Development of Narcolepsy Type 1 Following COVID-19 Infection in a Patient Previously Diagnosed With Idiopathic Hypersomnia: A Case Report.

Narcolepsy type 1 is a rare sleep disorder characterized by excessive daytime sleepiness (EDS) and cataplexy, thought to result from the immune-mediated destruction of hypocretin-producing neurons in genetically susceptible individuals. Viral infections have been implicated as potential environmental triggers. We present the case of a 17-year-old female National Collegiate Athletic Association (NCAA) Division I student-athlete with a prior diagnosis of idiopathic hypersomnia who developed new-onset cataplexy following COVID-19 infection. Initial polysomnography and multiple sleep latency testing demonstrated severe hypersomnolence without sleep-onset rapid eye movement periods. Several months later, she developed emotionally triggered episodes of muscle weakness consistent with cataplexy. Repeat multiple sleep latency testing demonstrated only one sleep-onset rapid eye movement period; however, given the development of typical cataplexy and the overall clinical presentation, a clinical diagnosis of narcolepsy type 1 was made. Cerebrospinal fluid hypocretin testing was not performed. Symptoms were refractory to multiple stimulant and antidepressant regimens but responded well to sodium oxybate in combination with solriamfetol, resulting in the resolution of EDS and cataplexy. This case highlights a possible temporal association between COVID-19 infection and the subsequent development of narcolepsy type 1 and underscores the importance of clinical judgment when objective diagnostic testing is inconclusive.