0666 Idiopathic Hypersomnia in the Sleep Apnea Population

Abstract Introduction Hypersomnia in OSA can have a significant impact on patient’s quality of life. While hypersomnia tends to improve with treatment, there remains a portion of patients where this persists. This can often be attributed to inadequately controlled OSA, however the prevalence of idiopathic hypersomnia (IH) within the adequately treated OSA population remains unknown. With the emergence of new management strategies for IH, this becomes important to assess. We aim to evaluate the prevalence of patients with adequately treated OSA at risk for idiopathic hypersomnia using the idiopathic hypersomnia severity scale. Methods Surveys were administered to patients with OSA on CPAP demonstrating compliance of at least 80%. Surveys included IHSS, insomnia severity scale (ISI) and Epworth sleepiness scale (ESS). Patients were included if they used CPAP 6h/night, had an ISI 14, no prior diagnosis of central hypersomnia and not on stimulant medication. IHSS 22 was considered high risk for IH based on prior validation studies. Results 54 patients met inclusion criteria; 7 (13%) were high risk for IH, 4 (57%) of which had ESS 10. Age, sex, race, ethnicity and CPAP use were similar between high and low risk patients. Patients with IHSS22 (high risk) had significantly higher BMI (p 0.05). Conclusion Of patients who have adequately controlled OSA and are compliant with CPAP, our data suggests that 13% of them may be at high risk for idiopathic hypersomnia. Of these patients 57% of them would not have been identified using ESS alone. This may be related to the symptom specific questions included on the IHSS such as those related to sleep inertia, total sleep time etc. While further testing with PSG/MSLT is needed to confirm a diagnosis of IH, which is currently being offered to the high risk patients, this preliminary data suggests that increased screening for IH in this population may be beneficial. Support (if any)