Updated on Thursday, January 08, 2009, 00:00 IST

Washington, Jan 8: Patients with Parkinson's disease show significant improvement after six months of deep brain stimulation, but the invasive treatment also carries the risk of serious complications, researchers reported.

The study in the January 7 issue of the Journal of the American Medical Association reported that patients showed improvement in motor skills and experienced an overall improvement in quality of life after six months of brain stimulation compared with other treatment.

The procedure, frequently used when medical treatment appears to be ineffective, involves surgically implanting electrodes that stimulate specific parts of the brain to reduce involuntary movements and trembling.

But the authors also noted that brain stimulation is associated with "less desirable consequences" including infection, nervous system disorders, psychiatric disorders, cardiac problems and "behavioral effects" and said more research is needed.

The study found that motor function following the procedure improved significantly, including a reduction in involuntary movements, in 71 per cent of patients, compared to 32 percent of patients receiving medical therapy.

The researchers said that after six months' treatment, brain stimulation patients gained an average of 4.6 hours per day without suffering impaired motor function or involuntary movements.

By contrast, the average change for the best medical therapy group showed zero hours without some form of motor dysfunction.

Bureau Report