Generalized Convulsive Seizures Research Articles

Reliable detection of generalized convulsive seizures using an off-the-shelf digital watch: A multisite phase 2 study.

The aim of this study was to develop a machine learning algorithm using an off-the-shelf digital watch, the Samsung watch (SM-R800), and evaluate its effectiveness for the detection of generalized convulsive seizures (GCS) in persons with epilepsy. This multisite epilepsy monitoring unit (EMU) phase 2 study included 36 adult patients. Each patient wore a Samsung watch that contained accelerometer, gyroscope, and photoplethysmographic sensors. Sixty-eight time and frequency domain features were extracted from the sensor data and were used to train a random forest algorithm. A testing framework was developed that would better reflect the EMU setting, consisting of (1) leave-one-patient-out cross-validation (LOPO CV) on GCS patients, (2) false alarm rate (FAR) testing on nonseizure patients, and (3) "fixed-and-frozen" prospective testing on a prospective patient cohort. Balanced accuracy, precision, sensitivity, and FAR were used to quantify the performance of the algorithm. Seizure onsets and offsets were determined by using video-electroencephalographic (EEG) monitoring. Feature importance was calculated as the mean decrease in Gini impurity during the LOPO CV testing. LOPO CV results showed balanced accuracy of .93 (95% confidence interval [CI] = .8-.98), precision of .68 (95% CI = .46-.85), sensitivity of .87 (95% CI = .62-.96), and FAR of .21/24 h (interquartile range [IQR] = 0-.90). Testing the algorithm on patients without seizure resulted in an FAR of .28/24 h (IQR = 0-.61). During the "fixed-and-frozen" prospective testing, two patients had three GCS, which were detected by the algorithm, while generating an FAR of .25/24 h (IQR = 0-.89). Feature importance showed that heart rate-based features outperformed accelerometer/gyroscope-based features. Commercially available wearable digital watches that reliably detect GCS, with minimum false alarm rates, may overcome usage adoption and other limitations of custom-built devices. Contingent on the outcomes of a prospective phase 3 study, such devices have the potential to provide non-EEG-based seizure surveillance and forecasting in the clinical setting.

Interictal respiratory variability predicts severity of hypoxemia after generalized convulsive seizures.

Severe respiratory dysfunction induced by generalized convulsive seizures (GCS) is now thought to be a common mechanism for sudden unexpected death in epilepsy (SUDEP). In a mouse model of seizure-induced death, increased interictal respiratory variability was reported in mice that later died of respiratory arrest after GCS. We studied respiratory variability in epilepsy patients as a predictive tool for severity of postictal hypoxemia, a potential biomarker for SUDEP risk. We then explored the relationship between respiratory variability and central CO2 drive, measured by the hypercapnic ventilatory response (HCVR). We reviewed clinical, video-electroencephalography, and respiratory (belts, airflow, pulse oximeter, and HCVR) data of epilepsy patients. Mean, SD, and coefficient of variation (CV) of interbreath interval (IBI) were calculated. Primary outcomes were: (1) nadir of capillary oxygen saturation (SpO2 ) and (2) duration of oxygen desaturation. Poincaré plots of IBI were created. Covariates were evaluated in univariate models, then, based on Akaike information criteria (AIC), multivariate regression models were created. Of 66 GCS recorded in 131 subjects, 30 had interpretable respiratory data. In the multivariate model with the lowest AIC value, duration of epilepsy was a significant predictor of duration of oxygen desaturation. Duration of tonic phase and CV of IBI during the third postictal minute correlated with SpO2 nadir, whereas CV of IBI during non-rapid eye movement sleep had a negative correlation. Poincaré plots showed that long-term variability was significantly greater in subjects with ≥200 s of postictal oxygen desaturation after GCS compared to those with <200 s desaturation. Finally, HCVR slope showed a negative correlation with measures of respiratory variability. These results indicate that interictal respiratory variability predicts severity of postictal oxygen desaturation, suggesting its utility as a potential biomarker. They also suggest that interictal respiratory control may be abnormal in some patients with epilepsy.

Seizures Cause Prolonged Impairment of Ventilation, CO2 Chemoreception and Thermoregulation.

