Parkinson's Disease

Parkinson's disease (PD) is a disorder of the central nervous system that affects between one and one-and-a-half million Americans. Because it is not contagious and does not have to be reported by physicians, the incidence of the disease is often underestimated.

PD may appear at any age, but it is uncommon in people younger than 30, and the risk of developing it increases with age. It occurs in all parts of the world, and men are affected slightly more often than women.

Primary Symptoms

Following is a list of the primary symptoms of Parkinson's disease. It is important to note that not all patients experience the full range of symptoms; in fact, most do not.

Rigidity is an increased tone or stiffness in the muscles. Unless it is temporarily eased by anti-Parkinson's medications, rigidity is always present. However, it increases during movement. It is often responsible for a mask-like expression of the face. In some patients, rigidity leads to sensations of pain, especially in the arms and shoulders.

Tremor is the symptom the public most often identifies with PD, but in fact, up to 25% of patients experience very slight tremor or none at all. When it is present, the tremor may be worse on one side of the body. Besides affecting the limbs, it sometimes involves the head, neck, face, and jaw.

Bradykinesia means slowness of movement. This symptom is characterized by a delay in initiating movements, caused by the brain's slowness in transmitting the necessary instructions to the appropriate parts of the body. When the instructions have been received, the body responds slowly in carrying them out.

Poor balance tends to affect people with PD. This is particularly true when they move abruptly, causing a sudden change in the position of their bodies. Some patients experience repeated falls due to poor balance.

Walking problems commonly include a decreased or non-existent arm swing; short, shuffling steps (festination); difficulty in negotiating turns; and sudden freezing spells (inability to take the next step).

The actual cause of PD is not known. Although a defective gene was recently found in a few families with extraordinarily high incidences of PD, most researchers believe that in the vast majority of cases, genetic factors alone are not responsible for causing the disease. Instead, it is suspected that Parkinson's usually results from the combination of a genetic predisposition and an as yet unidentified environmental trigger.

When PD occurs, degenerative changes are found in an area of the brain known as the substantia nigra, which produces dopamine, a chemical substance that enables people to move normally and smoothly. Parkinson's disease is characterized by a severe shortage of dopamine. It is this deficiency that causes the symptoms of PD.

Treating Parkinson's disease is not exclusively the doctor's job; there is much a patient can do to stay as well as possible for as long as possible.

Exercise: For people with Parkinson's, regular exercise and/or physical therapy are essential for maintaining and improving mobility, flexibility, balance and a range of motion, and for warding off many of the secondary symptoms mentioned above. Exercise is as important as medication for the management of PD.

Support groups: These groups play an important role in the emotional well-being of patients and families. They provide a caring environment for asking questions about Parkinson's, for laughing and crying and sharing stories and getting advice from other sufferers, and for forging friendships with people who understand each other's problems.

Staying active: PD seems to advance more slowly in people who remain involved in their pre-Parkinson's activities, or who find new activities to amuse them and engage their interest. In a word, getting joy out of life has proved to be good for the health.