Parkinson’s disease is a brain disorder that is diagnosed in an estimated 60,000 Americans each year. It occurs when nerve cells, or neurons, in certain parts of the brain die or become impaired and can no longer produce dopamine, the chemical that enables the body to coordinate muscles and movement. Symptoms begin to appear when approximately 80 percent of the cells that produce dopamine are damaged.
More than 1 million people with the disease typically show signs of tremors in the hands, arms, legs, jaw and face, as well slowness of movement, stiffness and problems with balance. Both men and women can be affected by Parkinson’s disease, which also crosses all social, ethnic, economic and geographic boundaries.
Although a small number of patients may be diagnosed under the age of 50, most cases of Parkinson’s disease are identified in people over 65. Blood tests and X-rays cannot be used to diagnose the disease. Rather, blood tests and brain scans, such as magnetic resonance imaging, may be done to rule out other conditions with similar symptoms. The diagnosis may then be confirmed after a thorough examination. There is no cure for Parkinson’s disease, but symptoms can be managed through medications, surgery or a combination of both.
One of the more commonly prescribed medications for Parkinson’s disease is levodopa. This medicine can reduce symptoms of slowness, stiffness and tremor. Levodopa works in the brain where it is converted into dopamine. It is always taken in conjunction with an enzyme inhibitor called carbidopa because blood enzymes would break down most of the levodopa before it could reach the brain.
Substitutes for levodopa, called dopamine agonists, have been developed that do not have to be taken with an enzyme inhibitor. However, these medications tend to cause other side effects. Medications that do not stimulate dopamine production also can be taken to manage symptoms of Parkinson’s disease. Medications should be managed under close physician supervision because each person reacts differently to different drugs.
Deep brain stimulation offers a surgical alternative to medications to treat symptoms of Parkinson’s disease. This procedure involves surgically implanting a battery-operated medical device called a neurostimulator. Similar to a heart pacemaker, it delivers electrical stimulation to specific areas of the brain that control movement and blocks abnormal nerve signals that cause symptoms. The neurostimulator is about the size of stopwatch and usually is implanted under the skin near the collarbone. It is attached by an extension wire passed under the skin of the shoulder, neck and head to an electrode, or lead, which is implanted into the brain through a small opening in the skull.
The deep brain stimulation system provides continuous symptom control and can be adjusted as needed. It does not damage healthy brain tissue and can be reversed if necessary. Medications may still be required, but at reduced levels for most patients.