Study backs deep brain stimulation for Parkinson's

WASHINGTON (Reuters) - Deep brain stimulation dramatically improves Parkinson's disease symptoms such as trembling and slowness of movement, offering hope to many with the incurable ailment, researchers said on Tuesday.

Six months of deep brain stimulation with a device made by Minneapolis-based Medtronic Inc led to better quality of life and 4-1/2 additional hours per day of good motor functioning for Parkinson's patients, but did not come without risks, the researchers said.

The small electrical device is implanted surgically in the chest, with wires leading to electrodes in the brain. It sends electrical signals to brain areas that control movement.

One of the 121 Parkinson's patients in the study who got deep brain stimulation, or DBS, died from bleeding in the brain caused by a ruptured blood vessel after the surgery.

And compared to the 134 patients in the study who received only standard medical treatment, those getting DBS were 3.8 times more likely to have a "serious adverse event" such as a post-surgical infection. Most were quickly resolved, the researchers said.

But motor functioning improved for 71 percent of the DBS patients. Their quality of life -- like carrying out daily activities, mobility and emotional well-being -- also rose.

"The study provides the medical community with the highest class of evidence for the benefits of deep brain stimulation for properly selected patients," Dr. William Marks, a University of California, San Francisco neurologist who helped lead the study, said in a telephone interview.

DBS may help patients whose symptoms are not well controlled by drugs, Marks said.

The study was published in the Journal of the American Medical Association.

"MAGNIFICENT BENEFITS"

Parkinson's disease is a brain disorder in which nerve cells in the brain that control muscle movement die, causing trembling, stiffness of the limbs and trunk, slowness of movement and impaired balance and coordination.

There is no cure and drugs used to control symptoms can lose their effectiveness over time or cause bad side effects, often leaving patients desperate to find a new approach.

Sharon Pederson, 51, a Northern California woman who got DBS in the study, said it restored her quality of life. "The bottom line for me is that without hope, you have nothing to go for with Parkinson's," Pederson said in a telephone interview arranged by Medtronic.

Deep brain stimulation was approved in 2002 by the U.S. Food and Drug Administration to treat Parkinson's, but only a small percentage of patients get it.

Marks, who has worked as a consultant to Medtronic, said DBS does not cure the disease or prevent it from worsening over time, and does not improve non-motor symptoms such as thinking, memory or speech problems. In fact, those who got DBS in the study had slightly lower performance on cognitive tests.

While the treatment is not appropriate for everyone with Parkinson's disease, "a surgery done on the right patient by the right team can have magnificent benefits that extend beyond what can be achieved with medicines alone," said Dr. Michael Okun of the National Parkinson Foundation.

The study was funded by the U.S. Department of Veterans Affairs and National Institutes of Health, with some additional funding from Medtronic.

(Editing by Julie Steenhuysen and Eric Beech)