Narcolepsy

Narcolepsy is a chronic disorder of wakefulness in which the boundary between being awake and entering sleep becomes unstable. In narcolepsy type 1, loss of orexin, also called hypocretin, signalling removes an important stabilizer of the wake state. Wakefulness can then be interrupted by irresistible sleep, while REM-related features can intrude into the transition between waking and sleeping. The finding that most strongly changes the nurse’s clinical suspicion is excessive daytime sleepiness accompanied by cataplexy. Cataplexy is a sudden, brief loss of voluntary muscle tone triggered by emotion such as laughter, surprise, anger, or excitement. The patient may buckle at the knees, drop the jaw, slur speech, or lose head and neck control while remaining conscious and able to recall the event. The muscles become temporarily unavailable; the patient has not necessarily lost awareness. Other REM-related symptoms include sleep paralysis on falling asleep or waking and vivid hallucinations at those transitions. Night-time sleep may be fragmented, so a patient can sleep for an apparently adequate number of hours and still be dangerously sleepy the next day. Narcolepsy type 2 causes...