1351 Secondary Narcolepsy After Electrocution and Chronic Pain: Insights into Sleep-Wake Dysregulation After a Decade of Diagnostic Delay

Abstract Introduction Excessive daytime sleepiness (EDS) is frequently attributed to sleep-disordered breathing, yet narcolepsy, particularly secondary narcolepsy after traumatic brain injury (TBI) is often overlooked. High-voltage electrocution can damage hypothalamic orexin-producing neurons, impairing sleep-wake regulation. Chronic pain further contributes to sleep fragmentation and non-restorative sleep. We present a case of secondary narcolepsy diagnosed more than a decade after severe electrocution, despite multiple prior sleep studies focused primarily on obstructive sleep apnea (OSA). Report of case(s) A 73-year-old male with a history of 2,300-V electrocution (in 2001) and chronic diffuse pain reported worsening daytime sleepiness and fatigue. He had undergone 4-5 prior sleep studies, including a 2006 PSG showing mild, position-dependent OSA (AHI 3.8 overall; 6.4 supine). A more recent PSG demonstrated nocturnal hypoxemia (SpO₂ ≤88% for 40 minutes) but did not explain persistent symptoms. Extensive evaluation for chronic dyspnea and fatigue-including cardiology workup and intervention did not yield improvement. In 2025, the patient completed a two-week sleep diary followed by polysomnography (PSG) and multiple sleep latency testing (MSLT). The 2025 MSLT demonstrated a mean sleep latency of 7.5 minutes with two sleep-onset REM periods (SOREMs), consistent with secondary narcolepsy without cataplexy (Narcolepsy Type 2). The accompanying PSG showed no clinically significant OSA. After more than 10 years of hypersomnolence, chronic pain, and repeated diagnostic evaluations focused on OSA, the patient was finally diagnosed with narcolepsy. Conclusion This case highlights the importance of considering secondary narcolepsy in patients with a history of electrocution or TBI, particularly when chronic pain and persistent EDS co-exist. Early use of PSG, followed by MSLT may prevent years of functional impairment and diagnostic delay. Increased awareness of narcolepsy in post-injury populations is essential for timely identification and treatment. Support (if any)