Relationship Between Sleep Characteristics and Sudden Unexplained Death Risk in Epilepsy

Sleep disorders and disturbances are generally underestimated in patients with epilepsy. The aim of this study is to determine the frequency of sleep disturbances and the comorbidity of sleep disorders in people with epilepsy without any complaints about sleep and their relation of sudden unexplained death in epilepsy (SUDEP) risk.

Sleep complaints and the presence of sleep disorders were assessed with 4 questionnaires in 139 patients with epilepsy. Subjective sleep features were evaluated with Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Berlin Questionnaire for sleep apnea, and restless legs syndrome with International Restless Legs Syndrome Study Group (IRLSSG) severity scale. The presence of rapid eye movement/nonrapid eye movement parasomnia was asked to the patients and their relatives who share the same house. The patients' SUDEP-7 scores were also determined and associations with sleep problems were investigated statistically.

Ninety-two patients with focal and 47 patients with generalized epilepsy were evaluated after their consent. The daily sleep quality was poor in 34 (24.5%) patients with PSQI. Daily sleepiness was present in 7 (5%) patients with ESS. Twenty-five patients (18%) had severe sleep apnea risk with the Berlin Questionnaire. Mild or severe RLS was detected in 24 patients (17.2%). There were no significant differences between focal or generalized epilepsy groups' scores. No statistically significant relationship was identified between SUDEP-7 scores and sleep quality or sleep-related disorders.

Our results emphasized a remarkable magnitude of the comorbidity of sleep disorders in patients with epilepsy, even for those who do not have complaints about sleep. As SUDEP cases are frequently seen during sleep, it is important to evaluate sleep in patients with epilepsy.