Parasomnias are a group of sleep disorders that cause unusual movement, perception, emotion or dreams while a person is between the different phases of sleep or awakening from a sleep.
Generally, these problems occur while the patient is partially aroused as they transit from being awake into non-rapid eye movement (NREM) sleep or into rapid eye movement (REM) sleep. Examples of the parasomnias usually experienced in clinical practice include sleep terrors, sleepwalking, confusional arousal, and REM sleep behavior disorder.
Also called night terrors, this is an arousal disorder that causes panic and loud screaming and even bodily harm if the person gets up and runs about. No attempt should be made to comfort the person as this can intensify the terror. People who experience sleep terrors usually forget the experience afterwards, although they may have a partial memory of it.
Sleepwalking can refer to simply sitting up and looking awake when you are not or actually leaving the bed and walking around and moving items, for example. The person may also talk or appear to be having an argument, although the words may not make sense. In adults, sleepwalking is often associated with the use of medication, alcohol, sedatives and mental disorders. Anxiety and fatigue are also associated with the disorder.
This refers to when a person becomes confused as they are waking up, perhaps partially remaining in a sleep state but with their eyes still open and looking around. In children, confusional arousal often causes a lot of moaning, movement and sometimes inconsolable crying.
REM sleep behavior disorder
This is the most common form of REM sleep parasomnia and refers to when the muscles become weak, meaning a person is vulnerable to injury as they try to act out events occurring in their dreams. This can lead to fracture, bruising or wounds to the person experiencing the disorder or those around them. Patients sometimes take protective measures such as tying themselves to the bed or using pillow barricades.
Reviewed by Sally Robertson, BSc