Abstracts

Rationale: Obstructive sleep apnea (OSA) is a highly prevalent, often overlooked, comorbidity in people with epilepsy (PWE). Positive airway pressure (PAP) therapy improved seizure control in retrospective series with short follow-up. Methods: We investigated the effect of PAP therapy on long-term seizure outcomes in adults with epilepsy who underwent polysomnography (PSG) at Cleveland Clinic (1997-2015). Seizure outcomes were compared from baseline to 1, 3 and 5 year post diagnostic PSG in patients without OSA (apnea-hypopnea index [AHI] 4 hr use >70% nights) was ascertained by device download. Seizure outcomes included mean % seizure reduction, =50% seizure reduction from baseline (%, responder rate), and = 50% seizure reduction or seizure free at both baseline and follow up (%, successful outcome). Seizure data were obtained from an electronic data entry system for patients and providers. Treatment groups were compared univariably and multivariably using logistic regression adjusting for factors associated with seizure outcome. Results: 197 subjects (age 43.9±14.8 years, 58% female, monthly seizure frequency 0[0.00, 1.00], 54% seizure free at baseline) were included. Mean follow-up was 5.4 ±4 years and 40% were followed for 5 years. 122 (62%) subjects had OSA including 73 (60 %) on PAP therapy (73% adherent) and 49 (40%) untreated. No OSA subjects were younger (37.7 years vs. 48/48), more likely to be female (78% vs. 44/51), and had lower BMI (27.5 vs. 34.6/31.1) than PAP-treated and Untreated OSA (p=0.001). Responder rate at 1 year was greater in PAP-treated (63%; p=0.001) and No OSA (44%; p=0.11) than Untreated OSA (14%). Successful outcome was achieved more often in PAP-treated (85%) than Untreated OSA (55%; p= < 0.001) or No OSA (65%; p=0.007) groups. After adjusting for baseline seizure freedom and AED standardized dose, PAP-treated OSA remained more likely to be successful than Untreated OSA (p < 0.001) and No OSA (p=0.009). No significant differences were found at other time points. Conclusions: This largest-to-date series found better 1-year seizure outcomes in PWE and PAP-treated OSA compared with Untreated OSA and No OSA, expanding existing literature supporting the impact of sleep therapies on seizure control in PWE. Funding: None