There are several different types of surgery that have been used to treat Parkinson’s disease.
- Brain Lesioning: a procedure where a surgeon uses a heat probe to destroy a small area of brain tissue that is abnormally active in patients with Parkinson’s disease. This produces a permanent effect on the brain; only one side of the brain may undergo lesioning at a time.
- Thalamic Surgery: once used for treating Parkinson’s disease; now used only for patients with essential tremor.
- Pallidotomy: a procedure that improves tremor, rigidity, and some other movement problems. Only one side of the brain may undergo pallidotomy at a time.
- Deep Brain Stimulation: a procedure where a surgeon places a thin electrode into the brain (there are several different areas where the electrode may be placed). The electrode is attached to a computerized pulse generator that is implanted underneath the skin in the chest — like a pacemaker. A physician can adjust the pulse generator to improve a patient’s control over tremor. This is a reversible procedure. One or both sides of the brain may be done at once.
Deep brain stimulation is a major advancement in treatment for Parkinson’s disease; however, this treatment is complicated and may take some trial and error before the effects are optimized. A patient may need several office visits to adjust the computerized pulse generator before a significant improvement is seen in symptoms.
Different “targets” for the electrode can produce different effects. An electrode in the Vim region of the thalamus only helps with tremor. An electrode in the globus pallidus or the subthalamic nucleus can improve tremor, rigidity, slow movement, and gait problems.
Deep brain stimulation surgery is often performed with the patient under only a local anesthetic or light sedation. A rigid frame holds the patient’s head in place while a MRI is performed to map the target site, then the electrode is implanted. A computer helps guide the instruments to the appropriate place with the least disturbance possible. The patient is under a deeper sedation while the pulse generator is implanted in the chest.