Sudden unexpected death in epilepsy (SUDEP) has been linked to respiratory dysfunction, but the mechanisms underlying this association remain unclear. Here we found that both focal and generalized convulsive seizures (GCSs) in epilepsy patients caused a prolonged decrease in the hypercapnic ventilatory response (HCVR; a measure of respiratory CO2 chemoreception). We then studied Scn1a R1407X/+ (Dravet syndrome; DS) and Scn8a N1768D/+ (D/+) mice of both sexes, two models of SUDEP, and found that convulsive seizures caused a postictal decrease in ventilation and severely depressed the HCVR in a subset of animals. Those mice with severe postictal depression of the HCVR also exhibited transient postictal hypothermia. A combination of blunted HCVR and abnormal thermoregulation is known to occur with dysfunction of the serotonin (5-hydroxytryptamine; 5-HT) system in mice. Depleting 5-HT with para-chlorophenylalanine (PCPA) mimicked seizure-induced hypoventilation, partially occluded the postictal decrease in the HCVR, exacerbated hypothermia, and increased postictal mortality in DS mice. Conversely, pretreatment with the 5-HT agonist fenfluramine reduced postictal inhibition of the HCVR and hypothermia. These results are consistent with the previous observation that seizures cause transient impairment of serotonergic neuron function, which would be expected to inhibit the many aspects of respiratory control dependent on 5-HT, including baseline ventilation and the HCVR. These results provide a scientific rationale to investigate the interictal and/or postictal HCVR as noninvasive biomarkers for those at high risk of seizure-induced death, and to prevent SUDEP by enhancing postictal 5-HT tone.SIGNIFICANCE STATEMENT There is increasing evidence that seizure-induced respiratory dysfunction contributes to the pathophysiology of sudden unexpected death in epilepsy (SUDEP). However, the cellular basis of this dysfunction has not been defined. Here, we show that seizures impair CO2 chemoreception in some epilepsy patients. In two mouse models of SUDEP we found that generalized convulsive seizures impaired CO2 chemoreception, and induced hypothermia, two effects reported with serotonergic neuron dysfunction. The defects in chemoreception and thermoregulation were exacerbated by chemical depletion of serotonin and reduced with fenfluramine, suggesting that seizure-induced respiratory dysfunction may be due to impairment of serotonin neuron function. These findings suggest that impaired chemoreception because of transient inhibition of serotonergic neurons may contribute to the pathophysiology of SUDEP.

Efficacy of lacosamide in the treatment of non-convulsive seizure and non-convulsive status epilepticus in septic patients: a narrative review

Non-convulsive seizures (NCS) and non-convulsive status epilepticus (NCSE) are of the acute complications of patients admitted to the intensive care unit (ICU), which lead to increased mortality and morbidity. In these cases, immediate treatment with antiepileptic drugs (AEDs) is important to prevent further damage to the brain. AEDs are the first line of treatment, however, most of these medications have many side effects. In the recent years, significant advances have been made in this area and lacosamide is one of the therapeutic options. The intravenous formulation of this drug is most popular due to the lack of drug-drug interaction and properly designed studies which have been conducted in this field. In this review, the latest findings on the effect of lacosamide on acute non-convulsive and generalized-convulsive seizures (G-CS) are evaluated in critically ill patients admitted to the ICU.

Sudden unexpected death in epilepsy.

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. 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. 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.

Heart rate variability in patients with refractory epilepsy: The influence of generalized convulsive seizures

ObjectivePatients with epilepsy, mainly drug-resistant, have reduced heart rate variability (HRV), linked to an increased risk of sudden death in various other diseases. In this context, it could play a role in SUDEP. Generalized convulsive seizures (GCS) are one of the most consensual risk factors for SUDEP. Our objective was to assess the influence of GCS in HRV parameters in patients with drug-resistant epilepsy. MethodsWe prospectively evaluated 121 patients with refractory epilepsy admitted to our Epilepsy Monitoring Unit. All patients underwent a 48-hour Holter recording. Only patients with GCS were included (n = 23), and we selected the first as the index seizure. We evaluated HRV (AVNN, SDNN, RMSSD, pNN50, LF, HF, and LF/HF) in 5-min epochs (diurnal and nocturnal baselines; preictal – 5 min before the seizure; ictal; postictal – 5 min after the seizure; and late postictal – >5 h after the seizure). These data were also compared with normative values from a healthy population (controlling for age and gender). ResultsWe included 23 patients, with a median age of 36 (min-max, 16–55) years and 65% were female. Thirty percent had cardiovascular risk factors, but no previously known cardiac disease. HRV parameters AVNN, RMSSD, pNN50, and HF were significantly lower in the diurnal than in the nocturnal baseline, whereas the opposite occurred with LF/HF and HR. Diurnal baseline parameters were inferior to the normative population values (which includes only diurnal values). We found significant differences in HRV parameters between the analyzed periods, especially during the postictal period. All parameters but LF/HF suffered a reduction in that period. LF/HF increased in that period but did not reach statistical significance. Visually, there was a tendency for a global reduction in our patients’ HRV parameters, namely AVNN, RMSSD, and pNN50, in each period, comparing with those from a normative healthy population. No significant differences were found in HRV between diurnal and nocturnal seizures, between temporal lobe and extra-temporal-lobe seizures, between seizures with and without postictal generalized EEG suppression, or between seizures of patients with and without cardiovascular risk factors. Significance/conclusionOur work reinforces the evidence of autonomic cardiac dysfunction in patients with refractory epilepsy, at baseline and mainly in the postictal phase of a GCS. Those changes may have a role in some SUDEP cases. By identifying patients with worse autonomic cardiac function, HRV could fill the gap of a lacking SUDEP risk biomarker.

