Medicines being tested for possible benefits to stroke sufferers could also help tackle multiple sclerosis, claim researchers.

Scientists say they have found that increased levels of glutamate - a common amino acid - may be a common cause of brain damage in both diseases.

Glutamate acts as a neurotransmitter within the brain and is tightly regulated by the nervous system. The uncontrolled dumping of large amounts of glutamate is known to be a major cause of brain damage in stroke.

New evidence, reported in the journal Nature Medicine, now suggests that a similar mechanism may be involved in MS, where glutamate can act on the specialised brain cells that produce myelin, the insulation for nerve fibres.

Nerve damage

Using a mouse model of MS, scientists found that a glutamate receptor blocker, NBQX, prevents glutamate-induced nerve damage and protects myelin-making cells from destruction, according to the report.

This raises the possibility that compounds used experimentally for the treatment of stroke may also prove useful for the treatment of MS.

"If we can verify this, we can use the research which is already being done on stroke to get a head start in the treatment of MS," said Peter Werner, assistant professor of neurology at Albert Einstein College of Medicine, in New York.

"This new concept may eventually lead to a better treatment of the destruction of brain cells in MS," he said. "It will not stop MS, but it may help ameliorate the damage."

Multiple sclerosis, an inflammatory disease that affects nearly 1 million people worldwide, arises when the immune system mistakenly damages myelin in the brain and spinal cord.