DIAGNOSIS: Narcolepsy. In narcolepsy, the transition from wakefulness to sleep is short (< 5 minutes) and abrupt due to deficient hypothalamic production of hypocretin. Hypocretin promotes gradual closure of wake centers and their production of arousal neurotransmitters such as norepinephrine and acetylcholine. In humans, the diagnosis Is confirmed by performing a polysomnogram and multiple sleep latency test. CSF levels of hypocretin are low, a finding that is not specific for narcolepsy, but helpful in ruling out other conditions.