People suffering from debilitating brain disorders such as multiple sclerosis and Parkinson's disease may benefit from stem-cell therapies within the decade, thanks to research reported this week.

In separate projects, scientists in Italy and Australia used stem cells to reduce or eliminate the symptoms of both diseases in animals.

"The potential of strategies such as this to treat neurological damage on a wide front is impressive," Stanford University neuroscientist Lawrence Steinman said of the Italian research, reported today in the journal Nature by Gianvito Martino and his colleagues at Milan's San Raffaele Hospital.

Adelaide-based biotechnology company BresaGen has not yet published details of its research for reasons of confidentiality, said director Chris Juttner.

Dr Martino's group cultured adult brain stem cells taken from mice and then injected them into the blood or spinal cord of mice suffering from an MS-like disease.

Up to 30 per cent of the mice recovered fully and the rest showed improvement.

"The most remarkable thing is the way the ... cells home in from the bloodstream to the area of damage," said stem-cell expert Martin Pera of Monash University.

The Adelaide team, working with BresaGen-funded researchers at the University of Georgia in the US, implanted brain cells from human embryonic stem cells into rats with Parkinson's disease-like symptoms.

Within eight weeks the symptoms were "significantly" decreased, said Dr Juttner who predicted human trials within three years.

At Griffith University in Brisbane, neurobiologist Alan Makay-Sim claimed this week's results increased hope that scientists can learn to "trigger the brain's own repair mechanism".

People with multiple sclerosis experience repeated immune system attacks on their brain and spinal cord.

In Parkinson's disease, degeneration of the brain cells leads to tremors and rigidity.