Pallidotomy (Posteroventral Pallidotomy) for Parkinson's Disease
Parkinson's disease, a part of the brain called the
globus pallidus is overactive. This causes a decrease in the activity of a
different part of the brain that controls movement.
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).
Usually, the outward symptoms of Parkinson's are distinctive enough for a doctor to make a diagnosis in the office. Tests can help your doctor determine whether you have Parkinson's disease or some other type of parkinsonism. If you don't have a response to the drugs used to treat Parkinson's disease, you may have one of these other types of movement disorders and your doctor will probably continue to search for the cause of your symptoms.
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.
Surgery on one side of
the brain affects the opposite side of the body. If you have tremor in your
right hand, for instance, the left side of your brain will be treated. The
procedure can be repeated on the other side of the brain if needed.
What To Expect After Surgery
The surgery usually requires a 2-day
hospital stay. Most people recover completely within about 6 weeks.
Why It Is Done
Pallidotomy may be considered when a
person with advanced Parkinson's disease has:
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 medicine can no
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.
How Well It Works
Pallidotomy may reduce tremor, muscle rigidity, slow movement, and other
motor symptoms. Balance and speech may be improved.1
It is not
known how long the effects of pallidotomy can be expected to last. Benefits may
fade over time in some people.
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. 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.
The effectiveness, lower risk, and
nondestructive nature of deep brain stimulation have made it the preferred
option for most people who are considering surgery to treat advanced
Parkinson's disease. But pallidotomy may be considered in some cases when
medicine has failed to control symptoms adequately and deep brain stimulation
is not appropriate. Like deep brain stimulation, pallidotomy neither cures
Parkinson's disease nor eliminates the need for medicine. After surgery,
treatment with levodopa and other medicines will be continued and the doses
adjusted as needed.