Parkinson's Disease belongs to a group of conditions called movement disorders.

Parkinson's Disease is chronic and progressive, meaning its symptoms grow worse over time. Parkinson's Disease occurs when nerve cells (neurons) in an area of the brain known as the substantia nigra, die or become impaired. Normally, these neurons produce an important brain chemical known as dopamine. Loss of dopamine results in abnormal nerve firing patterns within the brain that cause impaired movement. Studies have shown that most Parkinson's patients have lost 60 to 80% or more of the dopamine-producing cells in by the time symptoms appear. Although some cases of Parkinson's Disease appear to be hereditary, and a few can be traced to specific genetic mutations, most cases are sporadic, meaning that it does not seem to run in families.


Early symptoms of Parkinson's are subtle and develop gradually. As they become more pronounced, patients may have difficulty walking, talking, or completing other simple tasks. Not everyone with one or more of these symptoms has Parkinson's Disease, as these symptoms can also appear in other diseases. Parkinson's Disease symptoms often begin on one side of the body. However, as it progresses, the disease eventually affects both sides.  Even after the disease involves both sides of the body, the symptoms are often less severe on one side than on the other. The four main symptoms of Parkinson's Disease are: tremor, or trembling in hands, arms, legs, jaw, or head; rigidity, or stiffness of the limbs and trunk; bradykinesia, or slowness of movement; postural instability, or impaired balance.

Other symptoms that may be experienced in people with Parkinson's Disease include:

  • Depression. Fortunately, depression usually can be successfully treated with antidepressant medications.
  • Emotional changes. Some people with Parkinson's Disease become fearful and insecure.
  • Difficulty with swallowing and chewing.
  • Speech changes.
  • Urinary problems or constipation.
  • Skin problems. It is common for the skin on the face to become very oily, particularly on the forehead and at the sides of the nose. The scalp may become oily too, resulting in dandruff.
  • Sleep problems, including difficulty staying asleep at night, restless sleep, nightmares and emotional dreams, and drowsiness or sudden sleep onset during the day. 
  • Dementia or other cognitive problems. Some, but not all, people with Parkinson's Disease may develop memory problems and slow thinking. 
  • Orthostatic hypotension. Orthostatic hypotension is a sudden drop in blood pressure when a person stands up from a lying-down position that can lead to dizziness, lightheadedness, and, in extreme cases, loss of balance or fainting.
  • Muscle cramps and dystonia.
  • Pain. Many people with Parkinson's Disease develop aching muscles and joints because of the rigidity and abnormal postures often associated with the disease.  Treatment with levodopa and other dopaminergic drugs often alleviates these pains to some extent.
  • Fatigue and loss of energy.


Parkinson's Disease can be difficult to diagnose accurately because other conditions may produce symptoms of Parkinson's Disease and there are currently no blood or laboratory tests that can diagnose Parkinson's Disease. Therefore the diagnosis is based on medical history and a neurological examination. Early signs and symptoms of Parkinson's Disease may sometimes be dismissed as the effects of normal aging. The physician may need to observe the person for some time until it is apparent that the symptoms are consistently present. Doctors may sometimes request brain scans or laboratory tests in order to rule out other diseases. However, CT and MRI brain scans of people with Parkinson's Disease usually appear normal. Since many other diseases have similar features but require different treatments, making a precise diagnosis as soon as possible is essential so that patients can receive the proper treatment. A DAT Scan is a new type of brain imaging which is sometimes helpful in the evaluation of Parkinson’s Disease-type symptoms.

Course of Parkinson’s Disease

Parkinson's Disease gets worse with time. The average life expectancy of a Parkinson's Disease patient is generally the same as for people who do not have the disease. However, in the late stages of the disease, Parkinson's Disease may cause complications such as choking, pneumonia, and falls that can lead to death. Fortunately, there are many treatment options available for people with Parkinson's Disease. The progression of symptoms in Parkinson's Disease may take years to decades. In some people, however, the disease progresses more quickly. There is no way to predict what course the disease will take for an individual person. One commonly used system for describing how the symptoms of Parkinson's Disease progress is called the Hoehn and Yahr scale.

Staging of Parkinson's Disease

  • Stage 1 - Symptoms on one side of the body only.
  • Stage 2- Symptoms on both sides of the body. No impairment of balance.
  • Stage 3 - Balance impairment.  Mild to moderate disease. Physically independent.
  • Stage 4 - Severe disability, but still able to walk or stand unassisted.
  • Stage 5 - Wheelchair-bound or bedridden unless assisted.

Another commonly used scale is the Unified Parkinson's Disease Rating Scale (UPDRS). This much more complicated scale has multiple ratings that measure mental functioning, behavior, and mood; activities of daily living; and motor function. Both the Hoehn and Yahr scale and the UPDRS are used to measure how individuals are faring and how much treatments are helping them. With appropriate treatment, most people with Parkinson's Disease can live productive lives for many years after diagnosis.