Bilateral multiple periprosthetic hip fractures and joint dislocations secondary to general convulsive seizures

BackgroundDuring a seizure, there is a powerful and forceful contraction of muscles which may lead to fractures or joint dislocations. However, multiple periprosthetic hip fractures and joint dislocations secondary to seizures have not been reported.Case presentationA 49-year-old male developed spontaneous and bilateral multiple periprosthetic hip fractures and joint dislocations (including displaced fracture of the proximal right femur, avulsion fracture of the left lesser trochanter, left acetabular fracture and bilateral joint dislocations) secondary to generalized convulsive seizures which occurred within few hours after bilateral total hip arthroplasties (THAs). Bilateral open reconstruction and fixation were performed on the 21st day after primary THAs and on 2-year follow-up, the patient showed satisfactory functional outcome.ConclusionsMultiple periprosthetic hip fractures and joint dislocations secondary to seizure are extremely rare, and treatment targets for these injuries should focus on fracture healing and limb function recovery. Craniocerebral operation could bring an elevated risk of seizure; meanwhile, subsequent corticosteroid replacement threapy was complicated by secondary osteoporosis. Therefore, anti-osteoporotic and anti-epileptic therapy should be considered in this type of patients to avoid fracture and dislocation after arthroplasty.

Automated Analysis of Risk Factors for Postictal Generalized EEG Suppression.

Rationale: Currently, there is some ambiguity over the role of postictal generalized electro-encephalographic suppression (PGES) as a biomarker in sudden unexpected death in epilepsy (SUDEP). Visual analysis of PGES, known to be subjective, may account for this. In this study, we set out to perform an analysis of PGES presence and duration using a validated signal processing tool, specifically to examine the association between PGES and seizure features previously reported to be associated with visually analyzed PGES.Methods: This is a prospective, multicenter epilepsy monitoring study of autonomic and breathing biomarkers of SUDEP in adult patients with intractable epilepsy. We studied videoelectroencephalogram (vEEG) recordings of generalized convulsive seizures (GCS) in a cohort of patients in whom respiratory and vEEG recording were carried out during the evaluation in the epilepsy monitoring unit. A validated automated EEG suppression detection tool was used to determine presence and duration of PGES.Results: We studied 148 GCS in 87 patients. PGES occurred in 106/148 (71.6%) seizures in 70/87 (80.5%) of patients. PGES mean duration was 38.7 ± 23.7 (37; 1–169) seconds. Presence of tonic phase during GCS, including decerebration, decortication and hemi-decerebration, were 8.29 (CI 2.6–26.39, p = 0.0003), 7.17 (CI 1.29–39.76, p = 0.02), and 4.77 (CI 1.25–18.20, p = 0.02) times more likely to have PGES, respectively. In addition, presence of decerebration (p = 0.004) and decortication (p = 0.02), older age (p = 0.009), and hypoxemia duration (p = 0.03) were associated with longer PGES durations.Conclusions: In this study, we confirmed observations made with visual analysis, that presence of tonic phase during GCS, longer hypoxemia, and older age are reliably associated with PGES. We found that of the different types of tonic phase posturing, decerebration has the strongest association with PGES, followed by decortication, followed by hemi-decerebration. This suggests that these factors are likely indicative of seizure severity and may or may not be associated with SUDEP. An automated signal processing tool enables objective metrics, and may resolve apparent ambiguities in the role of PGES in SUDEP and seizure severity studies.

Seizure Clusters, Seizure Severity Markers, and SUDEP Risk.

Rationale: Seizure clusters may be related to Sudden Unexpected Death in Epilepsy (SUDEP). Two or more generalized convulsive seizures (GCS) were captured during video electroencephalography in 7/11 (64%) patients with monitored SUDEP in the MORTEMUS study. It follows that seizure clusters may be associated with epilepsy severity and possibly with SUDEP risk. We aimed to determine if electroclinical seizure features worsen from seizure to seizure within a cluster and possible associations between GCS clusters, markers of seizure severity, and SUDEP risk.Methods: Patients were consecutive, prospectively consented participants with drug-resistant epilepsy from a multi-center study. Seizure clusters were defined as two or more GCS in a 24-h period during the recording of prolonged video-electroencephalography in the Epilepsy monitoring unit (EMU). We measured heart rate variability (HRV), pulse oximetry, plethysmography, postictal generalized electroencephalographic suppression (PGES), and electroencephalography (EEG) recovery duration. A linear mixed effects model was used to study the difference between the first and subsequent seizures, with a level of significance set at p < 0.05.Results: We identified 112 GCS clusters in 105 patients with 285 seizures. GCS lasted on average 48.7 ± 19 s (mean 49, range 2–137). PGES emerged in 184 (64.6%) seizures and postconvulsive central apnea (PCCA) was present in 38 (13.3%) seizures. Changes in seizure features from seizure to seizure such as seizure and convulsive phase durations appeared random. In grouped analysis, some seizure features underwent significant deterioration, whereas others improved. Clonic phase and postconvulsive central apnea (PCCA) were significantly shorter in the fourth seizure compared to the first. By contrast, duration of decerebrate posturing and ictal central apnea were longer. Four SUDEP cases in the cluster cohort were reported on follow-up.Conclusion: Seizure clusters show variable changes from seizure to seizure. Although clusters may reflect epilepsy severity, they alone may be unrelated to SUDEP risk. We suggest a stochastic nature to SUDEP occurrence, where seizure clusters may be more likely to contribute to SUDEP if an underlying progressive tendency toward SUDEP has matured toward a critical SUDEP threshold.

