Abstracts

RATIONALE: Fatigue is one of the most common complaint of patients with epilepsy. Although effects of seizures on sleep structure have been studied, effects of antiepileptic drugs (AEDs) are poorly described. Many AEDs have central nervous system effects including excessive fatigue and decreased memory. This may be in part due to sleep disruption. This study was performed to examine effects of AEDs on sleep structure, using polysomnography.
METHODS: Adult patients with epilepsy treated with a single AED and admitted at the Epilepsy Monitoring Unit (EMU) of Columbia-Presbyterian Medical Center between 10/1997 and 04/2001 were included and had polysomnography recording that was scored according to the standard method. Stage 3 and stage 4 sleep were pooled as slow wave sleep. The first night in the EMU was not used in order to avoid the first night effect. Patients who were taking psychotropic drugs at the time of the recording, had a definite psychiatric diagnosis, had non-epileptic seizures or were sleep-deprived were excluded. Patients were told to go to sleep at 11 PM and were awakened at 7 am. Adult patients with epilepsy on no medication were also recorded and served as controls. Polysomnographies were performed with no seizure during the recording and no seizure in the 24 hours preceding the recording. T-test was used for statistical analysis.
RESULTS: 63 nights were recorded in 37 patients (between 1 and 5 nights per patient). All patients had localization-related epilepsy. Antiepileptic drugs were carbamazepine (CBZ), phenytoin (PHT), zonisamide (ZNS), valproate (VPA), lamotrigine (LTG) and gabapentin (GBP). Statistically significant results (p[lt]0.05)are as follows:
CBZ reduced rapid eye movement (REM) sleep (15.4%+/-4.9; controls 19.5%+/-5); VPA increased stage 1 sleep (14 %+/-8.1; controls 7.7%+/-4.4), PHT increased stage 1 sleep (14%+/-7.3 controls 7.7%+/-4.4), decreased slow wave sleep (8%+/-4.2; controls 11.1+/-4.4) and decreased REM sleep (13.5%+/-6.2; controls 19.5%+/-5); GBP increased slow wave sleep (21%+/-4; controls 11.1%+/-4.4).
CONCLUSIONS: In patients with localization-related epilepsy, CBZ disrupts sleep by decreasing REM sleep, VPA disrupts sleep by increasing stage 1 sleep, PHT disrupts sleep by increasing stage 1 sleep, decreasing slow wave sleep and decreasing REM sleep. However, GBP, LTG and ZNS do not disturb sleep significantly and GBP improves slow wave sleep. This may, in part, explain the improved tolerability of newer AEDs.
Support: Benjamin Legros received grants from the Belgian American Educational Foundation and the Commission for Educational Exchange between America, Belgium and Luxembourg.
Disclosure: Grant - Pfizer, Novartis, Elan; Consulting - Glaxo-Smith-Klein, Pfizer, Novartis, Elan, Ortho-McNeil; Honoraria - Glaxo-Smith-Klein, Pfizer, Novartis, Elan