True about narcolepsy:
A i.e. Sleep sudden; C i.e. Cataplexy; B i.e. Presents in IInd decadeNacrolepsyIt is a disorder most commonly present with uncontrollable sleep attacksQ in which patient abruptly falls asleep in inappropriate (eg while eating), embarrassing (eg during intercourse), and even dangerous (eg while driving) situations.Although sleep attacks have been described as brief (eg. lasting 15-20 minutes) and refreshing, this is not always true.The key features are?CataplexyQ (sudden, brief episodes of paralysis with loss of muscle tone) which occurs in most cases. Sleep paralysisQ (brief paralysis associated with onset of sleep or wakefulness)Hypnagogic hallucinationsQ (dream like experience while falling asleep but not yet asleep).It usually begins in second decade (10-20 years) Q i.e. adolescence & occurs equally in males and females.The strong genetic association with HLA DR2, specifically HLA DQB1 * 602 (>85%) suggests an autoimmune mechanism.In narcolepsy (esp. with cataplexy), Hypocretins (Orexins), the hypothalamic neuropeptide transmitter, regulating sleep-wake cycle, is decreased in brain and CSF along with the decrease in number of hypocretin-positive cells in hypothalamus.It results from defective REM sleep regulationQ. Sleep attacks & hypnagogic hallucinations are d/t REM intrusion, whereas cataplexy and sleep paralysis is atonia without REM.Diagnosis is confirmed by a sleep onset REM period (on all night PSG) or a positive MSLT in the sleep laboratory.Treatment includes:Stimulant drug eg. dexamfetamine to decrease sleepiness & frequency of sleep attacks.- Modafinil, a non amfetamine stimulant to decrease day time sleepiness with less side effects. - Clomipramine & other antidepressants to decrease cataplexy.
Sleep sudden
Presents in Ilnd decade
Cataplexy
All