The chance of developing dementia can rise significantly in the year following a stroke. A study presented at a major conference by the American Stroke Association highlights this risk.
Researchers examined health records from 180,000 individuals who experienced either an ischemic stroke, caused by a blood clot, or a hemorrhagic stroke, caused by bleeding. These individuals were followed for two decades. Within five years after their stroke, nearly one in five developed dementia.
In the first year after a stroke, the likelihood of dementia was about three times higher than in people who had not had a stroke. Stroke survivors also faced an 80 percent higher risk of dementia compared with those who survived a heart attack.
As time passed beyond five years, the risk rose further, reaching roughly one and a half times higher and staying elevated for the full twenty years of follow up.
Researchers propose that the association arises from stroke damage to brain regions that govern thinking and memory. The results emphasize the importance of preventing strokes, since the cognitive changes associated with dementia after a stroke are not easily reversed.
Earlier work by other scientists noted that improving hand function after a stroke can be a possible outcome with appropriate therapies and rehabilitation strategies. The current findings add to that broader context by underscoring how stroke impacts long-term cognitive health for survivors.