldwide have epilepsy and 8-17% of the deaths in patients with epilepsy are attributed to sudden unexpected death in epilepsy (SUDEP). The goal of the present work was to establish a biomarker for SUDEP so that preventive treatment can be instituted. Seizure activity in patients with SUDEP and non-SUDEP was analyzed, specifically, the scalp EEG extracted muscle activity (SMA) and the average wavelet phase coherence (WPC) during seizures was computed for two frequency ranges (1-12 Hz, 13-30 Hz) to identify differences between the two groups. Ictal SMA in SUDEP patients showed a statistically higher average WPC value when compared to non-SUDEP patients for both frequency ranges. Area under curve for a cross-validated logistic classifier was 81%. Average WPC of ictal SMA is a candidate biomarker for early detection of SUDEP.

Sudden unexpected death in epilepsy during cenobamate clinical development.

We assessed mortality, sudden unexpected death in epilepsy (SUDEP), and standardized mortality ratio (SMR) among adults treated with cenobamate during the cenobamate clinical development program. We retrospectively analyzed deaths among all adults with uncontrolled focal (focal to bilateral tonic-clonic [FBTC], focal impaired awareness, focal aware) or primary generalized tonic-clonic (PGTC) seizures who received ≥1 dose of adjunctive cenobamate in completed and ongoing phase 2 and 3 clinical studies. In patients with focal seizures from completed studies, median baseline seizure frequencies ranged from 2.8 to 11 seizures per 28 days and median epilepsy duration ranged from 20 to 24 years. Total person-years included all days a patient received cenobamate during completed studies or up to June 1, 2022 for ongoing studies. All deaths were evaluated by two epileptologists. All-cause mortality and SUDEP rates were expressed per 1000 person-years. A total of 2132 patients (n=2018 focal epilepsy; n=114 idiopathic generalized epilepsy) were exposed to cenobamate for 5693 person-years. Approximately 60% of patients with focal seizures and all patients in the PGTC study had tonic-clonic seizures. A total of 23 deaths occurred (all in patients with focal epilepsy), for an all-cause mortality rate of 4.0 per 1000 person-years. Five cases of definite or probable SUDEP were identified, for a rate of 0.88 per 1000 person-years. Of the 23 overall deaths, 22 patients (96%) had FBTC seizures, and all 5 of the SUDEP patients had a history of FBTC seizures. The duration of exposure to cenobamate for patients with SUDEP ranged from 130-620 days. The SMR among cenobamate-treated patients in completed studies (5515 person-years of follow-up) was 1.32 (95% CI 0.84-2.0), which was not significantly different from the general population. These data suggest that effective long-term medical treatment with cenobamate may reduce excess mortality associated with epilepsy.

De novo ADGRV1 variant in a patient with ictal asystole provides novel clues for increased risk of SUDEP

BackgroundVarious cardiac and autonomic manifestations are frequently reported during seizures. Among the seizure-related arrhythmia, ictal tachycardia is the most common, followed by ictal bradycardia, with ictal asystole being the rarest. The occurrence of ictal asystole may obscure the clinical presentation and delay the diagnosis, representing a life-threatening presentation of epilepsy, with an elevated risk of sudden unexpected death in epilepsy patients (SUDEP). These cardiac abnormalities are being increasingly recognized as the key to elucidating the mechanisms of SUDEP.Case presentationWe present a 35-year-old man with a history of focal-onset seizures with impaired consciousness since his mid-20 s. He developed different types of seizures for 2 years, described as tonic seizure and atonic seizure (drop attack). During such clinical events, he suffered from falls and cardiac arrest. However, thorough cardiac electrophysiology and imaging workup failed to reveal a cardiac etiology. Subsequent video electroencephalograph (EEG) monitoring was performed, and ictal bradycardia and ictal asystole were discovered. A cardiac pacemaker was implanted, and at 3-year follow-up, the patient did not suffer more atonic seizures, or falls. Genetic tests discovered a de novo variant of Adhesion G Protein-Coupled Receptor V1 (ADGRV1), which may provide a clue for the patient’s ictal asystole and the increased risk of SUDEP.ConclusionsConsidering the important impact of ictal bradycardia and asystole on the morbidity and potential mortality of epileptic patients, it is important to simultaneously utilize EEG and electrocardiogram to confirm the diagnosis. This case report highlights the link between the de novo variant of ADGRV1 and the ictal bradycardia/asystole phenotype and implicates the importance of genetic testing in adult epilepsy patients.

