Abstracts

Rationale: The aim of this study was to evaluate the coexistence and features of obstructive sleep apnea (OSA) in cryptogenic epilepsy patients compared to non-cryptogenic epilepsy patients (those with primary generalized and symptomatic epilepsy). Previous studies have documented the increased presence of OSA in various types of epilepsy patients but no study has specifically evaluated the cryptogenic population.Methods: Adult patients from the University of Pennsylvania Epilepsy Center and the General Neurology Clinic were given three validated questionnaires to evaluate their risk for OSA and sleepiness. These were the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ), the Multivariable Apnea Predication Index (MAP), and the Epworth Sleepiness Scale (ESS). These scores were used as measures of OSA risk. The formal diagnosis of OSA was also used in categorizing the patients.Results: In the unadjusted analysis, those with cryptogenic epilepsy were more likely to have previously diagnosed OSA or a high risk for OSA than non-cryptogenic epilepsy patients (40% vs 20%, p=0.04). This was most likely due to be due to a difference in BMI, as the cryptogenic group was noted to have higher BMIs. In the multivariate analysis, only BMI and age were associated with high OSA risk in the group studied (p<0.05).Conclusions: In the cryptogenic epilepsy group, OSA risk was greater than in the non-cryptogenic epilepsy group. This risk is even higher than what has previously been estimated for the general epilepsy population. This has broad implications for treatment. Cryptogenic epilepsy patients often lack treatment options such as resective epilepsy surgery or vagal nerve stimulator implantation. Reduction of BMI and treatment of sleep apnea may uniquely help this population achieve better seizure control.