1248 A case of delayed onset posttraumatic sleepiness

Abstract

Introduction: We report a case of delayed onset narcolepsy with cataplexy secondary to head trauma Report of Case: A 12-year-old boy sustained a fall from his bicycle in May 2009. He fell on his face and had loss of consciousness for a few minutes. He subsequently developed problems with headache, anosmia, loss of emotion and loss of memory for about 8 months. In 2010, he was diagnosed to have ADHD and was initiated on Ritalin. In early, 2011 he developed symptoms of aggressive behavior, hyperphagia, possible hypersexuality, hypersomnia for 18 hours daily, cataplexy, hypnagogic hallucinations and sleep paralysis. Multiple Sleep Latency Test revealed latency of 1.2 min, sleep onset REM in every nap. HLA typing for DQB1*0602 subtype was positive. Hypocretin levels in the CSF were undetectable. He was diagnosed to have Narcolepsy and treated with Modafinil. With stimulant medications, he experienced worsening aggressive behavior and psychosis. These were discontinued and he was then initiated on Sodium Oxybate with significant improvement in daytime sleepiness. Conclusion(s): Symptomatic narcolepsy with cataplexy is a rare condition. Its association with symptoms like aggressive behavior and hyperphagia is even rarer, and implies hypothalamic dysfunction beyond that seen in idiopathic narcolepsy. Etiology and pathogenesis of posttraumatic sleepiness are unclear. Lesions in the wake promoting brain areas might contribute to sleepiness after traumatic brain injury. Absent CSF hypocretin supports a mechanism of neuronal loss in the hypothalamus related to injury. Positive HLA typing suggests an autoimmune etiology. Autoimmune mediated cell loss could explain the delay between injury and onset of presentation. Traumatic brain injury could facilitate immune cell entry to the brain by disruption of bloodbrain barrier. Stimulation of the immune system could trigger narcolepsy by activating dormant T cell clones.