Abstracts

Rationale: Sleep disturbance was reported to be approximately 3-times more common in epilepsy patients than in the general population. The role of comorbidity, however, which is frequently accompanied itself by sleep disturbance, has not been investigated so far. The aim of the current study was to assess sleep disorders and circadian rhythm in epilepsy patients in whom relevant comorbidity was carefully excluded. Methods: A total of 200 consecutive patients (100 with generalized seizure onset, 100 with partial seizure onset; median age: 35 (18-74) years; median age at epilepsy onset: 17 (0-59) years) without relevant psychiatric, neurological or internal comorbidity were recruited at the outpatient epilepsy clinic of Innsbruck Medical University between November 2012 and November 2013. They were compared to 100 sex- and age-matched controls (median age: 33.5 (18.0-74.0) years). All participants underwent a comprehensive structured sleep questionnaire. This questionnaire contained specifically tailored questions to address the association between epilepsy and sleep disturbance, and validated questionnaires aiming at sleep quality (Pittsburgh Sleep Quality Index), excessive daytime sleepiness (Epworth Sleepiness Scale), circadian rhythm (Munich Chronotype Questionnaire), sleep disorders (Munich Parasomnia Scale, Innsbruck REM sleep behavior disorder Inventory), and quality of life (QOLIE-31). Results: Forty-one percent of epilepsy patients (82/200) reported on acute effects of epileptic seizures on the sleep wake rhythm: 82 patients (41.0%) indicated that nocturnal seizures resulted in increased sleepiness on the following day, 32 patients (16.0%) reported on the necessity of an immediate nap following a diurnal generalized seizure, and 10 patients (5.0 %) complained on disturbed nocturnal sleep after diurnal generalized seizures. In contrast to these direct influences of seizures on nocturnal sleep and daytime sleepiness, rates of chronically poor sleep, excessive daytime sleepiness, and lifetime prevalence of sleep disorders did not differ between epilepsy patients and controls (all p values n.s.). Apart from earlier sleep times on work days (p=0.001) and free days (p=0.008) in epilepsy patients, circadian variables were similarly distributed. Epilepsy was well controlled with 76% being seizure free for ≥1 year. Patients with generalized and partial epilepsies did not differ in rates of poor sleep, excessive daytime sleepiness, and sleep disorders (all ps n.s.) Sleep times on free days were longer in patients with generalized than patients with partial epilepsies (p=0.012). Conclusions: This large case-control questionnaire study revealed that seizures have an impact on acute sleep disturbances, whereas chronic sleep disorders are not more common in well-controlled epilepsy patients without relevant comorbidity than in healthy controls. This supports the notion that not epilepsy itself but insufficient seizure control as well as comorbidity are main contributors to sleep disorders in epilepsy.