Types of Surgery
Neurosurgery can be effective for Parkinson’s disease patients, particularly in middle to later stages of the disease, when medications do not adequately control motor symptoms that interfere with your daily activities.
We have a state-of-the-art surgical program for Parkinson’s disease. Neurosurgical options include:
- Deep Brain Stimulation (DBS)
In general, we recommend surgery for patients with:
- Bothersome motor fluctuations despite optimal use of medication
- An inability to control movements (dyskinesia) despite optimal use of medication
- Severe tremor that does not respond to medication
Patients who have developed dementia, or who have an atypical Parkinsonian syndrome do not benefit from surgical treatments.
Deep brain stimulation (DBS)
Deep brain stimulation (DBS) is the gold standard for the surgical care of patients with Parkinson’s disease. DBS is an FDA approved surgical procedure to implant an electrode, which delivers continuous electrical stimulation to a specific area of the brain – either the thalamus, globus pallidus (GPi), or the subthalamic nucleus (STN).
During the DBS procedure, our experienced neurosurgeon will place an electrode into the brain, connected by a wire to a battery source. We insert the electrode using local anesthesia while you are comfortable and awake. You need to be awake for this part of the surgery so we can best evaluate the benefit of stimulation and make sure we avoid bothersome side effects. This part of the surgery takes the longest so that we can be certain that the electrode is in the correct location.
General anesthesia is used for the next stage of the surgery. We implant the connecting wire under the scalp and neck and the battery in the chest wall just below the collar bone. All of the implanted hardware is hidden underneath the skin. We will make a series of stimulation adjustments in the weeks and months following implantation, which are completed at your neurologist’s office. Most DBS batteries need to be replaced every 3 to 5 years. We replace batteries as an outpatient procedure that involves a small incision in the chest.
The most important step when considering DBS surgery is proper patient selection. While there are no standardized criteria for DBS selection, there are some guidelines to assist in surgical selection. In general, the best surgical candidates have idiopathic Parkinson’s disease (not an atypical Parkinson syndrome), have a significant response to medication (evaluated with OFF and ON testing), have bothersome symptoms that are not controlled with medications (e.g., wearing off, on-off fluctuations, dyskinesias, etc.), and no or little cognitive dysfunction.
To help us best evaluate patients for surgery, we follow a four-step process:
- You will be referred to one of Parkinson’s disease specialists to confirm your diagnosis and evaluate any medication options that may be helpful.
- If DBS is deemed the best option, you will be asked to return for “OFF and ON testing”. This involves a complete motor evaluation when you have not taken any PD medications (i.e., OFF state) and then again when your medications are working best (i.e., ON state). This is the best way to accurately document your PD symptoms and how you respond to medications.
- Patients who are good surgical candidates are discussed at our monthly surgical conference. During this conference, our Parkinson specialists review your medical history, symptoms, response to medications, and discuss the appropriateness for surgical intervention.
- Finally, all surgical candidates must have comprehensive cognitive testing with a trained neuropsychologist. This is to ensure there are no psychiatric or cognitive issues that could interfere with optimal DBS outcomes.
Benefits of DBS
DBS reliably improves the cardinal symptoms of Parkinson’s disease – resting tremor, stiffness, and slowness. Because the stimulation is continuous, most patients notice fewer fluctuations throughout the day as compared to taking medications alone. In addition, some DBS patients can reduce their medication requirements. As a result, problems with abnormal involuntary movements caused by the medication may also improve.
Deep brain stimulation is a symptomatic therapy and has not proven to slow or halt the progression of Parkinson’s disease.
Pallidotomy involves destroying or cauterizing the globus pallidus interna (GPi). Pallidotomy is usually performed only on the side of the brain responsible for most of the disability. Performing surgery on both sides of the brain, called “bilateral pallidotomy,” increases the risk of cognitive decline and changes in speech. Risks of the procedure include bleeding, visual loss, memory changes, infection, and stroke.
Pallidotomy is an effective treatment for the following symptoms:
- Severe abnormal motor fluctuations caused by long-term use of levodopa.
- Painful cramping and twisting of muscles or limbs (dystonia.)
- Slowness or lack of movement (bradykinesia) and tremor.
Thalamotomy involves destroying or cauterizing part of the brain called the thalamus. It is an effective treatment for all types of tremors; however, it is less effective for rigidity, slowness or lack of movement or loss of control over movement.
Potential Risk of Surgery
The most serious risk of a surgical procedure is bleeding in the brain which can cause a stroke. The average risk of this happening in DBS is less than 2 percent. If stroke occurs, it usually occurs during, or within a few hours of surgery. For DBS some additional risks include:
- temporary swelling of the brain the first few days after surgery (this is normal). This may produce temporary mild disorientation, sleepiness, or personality changes.
- infection is a serious risk that occurs in about 4 percent of patients. It is usually not life-threatening and can be treated with antibiotics. In rare instances, it may require removal of the DBS system. In many cases, a new DBS system can be re-implanted when the infection has cleared.
Other Surgical Procedures
- Duopa therapy is a gel form of carbidopa/levodopa that is delivered directly to the gut. As with DBS, it is used to treat the motor symptoms of PD that are not optimally controlled with oral medications.
- Duopa is delivered via a tube that is surgically placed into your intestine, which is connected to an external pump. This system allows continuous delivery of carbidopa/levodopa to help reduce OFF and ON fluctuations.
- Duopa has the same potential side effects as oral carbidopa/levodopa. Additional risks include movement or dislocation of the tube, infection, and pump failure.
There are many studies focused on improving current medications and finding a cure for PD. You can find more information about research programs enrolling in your area at www.clinicaltrials.org and www.michaeljfox.org/trial-finder.