Predictors of sleepiness in epilepsy patients

Sleepiness, a common complaint of epilepsy patients, is frequently attributed to antiepileptic medications. To determine predictors of subjective sleepiness in epilepsy patients, we gave self-administered, validated surveys of sleepiness [Epworth sleepiness scale (our major outcome measure)] and sleep apnea [sleep apnea scale of the sleep disorders questionnaire (SA/SDQ)] to 158 epilepsy patients and 68 neurology patients without epilepsy (controls). An elevated Epworth score (>10) was more likely in epilepsy patients compared to controls after controlling for age and gender (p < 0.05). When Epworth scores were adjusted for SA/SDQ scores and restless legs symptoms (RLS), however, epilepsy patients showed only a nonsignificant trend toward elevated Epworth scores compared to controls (p = 0.08). SA/SDQ scores (p < 0.005) and RLS (p < 0.007) were significant predictors of elevated Epworth score in both epilepsy patients and controls. Among the epilepsy patients, the number or type of antiepileptic medication, seizure frequency, epilepsy syndrome (partial vs. generalized), and the presence of sleep-related seizures were not significant predictors (p > 0.10) of elevated Epworth score. Before attributing sleepiness in epilepsy patients to antiepileptic medications or uncontrolled seizures, clinicians should consider the possibility of a coexisting sleep disorder.