Deep-Brain Stimulation Receives FDA Approval For Patients with Advanced
The U.S. Food
and Drug Administration (FDA) late yesterday approved a new form of
treatment, using a so-called "brain pacemaker", for patients in the
advanced stages of Parkinson's disease. In studies conducted at Emory
University and 17 other locations, the treatment, known as bilateral
deep-brain stimulation (DBS), has been shown to relieve slowness, stiffness
and shaking that are associated with the debilitating disease. While
the treatment moderates symptoms, it does not reverse the progression
of the disease and is not a cure.
Also known as Activa®
Parkinson's Control Therapy, the treatment involves surgical implantation
of electrodes into specific areas of the brain. Those electrodes are
connected to a pulse generator device, similar to a cardiac pacemaker,
under the skin and 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 Parkinson's disease,"
says Emory University neurologist Jerrold Vitek, M.D., Ph.D. "Those
regions are the internal segment of the globus pallidus and the subthalamic
Initial studies indicate
that stimulating either of these two regions can reduce slowness, stiffness
and tremor of Parkinson's disease, as well as drug-induced involuntary
A recent multi-site, international
study showed promising results in treating Parkinson's patients with
bilateral DBS. Emory University was one of 18 sites involved in the
study. From that study, data submitted to the FDA showed that Activaš
Parkinson's Control Therapy
safely and effectively improved movement control and mobility in patients
with advanced stages of the disease, when drugs alone proved inadequate.
Dr. Vitek served as principal investigator of the study at Emory.
Not all Parkinson's patients
need bilateral stimulation, however. "If patients only show tremor,
slowness and stiffness on one side, then the unilateral implant is enough,"
Dr. Vitek points out. "But if patients show symptoms on both sides,
then the bilateral stimulation is recommended."
In 1997, the FDA approved
unilateral stimulation in the thalamus for the treatment of tremor,
which consists of stimulating just one side of the brain. Now, with
the approval of bilateral stimulation in the subthalamic nucleus and
the internal segment of the globus pallidus to treat all the cardinal
motor symptoms of Parkinson's disease, this good technique becomes even
better, according to researchers.
The cause of Parkinson's
is unknown, but the symptoms stem from the degeneration of neurons or
brain cells that produce dopamine. Dopamine is a neurotransmitter that
enables communication among the brain cells involved in motor control.
Activa Therapy's electrical stimulation acts on these malfunctioning
circuits of the brain.
Doctors say this "brain pacemaker,"
created by Medtronic, Inc., is so promising because once implanted,
benefits can be optimized and side effects minimized by simply adjusting
the stimulation. Patients can turn the device on and off with a hand-held
magnet. If a side effect develops, the voltage can be lowered or other
parameters of stimulation changed. And the therapy is reversible, meaning
patients will be able to pursue new treatments that may be developed
in the years ahead.