This is a procedure where electrodes are placed in targeted areas in brain, connected by wires to a type of pacemaker device (called an impulse generator, or IPG) implanted under the skin of the chest, below the collarbone. Globus pallidus interna and the subthalamic nucleus are the target areas in Parkinson's disease. The target for DBS in dystonia is the Globus pallidus interna and treatment of essential tremor usually targets the thalamus. Once activated, the device sends continuous electrical pulses to the target areas in the brain, modifying the brain circuits that are responsible for motor symptoms of PD. It can be done without actually destroying parts of the brain.
Unilateral DBS may be used if the symptoms are much more severe on one side. Bilateral DBS is used to treat symptoms on both sides.
Deep brain stimulation is used to treat several medical conditions, like Parkinson's disease, essential tremor, epilepsy, dystonia, obsessive-compulsive disorder, depression, etc. that fail to respond to conventional treatments.
PROCEDURE
The DBS system consists of three parts:
- A thin, insulated wire called a lead, or electrode that is placed into the brain
- The neurostimulator, similar to a heart pacemaker, which is usually placed under the skin near the collarbone, but may be placed elsewhere in the body
- Another thin, insulated wire called an extension that connects the lead to the neurostimulator
The procedure is commonly done in 2 stages.
Stage 1 is usually performed under local anaesthesia, i.e you are awake but pain-free. The head may be placed in a special stereotactic frame using screws to keep it still during the procedure. A burr hole is drilled in the skull through which the electrode is placed in the brain after precisely locating the target. The patient is asked to make various movements to assist in determining the location of the electrode.
Stage 2 is done under general anesthesia, where a small opening is made usually just below the collarbone to implant the neurostimulator. Another small opening is made behind the ear to pass the extension wire under the skin of the head, neck, and shoulder, which connects the lead/electrode to the neurostimulator. The skin is then closed, and the device and wires cannot be seen outside the body.
Once connected, electrical pulses travel from the neurostimulator, along the extension wire, to the lead, and into the brain.
DURATION
Hospital stay is usually for 7 days. First set of Programming for the stimulation is usually done 10 – 14 days after the surgery.
RECOVERY
Majority of the patients report significant improvement in their symptoms after having this treatment. You might still need to take medication, although at lower doses, which improves the quality of life. Depending on the type of work you do, you may return to work within 4 to 6 weeks. There are certain guidelines and limitations to be followed, and would be explained in details by the surgeon.
The DBS procedure can be reversed, if needed.
RISKS
DBS is considered to safe and effective when performed in properly selected patients by a competent surgeon.
Some risks associated with deep brain stimulation placement include:
- Breakage/movement of any part of the DBS system
- Bleeding
- Seizures
- Stroke
- Infection
- CSF leakage
- Speech/vision/memory/coordination problem
- Pain