Deep Brain Stimulation

What is Deep Brain Stimulation?

Deep brain stimulation (DBS) refers to a neurosurgical procedure that surgically implants electrodes into the specific target areas of the brain. This electrode continuously sends a constant or intermittent electrical pulse to the brain for controlling abnormal brain activity. For this reason, this sometimes referred to as a brain pacemaker.

Approved by the US Foods and Drug Administration (FDA), this brain stimulator helps to treat some neurological conditions such as Parkinson’s disease (PD), essential tremor, and sclerosis. Also, this helps to treat multiple movement disorders like tremors, stiffness, difficulty in walking, epilepsy, dystonia, and slowed movement. DBS helps to ease symptoms of certain conditions and reduce the amount of medicine you need. DBS provides many advantages over other surgical interventions for neuromodulation as a clinical tool ¹.

The DBS system includes three different components ²:

1. The electrode or lead: A thin, insulated wire inserted into the skull through a small opening and implanted into one or two target areas of the brain. This includes four platinum-iridium electrodes. The placement of the leads in the brain varies according to the symptoms.
2. The extension wire: An insulated wire that placed in one or two different areas of the brain and runs under the skin of the head, neck, and shoulder to make a connection between the electrode and implanted pulse generator (IPG).
3. The implanted pulse generator (IPG): This battery-powered neurostimulator implanted under the skin in the upper chest that sends electrical pulses to the brain and regulates neural activity at the specific target area.

Who needs Deep Brain Stimulation?

Every year hundreds of thousands of people suffer from certain untreatable neurological conditions who require deep brain stimulation as a last hope. To date, over 160,000 people used deep brain stimulation techniques for various neurological conditions ³. You may need deep brain stimulation (DBS) if you suffer from:

• The symptoms of Parkinson’s disease for over 5 years.
• A long-term movement disorder with tremor or stiffness, and your medications already lost their effectiveness.
• Troubling “on” or “off” fluctuations, with or without developing dyskinesia (an excessive twisting of the muscles of the hand, limb, or head).

Before considering a patient for a candidate for deep brain stimulation (DBS), a team of specialists including a neurologist, neuro-psychologist, and neurosurgeon will test the patient’s condition to determine whether the patient suits for this surgery. They will consider the patient’s thinking ability, current medication, and overall health. Before making the final decision, they will perform videotaping to see a variety of movements of the patient. After an extensive discussion, the team will decide about DBS surgery.

How is the Deep Brain Stimulation technique performed?

The entire DBS surgery requires an expert neurosurgeon, a neurologist, an anesthesiologist, and a surgical assistant to perform successfully. The surgery itself will require about 3 to 4 hours, but the entire process may take about 7 to 8 hours. The process includes ⁴:

• Attaching a stereotactic frame to your head with four pins to perform this procedure stereotactically.
• The team will perform a computerized tomography (CT) or magnetic resonance imaging (MRI) scan. The surgeon will use the MRI images to plan the trajectory of the electrode.
• Then the patient will lie on the table and the surgeon will secure the stereotactic head frame to prevent any kind of movement while inserting the electrodes.
• The patient will awake during the surgery.
• Surgeon will shave the surgical site in your head and use light sedation during the skin incision.
• Surgeon will give a small incision across the top of the head to expose the skull.
• Surgeons will make two quarter-sized burr holes on the left and right sides of the skull by using a drill.
• They will insert a recorded electrode precise depth and angle through the small opening inside the brain.
• After testing the accuracy of the recording electrode, they will replace this with a permanent DBS electrode or lead.
• After getting full satisfaction, the team will close the incision with sutures or staples and apply a bandage.

About 1 week later, the patient needs to revisit the hospital to implant the stimulator under his chest or abdomen. This process needs general anesthesia to perform accurately. A small incision requires for placing a neurostimulator under the skin of the chest, and the scalp needs to reopen to access the leads and connect these with an extension wire.

During any operations, complications may happen. General complications of this surgery include bleeding, infections, hemorrhage, stroke, seizure, etc. Infections after DBS implantation and IPG replacement encountered about 3% and 0.8% of patients in this study ⁵. Additional surgery may require due to the breakage of the extension wire and removal of the device due to infection or hardware malfunction.

Your surgeon will remove the stitch after 2 weeks from the incision area. This operation requires 6 weeks to heal completely. You need to keep the surgical area dry and clean to avoid any infection. A regular course of antibiotics may require to avoid any post-surgical infections. Consult with your doctor about any queries regarding your post-operative complications.

References

1. Bernstein, J. E., Kashyap, S., Ray, K. & Ananda, A. Infections in Deep Brain Stimulator Surgery. Cureus 11, 1–8 (2019).
2. Park, S. C. et al. Deep learning-based deep brain stimulation targeting and clinical applications. Front. Neurosci.13, (2019).
3. Lozano, A. M. et al. Deep brain stimulation: current challenges and future directions. Nat. Rev. Neurol. 15, 148–160 (2019).
4. Pycroft, L., Stein, J. & Aziz, T. Deep brain stimulation: An overview of history, methods, and future developments. Brain Neurosci. Adv. 2, 239821281881601 (2018).
5. LISTIK, C. et al. Deep brain stimulation treatment in dystonia: a bibliometric analysis. Arq. Neuropsiquiatr. 586–592 (2020) doi:10.1590/0004-282×20200016.