Effects of lateralized interictal epileptiform discharges on the sleep architecture of people with epilepsy: a case-control study

Abstract

AbstractBackground: Disruption of sleep architecture occurs in patients with epilepsy, with interictal epileptiform discharge (IED) being one possible cause. IED lateralization may exert different effects on sleep architecture, and different types of IEDs may affect the sleep architecture of patients with epilepsy. Therefore, we investigated the sleep architecture of people with epilepsy to determine the effects of IED lateralization on sleep architecture.Methods: A total of 119 patients with epilepsy who sought medical attention at our hospital between March 2018 and March 2022 and 106 healthy control participants were selected for this study. Patients with epilepsy were grouped based on the IED source determined by nocturnal scalp electroencephalography as left-sided, right-sided, simultaneous bilateral, and alternating bilateral. Polysomnography was performed to compare the effects of IED lateralization on sleep architecture among the different groups. Normally distributed data were tested for differences using thettest; the Mann–Whitney U test was used to analyze data with a non-normal distribution or heterogeneity of variance. Count data were compared using the chi-squared test, and comparisons of multiple groups were performed using analysis of variance.Results: Compared with the control group, the epilepsy group showed a statistically significant decrease in the percentage of rapid eye movement (REM) sleep (R%) and REM sleep time. The left-sided and right-sided IED groups exhibited significant decreases in R%, and the left-sided IED group showed a significant decrease in REM sleep time. Multiple linear regression analysis showed that the IED index was correlated positively withcomorbid hypertension, non-REM stage 1 (N1) sleep time, and sleep latency.Conclusions: An increase in the IED index correlates positively with comorbid hypertension, N1 sleep time, and sleep latency. Therefore, a worthwhile consideration for neurologists to reduce the IED index in clinical practice is to adopt methods that include sleep improvement techniques for patients with epilepsy.