Abstract Details

Title Surface-Electromyography (sEMG) Patterns of Clonic Bursts during Generalized Tonic-Clonic (GTC) Seizures

Topic Epilepsy/Clinical Neurophysiology (EEG)

Presentation(s) P4 - Poster Session 4 (5:30 PM-6:30 PM)

Poster/Presentation
Number 6-010

Objective To use sEMG to identify the differences between the muscle activity during the clonic phase of GTC seizures and voluntary muscle activation during acted seizures.

Background

Monitoring motor seizure activity outside of a clinical setting is based upon patient-reported outcomes. This complicates determination of the efficacy of anti-seizure medications (ASM) and poses a challenge in clinical practice. A wearable device that can accurately determine seizure frequency would improve seizure monitoring and treatment outcomes.

Design/Methods Single-channel sEMG data from 25 generalized tonic-clonic (GTC) seizures were previously recorded unilaterally from the biceps brachii at 1kHz in a prospective double-blinded regulatory clinical trial study of the SPEAC® System. Six GTC seizures were “acted” by healthy volunteers wearing the SPEAC System, whom were trained to exert sustained muscle contraction followed by rapid intermittent contractions. Muscle activity from each group were isolated and evaluated in Matlab by comparing: clonic burst duration, inter-burst interval, the slope of the initial discharge (first 30ms, normalized to burst rms amplitude), and the time to maximum amplitude (rise-time) of the clonic bursts.

Results Clonic epileptic and acted muscle potential bursts lasted an average of 150.3 ms and 217.3 ms respectively, with average inter-burst intervals of 316.2ms and 212.4ms, respectively. Burst duration and inter-burst intervals were significantly different using unpaired two-tailed t-tests (p<.05). Clonic bursts and acted bursts had normalized slopes of the initial discharges of 0.52 µV/µV/ms and 0.42 µV/µV/ms, respectively. The rise-time for each clonic bursts and acted bursts was 57 ms and 67 ms, respectively.

Conclusions Clonic motor activity that occurs during GTC seizures is consistent across patients and differs from non-seizure activation. Continuous sEMG recording in a patient’s home/community environment may be able to differentiate between GTC seizures, PNES, and non-seizure rhythmic activity. To this end, analyses will be expanded to evaluate bursts and discharges from PNES using sEMG.

Authors/Disclosures
Damon P. Cardenas, PhD (Brain Sentinel) PRESENTER	No disclosure on file
	No disclosure on file
Luke Whitmire, PhD (Brain Sentinel)	No disclosure on file
Jose E. Cavazos, MD, PhD (U Texas Health San Antonio)	Dr. Cavazos has received stock or an ownership interest from Brain Sentinel . The institution of Dr. Cavazos has received research support from NIH.

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