Stem cells injected into the brain of a stroke patient in world first

Doctors injected around two million cells into a healthy region of his brain called the putamen, close to where neurons were damaged by the stroke. They hope the injected cells will release chemicals that stimulate new brain cells and blood vessels to grow, while healing scar tissue and reducing inflammation.

The team, led by Professor Keith Muir at the University of Glasgow's Institute of Neuroscience and Psychology, expect to treat 11 more male patients aged between 60 and 85 in the trial, using progressively higher doses of five million, 10m and 20m cells.

The injections are being given to patients who have suffered ischaemic stroke, the most common type, caused by a blocked blood vessel in the brain. The operation requires a general anaesthetic and patients will be monitored for two years to see whether the procedure is safe and has any beneficial effect on their quality of life.

John Sinden, chief scientific officer at ReNeuron, the Surrey-based company that developed the cells, said of the first patient to receive the experimental injection: "He is really looking for some level of independence."

Animal studies suggest the cells are safe and effective at healing brain injuries.