A surgical treatment called deep brain stimulation is better than standard drug therapy for improving symptoms and quality of life for people with advanced Parkinson's disease, according to a study published Thursday.

The disease affects about one in every 200 people worldwide, leading to muscle tremors, stiff limbs and weakness.

Researchers in Germany randomly assigned 156 patients with advanced Parkinson's to take either medication or undergo deep brain simulation, and then followed participants for six months.

The electrical stimulation is like a pacemaker for the brain that "pinpoints these areas of the brain that are malfunctioning and stops their abnormal behaviour," said Dr. Andres Lozano of Toronto Western Hospital, the first surgeon in North America to do the operation.

Those who received electrical stimulation and drug therapy showed a 25 per cent improvement in symptoms, while the 78 people who received drugs alone had no improvement, the team reports in Thursday's issue of the New England Journal of Medicine.

The average amount of time that people were effectively immobilized and unable to walk or perform similar tasks dropped from 6.2 hours without brain stimulation to two hours with it, the researchers said.

"It helped me 100 per cent," said Art McPhee of New Haven, P.E.I., who had the surgery two years ago. He still has trouble walking, but is now able to go down the street to pick up his mail.

There were risks to the surgery, said Dr. Richard Camichioli of Capital Health in Edmonton. There were three deaths among those who had the surgery: a suicide, a surgical complication, and a case of pneumonia after surgery.

Overall, the benefits of the surgery outweighed the risks, the team concluded.

While about 15 per cent of people with Parkinson's would benefit from DBS, but in Canada, only about one per cent are getting it.

"Perhaps physicians and neurologists are uncertain as to the relative safety and benefits
of a brain operation for Parkinson's disease," said Lozano, considering many drugs are available.

Lozano said in his experience, the mobility improvement lasts more than five years, but the treatment cannot stop other worrisome complications of the disease, such as memory loss and dementia.

Of the study's 38 authors, 21 listed financial ties to Medtronic Inc., the manufacturer of the deep brain stimulation therapy tested in the study.