Undetectable mini-strokes could lead to Alzheimer's or Parkinson's

Researchers in the US have discovered that small, unnoticed strokes could cause widespread damage in the brain, potentially leading to neurodegenerative diseases such as Alzheimer’s and Parkinson’s.

A team of scientists led by David Kleinfeld from the University of California conducted tests on rats and induced mini strokes by blocking blood vessels to the brain.

They found that blocking just one of these blood vessels, called arterioles, resulted in a tiny stroke that caused cell death in several directions. Prior to these tests, it had been thought that strokes on such a small scale do not cause any lasting damage as they are undetectable on brain scans.

After the strokes, the rats were found to have difficulty judging distances and were treated with a drug called memantine, which is already used to treat Alzheimer’s in humans. Within 45 minutes, the damage to the brain appeared to have been reversed and cognitive function restored, even in rats where several vessels had been blocked.

The research appears in the December 2012 edition of the Nature Neuroscience journal.