Detection of generalized tonic-clonic seizures from ear-EEG based on EMG analysis

Purpose: Sudden unexpected death in epilepsy (SUDEP) is associated with generalized tonic-clonic seizures (GTCS) with most deaths occurring during sleep. Seizure detection devices have been suggested as a SUDEP prevention strategy. EMG-based GTCS detection can take advantage of the GTCS characteristic of sustained high-amplitude, high-frequency activity in the time-domain. Method: We present a GTCS-detection method based on median-filtered variance estimates on surface EMG measurements and describe its performance in a small exploratory proof-of-concept setting involving a group of 15 patients with 3 GTCS recorded with ear-EEG and another group of 6 patients with 11 GTCS recorded with scalp-EEG. Results: GTCS intervals were detected within 4.2-12.9 s of onset with 100% sensitivity (CI 29.2-100%) without false positives in 820.7 h of ear-EEG. The same detection method worked for the 11 GTCS from scalp EEG data with 100% sensitivity (CI 71.5-100%) and no false positives. Conclusions: Ear-EEG contains enough GTCS-specific EMG activity for GTCS detection to be feasible. Ear EEG could be considered for nocturnal GTCS monitoring as a supplement to SUDEP preventive interventions. (C) 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.