People who have a traumatic brain injury (TBI) may be more likely to have a future stroke, according to research that appears in the June 26, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology.
“Both stroke and traumatic brain injury are common, costly, and leading causes of severe disability in adults, and approximately 20 percent of strokes occur in adults under age 65,” said study author James F. Burke, MD, MS, of the University of Michigan and the Ann Arbor VA Healthcare System and a member of the American Academy of Neurology. “A large proportion of stroke risk is unexplained, especially in the young, so if we can identify new risk factors, we have the potential to prevent more strokes and improve outcomes.”
For the study, researchers looked at the records of adults who went to the emergency department or were admitted to a hospital for TBI or other trauma with no brain injury in the state of California during a five-year period.
A total of 435,630 people with traumatic brain injury were studied, along with 736,723 people with trauma with no brain injury. Over an average of 28 months following the injury, 11,229 people, or 1 percent, had an ischemic stroke. A total of 1.1 percent of those with TBI suffered a stroke, compared to 0.9 percent of those with trauma with no brain injury. With an ischemic stroke, blood flow to part of the brain is blocked. Eighty percent of strokes are ischemic.
After adjusting for factors that can affect stroke risk, such as age, high blood pressure and high cholesterol, as well as other disorders such as heart disease and the severity of the trauma, the researchers found that people with traumatic brain injury were 30 percent more likely to develop a stroke than those with trauma with no brain injury.
“While the stroke risk of one person with TBI is small, the overall link between TBI and stroke was substantial - as large as the link between the strongest stroke risk factor, high blood pressure, and stroke,” Burke said. “If further research establishes TBI as a new risk factor for stroke, that would stimulate research to help us understand what causes stroke after TBI and help us learn how to prevent these strokes.”
A Stroke is Not a TBI
A stroke is not a form of traumatic brain injury (TBI).
The word “traumatic” in the definition of TBI relates to the cause of the brain injury, not the fact that people feel traumatized from their brain injury. And of course, people with strokes or brain illnesses feel just as traumatized as people with TBI. But TBI’s result from external forces such as being hit by a car or bullet or falling off of a ladder or roof top.
Strokes, tumors, and brain illnesses are not TBI’s. The term “tbi survivor” has become so generalized, so popularized by the tbi community, that many people with a stroke or tumor think they are also tbi survivors. Not so. Instead, one is a stroke survivor, or a tumor survivor, or an anoxic brain injury survivor, or a meningitis survivor. Individuals with these other forms of acquired brain injury are not tbi survivors. However, they may lay claim to being abi survivors. Everyone with an acquired brain injury (and that would include from illness, stroke, toxin, trauma, or tumor) may lay claim to being an ABI survivor.
We at the Brain Injury Network are talking about this distinction in terminology because so many brain injury survivors are confused about it. So are some actual authorities in governments and schools, etc. The medical community could do a way better job of educating the public about these distinctions in terminology. Why they don’t do that sufficiently we at BIN have no idea. We would like authorities and experts to do a better job of educating patients and the public about these distinctions and classifications.
The study was supported by an advanced fellowship through the Department of Veterans Affairs.
The American Academy of Neurology, an association of more than 26,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, brain injury, Parkinson’s disease and epilepsy.
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.”
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American Academy of Neurology