Another option is called stimulation surgery and it involves implanting a device within the brain that transmits electrical impulses to the regions of the brain that cause Parkinson’s symptoms. This Deep Brain Stimulation helps stop tremors and encourage normal movement.
For both ablative and brain stimulation surgery, patients should ideally see a marked improvement when taking medication for Parkinson’s to be judged an optimal candidate. If a patient has “atypical Parkinson’s Disease”, an abnormal MRI, dementia, no improvement with medications, or one or more other diseases, then that person may not be a good candidate for either of these surgeries. In addition, these procedures are not performed on patients who are at the very beginning stages of the disease as medication often can be quite effective at this stage of the disease.
Types of Ablative surgery
The thalamus in the brain is involved with involuntary movements, such as tremors. In this surgery, the thalamus is destroyed. The procedure is done under a local anesthetic while the patient remains awake. After a tiny hole has been drilled in the skull, a tube is inserted into the precise location in the brain. A cold liquid which destroys the thalamus tissue is then placed into the tube. This can also be accomplished without making an incision by utilizing a focused beam of X-ray energy termed Gamma-knife therapy.
This type of surgery reduces a severe unilateral tremor but does not reduce any other symptoms of Parkinson’s, such as bradykinesia (slowed movement) or difficulty with gait or speech. If the patient has tremors on both sides of the body, the procedure may have to be done twice; once on the left thalamus and again for the right thalamus. Thalamotomy leaves a lesion in the ventral inferior medial nucleus of the brain.
This procedure treats the globus pallidus portion of the brain. Patients with Parkinson experience over-activity of the globus pallidus which in reduces the amount of activity in the other part of the brain responsible for initiating movement. During a pallidotomy, a lesion is created in the globus pallius interna.
Like Thalamotomy, the patient remains awake, a small hole is drilled in the skull, a tube is inserted, and a cold substance placed into the tube then destroys the targeted tissue. This can also be done with Gamma knife therapy. In the case of Pallidotomy, however, bradykinesia and rigidity may be decreased, as well as tremors. This treatment is best for patients with severe Parkinson’s that includes dyskinesias (involuntary movements) and fluctuations, which are characterized by periods when medications work well and periods when medications do not work. Pallidotomy is also particularly helpful for treating involuntary excessive movements of limbs that occur while taking high doses of Parkinson medications.