Clinical Specialties : Movement Disorders

Deep Brain Stimulation Treatment

Pacemakers for the Brain

What is Deep Brain Stimulation?
Deep Brain Stimulation (DBS) is a surgical option for patients with Parkinson’s disease (PD), Essential Tremor (ET) or dystonia. During DBS surgery electrodes are implanted within the brain to deliver electrical impulses. The stimulation offers patients relief from the tremors, rigidity, slowness of movement, stiffness and may help balance problems associated with their conditions. What makes this treatment so unique is that stimulation can be and usually is adjusted as a patient’s condition changes over time.

Deep brain stimulation is a new and improved variation of an old surgery. The old surgery involved destroying small parts of the brain within structures called the thalamus or globus pallidus with heat. Today, it is no longer necessary to destroy even small parts of the brain.

How does Deep Brain Stimulation work?
An electrode implanted in the brain emits pulses of energy to block the abnormal activity in the brain neurons which causes the symptoms. The success of deep brain stimulation surgery is directly related to finding the specific area in the brain for stimulation. See surgical technique below.

Who is a candidate for this surgery and when is it right for me?

  • Any patient who is dissatisfied with his/her increasing loss of control of movement
  • Any patient who exhibits symptoms causing a decline in the quality of life
  • Has had an adequate and reasonable trial of medications

How is Deep Brain Stimulation surgery done?
It is important to note that surgical techniques can vary among centers and surgeons. What follows is the technique used here at the University of Miami Miller School of Medicine.

Deep brain stimulation involves the implantation of a very thin lead containing four electrode contacts into a specific target area in the brain. The lead extends through a small opening in the skull below the skin and is connected to an extension wire with a connection behind the ear. The extension wire is connected to an impulse generator or “pacemaker” that is implanted under the skin just below the collarbone. Programming of the stimulation is easy and painless using an external magnetic control box.

The surgeon is aided by computerized brain-mapping technology to find the precise location in the brain where nerve signals generate the tremors and other symptoms. Highly sophisticated imaging and microelectrode recording equipment are used to map both the physical structure and the functioning of the brain by the surgeon and neurologist in the operating room.

At the Miller School of Medicine the procedure starts with an MRI image of the brain. On the day of the procedure, the patient undergoes placement of a temporary head frame. A CT scan of the brain is then obtained with the frame in place. The MRI and CT of the brain are loaded into a computer which fuses them into one picture. Accuracy is of paramount importance and this fusion along with microelectrode recordings of the brain neurons permits pinpoint accuracy. This is not performed routinely at all institutions in the United States.

After careful targeting of the pertinent area of the brain is achieved, the surgery begins. This consists of four portions. A local anesthetic is administered and the surgeon makes the small opening in the skull.

Then comes the placement of a microelectrode allowing the surgeon and the neurologist to confirm that the target chosen on the preoperative imaging studies is accurate. Once accuracy is confirmed, the next step is placement of the actual stimulator electrode. After the stimulator is in place, the patient is examined by the neurologist. This examination ensures that under stimulation the patient’s symptoms are improved and that side effects do not occur. The final part of the procedure is performed with the patient fully asleep. This is the placement of the programmable generator under the skin of the chest wall under the collarbone. The entire procedure takes approximately 2 ½ -3 hours. On average, the hospital stay is 24 hours.

The patient is awake during surgery to allow the neurologist to assess the patient’s clinical status along with the detailed brain recording. While the electrode is being advanced through the brain, the patient does not feel any pain because of the unique nature of the human brain and its inability to generate pain signals.

The stimulators are turned on for the first time three weeks after implantation.

How effective is Deep Brain Stimulation?
In properly selected patients, deep brain stimulation is remarkably safe and effective, although the surgery is not completely without risk. Beneficial effects have been demonstrated to last for several years. DBS in patients who initially responded well to medications, but over time have developed side effects, can experience between 50 to 80 percent improvement in such symptoms as tremor and slowness of movement with the stimulator. Patients on average report a 50 percent improvement in their walking. Similarly, patients with involuntary movements (dyskinesia) due to their medications, experience over 80 percent reduction in their severity. Some patients may be able to reduce their medications following deep brain stimulation.

Regarding Parkinson’s disease in particular, an important indicator of the effectiveness of any treatment is the duration of “on-time” without dyskinesia. This means the patient is mobile and can perform everyday tasks without experiencing the involuntary movements.

What risks are associated with Deep Brain Stimulation?
This is brain surgery and is not without risk. There is approximately a two to three percent chance of brain hemorrhage that may be of no significance, but may rarely cause paralysis, stroke, speech impairment or other major problems. This means that for every 100 patients who undergo surgery, two or three will experience a permanent or severe complication. However, this also means that most patients will have no complications. There is a 15 percent chance of a minor or temporary problem. Infections can occur. While treatment of infection may require removal of the electrode, the infections themselves have not caused lasting damage and are treated with antibiotics.

Who can be evaluated for Deep Brain Stimulation?
Patients with Parkinson’s disease, essential tremor, dystonia or tremor due to multiple sclerosis, with movement-related symptoms that cannot be controlled by medications can be evaluated as possible candidates for deep brain stimulation. In addition, patients who experience intolerable side effects from medication may also be candidates.

Deep brain stimulation has been successful in treating patients as young as 13 years of age. In general, surgery is performed on those under 75 years of age but we have implanted patients as old as 84 years of age. Each patient must be assessed individually concerning his or her stamina and overall health.

Has Deep Brain Stimulation been approved by the Food and Drug Administration?
Yes. In January of 2002 the FDA approved deep brain stimulation for the treatment of Parkinson’s disease. It had previously been approved for the treatment of Essential Tremor in 1997.

What happens after Deep Brain Stimulation surgery?
A series of adjustments in the electrical pulse will be made over weeks or months. It is necessary for patients to be able to travel to a location where the stimulation of their implanted pacemakers can be adjusted. The first few follow-up visits should be to the center where the surgery was performed, but subsequent electrical programming can take place at another medical center that has the necessary equipment and expertize.

Should I have Deep Brain Stimulation surgery or wait for Stem Cells?
As research progresses in the area of movement disorders and particularly Parkinson’s disease further treatment options may become available. One area of interest is that of stem cell transplantation. Although stem cell therapy is not available now, researchers are feverishly working to make this option a reality. This procedure would consist of implanting stem cells instead of a stimulator using the same techniques described above. These cells would eventually differentiate into neurons that would take the place of those missing in Parkinson’s disease, thus producing dopamine and reversing the further progression and symptoms of Parkinson’s disease. Due to the fact that deep brain stimulation is not destroying brain cells it most likely would not prevent you from future surgical therapeutic options.

Appointments
For appointments or more information, call (305) 243-2781 between 9a.m. and 5p.m. Eastern time, Monday through Friday.

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