Parkinson's disease affects nerve cells in the part of the brain controlling muscle movement. Parkinson's disease is progressive, meaning the signs and symptoms become worse over time. However, the disease often progresses gradually, and most people have many years of productive living after being diagnosed.
Parkinson's disease occurs when certain nerve cells in a particular area of the brain are damaged or destroyed. Normally, these nerve cells release dopamine, which causes the muscles to make smooth, controlled movements. Everyone loses some dopamine-producing nerve cells as they grow older, but people with Parkinson's disease lose half or more.
Age is one of the main risk factors for Parkinson's disease, and risk continues to increase with age. In fact, signs and symptoms of Parkinson's disease may be dismissed as the effects of aging, particularly in older adults with the disease. Other risk factors may include heredity, gender, and exposure to pesticides or herbicides.
The earliest symptom of Parkinson's disease may be an arm that does not swing when the person walks, a mild tremor in the fingers of one hand, soft, mumbling speech, and/or difficulty swallowing. A person with the disease may lack energy, feel depressed, and/or experience sleeping problems, slowed motion, rigid muscles, loss of automatic movements, and/or dementia.
As many as half the people with Parkinson's disease develop depression, which may occur months or even years before Parkinson's disease is diagnosed. Although physical limitations resulting from Parkinson's disease can be frustrating and stressful, depression is not usually a reaction to physical disability. It more likely arises from underlying brain changes associated with the disease itself. Getting treatment for depression can make it easier to handle other challenges of Parkinson’s disease.
A person experiencing any of the symptoms associated with Parkinson's disease should consult a healthcare provider – not only to diagnose the illness but also to rule out other causes. A diagnosis of Parkinson's disease is based on a medical history, observations of signs, and a neurological examination. As part of a medical history, a health provider will ask about current health status and any family history of Parkinson's.
For many people with Parkinson's, the initial response to treatment can be dramatic. Over time, however, the benefits of drugs frequently diminish or become less consistent although symptoms can usually still be fairly well controlled. Physical therapy may help people with Parkinson's disease improve mobility, range of motion, and muscle tone. Although specific exercises cannot stop the progression of the disease, improving muscle strength may improve confidence and capacity to perform the tasks of daily living. A person who has received a diagnosis of Parkinson's disease will need to work closely with a health provider to find the right treatment plan. Lifestyle changes such as eating a healthful diet and getting exercise may make it easier to live with Parkinson's disease.
When lifestyle changes are no longer enough, a health provider may recommend certain medications. Medications can help manage problems with walking, movement, and tremor by increasing the brain's supply of dopamine. Levodopa, a natural substance found in plants and animals, is converted into dopamine by nerve cells in the brain. Treatment with dopamine itself is not possible because dopamine does not cross the body's blood-brain barrier. Today, levodopa is combined with another drug, carbidopa, that helps more levodopa get to the brain and reduces some of the side effects of this therapy. During early treatment, side effects from carbidopa-levodopa therapy are usually not a major problem; however, the drug works less evenly and predictably as the disease progresses. Side effects may include hallucinations, nausea, and a drop in blood pressure when standing.
Another class of drugs used to treat Parkinson's, called dopamine agonists, are not changed into dopamine, but mimic the effects of dopamine in the brain, causing neurons to respond accordingly. The side effects of dopamine agonists are similar to those of carbidopa-levodopa. But dopamine agonists are less likely to cause involuntary movements and more likely to cause hallucinations or sleepiness. People taking any of these medications who start behaving in a way that is not normal should talk to their healthcare provider.
Surgical approaches may complement drug therapy to treat Parkinson's disease. A brain-implant device is now widely used to help control many Parkinson's symptoms. The deep-brain stimulator consists of a pacemaker-like unit implanted in the chest wall that transmits electric impulses through a wire to tiny electrodes inserted deep within the brain.
For more information, visit the National Institute of Neurological Disorders and Stroke: http://www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_disease.htm.
