Frequency of obstructive sleep apnea syndrome among patients with epilepsy attending a tertiary neurology clinic

Objectives: Epilepsy is a common neurological disorder with a median lifetime prevalence of 14 per 1000 subjects. Sleep disorders could influence epileptic seizure. The most common sleep disorder is obstructive sleep apnea syndrome (OSAS) which occurs in 2% of adult women and 4% of adult men in the general population. The aim of this study is to estimate the frequency of OSAS among patients with epilepsy and to study the seizure characteristics among those patients with co-morbid OSAS. Methods: Patients with a confirmed diagnosis of epilepsy who attended the Sultan Qaboos University Hospital neurology clinic were recruited for the study between June 2011 and April 2012. Patients were screened for OSAS by direct interview using the validated Arabic version of the Berlin questionnaire. Patients identified as high-risk underwent polysomnography. Results: A total of 100 patients with epilepsy (55 men and 45 women) were screened for OSAS. Generalized and focal seizure was found in 67% of male and 27% of female patients. Six percent of the participants had epilepsy of undetermined type. Only 9% of the sample was found to have high risk of OSAS based on the Berlin questionnaire. No significant correlation was found between risk of OSAS, type of epilepsy, and anti-epileptic drugs. Conclusion: The risk of OSAS was marginally greater in patients with epilepsy compared to the general population with the overall prevalence of 9%.