0741 Diagnosing Narcolepsy Type II in the Active Duty Population

Abstract

Abstract Introduction: Introduction There is a high prevalence of sleep disturbances in U.S. military personnel which can significantly impact continued military service. Narcolepsy is a rare sleep disorder and testing results are often variable, especially when cataplexy is absent. Given the high incidence of confounding sleep disorders in military personnel, including insufficient sleep duration and sleep-disordered breathing, a narcolepsy diagnosis may be even more challenging. As this diagnosis is often incompatible with continued military service, extra attention should be given to confounding diagnoses in military personnel. Methods This is a retrospective study of patients aged 18-65, who were diagnosed with narcolepsy type 1 or type 2 at an outside location and subsequently underwent repeat evaluation at our facility. Polysomnography, actigraphy, and multiple sleep latency test results from the time of the original diagnosis, if available, and repeat evaluation were reviewed. The initial diagnosis was compared to the results of repeat testing and the prevalence of narcolepsy vs. another sleep disorder was assessed. Results Two of twenty-three patients retained a diagnosis of narcolepsy on repeat testing. 10 patients were diagnosed with insufficient sleep syndrome (&lt 7 hours sleep/night), 5 displayed significant circadian misalignment (including irregular sleep/wake periods or delayed sleep phase), and 8 were diagnosed with mild obstructive sleep apnea. 7 of the 8 OSA patients had supine predominate OSA, which may have contributed to not being diagnosed on initial testing. The average total sleep time of the group was 6 hours and 49 minutes, consistent with insufficient sleep duration. Conclusion Narcolepsy type 1 and type 2 are exceedingly rare disorders with diagnostic test results that may be influenced by the presence of other common sleep disorders. In this study, re-evaluation resulted in a changed diagnosis in 91 percent of patients, emphasizing the importance of ruling out these confounding diagnoses. Support