Abstracts

RATIONALE: Anticonvulsant drugs are known to have both detrimental and beneficial effects on sleep, which can have important implications for both seizure control and optimal daytime functioning of patients with epilepsy. Phenobarbital, phenytoin, and carbamazepine may all decrease REM sleep, and gabapentin can increase slow wave sleep. There is relatively little information, however, regarding potential effects of the newest anticonvulsants, including levetiracetam (LVT) on sleep. We performed overnight polysomnograpy on patients with intractable epilepsy who were taking LVT, and compared sleep to similar patients who were taking no anticonvulsant drugs.
METHODS: Consecutive patients with localization-related epilepsy (based on history, interictal and ictal recordings) admitted for video-EEG monitoring were included. Control patients were taking no anticonvulsant drug. Patients taking LVT had to be taking at least 1000 mg/day, and have been on the drug at least 24 hours. If drugs were previously stopped, levels were less than half the minimal therapeutic dose (based on known half-life of the drug). Patients who had non-epileptic seizures or sleep disorders, were sleep-deprived, or were taking psychotropic drugs were excluded. Caffeine were not allowed. No patient had complex partial or secondarily generalized seizures during the recording or for at least 24 hours before. Polysomnography was scored in 30-second epochs, according to standard technique, by reformatting digital EEG to polysomnographic channels and parameters. Sleep efficiency was calculated as percentage asleep from sleep onset until awakening. The initial night of recording was not used in the analysis, however patients adhered to the sleep schedule on that night. All results were compared to control patients, using t-test.
RESULTS: Seven studies were performed in four patients taking LVT (1-2/patient). LVT dose was 1000-2750 mg/day (average 1792). Age was 20-37 (mean 26). A subset of control patients in the same age range were chosen (range 25-36; mean 31); this included 16 studies in 10 patients (1-2/patient). All results are LVT vs. control, +/-SEM. Total sleep time was similar (466 +/-11 vs 443+/-16 min). Stage 1 sleep was 7.7 +/- 1.9 vs 6.0=/-1.1%. Slow wave sleep was 14.7+/-1.6 vs 12.7+/-1.1%. REM was 22.1+/-1.1 vs 18.8+/-1.2%. Sleep efficiency was 97+/-1 vs 96+/-1. REM latency was 88+/-24 vs 112+/-17 min. None of these differences were statistically significant.
CONCLUSIONS: In this study, there were no significant differences in sleep parameters between patients taking therapeutic doses of LVT in monotherapy when compared to similar patients taking no drug. Patients taking LVT showed slight increases in slow wave sleep and REM sleep, and decreases in REM latency. Although the number of patients is small, this study has the advantage of examining effects in monotherapy and with confirmed absence of seizures, which are known to adversely affect sleep. The results suggest that LVT has no detrimental effects on sleep parameters in patients with epilepsy, and there may actually be improvements in essential sleep. These results will need to be confirmed in a larger group of patients.
(Disclosure: Consulting - UCB Pharma, Pfizer, Novartis, Honoraria - UCB Pharma, Pfizer, Novartis)