(HealthDay)—U.S. veterans who have suffered traumatic brain injuries may struggle with severe headaches years later, a new study finds.
The study included 172 vets who served in Afghanistan or Iraq between 2 and 11 years before the study began. Half suffered a traumatic brain injury (TBI) during deployment; half did not.
A TBI is caused by a bump, blow or jolt to the head that disrupts normal brain function. Besides headache, it can lead to post-traumatic stress, depression and sleep disorders, as well as problems with thinking and muscle control, the researchers explained.
The researchers assessed the number of vets with the worst headaches, which were described as "disabling" or "severe." A disabling headache was one so bad the veteran stopped all activity and was bedridden. A severe headache meant the vet could do only the most essential tasks; activity decreased by 50 percent to 90 percent.
Disabling or severe headaches were far more common among vets who had suffered a traumatic brain injury. Three out of four had such headaches, compared to one out of four vets without TBI. This difference lasted for up to 11 years.
The study was presented recently at the American Headache Society annual meeting, in Boston.
Dr. Peter Goadsby, chairman of the society's scientific program committee, called the findings "striking." These headaches can take a major toll on the vets' lives and families, he said.
"These new findings fill an important gap in our understanding of TBI—which many deployed troops experience—and its impact on headache severity over the long term that can be a key driver of disability for them," he said in a society news release.
Goadsby is a professor of neurology at King's College, London, and the University of California, San Francisco.
"We don't know exactly how TBI causes these severe headaches, but their long-term persistence suggests that processes related to TBI remain active or produce permanent changes in the brain, allowing the headaches to continue," he said. "These and other findings indicate that headaches following TBI will unfortunately continue to be a major problem for many veterans."
More than 330,000 U.S. military personnel have sustained a traumatic brain injury, the researchers noted.
Research presented at medical meetings is typically considered preliminary until published in a peer-reviewed journal.
Explore further: Head injuries tied to higher migraine risk for veterans
The U.S. National Institute of Neurological Disorders and Stroke has more on traumatic brain injury.