COVID-19-Induced Narcolepsy Type I With Cataplexy: A Short Report.

Narcolepsy type I is a rare neurological sleep disorder characterised by chronic excessive daytime sleepiness, cataplexy, and low orexin (hypocretin) levels. Infection with SARS-CoV-2 has been linked to neurological and neuropsychiatric sequelae, but cases of post-COVID narcolepsy remain extremely uncommon. We report a previously healthy 42-year-old Caucasian female who developed excessive daytime sleepiness, cataplexy, and hypnagogic/hypnopompic hallucinations within 3 months of confirmed SARS-CoV-2 infection. Polysomnography (PSG) showed disturbed nocturnal sleep with a high arousal index and periodic limb movements and mild sleep apnea, while the multiple sleep latency test (MSLT) showed a mean latency of 1 min with sleep-onset rapid eye movement (REM) periods in all naps. Cerebrospinal fluid hypocretin was markedly reduced (< 40 ng/L), confirming narcolepsy type I. Following the diagnosis, medical treatment was initiated-with methylphenidate for hypersomnolence followed by venlafaxine for cataplexy, which led to a substantial symptomatic improvement, enabling a return to daily functioning. The case contributes to the minimal literature on narcolepsy following COVID-19 and supports hypotheses of autoimmune-mediated destruction of hypocretin-producing neurons triggered by viral infection. Clinicians should maintain a high index of suspicion for primary sleep disorders in patients with persistent fatigue and hypersomnolence after COVID-19, as early recognition and targeted treatment markedly improve outcomes.