SUDEP counseling: Where do we stand?

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death in children and adults living with epilepsy. Several recent clinical practice guidelines have recommended that all individuals living with epilepsy and their caregivers be informed about SUDEP as a part of routine epilepsy counseling. Furthermore, several studies over the last two decades have explored the state of SUDEP counseling. Patients with epilepsy and their families want to be informed about the risk of SUDEP at or near the time of diagnosis, and preferably in person. Despite guideline recommendations, many pediatric and adult neurologists do not routinely inform individuals with epilepsy and their families about SUDEP. Some neurologists discuss SUDEP with only a subset of patients with epilepsy, such as those with risk factors like frequent generalized or focal to bilateral tonic-clonic seizures, nocturnal seizures, noncompliance, or medically refractory epilepsy. Proponents of routine SUDEP counseling argue that patients with epilepsy and their families have a "right to know" and that counseling may positively impact epilepsy self-management (i.e., behavioral modification and risk reduction). Some neurologists still believe that SUDEP counseling may cause unnecessary stress and anxiety for patients and their families (although this is erroneous) and that they also have a "right not to know." This narrative review explores the current gaps in SUDEP counseling, patients' and caregivers' perspectives of SUDEP counseling, and SUDEP prevention.

Heart rate variability modification as a predictive factor of sudden unexpected death in epilepsy: How far are we? A systematic review and meta-analysis.

Sudden unexpected death in epilepsy (SUDEP) is a sudden, unexpected death in people with epilepsy, with or without evidence of an epileptic seizure. The pathophysiological mechanism underlying SUDEP appears to be partly associated with an autonomic nervous system (ANS) dysfunction. Heart rate variability (HRV) analysis is a reliable, non-invasive method for detecting fluctuations in the ANS. In this systematic review we analyzed the data available in the literature on changes in HRV parameters in patients with SUDEP. We carried out a systematic search of the literature to identify the quantitative variations of HRV in epileptic patients with SUDEP. The following databases were used: Pubmed, Google Scholar, EMBASE, and CrossRef. A pooled analysis was carried out, and the results obtained were compared using mean difference (MD). The review was registered on the PROSPERO platform (CRD42021291586). Seven articles were included, with a total of 72 SUDEP cases associated with altered HRV parameters. Generally, a reduction of SDNN (standard deviation of the RR intervals) and RMSSD (root mean square differences of successive RR intervals) was reported in most SUDEP patients. According to MD, the SUDEP patients showed no differences in time and frequency domain parameters compared to controls. However, a trend toward increased low frequency and high frequency ratio (LF/HF) was observed in the SUDEP patients. HRV analysis is a valuable method for assessing cardiovascular risk and cardioautonomic impairment. Although a possible association between HRV variation and SUDEP has been reported, further studies are needed to assess the potential role of HRV modifications as a SUDEP biomarker.

Ictal ECG-based assessment of sudden unexpected death in epilepsy.

Previous case-control studies of sudden unexpected death in epilepsy (SUDEP) patients failed to identify ECG features (peri-ictal heart rate, heart rate variability, corrected QT interval, postictal heart rate recovery, and cardiac rhythm) predictive of SUDEP risk. This implied a need to derive novel metrics to assess SUDEP risk from ECG. We applied Single Spectrum Analysis and Independent Component Analysis (SSA-ICA) to remove artifact from ECG recordings. Then cross-frequency phase-phase coupling (PPC) was applied to a 20-s mid-seizure window and a contour of -3 dB coupling strength was determined. The contour centroid polar coordinates, amplitude (alpha) and angle (theta), were calculated. Association of alpha and theta with SUDEP was assessed and a logistic classifier for alpha was constructed. Alpha was higher in SUDEP patients, compared to non-SUDEP patients (p < 0.001). Theta showed no significant difference between patient populations. The receiver operating characteristic (ROC) of a logistic classifier for alpha resulted in an area under the ROC curve (AUC) of 94% and correctly classified two test SUDEP patients. This study develops a novel metric alpha, which highlights non-linear interactions between two rhythms in the ECG, and is predictive of SUDEP risk.

