Which of the following is the most impoant pa of brain involved in Narcolepsy
High-Yield Explanation
Answer is B (Hypothalamus): Narcolepsy in humans is caused by deficiency of hypocretin (Orexin) a neurotransmitter produced in the Hypothalamus. Recently several convergent lines of evidence suggest that the hypothalamic neuropeptide hypocretin (orexin) is involved in the pathogenesis of Narcolepsy'- Harrison's 181h/220 Narcolepsy Narcolepsy is a common sleep disorder charachterized by excessive daytime sleepiness, cataplexy (episodes of muscle weakness triggered by emotions), hypnagogic hallucinations and sleep paralysis. Narcolepsy (classic Tetrad) Excessive day Time somnolence Sudden weakness or loss of muscle tone without loss of consciousness often elicited by emotion (cataptexy) Hallucination at sleep onset (Hypnagogic Hallucination) or upon awakening (Hypnopompic Hallucination) Muscle Paralysis upon awakening Pathology /Pathogenesis Most impoant cause of narcolepsy is believed to be deficiency of neuropeptide Hypocretin (orexin) produced in Hypothalamus Autoimmune All narcoleptics with cataplexy are positive for HLA DQBI (0602)