Brain injuries can disrupt the body's production of the hormone melatonin, potentially leading to sleep problems, a new study suggests.
"We've known that people often have problems with sleep after a brain injury, but we haven't known much about the exact causes of these problems," study author Shantha Rajaratnam of Monash University in Victoria, Australia, said in a news release from the American Academy of Neurology.
In the new study, published in Neurology, researchers examined 23 people who had suffered severe traumatic brain injuries and 23 healthy people who were the same age. All of the participants were monitored for two nights in a sleep laboratory.
Levels of melatonin rose to higher levels in the evening hours in the healthy participants, sending the usual signal that it was time to start thinking about sleeping.
What the research showed
"These results suggest that the brain injury may disrupt the brain structures that regulate sleep, including the production of melatonin," Rajaratnam said. "Future studies should examine whether taking supplemental melatonin can improve sleep in people with brain injuries."
Those with brain injuries only spent about 82% of their time in bed actually asleep, compared to 90% among the healthy people. Those with brain injuries also were awake more than an hour during the night after first falling asleep, compared to an average of 27 minutes among the healthy participants. They also spent less time in deep sleep than the healthy participants, the study authors noted.
The researchers found that the differences remained even after they adjusted the results to account for the fact that the people with brain injuries had more depression and anxiety. - (HealthDay, News, May 2010)