1361 Improvement of Non-24-Hour Sleep–Wake Disorder with Tasimelteon in a Legally Blind Adolescent: A Case Report

Abstract Introduction Non-24-hour sleep–wake disorder (N24SWD) is a circadian rhythm disorder characterized by a progressively shifting sleep schedule that fails to align with the 24-hour day. It occurs most frequently in blind individuals who, due to a lack of environmental light stimulus, are unable to maintain a regular circadian rhythm. Tasimelteon, a melatonin-receptor agonist (MT1/MT2), is FDA-approved for treatment of N24SWD in blind adults, but data in pediatric patients remains limited. We present a case of a legally blind adolescent with chronic insomnia and actigraphic evidence of circadian dysregulation who demonstrates significant clinical improvement after initiation of Tasimelteon. Report of case(s) A 13-year-old male with a history of extreme prematurity, bilateral hearing impairment, legal blindness, and developmental delay presents with chronic sleep concerns. He previously followed neurology and had been treated for chronic insomnia with trazodone 25 mg, melatonin 5 mg, and clonidine 0.2 mg nightly. Despite this regimen, he fell asleep around 9:30–10:00 PM but experienced multiple nocturnal awakenings at 1:00 AM and 3:00 AM, achieving only ~5 hours of total sleep. Actigraphy was obtained to evaluate N24SWD. Over 5/27/21–6/7/21, average bedtime was 9:47 PM (range 6:16 PM–2:38 AM), wake time 7:56 AM (range 4:26 AM–11:12 AM), and total sleep time 8 h 55 m (range 5 h 36 m–13 h 11 m), demonstrating significant variability consistent with circadian rhythm disturbance. Melatonin timing was adjusted, and trazodone was increased to 50 mg with partial benefit. Tasimelteon was initiated in place of melatonin, followed by tapering of trazodone and reduction of clonidine to 0.1 mg. Within one week of starting Tasimelteon, the patient showed marked improvement in sleep consolidation and circadian stability, consistently sleeping from 9:00 PM to 7:00 AM (10 hours nightly). Improvements persisted, though with minor seasonal variation during school breaks. Conclusion This case highlights the potential efficacy of Tasimelteon in improving sleep continuity and achieving circadian entrainment in a legally blind adolescent with N24SWD. Tasimelteon may represent a safe and effective therapeutic option for pediatric patients with significant visual impairment and circadian rhythm disorders. Support (if any)