Science / Medicine : Study Links Infections and Strokes

Infections commonly precede strokes and may trigger the strokes by altering the body’s blood-clotting system, according to a USC study published this month in the journal Stroke. Neurologist Sebastian Ameriso and his colleagues evaluated 50 patients consecutively hospitalized for strokes and found that 17, or 34%, had had infections during the previous month.

In most cases, the infection was a relatively mild upper respiratory tract infection. Others included urinary tract infections and pneumonia. Compared with patients without infections, those with infection-associated strokes had several changes in the blood that indicate activation of the coagulation system. Such an activation would increase the tendency to form blood clots, which often precipitate strokes by interrupting blood flow to the brain.

Although the study provides evidence of a plausible link between infections and strokes, it does not prove that infections trigger strokes, said neurologist Mark Fisher. Until such proof is provided, it would be premature to recommend any precautions for people who have infections, he said.