Small Strokes Offer Big Info
Brain images after TIA predict future risk
Getting a CT scan of the brain within 24 hours of a transient ischemic attack (TIA) or a non-disabling stroke can predict when patients will be at the highest risk of another stroke or when symptoms may worsen, according to new research published in the American Heart Association journal Stroke.
"All patients should get a CT scan after a TIA or non-disabling stroke," said Jeffrey J. Perry, M.D., M.Sc., co-senior author of the study and associate professor of emergency medicine at the University of Ottawa in Canada. "Images can help identify patterns of damage associated with different levels of risk for a subsequent stroke or help predict when symptoms may get worse."
Of 2,028 patients who received CT scans within 24 hours of a TIA or non-disabling stroke, 814 (40.1 percent) had brain damage due to impaired circulation (ischemia).
Compared to patients without ischemia, the probability of another stroke occurring within 90 days of the initial episode was:
- 2.6 times greater if the CT image revealed newly damaged tissue due to poor circulation (acute ischemia);
- 5.35 times greater if there was previously damaged tissue (chronic ischemia) in addition to acute ischemia;
- 4.9 times greater if any type of small vessel damage occurred in the brain, such as narrowing of the small vessels, in addition to acute ischemia; and
- 8.04 times greater if acute and chronic ischemia occurred in addition to small vessel damage.
While 3.4 percent of the people in the study group had a subsequent stroke within 90 days, 25 percent of patients with CT scans showing all three types of damage had strokes.
"During the 90-day period, and also within the first two days after the initial attack, patients did much worse in terms of experiencing a subsequent stroke if they had additional areas of damage along with acute ischemia," said Dr. Perry.
"These findings should prompt physicians to be more aggressive in managing patients with TIA or non-disabling stroke who are diagnosed with acute ischemia, especially if there is additional chronic ischemia or small vessel damage," he said.