Firing up the brain

Electric jolts are better for Parkinson's disease than drugs.

Implanting electrodes to shoot electrical impulses into the brains of Parkinson’s patients improved their physical function more than the best drug therapy, a study showed.

Patients who received the deep brain stimulation had an average of 4.6 more hours a day free of involuntary movements than peers being treated only with drugs.

Parkinson’s disease afflicts people with involuntary moving, shaking and tremors. Deep brain stimulation began being used as a treatment in the 1990s. This is the first major study to compare the two treatments, said the study’s lead author, Frances Weaver, a neurology professor at Northwestern University in Chicago.

“There’s no cure for Parkinson’s, and when the medication’s not working, patients are looking for something else,” said Weaver. “This might be an appropriate treatment.”

The study found that 71 per cent of those receiving deep brain stimulation had improved motor function, compared with 32 per cent of those on the best drug therapy. The deep-brain stimulation group also reported better quality of life.

But 40 per cent of them had serious adverse reactions that included falls, gait disturbances and balance disorders, compared with 11 per cent of drug-therapy patients. About 10 per cent of the brain-stimulation patients had infections from the implant surgery, and one died of cerebral bleeding. Older patients didn’t improve as much as younger patients.

“There’s a prejudice against older patients because they don’t have the same big-bang effect as younger patients,” said Roy Bakay, a professor of neurosurgery at Rush University in Chicago. He recommends that patients older than 70 who are in good physical health get the electrode-implant surgery. “You don’t just stop living after 70,” he said.

The electrode device is implanted in the patient’s brain by drilling through the skull while the patient is awake, so doctors can make sure the electrodes are affecting the right parts, said study author William Marks, an associate professor of neurology at the University of California, San Francisco. Then wires are snaked under the skin to a pacemaker-like device implanted near the collarbone.

Parkinson’s disease is caused by the progressive death of brain cells that produce dopamine, a chemical that helps regulate movement. As it becomes more difficult for the brain to communicate, some cells begin to fire randomly. “The idea is to block or normalise the abnormal activity,” Marks said. “Think of it as a pair of noise-cancelling headphones.”