Surgery for Parkinson's disease available at MUSC
Parkinson’s disease patient William Walters of Charlotte, N.C., can get out of bed and walk rather than slowly shuffle, and he can cut and eat his own food instead of depending on his wife’s assistance.
Bill
Walters with five-year-old son, Walt, and wife, Vicki.
The dramatic changes in his quality of life, which he describes as nothing short of miraculous, are thanks to a deep brain stimulation procedure done at MUSC.
MUSC has successfully done six deep brain stimulation implantations for Parkinson’s Disease since Dec. 7 and is the only center in the state doing the procedure. The device used to stimulate the brain—Activa Parkinson’s Control Therapy—was approved for treatment of the general symptoms of Parkinson’s Disease by the U.S. Food and Drug Administration on Jan. 14, 2002. The system was approved for tremor control since 1997 and has been in very limited use for other symptoms of Parkinson's disease.
“This
is a major advance in the treatment of Parkinson’s Disease,” said MUSC
neurologist, Kenneth Bergmann, M.D. “The deep brain stimulation doesn’t
cure Parkinson’s Disease, but treats the disabling symptoms of the disease
with few side effects. For patients in advanced stages of Parkinson’s the
available medications alone are not adequate and frequently produce significant
and unacceptable side effects.”
In the late stages of the disease, when symptoms are at their worst, patients often experience random episodes of inability to move or involuntary motion as a side effect of Parkinson’s medication. The uncontrollable shaking and flailing that rack their bodies can lead to avoidance of public situations and self-isolation. Eventually, the combination of symptoms and side effects can cause patients to become totally dependent on others for their care.
The procedure—bilateral subthalamic nucleus (STN) stimulation—improves tremor, slowness, stiffness and walking difficulty in Parkinson’s disease patients. The therapy delivers carefully controlled pulses of electrical stimulation to precisely targeted areas deep within the brain which are involved with motor control.
Electrodes are surgically implanted in that area of the brain. Two insulated extension wires connect these electrodes to two implanted pulse generators or batteries (similar to a cardiac pacemaker) placed under the skin just beneath the collar bone.
The
electric stimulus delivered, just like doses of medication, can be changed
in response to changes in the patient’s condition. The deep brain stimulator
is regarded as a form of medication and its settings are monitored by the
patient’s neurologist along with other drugs they are taking. MUSC neurosurgeon
Steve Takacs, M.D., calls the procedure “electro-pharmacology.”
Takacs does the procedure in a different manner than most surgeons, using a technique he developed while at the University of Arizona. Deep brain stimulation implantation is more commonly performed in a staged fashion with lead implantation on one side followed by generator implantation two to three weeks later,” he explained. Then treatment of the other side is done in the same sequence.
“The reason for staging the implantation is that with the traditional targeting techniques, precise placement of one electrode may require between six and 12 hours with microelectrode mapping of the target.”
Takacs’ technique relies on an MRI-based imaging protocol, allowing visualization of the target with a minimum of mapping by microelectrode recording. “This radically reduces the length of surgery and allows us to complete all procedures in one operative session,” said Takacs. “The number of needle penetrations of the brain is reduced to a minimum, and the patient only has to be fitted in a head frame once, enduring only one MRI imaging session as both targets are determined simultaneously. The number of hospital admissions is reduced. More important, complications have been fewer with this method and clinical outcomes have been equivalent to that of other centers.”
But Takacs said the surgical procedure is just one part of the treatment and cannot be done in a vacuum. He feels the procedure should only be done in a center like MUSC with a comprehensive movement disorders program providing multi-disciplinary care for patients with Parkinson’s disease and other movement disorders. The patient who receives the deep brain stimulation surgery enters a long-term relationship with the medical team since constant monitoring is essential,” he said.
Parkinson’s disease affects an estimated one and a half million Americans. Its causes are unknown, but the symptoms stem from the degeneration of the brain cells that produce dopamine. Dopamine is a neurotransmitter that enables communication between the brain centers involved in motor control. The Activa Therapy’s electrical stimulation acts on these malfunctioning circuits in the brain.
“In early stages of Parkinson’s Disease, medication therapy is very effective,” explained Bergmann. “But our patients are very concerned about the future. They want to know whether they can get symptom relief when they get to the point where medical therapy is no longer effective. We can now reassure these patients that they can receive symptom relief down the road.”
Another advantage of the procedure is that it is reversible. There
is no destruction of brain tissue. Should a cure for the disease or a better
method of symptom control be found in the future, the stimulation system
can be removed.