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

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. 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. 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 1year 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. 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.

Association between postictal EEG suppression, postictal autonomic dysfunction, and sudden unexpected death in epilepsy: Evidence from intracranial EEG

ObjectiveThe association between postictal electroencephalogram (EEG) suppression (PES), autonomic dysfunction, and Sudden Unexpected Death in Epilepsy (SUDEP) remains poorly understood. We compared PES on simultaneous intracranial and scalp-EEG and evaluated the association of PES with postictal heart rate variability (HRV) and SUDEP outcome. MethodsConvulsive seizures were analyzed in patients with drug-resistant epilepsy at 5 centers. Intracranial PES was quantified using the Hilbert transform. HRV was quantified using root mean square of successive differences of interbeat intervals, low-frequency to high-frequency power ratio, and RR-intervals. ResultsThere were 64 seizures from 63 patients without SUDEP and 11 seizures from 6 SUDEP patients. PES occurred in 99% and 87% of seizures on intracranial-EEG and scalp-EEG, respectively. Mean PES duration in intracranial and scalp-EEG was similar. Intracranial PES was regional (<90% of channels) in 46% of seizures; scalp PES was generalized in all seizures. Generalized PES showed greater decrease in postictal parasympathetic activity than regional PES. PES duration and extent were similar between patients with and without SUDEP. ConclusionsRegional intracranial PES can be present despite scalp-EEG demonstrating generalized or no PES. Postictal autonomic dysfunction correlates with the extent of PES. SignificanceIntracranial-EEG demonstrates changes in autonomic regulatory networks not seen on scalp-EEG.

Vagus nerve stimulation for conservative therapy-refractive epilepsy and depression.

Numerous studies confirm that the vagus nerve stimulation (VNS) is an efficient, indirect neuromodulatory therapy with electrically induced current for epilepsy that cannot be treated by epilepsy surgery and is therapy-refractory and for drug therapy-refractory depression. VNS is an established, evidence-based and in the long-term cost-effective therapy in an interdisciplinary overall concept.Long-term data on the safety and tolerance of the method are available despite the heterogeneity of the patient populations. Stimulation-related side effects like hoarseness, paresthesia, cough or dyspnea depend on the stimulation strength and often decrease with continuing therapy duration in the following years. Stimulation-related side effects of VNS can be well influenced by modifying the stimulation parameters. Overall, the invasive vagus nerve stimulation may be considered as a safe and well-tolerated therapy option.For invasive and transcutaneous vagus nerve stimulation, antiepileptic and antidepressant as well as positive cognitive effects could be proven. In contrast to drugs, VNS has no negative effect on cognition. In many cases, an improvement of the quality of life is possible.iVNS therapy has a low probability of complete seizure-freedom in cases of focal and genetically generalized epilepsy. It must be considered as palliative therapy, which means that it does not lead to healing and requires the continuation of specific medication. The functional principle is a general reduction of the neuronal excitability. This effect is achieved by a slow increase of the effectiveness sometimes over several years. Responders are those patients who experience a 50% reduction of the seizure incidence. Some studies even reveal seizure-freedom in 20% of the cases. Currently, it is not possible to differentiate between potential responders and non-responders before therapy/implantation.The current technical developments of the iVNS generators of the new generation like closed-loop system (cardiac-based seizure detection, CBSD) reduce also the risk for SUDEP (sudden unexpected death in epilepsy patients), a very rare, lethal complication of epilepsies, beside the seizure severity.iVNS may deteriorate an existing sleep apnea syndrome and therefore requires possible therapy interruption during nighttime (day-night programming or magnet use) beside the close cooperation with sleep physicians.The evaluation of the numerous iVNS trials of the past two decades showed multiple positive effects on other immunological, cardiological, and gastroenterological diseases so that additional therapy indications may be expected depending on future study results. Currently, the vagus nerve stimulation is in the focus of research in the disciplines of psychology, immunology, cardiology as well as pain and plasticity research with the desired potential of future medical application.Beside invasive vagus nerve stimulation with implantation of an IPG and an electrode, also devices for transdermal and thus non-invasive vagus nerve stimulation have been developed during the last years. According to the data that are currently available, they are less effective with regard to the reduction of the seizure severity and duration in cases of therapy-refractory epilepsy and slightly less effective regarding the improvement of depression symptoms. In this context, studies are missing that confirm high evidence of effectiveness. The same is true for the other indications that have been mentioned like tinnitus, cephalgia, gastrointestinal complaints etc. Another disadvantage of transcutaneous vagus nerve stimulation is that the stimulators have to be applied actively by the patients and are not permanently active, in contrast to implanted iVNS therapy systems. So they are only intermittently active; furthermore, the therapy adherence is uncertain.

