Injection of stem cells into stroke victim's brain is a medical first

A Glasgow man in his 60s has become the world's first person to receive injections of foetal stem cells into the brain in order to repair damaged nerve tissue caused by stroke.

Doctors who carried out the surgery over the weekend said they do not expect to see any immediate improvement in the man's partial paralysis, as the clinical trial is aimed primarily at testing the safety of the controversial procedure.

The man, who has not been named, has been discharged from Glasgow's Southern General Hospital where the operation was carried out. He will be monitored closely for the next two years as an outpatient to see if he has suffered any side-effects of the treatment. Stem cells used in the operation were originally derived from a 12-week-old foetus that was aborted in California in 2003. The cells have since undergone extensive testing and purification and have been stored and replicated at a stem-cell facility near Edinburgh.

Professor Keith Muir, the principal investigator on the trial, said that foetal stem cells offer a potential new therapy for the thousands of people each year who suffer permanent disabilities caused by brain damage resulting from blocked blood vessels or internal bleeding.

"Stroke is a common and serious condition that leaves a large number of people with significant disability. In this trial we are seeking to establish the safety and feasibility of stem-cell implantation, which will require careful follow-up of the patients who take part," he said.

"If we were to see an improvement [in this patient] then it would be very nice, but I think I would be very cautious of making much of that in this type of study. It's a safety study and what we are following up for is anything that goes wrong, both for the short and long-term follow-up."

The clinical trial will recruit a total of 12 stroke patients who will receive injections of neural stem cells prepared and manufactured under government licence by a British stem-cell company, ReNeuron, which was set up in 1997 to make "off-the-shelf" treatments.

Professor Muir said that the first patient suffered an ischaemic stroke, caused by a blocked artery, about 16 months ago. The stem cells were injected using a specially-made needle some 22cm long, which had to be carefully inserted into the damaged area of the brain.

"We know he's suffered a fairly large area of damage as a result of the stroke – it's a fairly large part of the motor cortex and adjacent bits of brain tissue," Professor Muir said. "The stem cells were injected into an area of the brain that is close to the stroke damage, not into the area of damage itself. At this late stage after a stroke you are effectively dealing with a hole in the brain where the brain tissue used to be."

He added: "The area of damage is probably larger than a golf ball. If we see anything at all, I think we'd expect to see changes to the way the tissues are connected to one another. The idea of filling in a big hole where the cells go and proliferate is not going to happen.

"If we see anything, I suspect it will be much more akin to rewiring and promoting the repair process occurring naturally rather than filling in huge gaps in the head. I don't think that's a realistic prospect for this type of approach."