Deeper Dive: Deep Brain Stimulation

Deep brain stimulation (DBS) is a surgical procedure in which a device is implanted in a person to deliver electrical pulses to the brain to decrease motor symptoms of Parkinson’s disease (PD). Generally, DBS improves symptoms that had previously responded to medicine, like levodopa therapy.1,2

The electrical pulses are targeted to the areas of the brain that control movement to block abnormal signals that cause symptoms like:2

Areas of the brain that may be targeted include the subthalamic nucleus and the globus pallidus. The exact placement of the stimulation is based on each person’s specific needs.2

Who benefits from deep brain stimulation?

DBS may be considered for people who have had PD for 4 years or more and have:3

  • Significant “off” periods when their medicine is not working well
  • Dyskinesias (uncontrolled, abnormal movements)

Dyskinesias are a common side effect of long-term levodopa therapy. DBS can help relieve motor symptoms like:3

  • Stiffness or rigidity
  • Slowness (bradykinesia)
  • Tremor

It does not work well to treat balance impairments, freezing when walking, or non-motor symptoms of PD. Because DBS can worsen cognition or memory problems, it is not recommended for people with dementia.3

Both a neurologist and a neurosurgeon evaluate people with PD who may be candidates for DBS. Evaluation includes:3

  • Reviewing medicines and symptoms
  • Brain scans using magnetic resonance imaging (MRI) or computed tomography (CT) scans
  • Memory and thinking tests

The 3 parts of deep brain stimulation

There are 3 components to DBS:2

  • The lead or electrode – This is a thin, insulated wire that is implanted in the brain.
  • The extension – This is also an insulated wire. It is placed under the skin and connects the lead to the neurostimulator.
  • The neurostimulator or battery pack – This is implanted under the skin, usually near the collarbone. The neurostimulator gives the electrical pulse, which is carried through the extension wire to the lead in the appropriate location in the brain.

Figure 1. Deep brain stimulation

Components of deep brain stimulation, including the deep brain stimulation lead, extension, and neurostimulator

The procedure of deep brain stimulation

During surgery, the electrodes are placed into the brain. The battery-operated neurostimulator and extension wires are also placed into the person's body. The person undergoing the procedure may remain awake or may be under general anesthesia.2,3

A few weeks after the procedure, the neurostimulator’s settings are fine-tuned using a handheld programmer. The settings may be adjusted over time to determine the best combination of electrical stimulation and medicine for the person.2,3

The benefits of deep brain stimulation

Many people who receive DBS are able to reduce their medicine after the procedure. However, most still need to take some medicine. Many people experience a significant reduction in their motor symptoms. Reducing medicine after DBS also lessens the side effects of those drugs.2,3

The risks of deep brain stimulation

There are potential risks with DBS, including:2,3

  • Bleeding
  • Stroke
  • Infection
  • Complications associated with anesthesia

People considering DBS should discuss the risks and benefits of the procedure with their surgeon.2,3

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Written by: Emily Downward | Last reviewed: May 2021