Narcolepsy is a disorder of impaired expression of wakefulness and rapid-eye-movement (REM) sleep. This manifests as excessive daytime sleepiness and expression of individual physiological correlates of REM sleep that include cataplexy and sleep paralysis (REM sleep atonia intruding into wakefulness), impaired maintenance of REM sleep atonia (e.g. REM sleep behaviour disorder [RBD]), and dream imagery intruding into wakefulness (e.g. hypnagogic and hypnopompic hallucinations). Excessive sleepiness typically begins in the second or third decade followed by expression of auxiliary symptoms.
- Idiopathic insomnia: Insomnia arising in infancy or childhood with a persistent, unremitting course
- Psychophysiologic insomnia: Insomnia due to a maladaptive conditioned response in which the patient learns to associate the bed environment with heightened arousal rather than sleep; onset often associated with an event causing acute insomnia, with the sleep disturbance persisting despite resolution of the precipitating factor
- Paradoxical insomnia (sleep-state misperception): Insomnia characterized by a marked mismatch between the patients description of sleep duration and objective polysomnographic findings Continue reading