Deep Brain Stimulation

What is Deep Brain Stimulation?

Deep brain stimulation (DBS) is a surgical procedure used for the treatment of movement disorders and a variety of other disabling neurological symptoms 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. 

During a DBS treatment, the brain is accessed using craniotomy surgery. Electrodes are implanted in the brain to deliver electrical impulses that block abnormal activity in the brain that causes movement disorder symptoms. By working as a "brain pacemaker," the electrodes offer relief from tremors, rigidity, slow movement, stiffness and balance problems. The stimulation can be adjusted as a patient's condition changes over time.

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 Parkinson's disease (PD) symptoms. 

Before the treatment, 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 globus pallidus.

The DBS system consists of three components:

  • the lead
  • the extension
  • the neurostimulator.

The lead (also called an electrode)—a thin, insulated wire—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, connectng 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.

Unlike previous surgeries for PD, DBS does not damage healthy brain tissue by destroying nerve cells.  Instead the Parkinson's Disease treatment 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."

Intrathecal pumps are also being used to treat spasticity, which is sometimes difficult to treat with medications. The pumps deliver a stable dose of drug directly to the spinal cord, offering fewer side effects due to lower dosing.

Some information provided by the National Institute for Neurological Disorders and Stroke.