SUDEP in adults and children

Sudden unexpected death in epilepsy (SUDEP) represents an important cause of death in patients with epilepsy and it exceeds the expected rate of sudden death in the general population by nearly 24 times. We searched the electronic databases (Cochrane, EMBASE, Scopus, Medline, Pubmed) for studies related to etiology and risk stratification of SUDEP including data on Takotsubo cardiomyopathy (TKC) following seizures resulting in death or near death.: SUDEP is more common among males in the fourth decade of life. Risk for SUDEP is increased by early onset of seizures, low IQ, generalised tonic clonic seizures, nocturnal seizures and seizure frequency. Nonadherance to antiepileptic medications, absence of therapeutic drug level monitoring, presence of neuropathological lesions on imaging and certain subgroups like Dravet syndrome increase its risk. The risk for premature death in patients undergoing temporal lobe resection for drug resistant epilepsy decreased over time but remained above the standard population. Prolonged postictal electroencephalographic suppression was a risk factor for SUDEP in patients with generalised seizures which may indicate a cerebral electrical shutdown. Documented ictal/postictal hypoventilation, laryngeal spasm and cardiac rhythm abnormalities prior to SUDEP may suggest central apnea, neurogenic pulmonary edema, cardiac arrhythmia, or a combination of the above as a cause. Seizure triggered TKC does not seem to play a major role in the pathogenesis of SUDEP.

Phase-Amplitude Coupling Features Accurately Classify Multiple Sub-States Within a Seizure Episode.

Epilepsy is frequently characterized by convulsive seizures, which are often followed by a postictal EEG suppression state (PGES). The ability to automatically detect and monitor seizure progression and postictal state can allow for early warning of seizure onset, timely intervention in seizures themselves, as well as identification of major complications in epilepsy such as status epilepticus and sudden unexpected death in epilepsy (SUDEP). To test whether it is possible to reliably differentiate these ictal and postictal states, we investigated 52 seizure records (both intracranial and scalp EEG) from 19 patients. Phase-amplitude cross-frequency coupling was calculated for each recording and used as an input to a convolutional neural network model, achieving the mean accuracy of 0.890.09 across all classes, with the worst class accuracy of 0.73 for one of the later ictal sub-states. When the trained model was applied to SUDEP patient data, it classified seizure recordings as primarily interictal and PGES-like state (70% and 26%, respectively), highlighting the fact that in SUDEP patients seizures primarily exist in postictal states and don't show the ictal sub-state evolution. These results suggest that using frequency coupling markers with a machine learning algorithm can reliably identify ictal and postictal sub-states, which can open up opportunities for novel monitoring and management approaches in epilepsy.

Trend of Sudden Unexpected Death in Epilepsy Incidence Rate in Rural West China.

Objectives: To explore the trend of sudden unexpected death in epilepsy (SUDEP) incidence rate over time in rural west China.Methods: We scanned probable SUDEP patients from the epilepsy program between 2010 and 2019 in rural West China and performed a verbal autopsy for each eligible patient. We calculated the crude and sex-adjusted incidence rate of SUDEP per person-year over a calendar year and the year of follow-up. We calculated the incidence rate ratio with the Poisson model in STATA 12.0 and calculated the annual percentage change (APC) and average annual percentage change in Joinpoint Trend Analysis Software 4.8.0.1 to analyze the trend of SUDEP incidence rate.Results: In 2010–2019, 44 probable SUDEPs were identified from 10,128 patients with a total person-year of 31,347. The crude and sex-adjusted incidence rates of SUDEP were 1.40 and 1.45%0. Twenty-five (56.8%) of the 44 probable SUDEPs had no generalized tonic-clonic seizure 3 months before their death. The incidence of probable SUDEP decreased significantly in the calendar year [APC = −11.7, 95% confidence interval (CI): −21.7 to −0.3] and in time of follow-up (average annual percentage change = −21.2, 95% CI: −34.3 to −5.4). Comparing the first 5 years in follow-up with the subsequent 3 years, the incidence rate of SUDEP decreased significantly (estimated incidence rate ratio = 0.4, 95% CI: 0.2 to 0.8).Significance: SUDEP happened to 1.4 cases per thousand patient-years in convulsive epilepsy in rural west China between 2010 and 2019. The incidence rate of SUDEP presented a downward trend over the time of follow-up.

