Detection of epileptic-seizures by means of power spectrum analysis of heart rate variability: A pilot study

Abstract

To investigate whether epileptic seizures could be predicted or detected by means of spectral analysis of heart rate variability (HRV). Six patients with temporal lobe epilepsy (4 females, 2 males) participated in the prospective pilot study while enrolled for video/EEG monitoring (24 h/day, 2-4 days). ECG was continuously recorded and 30 min seizure-sessions (25-30 min pre-seizure to 30 sec-5 min post-seizure onset) and 30 min non-seizure-sessions (day- and night sessions for each patient, as control) were chosen for further HRV-analysis. Low frequency (LF) (0.04-0.15 Hz), High frequencies (HF) (0.15-0.40 Hz), LF/HF, LF/(LF+HF) and reciprocal HF-power was determined using continuous FFT- spectral analysis of 64 R-R interval windowing with maximum overlapping. Six seizures were recorded and analyzed from three patients (2 females, 1 male). All of the analyzed EEG-correlated seizures showed reciprocal HF-power peaks between 10 sec pre seizure-onset and 24 sec post seizure-onset with peak amplitudes 2.96-93.63 times higher than control maximum peak. For the other parameters we could not find significant difference between seizure and non-seizure sessions. Specifically high reciprocal HF-power peaks suggest suppressed parasympathetic activity just around seizure-onset time. Seizure detection using HRV-analysis seems to be a promising method for non-invasive seizure detection in the early phase of the clinical event (even preceding the onset).