Association of Peri-ictal Brainstem Posturing With Seizure Severity and Breathing Compromise in Patients With Generalized Convulsive Seizures.

To analyze the association between peri-ictal brainstem posturing semiologies with postictal generalized electroencephalographic suppression (PGES) and breathing dysfunction in generalized convulsive seizures (GCS). In this prospective, multicenter analysis of GCS, ictal brainstem semiology was classified as (1) decerebration (bilateral symmetric tonic arm extension), (2) decortication (bilateral symmetric tonic arm flexion only), (3) hemi-decerebration (unilateral tonic arm extension with contralateral flexion) and (4) absence of ictal tonic phase. Postictal posturing was also assessed. Respiration was monitored with thoracoabdominal belts, video, and pulse oximetry. Two hundred ninety-five seizures (180 patients) were analyzed. Ictal decerebration was observed in 122 of 295 (41.4%), decortication in 47 of 295 (15.9%), and hemi-decerebration in 28 of 295 (9.5%) seizures. Tonic phase was absent in 98 of 295 (33.2%) seizures. Postictal posturing occurred in 18 of 295 (6.1%) seizures. PGES risk increased with ictal decerebration (odds ratio [OR] 14.79, 95% confidence interval [CI] 6.18-35.39, p < 0.001), decortication (OR 11.26, 95% CI 2.96-42.93, p < 0.001), or hemi-decerebration (OR 48.56, 95% CI 6.07-388.78, p < 0.001). Ictal decerebration was associated with longer PGES (p = 0.011). Postictal posturing was associated with postconvulsive central apnea (PCCA) (p = 0.004), longer hypoxemia (p < 0.001), and Spo2 recovery (p = 0.035). Ictal brainstem semiology is associated with increased PGES risk. Ictal decerebration is associated with longer PGES. Postictal posturing is associated with a 6-fold increased risk of PCCA, longer hypoxemia, and Spo2 recovery. Peri-ictal brainstem posturing may be a surrogate biomarker for GCS severity identifiable without in-hospital monitoring. This study provides Class III evidence that peri-ictal brainstem posturing is associated with the GCS with more prolonged PGES and more severe breathing dysfunction.

Risk incidence of fractures and injuries: a multicenter video-EEG study of 626 generalized convulsive seizures

ObjectiveTo evaluate the incidence and risk factors of generalized convulsive seizure (GCS)-related fractures and injuries during video-EEG monitoring.MethodsWe analyzed all GCSs in patients undergoing video-EEG-monitoring between 2007 and 2019 at epilepsy centers in Frankfurt and Marburg in relation to injuries, falls and accidents associated with GCSs. Data were gathered using video material, EEG material, and a standardized reporting form.ResultsA total of 626 GCSs from 411 patients (mean age: 33.6 years; range 3–74 years; 45.0% female) were analyzed. Severe adverse events (SAEs) such as fractures, joint luxation, corneal erosion, and teeth loosening were observed in 13 patients resulting in a risk of 2.1% per GCS (95% CI 1.2–3.4%) and 3.2% per patient (95% CI 1.8–5.2%). Except for a nasal fracture due to a fall onto the face, no SAEs were caused by falls, and all occurred in patients lying in bed without evidence of external trauma. In seven patients, vertebral body compression fractures were confirmed by imaging. This resulted in a risk of 1.1% per GCS (95% CI 0.5–2.2%) and 1.7% per patient (95% CI 0.8–3.3%). These fractures occurred within the tonic phase of a GCS and were accompanied by a characteristic cracking noise. All affected patients reported back pain spontaneously, and an increase in pain on percussion of the affected spine section.ConclusionsGCSs are associated with a substantial risk of fractures and shoulder dislocations that are not associated with falls. GCSs accompanied by audible cracking, and resulting in back pain, should prompt clinical and imaging evaluations.

Periictal electroclinical characteristics of postictal generalized electroencephalographic suppression after generalized convulsive seizures.

