Brain Injuries Increase Risk of Stroke

July 28, 2011 -- People who have had a traumatic brain injury face a tenfold increase in the risk of having a stroke within three months, according to a new study.

Traumatic brain injury occurs when a blow or jolt to the head causes changes in a person’s normal brain function. It can result from injuries such as falls, vehicle accidents, and violence.

Although previous research has shown that traumatic brain injury can be associated with the future development of epilepsy, Alzheimer’s disease, and psychiatric conditions, this the first study to link it to the future risk of stroke. The study appears in the July 28 online issue of Stroke: Journal of the American Heart Association.

Traumatic Brain Injury and Stroke

To conduct the study, researchers used records from a nationwide Taiwanese database. They examined the records of 23,199 patients who received a diagnosis of traumatic brain injury between 2001 and 2003 and compared them to 69,597 people who did not have a traumatic brain injury. Each person was then followed for five years to identify whether they had a stroke.

In the three-month follow-up period, researchers found that 2.91% of patients with traumatic brain injury had a stroke compared with 0.30% of those who didn’t have a traumatic brain injury, a tenfold difference. After one year, the risk of stroke went down, but those who had a traumatic brain injury were still at significantly higher risk for stroke than those in the comparison group; they had about a 4.6 times higher risk. After five years, traumatic brain injury sufferers were 2.3 times more likely than those without such an injury to have a stroke.

Results further showed that a person who had a traumatic brain injury in which the skull bone was fractured was more at risk for a stroke than a person who had the injury but the skull bone remained intact.

In the article, the authors state that it is not known how traumatic brain injury may influence the incidence of strokes. However, they noted several possibilities, including the idea that a traumatic brain injury may damage the blood vessels in the brain, disturbing the blood supply to the brain and leading to a stroke.

In a news release, Herng-Ching Lin, PhD, senior study author and professor at the School of Health Care Administration in the College of Medicine at Taipei Medical University in Taiwan, calls for the use of imaging examinations, like MRI, and intensive medical monitoring support and intervention following a traumatic brain injury, especially in the first few months and years. He also says there is a need for initiatives to increase public awareness about the risk factors that cause stroke and the signs and symptoms of stroke in patients with traumatic brain injuries.

In the U.S., an estimated 1.7 million traumatic brain injuries occur each year, according to the CDC.

"Stroke is the most serious and disabling neurological disorder worldwide,” Lin notes in the news release. “Our study leads the way in identifying stroke as an additional neurological problem that may arise following traumatic brain injury.”