There is presently no cure for Parkinson's Disease. However, medications and other treatment options can provide dramatic relief from the symptoms. Parkinson's Disease medications fall into three categories.

  1. Medications that work directly or indirectly to increase the level of dopamine in the brain. The most commonly prescribed medications for Parkinson's Disease are substances, such as levodopa (L-dopa), that cross from the blood to the brain and are then changed into dopamine. Other drugs mimic dopamine or prevent or slow its breakdown.
  2. Medications that affect other neurotransmitters in the body in order to ease some of the symptoms of the disease. For example, anticholinergic drugs interfere with production or uptake of the neurotransmitter acetylcholine to help to reduce tremors and muscle stiffness, which can result from having more acetylcholine than dopamine.
  3. Medications that help control the non-motor symptoms of the disease, such as depression and sleep.

The following Parkinson Disease medications increase levels of dopamine in the brain (category 1).

  • Levodopa. The cornerstone of therapy for Parkinson's Disease is the drug levodopa (also called L-dopa). Although it can reduce the symptoms of Parkinson's Disease, it does not replace lost nerve cells and it does not stop the disease from progressing.
  • Dopamine agonists, such as bromocriptine, apomorphine, rotigotine (Neuprol), pramipexole (Mirapex), and ropinirole (Requip). These medications mimic the role of dopamine in the brain. They can be given alone or in conjunction with levodopa. They may be used in the early stages of the disease, or later on in order to lengthen the duration of response to levodopa in patients who experience wearing off or on-off effects.  They are generally less effective than levodopa in controlling rigidity and bradykinesia.
  • MAO-B inhibitors, such as selegiline (Elepryl) and rasagiline (Azilect). These drugs inhibit the enzyme monoamine oxidase B, or MAO-B, which breaks down dopamine in the brain. These medications can delay the need for levodopa therapy by up to a year or more.
  • COMT inhibitors, such as entacapone (Comtan) and tolcapone (Tasmar). These medications prolong the effects of levodopa by preventing the breakdown of dopamine. COMT inhibitors can decrease the duration of "off" periods, and they usually make it possible to reduce the person's dose of levodopa.
  • Amantadine. An antiviral drug, amantadine, can help reduce symptoms of Parkinson's Disease and levodopa-induced dyskinesia. It is often used alone in the early stages of the disease. It also may be used with an anticholinergic drug or levodopa. Anticholinergics, such as trihexyphenidyl, benztropine, and ethopropazine. Anticholinergics decrease the activity of the neurotransmitter acetylcholine and help to reduce tremors and muscle rigidity. Your doctor will prescribe one or more medications for Parkinson's Disease depending on several factors, including: type of symptoms, severity of symptoms, response to past treatment, and other medication conditions. Since no two people will react the same way to a medication, it may take time and patience to find the appropriate medications and dosages to provide maximal benefit. Even then, symptoms may not be completely alleviated. Neurosurgical procedures are also available for the treatment of severe cases of Parkinson's Disease that fail to respond to medical treatment, particularly tremor. However, since these procedures cause permanent destruction of brain tissue, they have largely been replaced by deep brain stimulation (DBS) for the treatment of Parkinson's Disease.

Complementary and Supportive Therapies

Diet. At this time there are no specific vitamins, minerals, or other nutrients that have any proven therapeutic value in Parkinson's Disease. Some early reports have suggested that dietary supplements might be protective in Parkinson's Disease. In addition, a phase II clinical trial of a supplement called coenzyme Q10 suggested that large doses of this substance might slow disease progression in patients with early-stage Parkinson's Disease. While there is currently no proof that any specific dietary factor is beneficial, a normal, healthy diet can promote overall well-being for Parkinson's Disease patients just as it would for anyone else. Eating a fiber-rich diet and drinking plenty of fluids also can help alleviate constipation. A high protein diet, however, may limit levodopa's effectiveness.

Exercise. Exercise can help people with Parkinson's Disease improve their mobility and flexibility. Some doctors prescribe physical therapy or muscle-strengthening exercises to tone muscles and to put underused and rigid muscles through a full range of motion. Exercises will not stop disease progression, but they may improve body strength so that the person is less disabled. Exercises also improve balance, helping people minimize gait problems, and can strengthen certain muscles so that people can speak and swallow better. Exercise can also improve the emotional well-being of people with Parkinson's Disease, and it may improve the brain's dopamine synthesis or increase levels of beneficial compounds called neurotrophic factors in the brain.  Although structured exercise programs help many patients, more general physical activity, such as walking, gardening, swimming, calisthenics, and using exercise machines, also is beneficial. People with Parkinson's Disease should always check with their doctors before beginning a new exercise program.

Other complementary therapies that are used by some individuals with Parkinson's Disease include massage therapy, yoga, tai chi, hypnosis, acupuncture, and the Alexander technique, which optimizes posture and muscle activity. There have been limited studies suggesting mild benefits with some of these therapies, but they do not slow Parkinson's Disease and there is no convincing evidence that they are beneficial.