Scientists have discovered a new way to make the brain repair itself after a stroke, it emerged yesterday, raising hopes that people left paralysed by the debilitating condition could have their mobility restored in the future.
Experiments on rats which suffered an induced stroke found that fewer of them were left paralysed after the treatment, which activated stem cells in their brains.
The research, by Ronald McKay of the National Institute of Neurological Disorders and Stroke in Maryland, America, was published last night in Nature magazine.
Proteins were used in the rats’ brains to activate stem cells which had been starved of oxygen.
This chemical process resulted in a "cascade" effect, which created new brain cells after the stroke in a complex reaction.
The treatment also improved the ability of existing cells to survive the lack of oxygen. When rats were given the treatment, many recovered from the loss of movement they suffered with the stroke.
The discovery will raise hopes for new treatments for stroke, using the body’s own stem cells to aid healing.
Other treatments using embryonic stem cells have been restricted because implanted cells come under attack from the body’s immune system.
The researchers wrote: "New cell therapies based on embryonic stem (ES) cells are supported by work in animal models of human disease.
"They are difficult to implement, however, because it is hard to grow tissue-specific precursors in the laboratory and it is difficult to deliver them to diffuse disease sites in the body without stimulating an immune response.
"The results that we present here suggest a general model of stem cell expansion that applies to many precursor cells of clinical interest and that may lead to strategies that promote regenerative responses through the activation of cells."
A spokesman for the Stroke Association last night gave the research findings a cautious welcome.
He said: "This is obviously very interesting research and it sounds exciting, but it will probably be a number of years before there is a practical application for this type of approach."
Along with heart disease and cancer, strokes are one of the biggest killers of Scots. Although the most recent figures show the death rate is falling, the condition still claimed the lives of 5,800 people north of the Border last year.
Earlier this year, researchers at Glasgow University said they had developed a new drug that could lead to more people who suffer a stroke making a full recovery.
A trial involving more than 1,700 patients in 154 hospitals around the world found that the treatment, currently known as NXY-059, had produced "promising" results. The researchers said they hoped the drug could have a profound effect and cut the number of patients who are left disabled after a stroke.
The trial was led by Professor Kennedy Lees, who said: "Patients who were given this drug were more likely to have made a full recovery from stroke after three months."
The drug could also be easily and safely administered without the need for specialist staff and equipment, meaning it could be used in any district hospital.
Another victim every three minutes
• EVERY year, more than 150,000 people in the UK have a stroke - one person every three minutes.
• Most of those affected are over 65, but anyone can have a stroke, including children and even babies. Strokes are slightly more common in men.
• Almost one in four men and one in five women aged 45 can expect to have a stroke if they live to 85.
• A stroke is the third most common cause of death in the UK and is the most common cause of severe disability.
• More than 250,000 people live with disabilities caused by stroke; about a third of people who have strokes suffer from some form of disability.
• There are two main types of stroke. The most common is an ischaemic stroke, which happens when a clot blocks an artery carrying blood to the brain. The second type is called a haemorrhagic stroke, which is caused when a blood vessel bursts and causes bleeding into the brain.
• Signs of a stroke include facial, arm or leg weakness, speech problems and a partial loss of vision.
• Eating healthily, exercising, not smoking and ensuring blood pressure is normal can help prevent a stroke.
• Immediate hospital treatment includes brain scans, tests on functions like swallowing and movement, monitoring oxygen, glucose and blood pressure, and, where appropriate, medication.