Study objectives: Determine prevalence and consequences of sleepiness and sleep disorders after traumatic brain injury (TBI).
Methods: Prospective evaluation with polysomnography (PSG), multiple sleep latency test (MSLT), Epworth Sleepiness Scale (ESS) and neuropsychological testing including Psychomotor Vigilance Test (PVT), Profile of Mood States (POMS), and Functional Outcome of Sleep Questionnaire (FOSQ).
Setting: Three academic medical centers with level I trauma centers, accredited sleep disorders centers, and rehabilitative medicine programs. Participants; Eighty-seven (87) adults at least 3 months post TBI.
Measurements and results: Abnormal sleep studies were found in 40 subjects (46%), including 20 (23%) with obstructive sleep apnea (OSA), 10 (11%) with posttraumatic hypersomnia (PTH), 5 (6%) with narcolepsy, and 6 (7%) with periodic limb movements in sleep (PLMS). Among all subjects, 22 (25%) were found to have objective excessive daytime sleepiness with MSLT score <10 minutes. There was no correlation between ESS score and MSLT (r = 0.10). There were no differences in age, race, sex, or education between the sleepy and non-sleepy subjects. Likewise, there were no differences in severity of injury or time after injury between sleepy and non-sleepy subjects. Sleepy subjects had a greater body mass index (BMI) than those who were not sleepy (p = 0.01). OSA was more common in obese subjects (BMI > or =30, p < 0.001). Sleepy subjects demonstrated poorer PVT scores (p < 0.05), better self-reported sleep related quality of life (FOSQ scores [p < 0.05]), and no differences in POMS.
Conclusions: There is a high prevalence of sleep disorders (46%) and of excessive daytime sleepiness (25%) in subjects with TBI. Sleepy subjects may be more impaired than comparable non-sleepy TBI subjects, yet be unaware of problems. Given the high prevalence of OSA (23%), PTH (11%), and narcolepsy (7%) in this population, there is a clinical indication for NPSG and MSLT.