Obstructive sleep apnea in epilepsy patients: the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) is a useful screening instrument for obstructive sleep apnea in a disease-specific population.
OBJECTIVE
To determine useful cutoffs on the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) in an epilepsy population.


BACKGROUND
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.


METHODS
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.


RESULTS
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%.


CONCLUSIONS
The SA-SDQ is a useful screening instrument for OSA in an epilepsy population. Our results indicate that the previously suggested cutoffs for OSA (36 for men and 32 for women) may be too high for this specific population. We suggest screening cutoffs of 29 for men and 26 for women.
Weatherwax
Kevin J
KJ
Michael S. Aldrich Sleep Disorders Center, Department of Neurology, University of Michigan Medical Center, University Hospital, 8D 8702, Box 0117, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0117, USA. kweath@umich.edu
Lin
Xihong
X
Marzec
Mary L
ML
Malow
Beth A
BA
D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000453:epidemiology; D004827:Epilepsy / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000453:epidemiology*; D011795:Surveys and Questionnaires