Parkinson's Disease

Parkinson's disease is both chronic and progressive. Over time, someone with Parkinson's develops increasing problems moving and talking. Although we tend to think of Parkinson's as an older person's disease, it can also strike younger people. However, according to the American Academy of Neurology (AAN), most people who have Parkinson's develop the first signs of the disease after the age of 40, and it is most often seen in people in their 70's and 80's.

Parkinson's actually belongs to a group of conditions called motor system disorders. These disorders all result from the loss of specific brain cells (Read about "The Brain"), which produce a chemical called "dopamine." Dopamine helps transmit signals within the brain.

AAN says that in Parkinson's disease, certain nerve cells, or neurons, may die or become impaired. (Read about "Nervous System") Normally, these are the neurons that produce dopamine. Without dopamine, the nerve cells fire out of control. The result is that patients are unable to direct or control their movements in a smooth manner.

Although Parkinson's has been known to develop in certain instances as a reaction to viral infection (Read about "Microorganisms") or drug use, no one knows the exact cause of Parkinson's. According to the National Institute of Neurological Disorders and Stroke (NINDS), however, Parkinson's is not usually inherited, although some people may have a genetic predisposition to it. (Read about "Genetics") Researchers also say that microscopic brain structures called Lewy bodies are regarded as a hallmark of classical Parkinson's disease. Lewy bodies can be found in other neurodegenerative disorders as well, such as dementia. (Read about "Dementia")

Symptoms and treatment

NINDS says there are four primary symptoms of Parkinson's:

• tremor or trembling in hands, arms, legs, jaw, and face which is most prominent when sitting quietly
• rigidity or stiffness of the limbs and trunk
• bradykinesia, or slowness of movement such as writing, walking, or speaking
• postural instability or impaired balance and coordination

Patients may also have difficulty walking, talking or completing other simple tasks. Early symptoms are subtle and occur gradually. They often exhibit what is referred to as a "shuffling gait." They will take very short steps to avoid losing their balance. They may also exhibit "masked faces," meaning they show little facial expression.

According to the National Parkinson Foundation, depression affects 40 percent of patients with this disease. (Read about "Depressive Illnesses") In some patients, there may also be other problems such as regulating blood pressure or heart rate, bowel and bladder control (Read about "Fecal Incontinence" "Incontinence") as well as anxiety and sleep disorders. (Read about "Anxiety" "Sleep")

Diagnosis of Parkinson's is made by a neurologist, based on the individual's symptoms and their severity. The drug levodopa is the most powerful drug to alleviate Parkinson's symptoms. Approved in 1970, according to FDA, levodopa helps restore muscle control when it is converted to dopamine in the brain. There are serious drawbacks to levodopa. For example, to relieve symptoms, many patients need to take fairly large doses, which can cause side effects such as nausea and dyskinesias (involuntary movements).

Because of this, levodopa is usually combined with other drugs designed to delay or block the conversion of levodopa to dopamine until it reaches the brain. Other types of drugs can also be used in combination with levodopa. A class of drugs called COMT inhibitors allows more dopamine to reach the brain. Other drugs that mimic dopamine's role in the brain may also be used. Drugs known as dopamine agonists stimulate the receptors in nerves in the brain that would normally be stimulated by dopamine. Unlike levodopa, dopamine agonists are not converted into dopamine. Instead, they act like it. Dopamine agonists may be used alone or in combination with levodopa to reduce symptoms of Parkinson's disease. This can delay the need for levodopa and thus delay the physical issues that can occur with long-term levodopa therapy. Other types of drugs used for Parkinson's include glutamate antagonists (which promote the release of dopamine). An older class of drugs known as anticholinergics can also be used.

As with any medication, it's important for patients to be aware of the potential for their medicine to interact with other medicines they might be taking. That includes both prescription and over-the-counter medicines. (Read about "Drug Interaction Precautions")

In some cases, surgery is an appropriate treatment. (Read about "Neurosurgery") Deep brain stimulation involves placing an electrical stimulator in the areas of the brain that control movement. The amount of stimulation delivered by the electrode is controlled by a pacemaker-like device. This procedure does not cure Parkinson's, but in some people, it may help ease symptoms.

AAN says that a well-balanced diet is important in maintaining a patient's general health and strength; however, a doctor may recommend reduced protein consumption, because protein may interfere with the absorption of a certain Parkinson's drug. In addition, some doctors recommend physical therapy (Read about "Rehabilitation") or muscle-strengthening exercises to keep muscles in good tone, and range-of-motion exercises for balance and strength. If you suspect Parkinson's disease, see your doctor as soon as possible.

Related Information:

    Essential Tremor

    Huntington's Disease