Parkinson’s Disease
In his 2000 autobiography Lucky Man, the actor Michael J. Fox describes his battle with Parkinson’s disease (PD) as a “Jekyll-and-Hyde melodrama” that cycles between times when his medication is working and times when it’s not, when he is possessed by the symptoms of his condition: rigidity, shuffling, loss of balance, and difficulty communicating, among others.
In a healthy brain, the chemical dopamine regulates movement by sending the proper signals to your brain. So, when the cells responsible for dopamine production break down, the body has trouble moving the way it’s supposed to. Symptoms of PD usually begin at about age 50 and slowly worsen over many years.
The four main symptoms of the disease are trembling arms and legs (tremor), stiff muscles, slow movement (bradykinesia), and problems with balance. Tremor often begins first, in just one arm or leg. But in time, PD affects muscles throughout the body and can lead to problems such as constipation or difficulty swallowing. Some patients also show signs of dementia.
Aging and exposure to environmental toxins (such as herbicides and pesticides) seem to be risk factors for PD, and having one or more close relatives with the disease increases a person’s chances as well. But scientists have not been able to find any direct causes.
PD can’t be detected in the blood, and diagnosis is often based on a doctor’s physical exam. A medication called levodopa seems to relieve symptoms, so a doctor may prescribe it to see how a patient reacts in order to decide on a diagnosis.
Levodopa (also called L-dopa) and another drug, carbidopa, are often combined to help produce dopamine in the brain. Other types of medications, including dopamine agonists, may also be prescribed. PD drugs can have unpleasant side effects, however, including hallucinations, confusion, and even compulsive gambling. The medicines’ effectiveness can also peter out after a few years, so doctors often try to keep patients with mild symptoms off medication for as long as possible.
1. For patients who have unstable reactions to levodopa, a surgical treatment called deep brain stimulation may be used. Tiny electrical wires are placed in the brain and send signals to the areas that control movement.
2. Depression is common in people with PD and sometimes develops even before motor symptoms.
3. Unconscious movements such as blinking, smiling, and swinging the arms while walking may be diminished or lost in people with PD. Some people with PD develop a staring expression or no longer seem animated when they speak.
