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
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
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%.
In fact, one-quarter of the TIA patients in his study suffered
some type of serious medical problem -- whether stroke, death, heart failure,
heart attack, or another TIA -- in the first three months following the TIA,
The researchers also were able to pinpoint specific risk
factors for stroke after a TIA: age over 65, diabetes, a TIA spell lasting
longer than 10 minutes, and temporary weakness or speech impairment during the
TIA, Johnston tells WebMD. "Each of these symptoms doubled their risk of
stroke," he says.
"It's what we've been saying all along -- that if you have
symptoms of stroke, get to the hospital," Johnston says. "Now we're
saying if your symptoms go away, you still need to get to the