Deep brain stimulation (DBS) is a surgical procedure used to treat a variety of disabling neurological symptoms—most commonly the debilitating symptoms of Parkinson’s 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.
DBS does not damage healthy brain tissue by destroying nerve cells. Instead the procedure blocks electrical signals from targeted areas in the brain.
At present, the procedure is used only for patients whose symptoms cannot be adequately controlled with medications.DBS uses a surgically implanted, battery-operated medical device called a neurostimulator—similar to a heart pacemaker and approximately the size of a 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 neurosurgeon uses magnetic resonance imaging (MRI) or computed tomography (CT) scanning to identify and locate the exact target within the brain where electrical nerve signals generate the PD symptoms.
Some surgeons may use microelectrode recording—which involves a small wire that monitors the activity of nerve cells in the target area—to more specifically identify the precise brain target that will be stimulated.
Generally, these targets are the thalamus, subthalamic nucleus, and a portion of the globus pallidus.
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.
The DBS system consists of three components:
There are many brain targets that the DBS lead may be placed within; which one should you choose?
View pictorial representations of each of the three main DBS targets used in Parkinson’s disease (figures were used with permission of Dr. Okun).
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). There is a 1-3% chance of infection, stroke, cranial bleeding, or other complications associated with anesthesia, per side that is done. It is best to discuss the risks associated with your neurologist because there are many risk factors, including underlying medical conditions.