Postictal generalized EEG suppression

Lamberts, Robert J.; Gaitatzis, Athanasios; Sander, Josemir W.; Elger, Christian E.; Surges, Rainer; Thijs, Roland D.

doi:10.1212/wnl.0b013e3182a6cbeb

Cited by 104 publications

(72 citation statements)

References 22 publications

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“…The only patient in whom IPA or focal IPA was not observed (Patient 16) had only one seizure recorded. This is consistent with a previous study reporting that the occurrence of PGES in scalp EEG recordings is dependent on the number of FBTCS seizures recorded 16 . We also found that IPA occurrence and duration may be associated with semiology patterns that define BTCS type, suggesting common or linked mechanisms.…”

Section: Discussionsupporting

confidence: 93%

Postictal clinical and electroencephalographic activity following intracranially recorded bilateral tonic–clonic seizures

et al. 2018

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Summary Objective: The dynamics of the postictal period, which may demonstrate such dramatic clinical phenomena as focal neurological deficits, prolonged coma and immobility, and even sudden death, are poorly understood. We sought to classify and characterize postictal phases of bilateral tonic-clonic seizures based on EEG criteria and associated clinical features. Methods: We performed a detailed electroclinical evaluation of the postictal period in a series of 31 bilateral tonic-clonic seizures in 16 patients undergoing epilepsy surgery evaluations for focal pharmacoresistant epilepsy with intracranial electrodes and time-locked video. Results: The postictal EEG demonstrated three clearly differentiated phases: attenuation, a burst-attenuation pattern, and a return to continuous background, with abrupt, synchronized transitions between phases. Postictal attenuation was common, occurring in 84% of seizures in 94% of patients in this study. There was increased power in gamma frequencies (> 25 Hz) during postictal attenuation periods relative to preictal baseline in 88% of seizures demonstrating the attenuation pattern (N=25 seizures, p<0.002). Such increases were seen in more than 90% of channels in 13 seizures (52%), and fewer than 10% of channels in three seizures (12%). Postictal immobility was seen in 87% of seizures, with either a flaccid (58%) or rigid/dystonic (29%) appearance. Clinical motor manifestations, including focal dystonic posturing, automatisms, head and eye deviation, and myoclonic jerking, continued or emerged within the first minute following seizure termination in 48% of seizures, regardless of EEG appearance. Significance: Intracranial postictal attenuation, which may be diffuse or focal, is so common that it should be regarded as an ubiquitous feature of bilateral tonic-clonic seizures, rather than an unusual event. The prominence of high frequency activity coupled with emerging clinical features, including rigid immobility and semiologies such as automatisms, during the postictal period support the presence of ongoing seizure-related neuronal activity in unrecorded brain regions.

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Section: Discussionsupporting

confidence: 93%

Postictal clinical and electroencephalographic activity following intracranially recorded bilateral tonic–clonic seizures

et al. 2018

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“…Some of these risk factors can be readily identified, such as male gender, intellectual disability, and the occurrence of nocturnal seizures, or only require once‐in‐a‐lifetime investigations, such as an extratemporal epileptogenic zone . Others might require repeated assessments due to intraindividual variability over time, such as the presence and duration of postictal generalized electroencephalography (EEG) suppression (PGES) . However, performing repeated video‐EEG to characterize the severity of GTCS in a given patient is not a realistic option.…”

Section: Identifying Biomarkers and Mechanisms Of Sudepmentioning

confidence: 99%

Wearable devices for sudden unexpected death in epilepsy prevention

et al. 2018

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Sudden unexpected death in epilepsy (SUDEP) is most often associated with the occurrence of generalized tonic-clonic seizures (GTCS), a seizure type that can now be detected with high sensitivity and specificity by wearable or bed devices. The recent development in such devices and their performance offer multiple opportunities to tackle SUDEP and its prevention. Reliable GTCS detection might help physicians optimize antiepileptic treatment, which could in turn reduce the risk of SUDEP. GTCS-triggered alarms can lead to immediate intervention by caregivers that are also likely to decrease the odd of SUDEP. The biosignals used to detect GTCS might provide novel SUDEP biomarkers, in particular, by informing on several important characteristics of the ictal and postictal periods (type of GTCS, duration of tonic phase, rotation in the prone position, presence and duration of postictal immobility and bradycardia, rise in electrodermal activity). Other biosensors not yet used for detecting GTCS might provide complementary information, such as the presence and intensity of ictal/postictal hypoxemia. The above biomarkers, if strongly predictive, could help identify patients at very high risk of SUDEP, enabling better assessment of individual risk, as well as selection of appropriate patients for clinical studies aiming at preventing SUDEP. The same biosignals could also be used as ancillary biomarkers to test the impact of various interventions before moving to highly challenging randomized controlled trials with SUDEP as a primary outcome.

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“…Other, more sensitive biomarkers are thus needed. 27 Automated video detection of respiratory arrest, 28 automated PGES detection, 29 or other closely related markers such as ictal increases of electrodermal activity 25 or interclonic intervals 30 could provide alternatives for recordings in a home environment. 22,23 In 2 of 22 cases, PCCA coincided with asystole (near SUDEP); 1 case with PCCA and without concurring asystole died from probable SUDEP during long-term follow-up (incidence = 5.1 per 1000 person years).…”

Section: Discussionmentioning

confidence: 99%

The yield of long‐term electrocardiographic recordings in refractory focal epilepsy

et al. 2019

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Objective:To determine the incidence of clinically relevant arrhythmias in refractory focal epilepsy and to assess the potential of postictal arrhythmias as risk markers for sudden unexpected death in epilepsy (SUDEP). Methods: We recruited people with refractory focal epilepsy without signs of ictal asystole and who had at least one focal seizure per month and implanted a loop recorder with 2-year follow-up. The devices automatically record arrhythmias. Subjects and caregivers were instructed to make additional peri-ictal recordings. Clinically relevant arrhythmias were defined as asystole ≥ 6 seconds; atrial fibrillation < 55 beats per minute (bpm), or > 200 bpm and duration > 30 seconds; persistent sinus bradycardia < 40 bpm while awake; and second-or third-degree atrioventricular block and ventricular tachycardia/fibrillation. We performed 12-lead electrocardiography (ECG) and tilt table testing to identify non-seizure-related causes of asystole. Results: We included 49 people and accumulated 1060 months of monitoring. A total of 16 474 seizures were reported, of which 4679 were captured on ECG. No clinically relevant arrhythmias were identified. Three people had a total of 18 shortlasting (<6 seconds) periods of asystole, resulting in an incidence of 2.91 events per 1000 patient-months. None of these coincided with a reported seizure; one was explained by micturition syncope. Other non-clinically relevant arrhythmias included paroxysmal atrial fibrillation (n = 2), supraventricular tachycardia (n = 1), and sinus tachycardia with a right bundle branch block configuration (n = 1). Significance: We found no clinically relevant arrhythmias in people with refractory focal epilepsy during long-term follow-up. The absence of postictal arrhythmias does not support the use of loop recorders in people at high SUDEP risk. K E Y W O R D Scardiac arrhythmias, ECG, epilepsy, implantable loop recorders, sudden unexpected death in epilepsy

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Postictal generalized EEG suppression

Cited by 104 publications

References 22 publications

Postictal clinical and electroencephalographic activity following intracranially recorded bilateral tonic–clonic seizures

Postictal clinical and electroencephalographic activity following intracranially recorded bilateral tonic–clonic seizures

Wearable devices for sudden unexpected death in epilepsy prevention

The yield of long‐term electrocardiographic recordings in refractory focal epilepsy

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