Periictal heart rate variability analysis suggests long-term postictal autonomic disturbance in epilepsy.
BACKGROUND
One of the possible pathomechanisms of sudden death in epilepsy (SUDEP) is a postictal dysregulation of autonomic nervous system. We performed a heart rate variability (HRV) analysis of the periictal state to analyze whether a cardiac autonomic disturbance exists after an epileptic seizure.


METHODS
We included 31 periictal video-EEG-ECG recordings of 31 patients with epilepsy who had consecutively undergone pre-surgical evaluation. Nine generalized tonic-clonic (GTCS), 15 complex partial, and seven simple motor seizures were included. HRV was evaluated by analyzing 5-min-long ECG epochs, sampling from baseline, direct preictal, early-postictal (<15 min after the seizure), and late-postictal (5-6 h after the seizure) periods.


RESULTS
The heart rate was elevated immediately after the seizures, but 5-6 h postictally returned to the baseline level. Time-domain components of HRV decreased after the seizure and this decrease lasted for 5-6 h. Low-frequency power decreased in the early-postictal phase and high-frequency power of HRV dropped in the late-postictal phase. GTCS had an impact on short-term but not on long-term postictal HRV decrease.


CONCLUSIONS
We found decreased HRV immediately after the seizures, which lasted at least 5-6 h postictally, indicating a long-term postictal disturbance of the autonomous nervous system. GTCS were accompanied by a more decreased HRV than other seizures. Our results may have relevance in explaining pathomechanism of SUDEP.
Toth
V
V
Department of Neurology, University of Pécs, Pécs, Hungary.
Hejjel
L
L
Fogarasi
A
A
Gyimesi
C
C
Orsi
G
G
Szucs
A
A
Kovacs
N
N
Komoly
S
S
Ebner
A
A
Janszky
J
J
D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology; D003645:Death, Sudden; D004562:Electrocardiography; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male