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A/Prof David R Williams |
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Surgery for Parkinsons disease & tremor |
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What is Deep Brain Stimulation? Deep brain stimulation (DBS) is a surgical procedure used to treat a variety of disabling neurological symptoms, most commonly the debilitating symptoms of Parkinsons disease (PD), such as tremor, rigidity, stiffness, slowed movement, and walking problems. The procedure is also used to treat essential tremor, a common neurological movement disorder. At present, the procedure is used only for patients whose symptoms cannot be adequately controlled with medications. It is a well established procedure, with over 50,000 operations having been done world wide, and over 500 in Australia. DBS uses a surgically implanted, battery-operated medical device called a neurostimulator, similar to a heart pacemaker and approximately the size of a small stopwatch, to deliver electrical stimulation to targeted areas in the brain that control movement, blocking the abnormal nerve signals that cause tremor and PD symptoms. Before the procedure, A/Prof Williams and the neurosurgeon use magnetic resonance imaging (MRI) and computed tomography (CT) scanning to identify and locate the exact target within the brain where electrical nerve signals generate the PD symptoms. Microelectrode recording (which involves a small wire that monitors the activity of nerve cells in the target area) is used to more specifically identify the precise brain target that will be stimulated. This target can be one of several parts of the brain circuits for movement, either the thalamus, subthalamic nucleus, and globus pallidus. The DBS system consists of three components: the lead, the extension, and the 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. In some cases it may be implanted lower in the chest or under the skin over the abdomen. Once the system is in place, electrical impulses are sent from the neurostimulator up along the extension wire and the lead and into the brain. These impulses interfere with and block the electrical signals that cause PD symptoms. Is there any permanent nerve damage from treatment? 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 patients condition changes. Some people describe the stimulator adjustments as "programming." What is the prognosis? Although most patients still need to take medication after undergoing DBS, many patients experience considerable reduction of their PD symptoms and are able to greatly reduce their medications. The amount of reduction varies from patient to patient but can be considerably 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. What research is being done? Ongoing research on DBS is being done in many centres, including in Melbourne, and you may be asked to enroll in one of our observational trials. Many scientists are trying to determine the site(s) in the brain where DBS surgery will be most effective in reducing PD symptoms. Where do I get more information? Click on any of the links on the right of this page for further information about DBS. We would be happy to put you in contact with people willing to discuss their experience with DBS. |
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Worldwide Education & Awareness for Movement Disorders deep brain stimulation |
