New Hope for Parkinson's Patients
Strong Physicians Implant "Brain Pacemakers" to Reduce Symptoms
February 06, 2002
The FDA recently put its stamp of approval on a revolutionary treatment that can enhance the quality of life for patients in the advanced stages of Parkinson's disease. Deep Brain Stimulation therapy involves implanting an electrode device in precisely targeted areas of the brain to deliver carefully controlled pulses of electrical stimulation to relieve the debilitating slowness, stiffness and shaking that characterize Parkinson's. This presents a whole new treatment option for advanced Parkinson's disease patients, and also is the first time where motor function is actually further improved.
"From my perspective, this is the single biggest advancement in treatment for Parkinson's in the last decade," said Dr. Timothy Counihan, assistant professor of neurology at the University of Rochester Medical Center (URMC) and co-director of the Strong Surgical Treatment Program for Movement Disorders. "For most patients, medication eventually becomes ineffective as the disease progresses, leaving the person with no real treatment alternatives but a slow, inexorable deterioration. Deep Brain Stimulation provides a marked improvement in motor function, allowing many patients to achieve a better quality of life."
According to Counihan, clinical trials using the electronic implants have shown that patients have up to a 60 percent improvement in motor function (as measured by the standard Unified Parkinson's Disease Rating scale) three years following the surgery, despite a substantial reduction in their medication usage, and despite the fact that the disease progressed during the same three-year period.
Dr. Robert Bakos, associate professor of neurosurgery at URMC, says that the surgery is unique because the patient is awake to help guide the placement of the electrodes.
"We use computers to pinpoint the specific area on the brain for placement of the electrodes, but then we work with the patient during the surgery to find the precise area that is the major source of Parkinson's disease symptoms," Bakos said. "We then ask the patient to hold a coffee cup or write on a pad as we fine-tune the electric impulse."
This surgery is followed by another minor procedure, where the electrodes are connected by lead wires under the skin to a pulse generator-similar to a pacemaker-implanted under the collarbone. Medtronics Inc. of Minneapolis, makes the device, called Activa Parkinson's Control Therapy.
"Because the amount of electricity is adjustable, we can provide significant symptom relief while minimizing side effects," Dr. Bakos added. "And the therapy is reversible, which means patients will be able to pursue new treatments that may be developed in the years ahead."
A Debilitating Disease
One million Americans are estimated to have Parkinson's disease, a progressive and degenerative movement disorder which gradually robs patients of their independence. The cause of Parkinson's is unknown, but the symptoms stem from the degeneration of neurons (brain cells) that produce dopamine. Dopamine is a neurotransmitter that enables communication among the brain cells involved in motor control. The electrical stimulation acts on the malfunctioning circuits in the brain.
Patients are typically put on medication to control the symptoms, however, after a long period of time-10 to 20 years-drugs become ineffective. In these late stages of the disease, patients often experience uncontrollable shaking and flailing as a side effect of Parkinson's medication. The combination of symptoms and side effects lead to avoidance of public situations and self-isolation, and eventually can cause patients to become totally dependent on others for their care.
To date, about 15,000 people worldwide have been implanted with "brain pacemakers" to treat their disease in Europe, Canada and Australia since 1995. Doctors at Strong Memorial Hospital have a waiting list of 20 people eligible for the surgery, and are working with insurance companies to provide coverage before scheduling the surgery. Medicare is currently working on its payment policy as well.