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Parkinson’s disease
Definition:
Parkinson's disease is a disorder of the brain characterized by shaking (tremor) and difficulty with walking, movement, and coordination. The disease is associated with damage to a part of the brain that is involved with movement. Alternative Names:
Paralysis agitans; Shaking palsy Text Continues Below
Causes, incidence, and risk factors:
Parkinson's disease was first described in England in 1817 by Dr. James Parkinson. The disease affects approximately 2 of every 1,000 people and most often develops after age 50. Sometimes Parkinson's disease occurs in younger adults, but is rarely seen in children. It affects both men and women and is one of the most common neurologic disorders of the elderly. In some cases the disease occurs within families, especially when it affects young people. Most late onset cases have no known cause. The term "parkinsonism" refers to any condition that involves a combination of the types of changes in movement seen in Parkinson's disease, which is the most common cause of these symptoms. Parkinsonism may be caused by other disorders (secondary parkinsonism) or by external factors like certain medications used to treat schizophrenia.
Parkinson's disease is caused by progressive deterioration of the nerve cells of the part of the brain that controls muscle movement. Dopamine, which is one of the substances used by cells to transmit impulses, is normally produced in this area. Deterioration of this area of the brain reduces the amount of dopamine available to the body. Insufficient dopamine disturbs the balance between dopamine and other transmitters, such as acetylcholine. Without dopamine, the nerve cells cannot properly transmit messages, and this results in the loss of muscle function.
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