April 28, 2010 -- Deep brain stimulation offers a clear benefit to patients with advanced Parkinson’s disease in terms of symptom control and quality of life, but as with any surgery, the procedure is not without risks, new research confirms.
The study is the second major trial in a little over a year to find deep brain surgery and medication to be better than medication alone for reducing the movement-related symptoms that worsen as Parkinson’s progresses.
The surgery has been used for over a decade to treat advanced Parkinson’s disease, but few studies have directly compared it to standard nonsurgical treatments.
The procedure involves the placement of electrodes deep within the brain that deliver stimulation to block the electrical signals that cause Parkinson’s-related movement disorders. A battery-operated device implanted under the skin, which is similar to a heart pacemaker but smaller, controls the stimulation.
Pros and Cons of Surgery
The new study included 366 patients in the U.K. with advanced Parkinson’s disease who were treated with either deep brain stimulation and medication or medication alone.
A year after roughly half the patients had the surgery, all completed a detailed questionnaire designed to measure quality of life, symptoms, functional ability, and emotional and intellectual status.
The responses showed that surgically treated patients had better mobility, less discomfort, and were able to perform day-to-day activities better than patients who did not have the surgery, study co-author Keith Wheatley, DPhil, of the U.K.’s University of Birmingham tells WebMD.
Roughly three-fourths of patients in both treatment groups initially cited the involuntary, jerky body movements known as dyskinesia as a reason for considering surgery.
A year later, almost half of the surgically treated patients (48%) reported having no dyskinesia symptoms during the day, compared to 14% of patients who did not have the surgery.
And 29% of the surgery patients reported being in complete control of motor movements throughout the day, compared to just 3% of patients treated only with drugs.
Surgically treated patients did experience more treatment-related complications. One in five reported serious treatment-related adverse events, and one patient died during surgery. The most common surgical complication was infection.
The study appears in the April 29 issue of Lancet Neurology.
“The risks were no greater than what you would expect to see with any surgery,” Wheatley says. “But patients need to understand the benefits and risks of this surgery so that they can make an informed decision about it.”
‘Many Who Could Benefit Aren’t Getting Surgery’
The patients who took part in the U.K. trial all had symptoms that could no longer be controlled with drugs alone, and most Parkinson's patients who have the surgery also have advanced disease.
Neurologist Michael Okun, MD, who serves as medical director for the National Parkinson Foundation, tells WebMD that about 10% to 20% of Parkinson’s patients have symptoms severe enough to qualify for surgery.
But he adds that a large percentage of patients who are good candidates are not getting the surgery.
He says studies like the U..K trial and a Veteran’s Administration trial published last year may help change that.
In that study, surgically treated patients followed for six months reported better symptom management and quality of life than patients treated with drugs alone.
Okun co-directs the Movement Disorders Center at the University of Florida at Gainesville.
“There is more and more evidence that for the right patient, surgery can make a huge difference in symptoms and quality of life,” Okun says. “But we are still missing a lot of people who do qualify and could benefit.”