Several surgical procedures are available for the treatment of
Parkinson’s disease. None of them cure the disease. These procedures may help relieve symptoms for a period of time.
During these surgical procedures, you will be sedated, but kept awake. This is important so that the surgeon can test various areas of the brain. This testing will highlight the abnormal brain tissue. You may be asked to describe sensations or to move parts of your body during the course of the procedure.
It is important to remember that not every person with Parkinson’s disease is a candidate for surgery. Surgery is usually reserved for those with advanced symptoms. Your doctor can help you get an expert opinion as to whether or not you are a good candidate.
The thalamus is an area of the brain the helps with movement. A thalamotomy is a procedure to destroy part of the thalamus. Newer imaging techniques and a special frame that holds the patient's head in a fixed position have helped make thalamotomy more precise. Destruction of part of the thalamus is accomplished with either heat (delivered through an electrode) or stereotactic radiosurgery.
Thalamotomy can help improve the tremors of Parkinson’s disease. It does not appear to have much effect on other Parkinson symptoms. Patients who experience improvement often still have relief 10 years after the procedure. This procedure is less commonly done.
The globus pallidus is another area of the brain involved in movement. Pallidotomy is a procedure to destroy the globus pallidus. Newer imaging techniques and a special frame that holds the patient's head in a fixed position have helped make pallidotomy more precise. Destruction of the globus pallidus is accomplished with either heat or stereotactic radiosurgery.
Pallidotomy can help improve many of the symptoms of Parkinson’s disease, including: TremorSlowness of movementShuffling walkMask-like faceRigidity
Patients may experience dramatic improvement after pallidotomy. Studies show that this improvement may be maintained for at least five years after the procedure is done. Pallidotomy is not commonly done anymore.
Thalamotomy and pallidotomy are not done as often anymore because they have a greater risk of irreversible side effects and complications. Deep brain stimulation is the more common treatment now.
In this technique, a stimulating electrode lead is placed into the subthalamic nucleus (just below the thalamus) or internal globus pallidus (part of the basal ganglia) to reduce symptoms of advanced Parkinson's disease. Or, it can be placed into the thalamus to reduce tremor. A wire is snaked out and attached to a generator that is implanted in the patient’s chest. A small, handheld magnet can be passed over the generator switch to turn it on and off.
When the device is activated, it sends an electrical impulse to its destination and acts as a kind of brain pacemaker. Complications with the device may require additional surgery. Other potential adverse effects include: DepressionHallucinationsTrouble with episodic memories (but improvement with other types of memory)Bleeding in the brain (a side effect of the surgery)Slurred speechTingling in head and handsProblems with balance
The generator requires replacement every 3-5 years.
Advantages of deep brain stimulation include: Less invasive procedure than thalamotomy and pallidotomyPotentially reversible (rather than causing irreversible tissue damage)Adjustable—neurologist specialized in deep brain stimulation can adjust the settings on the deep brain stimulator based on the patients’ symptoms
The risk of infection or breakage of the electrical leads is higher, though, because of the implanted device.
Close follow-up with a neurologist with expertise in movement disorders and deep brain stimulation is essential for optimizing benefit.
Research is underway to study the effects of dopamine-producing tissue implanted into the part of the brain responsible for the symptoms of Parkinson’s disease. Other studies are using viruses to transfer genes to the brain tissue to allow for greater dopamine availability. These procedures are still being investigated.