PURPOSE: To evaluate how insomnia is associated with seizure control and quality of life in patients with epilepsy.
METHODS: Consecutive patients with epilepsy attending clinical visits were surveyed with the Insomnia Severity Index (ISI). Patients had to be treated with at least one anticonvulsant and could not have had documented psychogenic pseudoseizure. The presence or absence of seizures and quality of life (QOLIE-P-10) within the past 4 weeks was recorded. Other variables included demographic and clinical data, sleep-wake timing, the Hörne-Östberg Morningness-Eveningness Questionnaire (MEQ), sleepiness (Epworth Sleepiness Scale (ESS), and mood (Center for Epidemiologic Studies Depression Scale, CES-D).
RESULTS: 207 patients completed surveys. 43% had clinically significant insomnia, and 51% had at least mild insomnia. 58% were seizure free. Mean ISI scores were significantly worse for those with continuing seizures, and more severe ISI scores correlated strongly with worse QOL. Younger age, shorter duration of epilepsy, use of sedative/hypnotics, medical and sleep comorbidities, delayed sleep timing and chronotype, excessive sleepiness, and depression were all associated with more severe insomnia. Those with unexpected health care visits over the most recent 4 weeks had worse insomnia. After adjustment for these covariates, more severe insomnia remained significantly associated with lack of seizure freedom and with worse QOL.
SIGNIFICANCE: Insomnia is common in epilepsy, and is associated with short term poor seizure control and worse QOL. Future studies must evaluate cause-and-effect relationships. Assessment of insomnia may be important in the comprehensive care of epilepsy and may influence control of epileptic seizures.
