Parkinson's disease Definition
Parkinson's disease is a condition that damages the nervous system. Its main symptoms are muscle stiffness, shaking, and slowness of movement.
What is going on in the body?
Parkinson's is a common disease. It affects one percent (1%) of the population older than age 65. It often starts between the ages of 45 and 65. It affects men and women equally and occurs in all ethnic groups. Nerves and nerve function are lost in a part of the brain. Over a period of months and years, continued loss of nerves occurs, which causes the symptoms of Parkinson's disease. This is a chronic, incurable progressive illness.
In Parkinson's disease, there is an imbalance of certain chemicals in the brain. The goal of current drug therapy is to restore the normal balance of these chemicals.
What are the signs and symptoms of the disease?
Parkinson's disease may cause:
The tremor of Parkinson's often starts on one side in the hand or arm. It is usually occurs when a person is still. It can worsen with stress. It usually goes away with sleep. The tremor can occur in one or all extremities and sometimes the jaw and tongue.
- tremors, or uncontrolled shaking when not moving
- muscular stiffness
- slowness of voluntary movement, called bradykinesia
- posture and walking disturbances
People with Parkinson's may have trouble getting out of a bed or chair, or walking. People with the disease often have a strange style of walking. They bend forward, take small steps, shuffle the feet, and have problems with turning. Affected people also have a tendency to fall forward or backward. Some people cannot stop a movement once it has started. A wheelchair may be needed in severe cases.
A person with Parkinson's may complain of being weak or tired. Poor muscle movement in the face can cause a blank look. Trouble swallowing, slurred or stuttered speech, and drooling are common. The ability to write, button a shirt and eat can become impaired. Shaking of the hand can occur at rest or when holding the hand in a certain position for a long time such as holding a telephone or holding and reading a paper.
Other symptoms of the disease include:
What are the causes and risks of the disease?
- depression or mood swings
- sexual dysfunction
- sleep disturbances
- dementia, which may cause impaired memory, thinking and other mental changes
- difficulty swallowing
- decreased eye blinking
- muscle cramps
- tiny writing
- a drop in blood pressure when getting up from a sitting position
- bladder and bowel control problems
- increased sweating
- hallucination or psychotic behaviour
The cause of Parkinson's disease is not known. Heredity may play a role in younger people with the disease. However, there is no clear gene problem that has been found.
What can be done to prevent the disease?
Because the cause is not known, there is no known way to prevent Parkinson's disease.
How is the disease diagnosed?
The history and physical examination are used to diagnose Parkinson's disease. No single test can diagnose the disease. A special brain x-ray, such as a CAT scan, can appear normal in the early part of the disease. Brain shrinkage and damage will appear later.
Sometimes muscle stiffness, resting tremors and slowness of voluntary movement are enough to point to Parkinson's. It is important to rule out other causes of these symptoms. Drugs, toxins, infections, and trauma can also cause these symptoms. Other brain disorders can mimic Parkinson's disease. These need to be ruled out.
What are the long-term effects of the disease?
Most of the signs and symptoms are long-term and progressive, but in some people, the disease can progress quickly. In addition to the many nervous system problems, other symptoms may also get worse. These include dementia, pain, an abnormal taste or smell sensation, or development of common infections such as pneumonia.
What are the risks to others?
This is not a contagious illness, and others are not put at risk.
What are the treatments for the disease?
The major goal of treatment is to control the signs and symptoms for as long as possible while minimising side effects. Symptoms can usually be well controlled for several years in the early stages of the disease.
Drugs are used. One of the most common drugs is a combination of levodopa and carbidopa. Although this is the most effective treatment for Parkinson's disease, the drug effects tend to be less predictable over time. Other drugs, such as amantadine, selegiline, or pergolide, cane be used. Newer drugs, such as cabergoline, are also used to treat Parkinson's disease.
Another treatment is surgery. Surgery can include destruction of a tiny overactive part of the brain. Another approach is deep brain stimulation with electricity, with electrodes or wires placed deep in the middle of the brain.
People may need other treatments to deal with the many problems associated with the disease. If dementia is present, close monitoring may be needed. Treatment with antidepressants, antipsychotic drugs or sedatives can also help relieve some symptoms. Physical, occupational and speech therapy may help. In-home care may be needed. There are drugs to help control other symptoms in late-stage Parkinson's. These drugs can help with problems related to bowel or bladder function or excessive sweating. There are also drugs to help with impotence.
What are the side effects of the treatments?
Drug therapies are complex. Different drugs have different side effects. Some of the most common side effects include excessive body motion, nausea, sleepiness, confusion, and dry mouth. Specific side effects depend on the drug used.
Surgery may cause difficulty with speech or paralysis on one side of the body. Deep brain stimulation usually requires more than one operation. There is also a risk of infection.
What happens after treatment for the disease?
People with Parkinson's disease need treatment for life. It is a progressive disease and adjusting or adding different drugs is usually needed frequently.
How is the disease monitored?
A family member or caretaker is important when it comes to monitoring this disease. These people can give the doctor day-to-day input on benefits and side effects of treatment. This can include the amount of tremor, movement, and other problems related to sleeping, bowel and bladder function, mental state and activities of daily living. Laboratory testing is usually not helpful. Contacting a local support group is usually beneficial.
Author: Thomas Fisher, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request