Hypersomnia following traumatic brain injury

Abstract

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.

Figure 1

Percentage of traumatic brain injury (TBI) subjects, trauma controls, and trauma-free controls endorsing between 0 and 4 of the following sleepiness items (I am sleeping or dozing most of the time —day or night, I sit around half-asleep, I sleep or nap more during the day, and I sleep longer during the night.) at 1 month and 1 year following injury (p < .001 for comparison among all 3 groups at 1 month and 1 year).

Figure 2

Percentage of subjects endorsing between 0 and 4 of the following sleepiness items (I am sleeping or dozing most of the time—day or night, I sit around half-asleep, I sleep or nap more during the day, and I sleep longer during the night.) at 1 month and 1 year following injury. Trauma controls are compared with subjects with traumatic brain injury divided into injury-severity subgroups (≤ 24 hour, 1–6 days, 7–13 days, ≥ 14 days), based on time from injury until commands were consistently followed (p < .001 at 1 month; p < .01 at 1 year).