An international, multisite study is showing promising results in treating
patients with advanced stages of Parkinsons disease. Emory was selected
as one of 18 institutions to study the effects of a treatment called deep-brain
stimulation (DBS) on Parkinsons patients. The complete findings
of the trial were reported in the Sept. 27 issue of The New England
Journal of Medicine.
DBS involves surgical implantation of electrodes into specific areas of
the brain. These electrodes are connected to a pulse-generator device
(similar to a cardiac pacemaker) under the skin near the collarbone.
The DBS device delivers controlled electrical stimulation to regions
of the brain involved in the development of the motor symptoms associated
with Parkinsons disease: the internal segment of the globus pallidus
and the subthalamic nucleus, said neurologist Jerrold Vitek, associate
professor of neurology and principal investigator of the Emory arm of
Initial results indicate that stimulating either of these two regions
can reduce slowness, stiffness and tremor of Parkinsons disease,
as well as drug-induced involuntary movements.
The study, which concluded in 1999, was carried out in patients whose
condition could not be further improved with medication alone. The trials
duration included enrollment, study time and follow-up phases. The majority
of participants were enrolled in Europe; approximately 25 patients were
enrolled in the United States.
DBS has been approved by the Food and Drug Administra-tion (FDA) only
for use in the thalamus to treat tremor, which consists of stimulating
just one side of the brain.
We hope this studys positive outcome will encourage the FDA
to move toward approving DBS on both sides of the brain, as well as the
sites tested in this study, and not just a single side or site,
said Mahlon DeLong, chair of the Department of Neurology and a longtime
researcher of Parkinsons disease.
Patients who are the best candidates for DBS are those whove
reached the end of their rope with medication and are constantly plagued
with complications of medical therapy, DeLong said.
This device is promising because, once implanted, benefits can be optimized
and side effects minimized by adjusting stimulation parameters. If a side
effect develops, the voltage can be lowered or other parameters of stimulation
Vitek and DeLong said this study shows significant potential in treating
patients with Parkinsons disease. Since there is no cure to this
degenerative neurological disorder, both doctors believe DBS offers new
hope to patients in whom medical therapy is no longer adequate in controlling
the symptoms of Parkinsons.