Parasomnias are undesirable physical events or experiences that occur during entry into sleep, within sleep, or during arounsals from sleep.

Parasomnias encompass abnormal sleep-related movements, behaviors, emotions, perceptions, dreaming, and autonomic nervous system functioning. They involve sleep-related behaviors and experiences over which there is no conscious control, and therefore, can result in injuries, sleep disruption, or adverse health and psychosocial effects which can affect the patient, the bed partner or both. Parasomnias often involve complex, seemingly purposeful, and goal-directed behaviors which presumably are performed with some personal meaning to the individual at the time. Generally, parasomnias occur during either non-REM (light to deep) sleep or REM (dream) sleep.


Confusional arousals
consist of confusion during and after arousals from sleep, most typically from deep sleep during the first part of the night. The patient may appear to be awake during some or most of a confusional arousal, but usually is disoriented in time and space, slow of speech and responds poorly to suggestions or commands. Repeated confusional arousals are most universal in children before the age of 13 and become less common with age.

Sleepwalking consists of complex behaviors usually initiated during deep sleep. Episodes may include behavior such as sitting up in bed, walking, running, eating, getting dressed or even driving a car. However, coordination is poor and speech is often unintelligible.

Sleep Terrors are characterized by a sudden arousal from deep sleep with a scream or cry usually accompanied by fear, although the dream content cannot usually be recalled. Generally, sleep terrors occur in children between the ages of 2 and 10 and may occur in adults, usually in response to stress.


are disturbing mental experiences that generally occur during the last third of the night when REM sleep is plentiful. Dream recall is usually vivid and detailed. Most adults will experience nightmares occasionally, but if these occur frequently and cause chronic daytime sleepiness, an evaluation of the problem is needed.

Sleep Paralysis is the inability to perform voluntary movements either at sleep onset or upon awakening. Paralysis usually lasts only a few minutes and disappears spontaneously or by external stimulation.

REM Sleep Behavior Disorder (RBD)
Patients with RBD have muscle activity during dream sleep which permits the "acting out" of a dream. This causes very intense and vigorous sleep behaviors accompanied by vivid dreams. Most patients with RBD complain of sleep injury but rarely of sleep disruption. RBD is most common in men over 50 years old with an underlying neurological disorder such as dimentia, Parkinson's, narcolepsy or a stroke.