In Parkinson's disease, the brain’s globus pallidus region is overactive, causing a decrease in the activity of another area of the brain that controls movement. This over activity leads to symptoms, such as rigidity, movement disorders or tremors.
Pallidotomy
Pallidotomy is a surgical procedure developed in the 1950s to treat symptoms of Parkinson's disease. This surgery became less frequent in the 1960s when medical therapy for Parkinson's disease was introduced. Recently, improvements in technology have caused renewed interest and use of pallidotomy.
In pallidotomy, the surgeon destroys a portion of the globus pallidus by creating a scar or lesion. This lesion interrupts the overactive nerve signal transmission, reducing the brain activity in that area and helping relieve movement symptoms associated with Parkinson's disease, as well as treating rigidity and reducing tremor.
Thalamotomy
Thalamotomy is a similar procedure to pallidotomy. However with this procedure, a small surgical lesion is created in the thalamus, the part of the brain that translates and relays information to areas of the cortex. The thalamus also plays an important role in regulating states of sleep and wakefulness.
Procedural Details
Before pallidotomy is performed, a CT or MRI is conducted to help locate the area of the globus pallidus, the structure in the brain involved in the regulation of voluntary movements at a subconscious level.
The surgical procedure lasts about one hour and is completely painless because the area of the brain being operated on lacks pain receptors.
Medications
Most patients need to continue medications, though the medications may be reduced or may be more effective for longer periods of time.
The patient's primary care provider is critical to this program, since that provider will be involved in adjusting the patient's medications and in overseeing the patient's routine health care needs.
Considerations
Pallidotomy may be inappropriate for certain patients. Patients with cognitive difficulties and memory problems, severe joint deformities or underlying medical conditions, such as severe hypertension, multiple strokes or brain tumors may not be good candidates for this procedure.
Age itself is not an exclusionary factor, but patients older than age 75 may have increased risk of complications, such as stroke or death, or may be less likely to respond to the procedure.
Certain conditions may also preclude patients from benefiting from thalamotomy.
Effectiveness
Pallidotomy is a procedure designed to treat symptoms but not cure Parkinson's disease. However, in some cases, the major symptoms of the disease are completely eliminated. In most cases, the symptoms are alleviated.
Pallidotomy takes about four to five hours, including prep time. The procedure is completely painless and offers immediate relief. The treatment has also been shown to be effective for up to 10 years.
Thalamotomy does not help some of the symptoms of Parkinson's disease, such as slowed movements.