['To determine useful cutoffs on the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) in an epilepsy population.', 'Epilepsy and obstructive sleep apnea (OSA) frequently coexist, and treating OSA in epilepsy patients may reduce seizure frequency and improve daytime sleepiness. The SA-SDQ, a 12-item validated measure of sleep-related breathing disorders, may be a useful tool to screen epilepsy patients for OSA, although appropriate cutoff points have not been established in this population. Previously suggested SA-SDQ cutoff points for OSA in a non-epilepsy population were 32 for women and 36 for men.', 'One hundred twenty-five subjects with epilepsy undergoing polysomnography completed a survey about their sleep, including the 12-item SA-SDQ scale. Receiver-operating characteristics curves were constructed to determine optimal sensitivity and specificity.', 'Sixty-nine of the 125 subjects (45%) had apnea-hypopnea indices greater than five, indicating OSA. The area under the curve was 0.744 for men and 0.788 for women. For men, an SA-SDQ score of 29 provided a sensitivity of 75% and a specificity of 65%. For women, an SA-SDQ score of 26 provided a sensitivity of 80% and a specificity of 67%.'] Is obstructive sleep apnea in epilepsy patients : the Sleep Apnea scale of the Sleep Disorders Questionnaire ( SA-SDQ ) a useful screening instrument for obstructive sleep apnea in a disease-specific population?