Abstracts

Sudden unexpected death in epilepsy (SUDEP) may be related to impaired autonomic cardiac control. The cause of such impairment is not known: is it the specific type of epilepsy, ictal or interictal epileptiform discharges or the treatment with antiepileptic drugs (AEDs)? The aim of our study was to assess heart rate variability (HRV) by spectral analysis in patients with epilepsy before and after withdrawal of AEDs., The study was a prospective randomised and double blinded withdrawal study of seizure free patients on AED monotherapy. 24 h ambulatory ECG was performed before AED withdrawal and 4 months after withdrawal. Mean of the standard deviation of all filtered RR intervals for all 5 minute segments of the analyses (SDNN-i) and different power analysis were studied., HRV at the baseline did not differ significantly between the withdrawal group (n=57) and the non-withdrawal (n= 69). The SDNN-i in the withdrawal group improved significantly in patients [lt] 45 years (6.2ms, p=0.05). Apart from high frequency power the other power variables also increased after withdrawal, but not to a statistically significant extent. The heart rate variability decreased with age in both groups, but less in the withdrawal group. Interictal epileptiform activity did not significantly influence the heart rate variability., We found a significant increase in SDNN-i in the patients below 45 years after AED withdrawal. This indicates a potential positive effect of AED-withdrawal in this age group. This finding may be important in understanding the pathophysiology of SUDEP which occurs most frequently in the age group 20- 45 years., (Supported by Norwegian Foundation for Health and Rehabilitation (EXTRA FUND), The Norwegian Epilepsy-association and The Norwegian Chapter of the International League Against Epilepsy.)