Unlocking the secret of Parkinson's Disease

New treatments are helping relieve symptoms

What do Michael J. Fox, Muhammad Ali, the late Johnny Cash and Pope John Paul II have in common? Parkinson's disease-a progressive neurological disorder affecting 1.5 million Americans.
Most people recognize Parkinson's disease by its symptoms:

- tremors in the hands, arms, legs, jaw and face
- rigidity of the legs and body
- a slowness of movement called bradykinesia
- difficulty with balance

Symptoms often start out subtly, but become increasingly severe, making movement control difficult, says William Gulledge, M.D., a neurologist on the medical staff at Baylor All Saints Medical Center.

Malfunctioning messenger
Parkinson's was first diagnosed in the early 1800s, but today medical experts still don't know what causes it, Dr. Gulledge admits. They do know that the incidence increases with age, peaking between ages 65 and 80.

What exactly is this mysterious disease? It starts in an area of the brain called the substantia nigra, which produces a chemical messenger called dopamine. Dopamine's job is to transport electrical signals to the part of the brain that controls movement and coordination. In people with Parkinson's, cells in the substantia nigra malfunction and die.

According to the National Parkinson's Foundation, when approximately 80 percent of the dopamine-producing cells are damaged, symptoms of Parkinson's begin to appear.

Today's treatments
There is currently no cure or prevention for Parkinson's. Instead, treatment focuses on increasing dopamine levels and bringing patients relief from symptoms.

Levodopa, the most commonly prescribed medication for Parkinson's disease, acts as a "counterfeit" dopamine, Dr. Gulledge explains. Last year, the FDA approved a new drug that combines levodopa with a chemical called carbidopa and a COMT inhibitor. The new drug prevents the breakdown of levodopa before it reaches the brain, which helps prolong its effectiveness.

Deep brain stimulation, a surgical treatment approved by the FDA in 2002, involves implanting an electrode into the brain and a pacemaker-like device under the collarbone. Electrical signals from the device suppress Parkinson's symptoms.

The future holds promise as research brings insights into how the brain works and the potential for therapies that will restore dopamine-producing cells and detect and prevent the disease.

By Janan Talafer

For more information about deep brain stimulation at a Baylor facility, call 1-800-4BAYLOR.