Small Stroke May Mean a Bigger One Is Close Behind
Dec. 12, 2000 -- The symptoms can be so fleeting, it's easy to ignore them. Yet, a new study shows the subtle, temporary signs of transient ischemic attacks -- or TIAs -- should be taken more seriously by both patients and doctors.
TIA, like a stroke, results from a blood clot in the blood vessels leading to the brain or in the brain itself. The clot temporarily impairs some aspect of brain function, causing stroke-like symptoms such as weakness, numbness in the limbs, difficulty speaking, and double vision. Yet, the symptoms often last only a few minutes to a few hours.
However, "these patients are at substantial risk of stroke, death, heart failure, heart attack, or another TIA," says lead researcher S. Claiborne Johnston, MD, MPH, assistant professor of neurology at the University of California at San Francisco. His study is published in this week's issue of the Journal of the American Medical Association.
"Anyone with symptoms, no matter how transient, should get to the hospital immediately," he tells WebMD. "The risk of stroke is quite high in the first few days, first few months after a TIA."
Johnston's study is the first large-scale analysis of these "mini strokes," a common disorder that affects from 300,000 to 1 million people in the U.S. every year.
Because of their very fleeting nature, TIAs are not only difficult to diagnose, but the effect on stroke risk has been unclear, Johnston says. "Many go undetected," he tells WebMD. "Largely, physicians have had to rely on their own experience in determining which [patients] were at greater risk for stroke." Only two previous studies of TIA have been performed, both involving small numbers of patients, the last study dating back 15 years.
In his study, Johnston analyzed data on more than 1,700 TIA patients with an average age of 72. During the 90 days after the first TIA, more than 10% of patients returned to the emergency room with a stroke; half of those strokes occurred in the first two days after the TIA.
Moreover, the strokes were fatal for 21% of patients and disabling for another 64%.