Abstracts

Rationale: Various studies have reported increased prevalence of sleep disorders and daytime sleepiness in patients with epilepsy. Studies have also suggested that patients with epilepsy have macrostructure sleep abnormalities. These include increased arousal indices, increased sleep onset latencies, fragmented or reduced REM sleep, increased stage shifts and increased N1 sleep and decreased N2 and N3 sleep in epilepsy patients compared to controls. Most of these studies focused on school aged and teenaged children. However, there is limited data in pre-school aged children with epilepsy. Methods: We reviewed records of patients with epilepsy who had normal polysomnography. We selected an age matched control group from patients who also had normal polysomnography in our sleep lab. We excluded children with neurological disorders from the control group. The patients and controls were divided into two groups based on their ages: P (preschool aged): 1-5 years; S (school aged): 5 or more years. Fifteen of the epilepsy patients had focal epilepsy, 6 had generalized epilepsy and 3 patients had unknown type of epilepsy. We compared sleep efficiency, % time for stages REM, N1, N2 and N3; arousal indices and sleep latencies on polysomnography of the epilepsy patients with the control group. Results: We analyzed 24 epilepsy patients and 24 controls. The group P had 7 patients and the group S had 17 patients aged 3 1.5 and 10.8 3.6, respectively. The patients in the control group were aged 2.9 1.3 and 11 3.6, respectively. There was no statically significant difference between the ages in the epilepsy and the control groups. [p =0.89 and 0.87 respectively] For the group P, there was a significant difference in the onset latencies between the epilepsy and the control groups. [Group P: 15.6 34; Control group: 65.5 36.1; p =0.017] For the group S, there was a significant difference in the arousal indices between the groups. [Group S: 6.8 1.8; Control group: 4.8 1.4; p =0.001] When analyzing all ages together with the control group, we found that the arousal indices were significantly higher for epilepsy patients [p =0.002]. We did not find significant differences for the other parameters. [Table 1] Conclusions: In our study, we found that older children with epilepsy have significantly higher arousal indices when compared with age matched controls without neurological disorders. In addition, younger children with epilepsy have significantly prolonged sleep latencies, but have no significant change in arousal indices. We did not find significant differences for the other parameters. Our data suggest that patients with epilepsy are prone to have sleep onset and sleep maintenance problems which could be contributing to daytime sleepiness in these patients. Further study is needed to address this issue.