The curious case of the Zzz's

Excessive daytime sleepiness is a common presenting symptom that may present a diagnostic challenge for the sleep medicine clinician. We present a case of an adolescent female with excessive daytime sleepiness and "sleep attacks" who was evaluated using a 2-week sleep log, wrist actigraphy, baseline polysomnogram, and Multiple Sleep Latency Test. Multiple Sleep Latency Test results noted a short mean sleep latency without sleep onset rapid eye movement periods, concerning for possible central disorders of hypersomnolence. However, actigraphy data noted a habitual bedtime of midnight or later, resulting in less than recommended total sleep time for her age on weekdays with extended sleep periods on the weekends. The most unique actigraphy finding was exposure to ambient light throughout most overnight sleep periods. When actigraphy results were discussed with the patient, she revealed recent onset of severe anxiety with fear of sleeping in the dark. This case highlights the importance of thorough clinical evaluation, and careful interpretation of objective tests, when evaluating for causes of excessive daytime sleepiness. Dang L, Kanney ML, Hsu DP. The curious case of the Zzz's. . 2023;19(5):1009-1012.