OBJECTIVE: Sleep is a complex neurologic process that is generated by and primarily benefits the brain. Sleep can be disrupted by a wide range of brain injuries, many of which may occur in children with neoplasms of the central nervous system (CNS). The specific sleep problems that have been associated with brain injuries include sleepiness, apnea, insomnia, and loss of circadian rhythmicity. The objective of this study was to characterize the sleep problems seen in children with neoplasms of the CNS through a comprehensive clinical and objective sleep evaluation. METHODS: A retrospective case series review was conducted of all children with neoplasms of the CNS referred to the sleep clinic for a clinical evaluation between 1994 and 2002. The sleep evaluation of the 14 children in this report included a sleep history, a sleep log, and a polysomnogram. In the 12 children with complaints of daytime sleepiness and/or fatigue, a multiple sleep latency test was performed the day after the polysomnogram. Three children also had a 2-week actigraphic study. RESULTS: The most common sleep complaint in this group of children was excessive daytime sleepiness (EDS), present in 9 of the 14 children. In these children, the sleepiness was manifest by 1 or more of the following symptoms: 1) an increase in total sleep time per 24 hours; 2) the resumption of daytime naps that had been previously discontinued at a younger age; 3) an inability to awaken in the morning to begin the days activities; or 4) the inability to remain awake during activities of daily living, such as school. Of the 9 children with daytime sleepiness, 8 had brain tumors requiring neurosurgical procedures at the time of their diagnosis, 6 of whom required ventricular shunting. The children with the most severe sleepiness had evidence of hypothalamic/pituitary injury with deficiencies in both anterior and posterior pituitary hormones. Five of the children with EDS had polysomnographic evidence of symptomatic narcolepsy with rapid eye movement sleep present on 2 or more of the daytime naps. The symptoms of EDS were effectively controlled with modest doses of daytime stimulant medication and/or scheduled naps. Central apnea leading to respiratory insufficiency and requiring mechanical ventilation to correct was present in 2 children with tumors involving the medulla. Although snoring with possible obstructive sleep apnea was the reason for referral to the sleep clinic in 5 children, none of the children in this series had polysomnographic evidence of significant obstructive sleep apnea. The other sleep problems seen in these children were hypoxia in 2 children, fatigue in 3 children, and seizures during sleep in 1 child. The interval between tumor diagnosis and sleep evaluation varied from 0 months to 9 years (mean: 42 months). The treatment of the sleep problems of this group of children took many forms, including stimulants, scheduled naps, mechanical ventilation, supplemental oxygen, and anticonvulsants. CONCLUSIONS: Brain injuries, which invariably are present in children with neoplasms of the CNS, may result in a variety of diagnosable and treatable sleep disorders. The sleep symptoms did not appear to be directly related to the specific therapy the child received, nor the presence of residual tumor. Rather, the primary determinant of the sleep symptoms was the area of the brain that was damaged, regardless of how the damage occurred. Children who sustained damage to the hypothalamic/pituitary region developed EDS regardless of whether the damage was the result of the tumor, surgery, hydrocephalus, or radiation to the whole brain or localized to the suprasellar area. The only children who developed respiratory insufficiency had an injury to the medulla. This observation is consistent with the view that sleep is a specific, albeit complex, neurologic process that is controlled by specific brain regions. EDS and respiratory insufficiency were the most commonly diagnosed severe sleep disorders in these children. The sleep problems of children with brain tumors may develop before, but more often soon after, their tumor diagnosis and treatment. However, the sleep symptoms may not be appreciated by medical providers until years after their onset, which may delay the beginning of effective interventions.