University of Leeds scientists have shown how stroke victims could be more vulnerable to Alzheimers disease years or even decades after making a full recovery.

It has been known for some time that the two conditions were linked, but now the Leeds team has shown how an incident of reduced oxygen to the brain caused by the stroke can leave the patient vulnerable to the gradual build-up of toxic chemicals which can cause Alzheimers.

The research was led by Professor Chris Peers of the Universitys school of medicine, who explained: Our research is looking into what happens when oxygen levels in the brain are reduced by a number of factors, from long-term conditions like emphysema and angina, to sudden incidents such as a heart attack, stroke or even head trauma. Even though the patient may outwardly recover, the hidden cell damage may be irreversible.

It could even be an issue for people who snore heavily, whose sleep patterns are such that there will be times in the night when their brain is hypoxic deprived of sufficient oxygen. It can be anything that stops the heart and lungs working together to their optimal capabilities.

The research centred on the damage done by these low-oxygen incidents to a group of brain cells called astrocytes. When the brain is functioning normally, it makes connections through the release of tiny amounts of chemical across the synapses. Once the chemical has been transmitted, it is mopped up by the astrocytes.

The Leeds team which also includes Dr John Boyle in the Faculty of Medicine and Health and Dr Hugh Pearson of the Faculty of Biological Sciences has shown that if at some point the astrocytes have become hypoxic, they are less able to mop up these transmitters, allowing the residual chemicals to accumulate and become toxic.

This is an important factor in whats going on in hypoxic brains, said Prof Peers, whose work received funding from the Alzheimers Society and
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Contact: Simon jenkins
s.jenkins@leeds.ac.uk
44-011-334-35764
University of Leeds
4-Jun-2007