Pallidotomy

Pallidotomy is a procedure where a tiny electrical probe is placed in the globus pallidus (one of the basal ganglia of the brain), which is then heated to 80 degrees celsius for 60 s, to destroy a small area of brain cells. Pallidotomy is used to treat dyskinesias in patients with Parkinson's disease.

Stereotactic pallidotomy was pioneered by Dr. Hirotaro Narabayashi.

In a pallidotomy, the surgeon destroys a tiny part of the globus pallidus by creating a scar. This reduces the brain activity in that area, which may help relieve movement symptoms such as tremor and stiffness (rigidity).

Before surgery, detailed brain scans using MRI are done to identify the precise location for treatment.

The person is awake during the surgery, but the scalp area where instruments are inserted is numbed with a local anesthetic. The surgeon inserts a hollow probe through a small hole drilled in the skull to the target location. An extremely cold substance, liquid nitrogen, is circulated inside the probe. The cold probe destroys the targeted brain tissue. The probe is then removed, and the wound is closed.

The surgery usually requires a 2-day hospital stay. Most people recover completely within about 6 weeks.

Pallidotomy may be considered when a person with advanced Parkinson's disease has:

-Developed severe motor fluctuations, such as dyskinesias and on-off responses, as a result of long-term levodopa treatment. -Severe or disabling tremor, stiffness (rigidity), or slow movement (bradykinesia) that medication can no longer control. -Pallidotomy probably is not a good choice for treatment when a person has not responded to levodopa. Some studies suggest that people with parkinsonian symptoms who do not improve with levodopa therapy do not gain much benefit from pallidotomy.

The most striking effect of pallidotomy is a reduction in the involuntary movements (dyskinesias) that are caused by long-term levodopa therapy. This improvement can be seen almost immediately. By reducing these side effects, pallidotomy enables some people to adjust their levodopa dosage, which allows for better symptom control.

Pallidotomy may reduce tremor, muscle rigidity, slow movement, and other motor symptoms. Balance and speech may be improved.

It is not known how long the effects of pallidotomy can be expected to last. Benefits may fade over time in some people.

Doctors rarely perform pallidotomy anymore. Instead, doctors use deep brain stimulation, a procedure that does not destroy brain tissue and has fewer risks than pallidotomy.

This type of brain surgery has less risk today than in the past because technology allows the surgeon to identify with great precision the area of the brain that will be treated. Serious permanent complications are not common, although less serious side effects are.

Complications of pallidotomy can include a stroke caused by bleeding in the brain, which may result in:

-Partial loss of vision on one side. -Temporary facial paralysis. -Weakness, loss of sensation, or loss of voluntary movement (paralysis) on one side of the body. -Loss of speech, or slurred speech and difficulty swallowing. (This is more common when pallidotomy is done on both sides of the brain.) -Temporary balance problems. -Numbness around the mouth (leading to drooling) and in the hands. -Death in some cases.

Many people who have a stroke recover fully and benefit from pallidotomy. Pallidotomy has caused problems with thought and memory (cognitive impairment) in some people.

Other risks include:

-Infection. -Seizures.