Sleep organization in children with partial refractory epilepsy

Although it is currently known that sleep can influence epilepsy and epilepsy can influence sleep organization, few data have been published on this mutual interaction concerning the pediatric population. The objective of this study was to verify the eventual presence of sleep alterations in children with partial refractory epilepsy. Seventeen patients with partial refractory epilepsy were submitted to whole-night polysomnography as part of their epilepsy investigation. Polysomnographic recordings were performed on a digital video-electroencephalography (EEG) system and consisted of the registration of EEG (24 channels), electro-oculogram, electromyogram, electrocardiogram, and nasal airflow and abdominal respiratory movements. Sleep stages were visually scored following standard criteria, and ictal events were classified according to the international classification of seizures. The patients were also subdivided into two subgroups based on the presence or absence of ictal episodes during the recording night. The results concerning sleep organization were compared with those obtained from a normal control group. The analysis of the sleep parameters showed a reduction of total time in bed and total sleep time in both subgroups of epileptic children; there was a higher number of stage shifts per hour in the control group than in both epileptic subgroups. The percentage of stage 2 shifts is significantly reduced in patients with epilepsy and seizures during the night and the percentage of stage 3 to 4 shifts is increased. Nonsignificant differences are evident for the number of awakenings per hour and the percentage of stage 1 shifts. The percentage of rapid eye movement (REM) sleep is reduced, and first REM latency is increased in both epileptic subgroups, compared with normal controls, without statistical significance. Nine of 17 patients had seizures during the polysomnographic recording; nocturnal ictal events occurred mostly during non-REM sleep stage 2. Our results show that patients with partial refractory epilepsies have only mild sleep structure abnormalities, and this can be considered as an effect of the epileptic syndrome per se or as a result of the chronic antiepilepsy drug treatment.