Frontal lobe hypometabolism associated with Sudden Unexpected Death in Epilepsy (SUDEP) risk: An objective PET study

ObjectiveAbnormalities of brain structures and neuronal networks have been identified in MRI studies of patients with Sudden Unexpected Death in Epilepsy (SUDEP) as well as in those at elevated risk. The goal of this study was to identify common patterns of objectively detected brain glucose metabolic abnormalities associated with SUDEP patients and those at high SUDEP risk. MethodsPatients with refractory epilepsy (n = 78, age: 16–61 years, 44 females), who underwent comprehensive presurgical evaluation, were assessed for their risk of SUDEP using the revised SUDEP-7 inventory. From the 57 patients with low SUDEP risk, 35 were selected to match their demographic and clinical characteristics to those with high SUDEP risk (n = 21). [18F]fluoro-deoxy-glucose positron emission tomography (FDG-PET) abnormalities were evaluated in the high- and low-SUDEP risk subgroups compared to FDG-PET scans of a healthy adult control group using statistical parametric mapping (SPM). Individual FDG-PET scans of 4 additional patients, who died from SUDEP, were also analyzed by SPM. ResultsMean SUDEP-7 score was 6.1 in the high and 2.7 in the low SUDEP risk group. MRI showed no lesion in 36 patients (64%). Statistical parametric mapping analysis of the high SUDEP risk subgroup showed bilateral medial frontal and inferior frontal hypometabolism as a common pattern. The low-risk group showed no specific common metabolic abnormalities on SPM group analysis. Individual PET scans of all 4 patients who died from SUDEP also showed bilateral frontal lobe hypometabolism. ConclusionsThese data show that bilateral frontal lobe involvement on FDG-PET, especially the medial and inferior frontal cortex, may be a common metabolic pattern associated with high SUDEP risk and SUDEP itself, in patients with refractory focal epilepsy.

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

Sudden unexpected death in epilepsy (SUDEP) is a significant cause of mortality in epilepsy. The aim of this study is to evaluate the validity of the SUDEP-7 inventory and its components as tools for predicting SUDEP risk, and to develop and validate an improved inventory. The study included 28 patients who underwent video-electroencephalography (EEG) monitoring and later died of SUDEP, and 56 age- and sex-matched control patients with epilepsy. The SUDEP-7 score, its individual components, and an alternative inventory were examined as predictors of SUDEP. SUDEP-7 scores were significantly higher among SUDEP patients compared with controls, both at time of admission (p=0.024) and most recent follow-up (p=0.016). SUDEP-7 scores declined only among controls, who demonstrated reduced seizure frequency. Seizure freedom after epilepsy surgery was also associated with survival. Several components of the SUDEP-7 inventory were independently associated with higher risk of SUDEP, including more than three generalized tonic-clonic (GTC) seizures (p=0.002), one or more GTC seizures (p=0.001), or one or more seizures of any type within the last year (p=0.013), and intellectual disability (p=0.031). In stepwise regression models, SUDEP-7 scores did not enhance the prediction of SUDEP over either GTC seizure frequency or seizure frequency alone. A novel SUDEP-3 inventory comprising GTC seizure frequency, seizure frequency, and intellectual disability (p<0.001) outperformed the SUDEP-7 inventory (p=0.010) in predicting SUDEP. Our findings demonstrate the limitations of the SUDEP-7 inventory. We propose a new three-item SUDEP-3 inventory, which predicts SUDEP better than the SUDEP-7.

Proteomics and Transcriptomics of the Hippocampus and Cortex in SUDEP and High-Risk SUDEP Patients.

