Sleep-wake pattern, chronotype and seizures in patients with epilepsy

Although mounting evidence suggests that sleep and epilepsy are reciprocal and seizures influence circadian rhythms, sleep-wake pattern and seizure control have not been widely researched. This study aimed to investigate the association of sleep-wake pattern, sleep quality, and chronotype with seizures in patients with epilepsy (PWE).

160 consecutive PWE (aged 20-49 years, focal epilepsy, FE: generalized epilepsy, GE=127:33) and 130 age-gender matched healthy controls (HC) were enrolled. All subjects completed a sleep diary for more than 2 weeks, Pittsburgh Sleep Quality Index (PSQI), Epworth sleepiness scale (ESS), and the Morningness-Eveningness questionnaire (MEQ). Detailed seizure history was reviewed for the last 1 year.

Sleep-wake patterns on workdays were different between PWE and HC (p<0.001), although PSQI, ESS, and MEQ did not differ. Social jetlag (difference of mid-sleep time between workdays and free days) was more evident in PWE (1.4h) than HC (0.7h, p<0.001). GE showed lower MEQ, later mid-sleep time on both workdays and free days, and larger social jetlag than FE. Higher seizure frequency was positively correlated with higher PSQI and ESS after adjusting for age, gender, and number of antiepileptic drugs (p<0.05). PWE with lower MEQ presented worse sleep quality.

Contrary to HC, PWE maintained sleep-wake patterns more regularly during workdays and free days. GE patients reported more eveningness-preference; however, their sleep quality was not worse than FE. Although sleep quality may affect seizure frequency, sleep-wake patterns and chronotype were not related to seizures in PWE.