Daytime sleepiness and changes of sleep architecture in patients with epilepsy

The relationship between epilepsy and sleep has been known for many years. Yet is still not well understood because of it's reciprocal and intrinsic influences. Epileptic manifestations during sleep may lead to fragmentation of sleep stages. On the other hand insomnia or other sleep disorders may cause sleep deprivation and increase number of epileptic seizures in patients with epilepsy. The study is designed to compare daytime sleepiness and architecture of sleep in patients with epilepsy and control subjects. We tried to evaluate factors that have influence on sleep architecture of patients with epilepsy.

We evaluated the daytime sleepiness through a certain type of questionnaire called Epworth Scale of Sleepiness (ESS). The questionnaire was filled out by patients with epilepsy (83 patients) and a group of healthy controls (80 persons). Furthermore we evaluated the quatity of night sleep in both groups using polysomnograph (electroencephalography - EEG, electrooculography - EOG, electromyography - EMG). Sleep stages were scored according to Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects (Rechtschaffen, Kales, 9). Multiple sleep latency test (MSLT) was performed in the group of patients with epilepsy in order to objectivise daytime sleepiness.

Measuring by Epworth scale of sleepiness we found out that the patients with epilepsy suffered from a significantly higher daytime sleepiness than the healthy controls. Patients with epilepsy also experienced significant changes in sleep architecture, the reduction of NREM S3, S4 and REM stages and the increase of NREM S2 stage. These changes were not related to used antiepileptic medication.