ObjectiveTo identify the molecular signaling pathways underlying sudden unexpected death in epilepsy (SUDEP) and high-risk SUDEP compared to control patients with epilepsy.MethodsFor proteomics analyses, we evaluated the hippocampus and frontal cortex from microdissected postmortem brain tissue of 12 patients with SUDEP and 14 with non-SUDEP epilepsy. For transcriptomics analyses, we evaluated hippocampus and temporal cortex surgical brain tissue from patients with mesial temporal lobe epilepsy: 6 low-risk and 8 high-risk SUDEP as determined by a short (<50 seconds) or prolonged (≥50 seconds) postictal generalized EEG suppression (PGES) that may indicate severely depressed brain activity impairing respiration, arousal, and protective reflexes.ResultsIn autopsy hippocampus and cortex, we observed no proteomic differences between patients with SUDEP and those with non-SUDEP epilepsy, contrasting with our previously reported robust differences between epilepsy and controls without epilepsy. Transcriptomics in hippocampus and cortex from patients with surgical epilepsy segregated by PGES identified 55 differentially expressed genes (37 protein-coding, 15 long noncoding RNAs, 3 pending) in hippocampus.ConclusionThe SUDEP proteome and high-risk SUDEP transcriptome were similar to those in other patients with epilepsy in hippocampus and cortex, consistent with diverse epilepsy syndromes and comorbid conditions associated with SUDEP. Studies with larger cohorts and different epilepsy syndromes, as well as additional anatomic regions, may identify molecular mechanisms of SUDEP.

Origin of post-ictal and post-anesthesia adverse effects and possibly of SUDEP

The origin of post-ictal malfunctions is debatable. We want to propose a novel idea of a cause of these adverse results occurring following epileptic seizures and anesthesia. Previously we have put forward the idea that epileptic seizures termination is caused by the function of the glymphatic system in the brain. A new measurement shows that this system can be much faster than what was estimated before. Moreover, the method enabling this speeding was actually measured in brains of epilepsy subjects. So, the main objection to our model is relegated. As a possible consequence of the glymphatic process, there can be an excess cleaning of the brain's interstitial fluid. We discuss possible adverse results of this process. This over-cleaning (that can, to a lower extent, occur also during anesthesia) which results post-ictally from the previous overexpression of fluid materials by the neurons during their seizure operation, can reduce ingredients essential for regular neuronal functioning, thereby leading to function reduction and EEG suppression which last until those materials are replenished. We argue that this ingredients' scarcity is the cause of post-ictal generalized EEG suppression (PGES), of post-ictal immobility (PI) and possibly of Sudden Unexpected Death in Epilepsy Patients (SUDEP). Similarly, such cleaning can lead to morbidity and even mortality problems following anesthesia.If our assumption is correct, this understanding of the process of the problems' origin can lead to a method to remedy them by judicial supplement of the lost materials.

Cardiac Autonomic Dysfunction and Risk of Sudden Unexpected Death in Epilepsy.

We aimed to test whether patients who died of sudden unexpected death in epilepsy (SUDEP) had an abnormal cardiac autonomic response to sympathetic stimulation by hyperventilation. We conducted a retrospective, observational, case-control study of a group of patients who died of SUDEP and controls who were matched to the patients for epilepsy type, drug resistance, sex, age at EEG recording, age at onset of epilepsy, and duration of epilepsy. We analyzed the heart rate (HR) and HR variability (HRV) at rest and during and after hyperventilation performed during the patient's last EEG recording before SUDEP. In each group, changes over time in HRV indexes were analyzed with linear mixed models. Twenty patients were included in each group. In the control group, the HR increased and the root mean square of successive RR-interval differences (RMSSD) decreased during the hyperventilation and then returned to the baseline values. In the SUDEP group, however, the HR and RMSSD did not change significantly during or after hyperventilation. A difference in HR between the end of the hyperventilation and 4 minutes after its end discriminated well between patients with SUDEP and control patients (area under the receiver operating characteristic curve 0.870, sensitivity 85%, specificity 75%). Most of patients with subsequent SUDEP have an abnormal cardiac autonomic response to sympathetic stimulation through hyperventilation. An index reflecting the change in HR on hyperventilation might be predictive of the risk of SUDEP and could be used to select patients at risk of SUDEP for inclusion in trials assessing protective measures.