The aim of this study was to investigate the demographic, clinical, and electrophysiological characteristics of postictal generalized electroencephalography (EEG) suppression (PGES), thereby facilitating the recognition of PGES and providing clues regarding its risk factors, pathophysiology, and relationship with sudden unexpected death in epilepsy patients (SUDEP).We retrospectively reviewed 237 generalized convulsive seizures (GCSs) in 126 patients during long-term video-EEG (VEEG) recordings. The associations of PGES and prolonged PGES (duration >20 seconds) with person- and seizure-specific variables were evaluated independently using SPSS software.Eighty patients (63.5%, 80/126) exhibited PGES after 127 GCSs (53.6%, 127/237) with an average PGES duration of 41.31 ± 24.03 seconds. The tonic phase was significantly prolonged in patients with PGES and prolonged PGES. PGES was independently associated with ictal semiology, which was attributable to the different proportions of GCS type 1. After seizure termination, patients with PGES had a higher percentage of postictal unresponsiveness and immobility, including oropharyngeal immobility. Between prolonged and short-duration PGES, the former was more likely to phase out gradually followed by immediate body movement, whereas the latter tended to have an abrupt, evoked termination followed by delayed body movement.Prolonged tonic duration, GCS type 1, postictal unresponsiveness, and immobility were more prone to occur with PGES, which might imply that hyperactivation of inhibitory neural networks underlies the pathophysiology of PGES and subsequent SUDEP. Any form of periictal bedside care, whether it constitutes effective medical intervention or not, is advisable due to its possible contribution to the interruption of PGES. Regardless of the PGES termination pattern, the neural network resuscitation process was progressive.

Time courses of HMGB1 and other inflammatory markers after generalized convulsive seizures

PurposeNeuroinflammation and disruption of blood brain barrier (BBB) are important players in epileptogenesis, ictogenesis and pharmacoresistance. In this context, we investigated blood levels of HMGB1 and other inflammatory and BBB markers after generalized and focal to bilateral tonic-clonic seizures in serum, summarized under the term generalized convulsive seizures (GCS). MethodsWe included consenting adults who were admitted to the epilepsy monitoring unit. Blood samples were drawn at baseline and immediately after a GCS as well as after 2, 6 and 24 h. We measured leukocytes, c-reactive protein (CRP), the danger-associated molecular patterns (DAMPs) high mobility group box 1 (HMGB1) and S100, receptor of advanced glycation end products (RAGE) alongside the BBB markers intercellular adhesion molecule-1 (ICAM1) and matrix metalloproteinase 9 (MMP9). Noradrenaline and lactate measurements were available from a previous study. P-levels <0.05 were regarded as significant. ResultsTwenty-eight patients with 28 GCS were included. Leukocytosis occurred immediately after GCS and normalized within two hours (p < 0.001). S100 and HMGB1 both increased by ∼80 % (p < 0.001). MMP9 peaked after six hours with levels at 48.6 % above baseline. RAGE decreased by 17.6 % with a nadir at 24 h. CRP increased by 118 % with a peak at 24 h. ICAM1 remained stable (p = 0.068). Postictal HMGB1 correlated with postictal leukocytosis (r = 0.42; p = 0.025) and with MMP9 levels six hours later (r = 0.374; p = 0.05). Postictal lactate levels correlated with MMP9 at 6 h (r = 0.48; p = 0.01) and CRP at 24 h (r = 0.39; p = 0.04). Postictal noradrenaline correlated with lactate (r = 0.57; p = 0.02) and leukocytes (r = 0.39; p = 0.047). DiscussionThe serum level of the DAMPs HMGB1 and S100 increase immediately after GCS. The hypothetical mechanism includes central nervous processes, such as glutamate toxicity and ROS release from seizing neurons but also muscular tissues. BBB breakdown is marked by the release of MMP9. Further research is needed to understand the complex interactions between electrical and metabolic stress, neuroinflammation and BBB mechanics in seizures and epilepsy. ConclusionOur study reveals signs of inflammation, neuronal damage and transitory disruption of BBB following single GCS, underscoring the widespread and possibily detrimental effects of recurrent seizures on brain properties. The long term impact on the disease course, however, is unclear.

Prone, lateral, or supine positioning at seizure onset determines the postictal body position: A multicenter video-EEG monitoring cohort study

PurposeMost patients who die from sudden unexpected death in epilepsy (SUDEP) are found in the prone position. We evaluated whether changes in body position occur during generalized convulsive seizures (GCSs). MethodGCSs in patients undergoing video-EEG-monitoring between 2007 and 2017 at epilepsy centers in Frankfurt and Marburg were analyzed in relation to changes in body position. ResultsA total of 494 GCSs were analyzed among 327 patients. At seizure onset, positions included supine (48.2 %), right lateral (19.0 %), left lateral (15.6 %), sitting or standing (14.0 %), and prone (3.2 %). Between seizure onset and the start of generalization, 57.5 % of participants altered body positions. During four seizures, patients adopted a prone position, while, in five seizures, patients moved from a prone position. Patients who experienced GCS onset while in a nonprone position had a 2.1 % risk of entering the prone position by the end of their seizure. In contrast, 56.2 % of those in an initial prone position remained so at the end of the GCS, with an odds ratio for maintaining that position of 60.2 (95 % confidence interval: 29.1–124.3; p < 0.001). The likelihood of ending up in the prone position post-GCS did not vary among patients with different nonprone starting positions (p = 0.147). ConclusionsSeizures in prone position occur during sleep and the highest risk for postictal prone positioning appears to be being in the prone position at GCS onset. Epilepsy patients should therefore be advised to go to sleep in a supine or lateral position to reduce their SUDEP risk.

