Hypersomnia following traumatic brain injury.

STUDY
OBJECTIVES: To evaluate the prevalence and natural history of sleepiness following traumatic brain injury.
METHODS: This prospective cohort study used the Sickness Impact Profile to evaluate sleepiness in 514 consecutive subjects with traumatic brain injury (TBI), 132 non-cranial trauma controls, and 102 trauma-free controls 1 month and 1 year after injury.
RESULTS: Fifty-five percent of TBI subjects, 41% of non-cranial trauma controls, and 3% of trauma-free controls endorsed 1 or more sleepiness items 1 month following injury (p < .001). One year following injury, 27% of TBI subjects, 23% of non-cranial trauma controls, and 1% of trauma-free controls endorsed 1 or more sleepiness items (p < .001). Patients with TBI were sleepier than non-cranial trauma controls at 1 month (p < .02) but not 1 year after injury. Brain-injured subjects were divided into injury-severity groups based on time to follow commands (TFC). At 1 month, the non-cranial trauma controls were less sleepy than the 1- to 6-day (p < .05), 7- to 13-day (p < .01), and 14-day or longer (p < .01) TFC groups. In addition, the < or = 24-hour group was less sleepy then the 7- to 13-day and 14-day or longer groups (each p < .05). At 1 year, the non-cranial trauma control group (p < .05) and the < or = 24-hour TFC group (p < .01) were less sleepy than the 14-day or longer TFC group. Sleepiness improved in 84% to 100% of subjects in the TBI TFC groups, as compared with 78% of the non-cranial trauma control group (p < .01).
CONCLUSIONS: Sleepiness is common following traumatic injury, particularly TBI, with more severe injuries resulting in greater sleepiness. Sleepiness improves in many patients, particularly those with TBI. However, about a quarter of TBI subjects and non-cranial trauma control subjects remained sleepy 1 year after injury.