Mild Head Injuries Increase Risk Of Sleep Disorders

"As many as 40 to 65 percent of people with mild traumatic brain injury complain of insomnia," said study author Liat Ayalon, PhD, with the University of California, San Diego. "This is concerning since sleeping problems may exacerbate other brain injury symptoms such as headache, emotional distress, and cognitive impairment, making the rehabilitation process much harder."

For the study, researchers assessed 42 people who reported to the Sheba Medical Center in Israel with complaints of insomnia after mild traumatic brain injury. Those suspected of having a circadian rhythm sleep disorder (CRSD) (i.e. problems with the timing of sleep) underwent scans, sleep studies, and had their oral temperature and saliva melatonin measured.

The study found 15 of the 42 patients, or 36 percent, had a CRSD. Of those, eight people had a delayed sleep phase syndrome with problems falling asleep and waking up, and seven people had irregular sleep-wake patterns.

"The frequency of sleep disorders in this study is considerably higher than the rate of these disorders among people attending sleep clinics for insomnia, which is seven to 10 percent," said Ayalon.

Ayalon said these findings suggest that sleep disorders that involve changes in the timing of sleep may be relatively frequent among brain injury patients and should be considered when these patients report sleeping problems to avoid misdiagnosis. "Misdiagnosis of these patients as insomniac may lead to prescription of medications, which help people fall asleep but don't help normalize the sleep-wake cycle," said Ayalon.

In addition, Ayalon said since circadian rhythm sleep disorders are often associated with cognitive and psychological problems, treatment might ultimately lead to improvement in other brain injury related symptoms. Ayalon said further studies are needed to explain the mechanism behind CRSDs in people with brain injury.