Autonomic dysregulation in children with epilepsy with postictal generalized EEG suppression following generalized convulsive seizures

ObjectivePostictal generalized electroencephalographic suppression (PGES) has been associated with sudden unexpected death in epilepsy (SUDEP) in adults. Decreased heart rate variability (HRV) is one clinical marker of SUDEP in adults with epilepsy. The objective of this study was to analyze the characteristics of HRV associated with generalized convulsive seizures (GCS) ± PGES in children. MethodsNine hundred and seventy-seven consecutive children who underwent prolonged scalp video-EEG (vEEG) and 1-lead electrocardiogram (ECG) monitoring at the Hospital for Sick Children, Toronto, Ontario, Canada were reviewed retrospectively from 2009 to 2011. Thirty-five children had GCS captured during their vEEG with or without PGES and met inclusion criteria. Children were subdivided into three age groups and compared with age-matched controls: 3–6 years; 7–12 years; and 13–18 years. Interictal HRV was measured at 5 min during N2 sleep. Preictal HRV was measured at 1 h prior to GCS onset, and postictal HRV was measured at 3 min post-GCS cessation. Low frequency (LF: ms2, 0.04–0.15 Hz) and high frequency (HF: ms2, 0.15–0.4 Hz) bands of heart rate oscillations were analyzed during the interictal and preictal periods. The root mean square of successive differences (RMSSDs) was analyzed during the following time points: interictal; preictal; and postictal. ResultsThirty-five children had GCS: 18 children with PGES [3–6 years (n = 2); 7–12 years (n = 6); 13–18 years (n = 10)] and 17 children without PGES [3–6 years (n = 6); 7–12 years (n = 5); 13–18 years (n = 6)]. Seventeen additional age-matched controls were identified [3–6 years (n = 3); 7–12 years (n = 5); 13–18 years (n = 9)]. Seventy-four GCS were captured consisting of 36 GCS + PGES and 38 GCS − PGES. There was no difference of interictal HRV among children with GCS ± PGES and controls. The preictal LF and HF in 36 GCS + PGES were significantly higher compared with 38 GCS − PGES (p < 0.01). The postictal RMSSD in 36 GCS + PGES was significantly higher compared with 38 GCS − PGES (p < 0.01). The pre- to postictal RMSSD change was significantly lower in children with GCS + PGES than in those with GCS − PGES (p = 0.035). ConclusionsIn summary, the preictal HRV in GCS + PGES was significantly higher than in children with GCS − PGES. The higher remaining postictal RMSSD in children with GCS + PGES is a potential indicator of autonomic dysregulation. In certain children with epilepsy, autonomic dysregulation may contribute to poor recovery from a GCS with subsequent PGES, thereby contributing to SUDEP. Heart rate variability and autonomic regulation in children with epilepsy should be further studied prospectively in order to better understand the mechanism by which PGES may lead to SUDEP.

Cardiac stress after electroconvulsive therapy and spontaneous generalized convulsive seizures: A prospective echocardiographic and blood biomarker study

AimKnowledge about cardiac stress related to seizures in electroconvulsive therapy (ECT) and spontaneously occurring generalized convulsive seizures (GCS) is limited. The aim of the present study was to analyze cardiac function and circulating markers of cardiac stress in the early postictal period after ECT and GCS. MethodsPatients undergoing ECT in the Department of Psychiatry, Psychotherapy and Psychosomatics and patients undergoing diagnostic video-EEG monitoring (VEM) in the Department of Neurology were prospectively enrolled between November 2017 and November 2018. Cardiac function was examined twice using transthoracic echocardiography within 60 min and >4 h after ECT or GCS. Established blood markers (troponin T high-sensitive, N-terminal pro brain natriuretic peptide) of cardiac stress or injury were collected within 30 min, 4 to 6 h, and 24 h after ECT or GCS. In the ECT group, the troponin T values were also correlated with periprocedural heart rate and blood pressure values. Because of organizational or technical reasons, the measurement was not performed in all patients. ResultsTwenty patients undergoing ECT and 6 patients with epilepsy with a GCS during VEM were included. Postictal echocardiography showed no wall motion disorders and no change in left ventricular and right ventricular functions. Four of 17 patients displayed a transient increase in high-sensitive cardiac troponin T 4–6 h after the seizure (3 patients with ECT-induced seizure). None of these 4 patients had signs of an acute cardiac event, and periprocedural blood pressure or heart rate peaks during ECT did not significantly differ in patients with and without troponin T elevation. ConclusionsSigns of mild cardiac stress can occur in some patients following ECT or GCS without clinical complications, probably related to excessive catecholamine release during the seizure.

