HEART-RATE-VARIABILITY IN PATIENTS WITH EPILEPSY

Autonomic function was studied by the use of spectral analysis of hear t-rate variability in patients with epilepsy in relation to type of ep ilepsy and anti-epileptic drug therapy. A total of 21 patients with ju venile myoclonic epilepsy (JME) and 21 with temporal lobe epilepsy (TL E) were included; 18 patients were treated with carbstmazepine (CBZ), 16 with valproate (VPA) and seven with phenytoin (PHT). One healthy dr ug free control, matched for age and sex, was selected for each patien t. Patients and controls underwent an ambulatory 24 h EKG. Heart-rate variability was analyzed in time and frequency domains. Patients with TLE had significantly lower S.D. of the RR-intervals, lower low freque ncy power and a lower low frequency/high frequency power ratio than th eir controls. A lower low frequency/high frequency power ratio was the only significant difference between the JME patient group and their c ontrols. Treatment. however, may have had a considerable influence on the hear? rate Variability in the epilepsy patients. Patients on CBZ h ad significantly lower S.D, of RR-intervals, low frequency power and a low frequency/high frequency power ratio than did their matched healt hy drug free controls. The ratio of low frequency/high frequency power was also lower in patients on VPA compared with their controls, but a part from that no differences could be demonstrated between this treat ment group and the controls. In conclusion, patients with epilepsy app ear to have an altered autonomic control of the heart, with a reductio n in some heart-rate variability measures, suggesting a decreased symp athetic tone, which may be related to the drug therapy or the epilepsy as such. Further studies are warranted to explore these changes and t heir possible relevance for sudden death in epilepsy. (C) 1998 Elsevie r Science B.V. All rights reserved.