ARTICLE IN BRIEF
Investigators reported that a four-week stroke incidence of 0.013 percent suggests that 260 young people have an ischemic stroke after a traumatic injury every month in the US. Further research is needed to identify the highest risk groups, such as those with head or neck injury, and opportunities for stroke prevention.
SAN DIEGO—In the US, an estimated 200 people a month, 50 years old or younger, suffer strokes subsequent to head or neck trauma, researchers said here at the International Stroke Conference sponsored by the American Heart Association/American Stroke Association.
“About 10 percent of the people who had a stroke were diagnosed with a tear in a blood vessel leading to the brain — arterial dissection — but not all the patients were diagnosed with it prior to the stroke,” said Heather Fullerton, MD, pediatric vascular neurologist and director of the University of California at San Francisco Pediatric Stroke and Cerebrovascular Disease Center.
“We were interested in this issue of trauma increasing the risk of stroke,” she explained. “We know that trauma can injure the blood vessels leading to the brain which can lead to thrombus formation in those blood vessels and then secondarily lead to ischemic stroke.”
“We wanted to take a cohort of patients exposed to trauma and determine what their risk of stroke is,” Dr. Fullerton continued. While there are some data available on trauma and children as it applies to stroke incidence, similar information on young adults is lacking, she added.
“In pediatric studies we did previously, it seemed that the risk period for stroke after a traumatic event was quite short,” she told Neurology Today. “Most of the strokes that occurred after trauma occurred within a week of the incident. That is why we selected four weeks as the cutoff for our larger trauma study in order to capture all the strokes.”
“Our take-home message from this study is that strokes affect young people and not just older people, particularly after a traumatic event,” Dr. Fullerton said. “So if you have weakness on one side of the body or other signs of stroke, people should seek emergent care — and especially if they have had a recent traumatic event.”
Using the Kaiser Permanente Northern California health care database to gather information about trauma incidents and their relationship to stroke, Dr. Fullerton and colleagues identified 1.3 million patients who were seen in an emergency department or admitted to a hospital for a trauma diagnosis from 1997 to 2011.
For the study, Dr. Fullerton only reviewed the records of individuals who were 50 years old or younger. They were then followed for four weeks to determine if they were subsequently diagnosed with an ischemic stroke.
She said that researchers found evidence of blood vessel tears when they were reviewing the records of patients who eventually did have strokes after experiencing trauma.
Among their findings, the research team determined that an estimated 11 strokes occurred in every 100,000 patients who went to the emergency department for trauma; and they had a stroke within four weeks of having an event significant enough to require a trip to the hospital. Of those seen for trauma, the risk of stroke was three times higher when the injury was to the head or neck, Dr. Fullerton said in an official conference press briefing.
Dr. Fullerton said that stroke subsequent to trauma occurred more often in adults than in children; the rate was about 48 per 100,000 in adults and about 2.5 per 100,000 for children. When the statistics are extrapolated to the general population, “a four-week stroke incidence of 0.011 percent suggests that 214 young people have an ischemic stroke after a traumatic injury every month in the United States.” [See “More Data on the Study Population.”]
Dr. Fullerton said that scientists now believe that the strokes may be due to arterial dissection as a result of trauma. “Further research is needed to determine the highest risk group, such as those with head or neck injuries, and study opportunity for stroke prevention,” Dr. Fullerton said. She said the report should be considered preliminary. She and colleagues will be performing nested case control studies to “dig into a lot more detail about the traumatic event to try to figure out predictors of stroke.”
Dr. Fullerton said that knowing how often trauma is involved in stroke is the first step in developing programs that may be able to predict and prevent the stroke.
Commenting on the study, James C. Grotta, MD, FAAN, director of stroke research at the Center for Innovation and Research at Memorial Hermann Hospital Texas Medical Center in Houston, told Neurology Today: “The most common problem that causes stroke in trauma is dissection of the artery wall. This can occur with relatively minor trauma. With better imaging we can detect this more readily.
“There is a fine line between someone overreacting to every fall and thinking they are going to have a stroke and the appropriate recognition that there should be a normal amount of pain with the trauma,” he continued. “But if that pain persists in an atypical fashion or you have other symptoms, immediate attention may be needed,” Dr. Grotta said.
“I have had patients who were triathletes and just the repetitive swimming motion in turning their head back and forth appears to have caused damage to arteries in the neck, and that eventually led to strokes. These patients didn't even have to have trauma. We see the same thing in minor motor vehicle accidents where there can be whiplash injuries,” said Dr. Grotta, who serves on the Neurology Today editorial advisory board.
Press briefing moderator Bruce Ovbiagele, MD, FAAN, professor of neurology at the Medical University of South Carolina, Charleston, commented: “We generally think about stroke as occurring among people over the age of 50. I think this is extremely useful in making us aware that stroke can occur in younger people and it may be related to injuries suffered in traumatic events. We are all beginning to look now at how trauma impacts stroke. This is one of the important aspects of this study. It is making us look.”
He suggested that trauma patients when discharged from the hospital should be given a list of signs and symptoms to alert them of the possibility of a stroke.
MORE DATA ON THE STUDY POPULATION
- The 4-week stroke incidence after any traumatic injury was 0.013% (95% CI 0.011, 0.015).
- Patients with stroke had a mean age of 37.7 years versus 24.0 years in those without stroke (p<0.0001).
- Patients with injury to the head or neck were more likely to have a stroke compared with those with other types of injuries. The 4-week stroke incidence after head or neck injury was 0.07 percent (95% CI 0.05, 0.09) among adults and 0.005 percent (95% CI 0.001, 0.01) among children (p<0.0001).
- Of the 197 stroke cases, 16 percent (95% CI 11, 22) had a diagnostic code for cranio-cervical dissection.