SYDNEY -- Doctors have successfully implanted adult stem cells into the spinal cords of patients with motor neurone disease as the first step in what may be a cure for the usually terminal disease, a medical conference was told.

The procedure, carried out on seven Italian patients, proved to be safe and well tolerated, Italian researcher Doctor Letizia Mazzini told the 13th International Symposium on Motor Neurone Disease in Melbourne.

In the procedure, healthy stem cells were taken from the bodies of the patients.

The cells were then multiplied and implanted in the patients' surgically opened spinal cords without any major side effects, AFP quoted Mazzini as saying.

A leading Australian MND expert, Professor Perry Bartlett, said the trial was a potential first step in the use of stem cell therapy to treat and possibly one day cure MND, also known as Lou Gehrig's disease. "It shows that if stem cells are injected in they don't cause any harm," Prof. Bartlett said. "It's the first step along the way in terms of therapy."

MND is a rapidly progressing and fatal disease that can strike at any time, but occurs mainly around the age of 40-70.

The cause is unknown although in 10 percent of cases it is genetic. MND affects the nerve cells, or motor neurones, in the brain and spinal cord, causing their gradual death and resulting in immobility and eventual respiratory failure.

The intellect and senses remain unaffected.

Bartlett said Australian efforts in the battle against MND were currently focused on finding ways to drive existing cells in the brain and spinal cord to replace those destroyed by the disease.

His team hoped to find a drug which would stimulate the production of new nerve cells in the central nervous system, he added.

This would eliminate the need for invasive surgery, remove the problem of rejection and bypass the ethical minefield that was stem cell research.

Another option for MND could involve changing the environment in which the neurones existed to prevent them dying, either by injecting cells from other parts of the body or with a medicine.

"We may not have to physically replace the neurones, we may be able to actually change the environment," he said.

The Motor Neurone Disease Association of Australia welcomed the Italian trial, saying it should provide a source of optimism for the 1,500 Australians with the disease.

"The work of Mazzini and her colleagues fills the Australian and international MND communities with hope and optimism," President Alan Kennedy said.

A recent survey of 200 Dutch doctors found one in five MND patients end their own lives or die with the assistance of a doctor.