Postictal serotonin levels are associated with peri-ictal apnea

To determine the relationship between serum serotonin (5-HT) levels, ictal central apnea (ICA), and postconvulsive central apnea (PCCA) in epileptic seizures. We prospectively evaluated video EEG, plethysmography, capillary oxygen saturation (SpO2), and ECG for 49 patients (49 seizures) enrolled in a multicenter study of sudden unexpected death in epilepsy (SUDEP). Postictal and interictal venous blood samples were collected after a clinical seizure for measurement of serum 5-HT levels. Seizures were classified according to the International League Against Epilepsy 2017 seizure classification. We analyzed seizures with and without ICA (n = 49) and generalized convulsive seizures (GCS) with and without PCCA (n = 27). Postictal serum 5-HT levels were increased over interictal levels for seizures without ICA (p = 0.01), compared to seizures with ICA (p = 0.21). In patients with GCS without PCCA, serum 5-HT levels were increased postictally compared to interictal levels (p < 0.001), but not in patients with seizures with PCCA (p = 0.22). Postictal minus interictal 5-HT levels also differed between the 2 groups with and without PCCA (p = 0.03). Increased heart rate was accompanied by increased serum 5-HT levels (postictal minus interictal) after seizures without PCCA (p = 0.03) compared to those with PCCA (p = 0.42). The data suggest that significant seizure-related increases in serum 5-HT levels are associated with a lower incidence of seizure-related breathing dysfunction, and may reflect physiologic changes that confer a protective effect against deleterious phenomena leading to SUDEP. These results need to be confirmed with a larger sample size study.

Biomarkers for SUDEP: Are We There Yet?

To characterize peri-ictal apnea and postictal asystole in generalized convulsive seizures (GCS) of intractable epilepsy. This was a prospective, multicenter epilepsy monitoring study of autonomic and breathing biomarkers of sudden unexpected death in epilepsy (SUDEP) in patients ≥18 years old with intractable epilepsy and monitored GCS. Video electroencephalography, thoracoabdominal excursions, nasal airflow, capillary oxygen saturation, and electrocardiogram were analyzed. We studied 148 GCS in 87 patients. Nineteen patients had generalized epilepsy, 65 had focal epilepsy, 1 had both, and the epileptogenic zone was unknown in 2. Ictal central apnea (ICA) preceded GCS in 49 (40.4%) of 121 seizures in 23 patients, all with focal epilepsy. Postconvulsive central apnea (PCCA) occurred in 31 (22.1%) of 140 seizures in 22 patients, with generalized, focal, or unknown epileptogenic zones. In 2 patients, PCCA occurred concurrently with asystole (near-SUDEP), with an incidence rate of 10.2 per 1000 patient-years. One patient with PCCA died of probable SUDEP during follow-up, suggesting a SUDEP incidence rate 5.1 per 1000 patient-years. No cases of laryngospasm were detected. Rhythmic muscle artifact synchronous with breathing was present in 75 of 147 seizures and related to stertorous breathing (odds ratio: 3.856, 95% confidence interval: 1.395-10.663, P = .009). Postconvulsive central apnea occurred in both focal and generalized epilepsies, suggesting a different pathophysiology from ICA, which occurred only in focal epilepsy. Postconvulsive central apnea was seen in 2 near-SUDEP cases and 1 probable SUDEP case, suggesting that this phenomenon may serve as a clinical biomarker of SUDEP. Larger studies are needed to validate this observation. Rhythmic postictal muscle artifact is suggestive of post-GCS breathing effort rather than a specific biomarker of laryngospasm. Hypoxemia Following Generalized Convulsive Seizures: Risk Factors and Effect of Oxygen Therapy Sylvain Rheims, MD, PhD, Blanca Mercedes Alvarez, MD, Veriano Alexandre, MD, PhD, Jonathan Curot, MD, Louis Maillard, MD, PhD, Fabrice Bartolomei, MD, PhD, Philippe Derambure, MD, PhD, Edouard Hirsch, MD, PhD, V´eronique Michel, MD, Francine Chassoux, MD, PhD, Didier Tourniaire, MD, Arielle Crespel, MD, Arnaud Biraben, MD, Vincent Navarro, MD, PhD, Philippe Kahane, MD, PhD, Bertrand De Toffol, MD, PhD, Pierre Thomas, MD, PhD, Sarah Rosenberg, MD, PhD, Luc Valton, MD, PhD, Laurent Bezin, PhD, and Philippe Ryvlin, MD, PhD, on behalf of the REPO2MSE Study Group. Neurology. 2019;92:e183-e193. To analyze the factors that determine the occurrence or severity of postictal hypoxemia in the immediate aftermath of a generalized convulsive seizure (GCS). We reviewed the video electroencephalography (EEG) recordings of 1006 patients with drug-resistant focal epilepsy included in the REPO2MSE study to identify those with ≥1 GCS and pulse oximetry (SpO2) measurement. Factors determining recovery of SpO2 ≥ 90% were investigated using Cox proportional hazards models. Association between SpO2 nadir and person- or seizure-specific variables was analyzed after correction for individual effects and the varying number of seizures. A total of 107 GCS in 73 patients were analyzed. A transient hypoxemia was observed in 92 (86%) GCS. Rate of GCS with SpO2 < 70% dropped from 40% to 21% when oxygen was administered early (P = .046). Early recovery of SpO2 ≥ 90% was associated with early administration of oxygen (P = .004), absence of postictal generalized EEG suppression (PGES; P = .014), and extratemporal lobe epilepsy (P = .001). Lack of early administration of O2 (P = .003), occurrence of PGES (P = .018), and occurrence of ictal hypoxemia during the focal phase (P = .022) were associated with lower SpO2 nadir. Postictal hypoxemia was observed in the immediate aftermath of nearly all GCS, but administration of oxygen had a strong preventive effect. Severity of postictal hypoxemia was greater in temporal lobe epilepsy and when hypoxemia was already observed before the onset of secondary GCS.

