Deep Brain Stimulation (DBS) Using a Brain Pacemaker for Parkinson's Disease and Other Neurological Movement Disorders

A brain pacemaker is a medical device used in neurosurgery. Surgeons implant electrodes into the patient’s brain that are connected to a pulse generator. This generator is located in the chest area and sends electrical impulses to the brain at regular intervals.

Depending on the frequency of the electrical current, the brain pacemaker either stimulates the affected region of the brain or deactivates it. The brain pacemaker is reversible, meaning doctors can remove it later. In 1995, a brain pacemaker was approved for the first time in the EU for the treatment of essential tremor.

Tremor is a condition characterized by muscle tremors with no known cause. In 1998, approval followed for treatments for Parkinson’s disease.

It is now used to treat several conditions:

• Parkinson’s disease
• Tourette syndrome
• Essential tremor
• Tremor associated with multiple sclerosis
• Dystonia
• Epilepsy
• Obsessive-Compulsive Disorder

In addition, studies are underway on the use of deep brain stimulation in patients suffering from the following conditions:

• Addiction syndrome (following drug use)
• Cluster headaches or
• Depression

Electrodes and leads are connected to a neurostimulator inside the skull © RFBSIP | AdobeStock

The primary target group for brain pacemakers is people over 60 with Parkinson’s disease who have been living with the condition for many years. If prescribed medications are no longer effective or if the patient is struggling with severe side effects, surgery may be considered. Studies by German and French neurologists show that the procedure can also be beneficial for younger people. 

A brain pacemaker is particularly helpful for younger people with:

• Obsessive-compulsive disorder
• epilepsy, or
• Tourette syndrome

According to these findings, even patients who have only recently been diagnosed can benefit from a brain pacemaker.

Study participants reported:

• an improved quality of life
• greater mobility, and
• increased activity in daily life

In addition, patients were able to significantly reduce their medication intake.

People with epilepsy benefit from deep brain stimulation @ Tunatura /AdobeStock

The brain pacemaker essentially consists of three parts:

1. Electrodes
2. Extension
3. Neurostimulator

The brain pacemaker may contain one or more electrodes. These are thin wires that are placed by the neurosurgeon with millimeter precision in the target region of the brain.

The extension leads also consist of a thin cable and connect the electrodes to the neurostimulator. They run under the skin, extending from the head down the neck to the chest area.

The neurostimulator is usually located under the collarbone. The device contains electronic circuits and a battery. The neurostimulator is the actual brain pacemaker and generates electrical impulses that travel through the extension to the electrode.

Settings are adjusted using a programming device that allows the doctor to make adjustments externally. The patient is usually also given a small device. This allows the patient to turn the neurostimulator on and off or adjust the stimulation. The mechanism of action of the brain pacemaker is not yet fully understood, although various theories are under discussion.

The primary purpose of the brain pacemaker is to reduce motor symptoms in Parkinson’s disease, an incurable condition. In Parkinson’s, atrophied nerve cells in the brain can no longer produce sufficient amounts of the neurotransmitter dopamine. 

This results in typical symptoms such as:

• muscle stiffness
• Bradykinesia, or
• Tremors

Medications can usually keep the symptoms under control. However, after years of use, the effectiveness of the medications decreases. As a result, periods of poor and good mobility alternate (fluctuations). Patients do not know when or to what extent the symptoms will recur. They often end up leaving the house less frequently and suffer increasingly from the disease.

A brain pacemaker may be the solution at this stage of the disease. Deep brain stimulation stimulates the basal ganglia (brain regions important for movement). This significantly reduces symptoms. Studies show that the electrical impulses reduce symptoms in up to 80 percent of cases.

As a result, they lead to significantly improved mobility:

• reduction of tremors, akinesia, and muscle rigidity
• Extending periods of good mobility
• Shorter periods of poor mobility
• Reduction of uncontrolled movements (dyskinesias)
• Improved quality of life and ability to perform daily activities
• Reduced need for medication

Deep brain stimulation can provide relief for people with severe and debilitating tremors @ Alessandro Grandini /AdobeStock

The implantation of a brain pacemaker is performed in two steps. 

1. First, under local anesthesia, doctors place the electrodes. The neurosurgeon drills small holes in the skull and inserts the electrodes. To ensure optimal positioning, the surgeon performs a magnetic resonance imaging (MRI) scan and/or a computed tomography (CT) scan at the same time. 

During this phase, the patient is usually fully conscious. This allows them to provide the surgeon with helpful feedback on the physical effects of the electrode placement.

2. The second step of the implantation follows immediately afterward or the next day. Under general anesthesia, the surgeon then implants the extension lead and the neurostimulator.

The basic settings of the neurostimulator are configured during the surgery. The doctor and the patient work together to determine the fine-tuning settings in the weeks that follow. Depending on the model, the batteries in the neurostimulator can last up to seven years. They are replaced later under local anesthesia.

Deep brain stimulation is not without controversy, as it does carry some risks. The procedure can result in vascular injury and bleeding.

This, in turn, can cause paralysis or speech disorders. There is also a risk of epilepsy or encephalitis or meningitis. It is also possible for the electrodes to slip or be misplaced, necessitating a further procedure.

The electrodes can cause side effects. Depending on their location, speech, vision, or sensory disturbances may occur. 

Patients also report:

• Difficulty performing multiple tasks at once
• Increased impulsivity
• Irritability or
• impatience 

For these reasons, it is important that this procedure be performed by highly specialized professionals.

What is a brain pacemaker?

A brain pacemaker is an implanted device used for deep brain stimulation. Similar to a cardiac pacemaker, the system sends electrical impulses that stimulate specific regions of the brain via electrodes. Deep brain stimulation is primarily used to treat neurological movement disorders such as Parkinson’s disease, dystonia, or essential tremor.

How does deep brain stimulation work?

In deep brain stimulation, two thin electrodes are implanted into specific regions of the brain using a stereotactic procedure. The electrodes are often located in the brain near the subthalamic nucleus or the thalamus. The electrical stimulation modulates pathologically altered signals in the brain and can improve symptoms such as tremor or movement disorders. Internationally, this procedure is also known as deep brain stimulation.

What does the surgery to implant a brain pacemaker involve?

The implantation of a brain pacemaker is performed as part of a neurosurgical procedure. First, the electrodes are inserted into the brain, and their positioning is verified. The pulse generator is then implanted beneath the collarbone and connected to the electrodes. Depending on the clinic, the surgery is performed under local anesthesia or in combination with other anesthetic methods.

For which conditions is DBS used?

Deep brain stimulation is primarily used to treat Parkinson’s disease, dystonia, and essential tremor. In addition, deep brain stimulation is being investigated as a treatment for certain neurological disorders. The method is also used or being researched in specialized centers for epilepsy, depression, and obsessive-compulsive disorder. However, the treatment of movement disorders remains one of the most common applications.

What are the risks and side effects of a brain pacemaker?

Like any surgery, the implantation of electrodes carries risks. Possible side effects include infections, bleeding, or temporary neurological symptoms. After the brain pacemaker is implanted, adjusting the stimulation parameters may occasionally cause unwanted effects. Regular follow-up visits at a neurology or neurosurgery clinic usually allow for effective management of risks and side effects and optimal adjustment of the stimulation.