MONDAY, Aug. 8 (HealthDay News) -- The benefit of deep brain
stimulation in controlling tremors and improving motor function for
those with Parkinson's disease appears to last at least 10 years,
according to a small new study by Canadian researchers.
Parkinson's disease is one of several conditions called motor
system disorders, which are caused by the loss of
dopamine-producing brain cells. The main symptoms of Parkinson's
disease are tremors or trembling in hands, arms, legs, jaw and
face; rigidity or stiffness of the limbs and trunk; slowed
movement; and impaired balance and coordination.
As the disease progresses, patients can have difficulty walking,
talking or doing other simple tasks, according to the U.S. National
Institute of Neurological Disorders and Stroke.
In deep brain stimulation, a surgeon implants a small device
called a neurostimulator under the skin near the collar bone. The
doctor then positions wires from the device with electrodes on
their ends in areas of the brain that control motor function. The
device works by electrically stimulating these areas, blocking
abnormal nerve signals that cause the tremor in Parkinson's disease
"Deep brain stimulation is still effective in improving motor signs in advanced Parkinson's disease patients 10 years after the surgery," said lead researcher Dr. Elena Moro, an assistant professor of neurology at the University of Toronto.
"However, this surgery does not stop the slow progression of the disease over time, as documented by the progressive loss of benefit that both deep brain stimulation and the drug levodopa show in improving walking, balance and speech over the years," she said. (Levodopa combined with carbidopa is the most widely used drug treatment for Parkinson's disease.)
Parkinson's disease patients who are considering deep brain
stimulation surgery should always ask their doctor how long the
benefit lasts after surgery, Moro said. "Our study can provide both
patients and physicians with this important answer," she said.
"Deep brain stimulation is not a cure but a symptomatic treatment," Moro said. "Parkinson's disease progresses over time."
Although deep brain stimulation is considered safe, like all
surgeries it carries some risks. Complications and side effects of
the surgery can include infection, bleeding in the brain, stroke,
seizures, speech and breathing problems, and heart problems,
according to Mayo Clinic. The report noted that two of the patients
in the study developed a serious device-related infection between 5
and 10 years after surgery.
The report was published in the Aug. 8 online edition of the
Archives of Neurology.
For the study, Moro and colleagues examined 18 patients with
advanced Parkinson's disease who were given implants for deep brain
stimulation in 1996 to 2000. The researchers assessed the patients'
motor function before implanting the device and again after one,
five and 10 years.
At the 10-year assessment, Moro's team found that deep brain
stimulation, along with medication, was tied to significantly
better motor function. However, there was some progressive
worsening of walking, posture and balance, the researchers
The authors also noted that the study's limitations included its
small size and the lack of a control group.
Commenting on the study, Dr. Michael S. Okun, medical director
of the National Parkinson Foundation, said that "this paper is
important as it underscores the potential long-term benefits that
may be achieved with deep brain stimulation."
The paper also shows that Parkinson's disease progressed despite
the deep brain stimulation, Okun said. "Patients should be aware
that deep brain stimulation is a potent symptomatic therapy with
long-term benefits, but is not a cure," he concluded.
Another expert, Frances Weaver, director of the Center for
Management of Complex Chronic Care at the Hines VA Hospital in
Illinois, said these results might not apply to all patients with
This group of patients was relatively young, she said. They were
diagnosed with Parkinson's disease at an average age of 40 and
received treatment with deep brain stimulation when they were in
their 50s, she said.
"The majority of persons with Parkinson's are diagnosed in their 60s," Weaver said. "This study includes a younger sample, likely representing more early-onset Parkinson's disease patients, and the results may not generalize to the overall Parkinson's disease population," she said.
Currently, there is no cure for Parkinson's disease and
treatment is focused on treating its symptoms.
For more information on Parkinson's, visit the
U.S. National Institute of Neurological Disorders and