Brain ‘Pacemaker' Beneficial for Parkinson's
Deep Brain Stimulation Improves Movement Symptoms
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
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
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
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
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
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
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
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
Okun co-directs the Movement Disorders Center at the University of Florida
“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.”