Patients With Epilepsy and Obstructive Sleep Apnea Have More Frequent Seizures
A pilot study of 49 adult patients with refractory focal, generalized, or unclassified epilepsy syndromes enrolled prospectively found those with probable obstructive sleep apnea (OSA) had more frequent focal seizures. Higher risk of sudden unexplained death from epilepsy (SUDEP) also correlated with higher scores on measures of OSA.(Epilepsia:September 24, 2018.)
This study, conducted at the Mayo Clinic Epilepsy Monitoring Unit, used oxyhemoglobin desaturation index (ODI) and the Sleep Apnea–Sleep Disorders Questionnaire (SA‐SDQ) and STOP‐BAG screening tools to identify probable OSA. Information on the risk of sudden unexplained death from epilepsy (SUDEP) was also collected sing the revised SUDEP Risk Inventory (rSUDEP-7). Seizure characteristics for those with and without probable OSA were compared and analyzed to determine relationships between probable OSA, clinical features of epilepsy, and risk of SUDEP.
The mean ODI for 17 (35%) patients with probable OSA was 11.3 ± 5.1/h (range = 5.1‐22.8), and these patients were older, weighed more, and were more likely to have a focal epilepsy syndrome of longer duration than patients who did not have probable OSA (P < .05). For all patients, the median rSUDEP‐7 score was 3 ± 1.4 (range = 0‐6). Higher ODI scores positive correlated with higher rSUDEP-7 scores (P = .036), and an rSUDEP-7 score of 5 or more was associated with probable OSA using ODI score, SA-SDQ, and STOP-BAG questionnaire criteria (P < .05).
Future studies regarding presence of OSA in patients with epilepsy using polysomnography and measuring risk of SUDEP are needed to confirm whether OSA is predictive of SUDEP risk, and to examine whether probable OSA increases nighttime seizure frequency as well as overall seizure frequency and duration in a larger population.