Deep Brain Stimulation
The Movement Disorders Center at the University of North Carolina Hospitals, a Parkinson’s Foundation Center of Excellence, is proud to offer a state-of-the-art program for deep brain stimulation (DBS) therapy.
Deep brain stimulation therapy is used to treat a number of neurologic disorders. DBS in select brain regions has provided remarkable therapeutic benefits for otherwise treatment-resistant movement disorders such as Parkinson’s disease, tremor and dystonia. The Food and Drug Administration (FDA) approved DBS as a treatment for essential tremor in 1997, for Parkinson’s disease in 2002, and dystonia in 2003.
The DBS system consists of three components: the lead, the extension, and the implanted pulse generator (neurostimulator). The lead, also called an electrode, is a thin, insulated wire that is inserted through a small opening in the skull and implanted in the brain. The tip of the electrode is positioned within the targeted brain area. The extension is an insulated wire that is passed under the skin of the head, neck, and shoulder, connecting the lead to the neurostimulator.
The neurostimulator (the “battery pack”) is the third component and is usually implanted under the skin near the collarbone. The whole system lies under the skin. The pacemaker device delivers a constant fast-frequency stimulus to the tip of the electrode implanted in the brain. This stimulus interrupts a specific circuit in the brain that is overactive in the disease state. This interruption of the diseased overactive circuit can significantly improve the symptoms of the disease.
Deep brain stimulation is most beneficial for two types of Parkinson’s disease (PD) patients:
(1) patients with uncontrollable tremor for which medications have not been effective; and
(2) patients with symptoms that are well treated with medications, but who experience severe motor fluctuations, including wearing off and dyskinesias despite attempts to control such fluctuations with changes in medications.
DBS does not cure Parkinson’s, but it can help manage some of its symptoms and subsequently improve the patient’s quality of life.
Unlike previous surgeries for PD, DBS does not damage healthy brain tissue by destroying nerve cells. Instead, the procedure blocks electrical signals from targeted areas in the brain. Thus, if newer, more promising treatments develop in the future, the DBS procedure can be reversed. Also, stimulation from the neurostimulator is easily adjustable without further surgery if the patient’s condition changes. Some people describe the stimulator adjustments as “programming.”
Although most patients still need to take medication after undergoing DBS, many PD symptoms improve after DBS and often times the daily dose of anti-Parkinson’s medications is reduced. The amount of reduction varies from patient to patient but can be noticeably reduced in most patients. The reduction in dose of medication leads to a significant improvement in side effects such as dyskinesias (involuntary movements caused by long-term use of levodopa). In some cases, the stimulation itself can suppress dyskinesias without a reduction in medication.
DBS is also used to treat essential tremor. In many cases, the tremor is mild enough to be effectively treated with medication. However, in severe cases medications may not be effective and tremor can become profoundly disabling. Patients may need help with all activities of daily living such as dressing, bathing or driving a car. Patients may also have frequent spills when eating or drinking. When essential tremor is severe, DBS may improve a patient’s ability to perform daily activities.
The UNC Department of Neurology works with Dr. Robert K. McClure in the Department of Psychiatry to determine an OCD patient’s candidacy for DBS. Potential candidates are those with severe OCD refractory to multiple medications and behavioral therapies. We were one of the first centers in the United States to perform this operation for OCD.
DBS is an FDA-approved therapy for dystonia. It can be performed for both generalized and focal dystonia. Dystonia can be very disabling due to impairment of motor skills as well as significant pain. There are multiple medications along with botulinum toxin that can be effective to treat dystonia. When medications or other non-surgical therapies are not successful, deep brain stimulation can be a very effective treatment.
All patients considering DBS for dystonia will be evaluated by a neurologist who specializes in movement disorders to determine a patient’s candidacy for the treatment. The neurologist will provide a lot of information to the patient and their family about DBS therapy and may also make some nonsurgical treatment recommendations. If a patient is considered a good candidate, they will also meet with the neurosurgeon who will assess their benefits and risk of surgery.
Patient Evaluation
All patients considering DBS must be evaluated by a neurologist who specializes in movement disorders. The evaluation is necessary to determine whether the patient suffers from Parkinson’s disease, essential tremor, or generalized dystonia rather than one of the less common, but similar, movement disorders. A cognitive evaluation is important in order to assess the patient’s ability to participate accurately and actively in the surgical implantation of the stimulator, as well as in the post-operative process of programming the stimulator. Lastly, a neurosurgeon will evaluate the patient to assess the risks and benefits of surgery as well as to clarify the expected outcomes of surgery.
DBS Educational & Support Group
The UNC Movement Disorders Center facilitates a meeting about twice per year for people with Parkinson’s (and occasionally for people with essential tremor who have already undergone DBS surgery) and their family members to gather, learn and relate. We have a different expert presenter for each group. Meetings are held at the Seymour Senior Center on Homestead Road in Chapel Hill.
For more information or to be placed on the group’s listserv to be notified about upcoming meetings, please contact the center coordinator, Maggie Ivancic, MSW, LCSWA, at (919) 843-1657 or mivancic@neurology.unc.edu.