Busier immune response to stroke linked to cognitive declines | Science News

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Stroke victims with busy immune responses may also see mental declines

A small study hints at a way to predict who might fare worse among survivors

9:48am, March 12, 2019
brain scans

BRAIN ATTACK  Most strokes in the United States are caused by a blood clot in the brain. Now scientists have linked a person’s immune response shortly after a stroke with a later loss in cognitive ability.

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How active a person’s immune system is soon after a stroke may be tied to later mental declines, a new study finds.

Researchers took blood samples from 24 stroke patients up to nine times over the course of a year. Twelve of the patients also completed a mental-skills test at four points during that time. Patients who had highly active immune cells on the second day after a stroke were more likely to see their test scores decline a year later, researchers report online March 12 in Brain.

“The people who either got better on the task or stayed the same had less of an immune response at day 2 [after the stroke], and the people who had more of an immune response at day 2 were more likely to decline and do worse later,” says study coauthor Marion Buckwalter, a neuroscientist at Stanford University School of Medicine.

A stroke occurs when the brain loses oxygen, due to a blocked or burst blood vessel. Buckwalter and her colleagues used a technique called mass cytometry that analyzes thousands of immune cells and their signaling molecules — which indicate how active a cell is — from blood samples of patients who had suffered a stroke. The researchers also tested patients’ memory, concentration, language skills and other thinking skills using the Montreal Cognitive Assessment.

It’s unclear why some patients have a more active immune response than others in the days after a stroke. But with more research, it’s possible that the response may be a way to predict which patients will fare worse after a stroke, the researchers say.


A.S. Tai et al. A year-long immune profile of the systemic response in acute stroke survivors. Brain. Published online March 12, 2019. doi:10.1093/brain/awz022.

Further Reading

L. Sanders. Over-the-hill cells may cause trouble in the aging brain. Science News. Vol. 194, October 27, 2018, p. 13.

R. Ehrenberg. Post-stroke shifts in gut bacteria could cause additional brain injury. Science News. Vol. 190, August 6, 2016, p. 7.

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