1145 Excessive Daytime Sleepiness in a Child With a History of Henoch-Schonlein Purpura

Abstract

Introduction: Narcolepsy type-1 can have a genetic association with HLA subtypes, but case reports suggest there are other precipitating factors including head trauma, sustained sleep deprivation and infections. Studies have also linked narcolepsy onset to elevated anti-streptococcal antibodies, H1N1 influenza infections and H1N1 vaccines leading to an autoimmune response. Report of Case: We describe a 10-year-old patient with a history of Henoch-Schonlein Purpura (HSP) presenting to the sleep medicine clinic for consultation of excessive daytime sleepiness. Symptoms began after she developed HSP at five-years-of-age and became more apparent after her second HSP episode. Sleep history revealed she slept for 18-hours per-day (including 5 hours of daytime naps). She also described cataplexy-like events where she collapsed from her knees giving out, suddenly dropped items in her hand and had staring spells in class. Additionally, she had symptoms suggestive of hypnogogic sleep paralysis and hallucinations with reports of hearing voices throughout the day. Work-up included actigraphy, overnight polysomnography (PSG), and multiple sleep latency test (MSLT). Overnight PSG revealed a diagnosis of mild obstructive sleep apnea. MSLT showed sleep during 2-of-4 naps with sleep-onset REM periods (SOREMs) during both naps. Despite a prolonged mean sleep latency (16-minutes) on MSLT, she had two SOREMs (diagnostic of narcolepsy) and a sleep latency of 5-minutes on the overnight PSG. She also underwent EEG and MRI, both of which were normal. Conclusion(s): It can be challenging to evaluate the degree of sleepiness in children as they are less likely to fall asleep during an MSLT. But our patients" symptoms of atypical cataplexy, sleep paralysis and hypnogogic hallucinations with 2 SOREMs may suggest an atypical presentation narcolepsy-type-1 secondary to HSP. Both diseases are suggested to have an autoimmune mediated process and to our knowledge this is the first case report linking these two disease processes.