Blood Pressure in Seizures and Epilepsy

In this narrative review, we summarize the current knowledge of neurally mediated blood pressure (BP) control and discuss how recently described epilepsy- and seizure-related BP alterations may contribute to premature mortality and sudden unexpected death in epilepsy (SUDEP). Although people with epilepsy display disturbed interictal autonomic function with a shift toward predominant sympathetic activity, prevalence of arterial hypertension is similar in people with and without epilepsy. BP is transiently increased in association with most types of epileptic seizures but may also decrease in some, illustrating that seizure activity can cause both a decrease and increase of BP, probably because of stimulation or inhibition of distinct central autonomic function by epileptic activity that propagates into different neuronal networks of the central autonomic nervous system. The principal regulatory neural loop for short-term BP control is termed baroreflex, mainly involving peripheral sensors and brain stem nuclei. The baroreflex sensitivity (BRS, expressed as change of interbeat interval per change in BP) is intact after focal seizures, whereas BRS is markedly impaired in the early postictal period following generalized convulsive seizures (GCS), possibly due to metabolically mediated muscular hyperemia in skeletal muscles, a massive release of catecholamines and compromised brain stem function. Whilst most SUDEP cases are probably caused by a cardiorespiratory failure during the early postictal period following GCS, a profoundly disturbed BRS may allow a life-threatening drop of systemic BP in the aftermath of GCS, as recently reported in a patient as a plausible cause of SUDEP in a few patients.

Don't Just Stand There: Do Something! The Case for Peri-Ictal Intervention.

Hypoxemia Following Generalized Convulsive Seizures: Risk Factors and Effect of Oxygen Therapy Rheims S, Alvarez BM, Alexandre V, Curot J, Maillard L, Bartolomei F, et al; the REPO2MSE Study Group. Hypoxemia following generalized convulsive seizures: risk factors and effect of oxygen therapy. Neurology. 2019;92(3):e183-e193. doi:10.1212/WNL.0000000000006777Objective:To analyze the factors that determine the occurrence or severity of postictal hypoxemia in the immediate aftermath of a generalized convulsive seizure (GCS).Methods:We reviewed the video-electroencephalogram (EEG) recordings of 1006 patients with drug-resistant focal epilepsy included in the REPO2MSE study to identify those with ≥1 GCS and pulse oximetry (SpO2) measurement. Factors determining recovery of SpO2 ≥90% were investigated using Cox proportional hazards models. Association between SpO2 nadir and person- or seizure-specific variables was analyzed after correction for individual effects and the varying number of seizures.Results:A total of 107 GCS in 73 patients were analyzed. A transient hypoxemia was observed in 92 (86%) GCS. Rate of GCS with SpO2 <70% dropped from 40% to 21% when oxygen was administered early (P = .046). Early recovery of SpO2 ≥90% was associated with early administration of oxygen (P = .004), absence of postictal generalized EEG suppression (PGES; P = .014), and extratemporal lobe epilepsy (P = .001). Lack of early administration of O2 (P = .003), occurrence of PGES (P = .018), and occurrence of ictal hypoxemia during the focal phase (P = .022) were associated with lower SpO2 nadir.Conclusion:Postictal hypoxemia was observed in the immediate aftermath of nearly all GCS, but administration of oxygen had a strong preventive effect. Severity of postictal hypoxemia was greater in temporal lobe epilepsy and when hypoxemia was already observed before the onset of secondary GCS.