Association between semiologic, autonomic, and electrographic seizure characteristics in children with generalized tonic-clonic seizures

Abstract

Introduction: Generalized tonic-clonic seizures (GTCS) are associated with elevated electrodermal activity (EDA) and postictal generalized electroencephalographic suppression (PGES), markers that may indicate sudden unexpected death in epilepsy (SUDEP) risk. This study investigated the association of GTCS semiology, EDA, and PGES in children with epilepsy. Methods: Patients admitted to the Boston Children's Hospital long-term video-EEG monitoring unit wore a sensor that records EDA. We selected patients with at least one GTCS and reviewed video-EEGs for semiology, tonic and clonic phase duration, total clinical seizure duration, electrographic onset, offset, and PGES. We grouped patients into three semiology classes: GTCS 1: bilateral symmetric tonic arm extension, GTCS 2: no specific tonic arm extension or flexion, GTCS 3: unilateral or asymmetrical arm extension, tonic arm flexion or posturing that does not fit into GTCS 1 or 2. We analyzed the correlation between semiology, EDA, and PGES, and measured the area under the curve (AUC) of the ictal EDA (seizure onset to one hour after), subtracting baseline EDA (one-hour seizure-free before seizure onset). Using generalized estimating equation (GEE) and linear regression, we analyzed all seizures and single episodes per patient. Results: We included 30 patients (median age 13.8 ± 3.6 years, 46.7% females) and 53 seizures. With GEE, GTCS 1 was associated with longer PGES duration compared to GTCS 2 (Estimate (b) = À26.32 s, 95% Confidence Interval (CI): À36.46 to À16.18, p < 0.001), and the presence of PGES was associated with greater EDA change (b = 429604 lS, 95% CI: 3550.96 to 855657.04, p = 0.048). With single-episode analysis, GTCS 1 had greater EDA change than GTCS 2 ((b = À601339 lS, 95% CI: À1167016.56 to À35661.44, p = 0.047). EDA increased with PGES presence (b = 637500 lS, 95% CI: 183571.84 to 1091428.16, p = 0.01) and duration (b = 16794 lS, 95% CI: 5729.8 to 27858.2, p = 0.006). Patients with GTCS 1 had longer PGES duration compared to GTCS 2 (b = À30.53 s, 95% CI: À44.6 to À16.46, p < 0.001) and GTCS 3 (b = À22.07 s, 95% CI: À38.95 to À5.19, p = 0.016). Conclusion:In children with epilepsy, PGES correlates with greater ictal EDA. GTCS 1 correlated with longer PGES duration and may indirectly correlate with greater ictal EDA. Our study suggests potential applications in monitoring and preventing SUDEP in these patients.

Electrodermal activity response during seizures: A systematic review and meta-analysis

“…Of the included studies, six were included for meta-analysis [17,18,[25][26][27][28]. The remaining 13 studies [19,20,[29][30][31][32][33][34][35][36][37][38][39] were only considered for qualitative analysis, as they did not report the frequency of seizures with an EDA response.…”

“…The nineteen studies included a total of 550 participants (46% male, 44% female, 10% not recorded), and 1115 recorded seizures. Five studies [28,31,37,40,41] included both adult and pediatric populations, four [19,26,27,29] included only adults, with another six [17,18,20,34,38,39] including only children or young adults. Four studies [30,32,33,35] did not report the age of participants.…”

“…Six studies [18,28,31,[37][38][39] included a mixture of genetic and structural/metabolic epilepsies and one study [19] included temporal lobe epilepsies. The remaining twelve studies [17,20,25-27, 29,30,32-35,41] did not report the epilepsy type.…”

“…One study included only focal seizures (excluding FBTCS) [19]. Three studies included only GTCS [26,38,39]. One study included only motor vs non-motor seizures (generalized vs focal unspecified) [32].…”

“…Eighteen studies [17][18][19][20][25][26][27][28][29][30][31][32][33][34][35][37][38][39] used scalp EEG, sixteen of which were video-EEG. One study [36] did not report the type of EEG recording used.…”