People surviving a stroke likely to develop dementia

People who have survived a stroke are twice as likely to develop dementia, a major study has found.

Data from 3.2million people — the largest study ever done into the subject — suggests the damage done by a stroke has a serious impact on dementia risk.

Experts have long thought that there was a link, because the risk of strokes and dementia are both raised by high blood pressure and cardiovascular problems.

But the new study by Exeter University found even after blood pressure, diabetes and cardiovascular disease is taken into account, having a stroke significantly increases the risk of dementia.

The research, published in the Alzheimer's & Dementia journal, found the biggest risk of developing dementia is immediately after a stroke, but it then persists for years.

Strokes increase a person's risk of dementia by up to 100 per cent. Researcher Dr Ilianna Lourida, of the University of Exeter Medical School, said: “We found that a history of stroke increases dementia risk by around 70 per cent, and recent strokes more than doubled the risk [ a 100 per cent increase].

“Given how common both stroke and dementia are, this strong link is an important finding.

“Improvements in stroke prevention and post- stroke care may therefore play a key role in dementia prevention.”

A stroke occurs when a blood clot blocks an artery or there is major bleed in the head, reducing blood flow to the brain.

Roughly 57,000 people in England have a stroke each year, of whom 32,000 are killed.

Of those who survive, 65 per cent leave hospital with a disability. Some 25 per cent of survivors have a second stroke within five years.

The attacks used to be considered a hazard of old age.