Delayed sleep phase disorder after traumatic brain injury.

Sleep-wake schedule disorder is defined by DSM-III-R as a mismatch between the normal sleep-wake schedule for a person's environment and his or her circadian sleep-wake pattern. The authors report a case in which a sleep-wake schedule disorder arose after a closed head injury. Sleep-wake schedule disorder has not been described as an outcome of closed head injury. As patients with sleep-wake schedule disorders may present with insomnia, this case suggests the possibility that some of the insomnia that frequently follows closed head injury may represent sleep-wake schedule disorders.