The risk of having a stroke within three months following a traumatic brain injury is multiplied by ten.
"Know the symptoms of a stroke if you've had TBI."
Herng-Ching Lin, senior study author and professor at the school of health care administration within the college of medicine at Taipei Medical University in Taiwan, said a traumatic brain injury could trigger either a hemorrhagic stroke, that occurs when blood vessels burst in the brain, or an ischemic stroke, that happens when an artery in the brain is blocked.
This is the first research that has shown a connection between traumatic brain injury and stroke. In the United States, about one for every 53 people suffer a traumatic brain injury each year.
Researchers used records from a national Taiwanese database to examine the risk of stroke in traumatic brain injury patients over a five-year period. Records included 23,199 adult traumatic brain injury patients who received care between 2001 and 2003. The control group included 69,597 patients who did not suffer traumatic brain injury. The average age of patients was 42, and 54 percent of patients were men.
During the first three months after injury, 2.9 percent of traumatic brain injury patients had a stroke versus 0.3 percent of those without the injury, a tenfold difference. Investigators found that the stroke risk gradually decreases over time.
After one year, the risk of stroke is about 4.6 times higher for those who suffered a traumatic brain injury, and at five years the risk drops to 2.3 times greater.
Incredibly, patients with traumatic brain injury who also experienced a skull fracture were 20 times more likely to have a stroke during the first three months following the injury. That risk also decreased over time.
Investigators also observed that the risk of subarachnoid hemorrhage, defined as bleeding in the area between the brain and the thin tissues that cover the brain, and intracerebral hemorrhage, which is bleeding in the brain caused by the rupture of a blood vessel, increased significantly in patients with traumatic brain injury.
The study was published in Stroke: Journal of the American Heart Association.