Parasomnias (Disorders of Arousals)
A “parasomnia” also called a “disorder of arousal” is an unusual behaviour that occurs during sleep. It is more common in children but can be seen in older children and adults as well. The exact cause of parasomnias is not known. Parasomnias may be genetic, as they often run in families. Parasomnias can also be triggered by other sleep disorders, such as obstructive sleep apnea. Some parasomnias can be the result of a brain disorder.
During an episode of parasomnias the child awakens from sleep but is confused, has limited understanding and is not responsive to parents trying to intervene. The most common parasomnias in children include sleepwalking, confusional arousals and sleep terrors and are usually seen in the first one-third of the night.
During episodes of sleepwalking the child can do various simple or complex actions. These can include getting out of the bed and moving around in the house, going up and down stairs, moving furniture, or urinating in inappropriate places. Children can injure themselves by falling, colliding, jumping or mishandling a sharp object. Episodes of sleepwalking usually last for a short period of 10-15 minutes but can last upto 30-45 minutes.
During episodes of confusional arousals the child wakes up very confused. The speech is slow with inappropriate responses to questions or requests. The episode of arousals may last a few minutes up to an hour. Children with confusional arousals do not remember the event the next day.
Sleep terrors, also called night sleep terrors, is a frightening event for parents. The child suddenly gets up from sleep very confused, shows signs of panic and terror such as screaming, flailing, or kicking. This is associated with rapid heart rate and breathing, flushing of the skin and sweating. The child is not responsive to carers trying to wake or comfort them. Sleep terrors usually last for about 10 minutes, but can continue for 30 to 40 minutes. Post sleep terror episode children fall back into sleep and have no memory of the event the next morning.
Parasomnias are usually diagnosed based on descriptions from parents or siblings who might be present at the time of the episode. A video recording if available is extremely useful. Sleep study or polysomnography might be required in children where the parasomnia is unusual or atypical, potentially injurious or there is a doubt of a seizure/fits. Sleep study may also be needed to evaluate associated problems like obstructive sleep apnea (OSA) or periodic limb movement disorders.