ID 62 – Autonomic cardiac changes during temporal epilepsy: A sEEG study combined with time–frequency heart rate variability analysis

Abstract

Objective The aim of the present study was to assess (1) autonomic changes and (2) which cerebral regions, engaged in autonomic control such as insula, amygdala, and hippocampus are involved in vegetative cardiac changes during temporal lobe seizures. Methods fifty nine temporal lobe seizures in 9 patients were studied for presurgical evaluation of drug-refractory epilepsy with stereotactic EEG electrodes. The time course of insular, amygdalar, and hippocampal formation ictal activities were studied with quantitative indices based on EEG-high frequency content. RR intervals (RR) and time–frequency spectral analysis were performed to assess parasympathetic (high frequency power (HF)) and sympathetic (low frequency/high frequency (LF)/(HF) ratio) reactivity. Results RR decreased during temporal seizures, reaching a maximal level at the 25 s, maintained for 42 s, and then gradually increases during 35 s. This RR decrease was associated with a significant increase in sympathetic activity (LF/HF ratio) without any parasympathetic (HF) change. Theses autonomic changes were accompanied by an early increase in EEG activity in hippocampal formation, but not in insula and amygdala. Conclusions temporal lobe seizures are accompanied by an early increase in sympathetic cardiac activity which seems depend on hippocampal formation. Key message Autonomic change during temporal seizure seems to be associated with hippocampus activity.