Deep Brain Stimulation (DBS) Surgery

Deep Brain Stimulation (DBS) Surgery Overview

Deep brain stimulation (DBS) is a neurosurgical treatment in which electrodes are implanted in an area of the brain and connected to a pulse generator—a pacemaker-like device placed under the skin, just below the collarbone. This pulse generator is then programmed to deliver electrical pulses into the targeted areas of the brain.

These pulses change the brain’s electrical activity pattern to regulate abnormal signals that are caused by Parkinson’s disease, dystonia, essential tremor, and epilepsy.

The DBS device consists of three distinct parts:

1. The electrode or lead: A thin, insulated wire inserted through a small opening made in the skull and implanted in a specific area of the brain, depending on the disorder.
2. The extension: This is an insulated wire passed under the skin of the head, neck, and shoulder, connecting the lead to the implanted pulse generator.  
3. The pulse generator: The “battery pack” of the treatment, the pulse generator is most commonly implanted under the skin beneath the collarbone. 

Deep brain stimulation aims to improve disease symptoms and medication side effects, although in some cases, treatment addresses one but not both. In movement disorders like Parkinson’s disease, dystonia, or essential tremor, symptoms can include rigidity, tremor, and dystonic movements; involuntary, erratic, or twisting movements of the face, arms, legs, or trunk (dyskinesias), and motor fluctuations. In epilepsy, DBS works to reduce the overall seizure burden, including the frequency, severity, and duration of seizures.

Your healthcare provider may also explore DBS when medications are ineffective or initially effective but become less effective, or their side effects interfere with daily activities.

While DBS is a surgical treatment and all surgeries have risks, the risks associated with it are relatively low. Treatment won’t cure your condition, but it can offer significant relief. Medication may still be needed to help manage symptoms, although it’s often taken at reduced dosages following the DBS procedure.

With asleep DBS, the goal is to preoperatively plan the placement of the electrodes in the targeted areas. Asleep DBS surgery is performed while a patient is under general anesthesia and a computed tomography (CT) machine is used to target and verify the placement of electrodes during surgery.

Here’s how it works:

1. Preoperative imaging: Prior to surgery, your medical team will use highly detailed magnetic resonance imaging (MRI) or CT imaging to precisely locate the areas of your brain where the electrodes should be implanted.
2. Electrode implantation: Under anesthesia, your neurosurgeon will attach a stereotactic frame to your head to keep it still and guide the placement of the electrodes to the precise location established during preoperative planning. A small hole is drilled in your skull after the frame is placed and the electrodes are gently positioned in the correct location in your brain using image guidance and metal attachments that connect to the stereotactic frame. 
3. Programming: After the electrodes are successfully implanted, they’reconnected to the pulse generator, the pacemaker-like device implanted just below your collarbone. Once you’ve recovered from the procedure, your medical team will program the pulse generator to deliver the appropriate amount of electrical impulses to relieve your symptoms.
4. Follow-up care: Most patients are required to stay in the hospital for one day after surgery. Frequent follow-up appointments with your medical team are also scheduled to monitor your progress and adjust the pulse generator for the best settings specific to you. You may even see a reduction in medication usage following DBS surgery.

Overall, asleep DBS offers a more comfortable and less stressful patient experience. Even if you’re not apprehensive about the prospect of awake brain surgery, research has shown no additional benefits to choosing awake surgery over asleep surgery.

In other words, good candidates for DBS almost always make excellent candidates for asleep DBS.

DBS for Movement Disorders

When it comes to movement disorders, DBS can target specific areas that control movement—like the subthalamic nucleus (STN), the globus pallidus internus (GPi), or the ventral intermediate nucleus (VIM) of the thalamus—and modulate the dysfunctional neural circuits causing symptoms. This, in turn, leads to improved motor control because the stimulation normalizes electrical activity.

DBS has been shown to be highly effective in reducing motor symptoms in movement disorders like Parkinson’s, frequently resulting in a significant reduction in medication.

DBS for Epilepsy

The goal of DBS in epilepsy is to interrupt the abnormal electrical activity that leads to seizures and reduce their frequency, intensity, and duration; particularly when seizures are drug-resistant. Common target areas include the anterior nucleus of the thalamus (ANT) and the centromedian nucleus (CM) of the thalamus. However, the type of epilepsy and the specific patterns of seizure activity will determine an individual’s targeted areas.

While the efficacy of DBS for epilepsy can vary—it’s reported to reduce seizure frequency by nearly 50 percent in many patients—complete eradication of symptoms is less common than with DBS for movement disorders.

Programming and Adjustment

DBS systems for both movement disorders and epilepsy require careful programming and regular adjustments to optimize the effects of deep brain stimulation. That said, system settings will vary across different diseases, their objective targets, and within each patient, depending on their desired outcomes.