Parkinson's Disease

PARKINSON'S DISEASE

Parkinson's disease (PD) is a progressive, neurological disease first described in 1817 by James Parkinson. The pathology is not completely understood, but there appears to be consistent changes in the melanin-containing nerve cells in the brainstem, where there are varying degrees of nerve cell loss with reactive gliosis along with eosinophilic intracytoplasmic inclusions. Biochemical studies have shown below normal levels of dopamine in the caudate nucleus and putamen (Diccionario de Ciencias Medicas). It belongs to a group of conditions called motor system disorders, which are the result of the loss of dopamine-producing brain cells.

HOW MANY PEOPLE ARE AFFECTED?

In the United States, at least 500,000 people are believed to suffer from Parkinson's disease, and about 50,000 new cases are reported annually. These figures are expected to increase as the average age of the population increases. The disorder appears to be slightly more common in men than women. The average age of onset is about 60. Both prevalence and incidence increase with advancing age; the rates are very low in people under 40 and rise among people in their 70s and 80s. Parkinson's disease is found all over the world. The rates vary from country to country, but it is not clear whether this reflects true ethnic and/or geographic differences or discrepancies in data collection (ninds.nih.gov)

SYMPTOMS

The four primary symptoms of PD are tremor, or trembling in hands, arms, legs, jaw, and face; rigidity, or stiffness of the limbs and trunk; bradykinesia, or slowness of movement; and postural instability, or impaired balance and coordination, difficulty in initiating physical and mental activity (biological psychology, 83)

As these symptoms become more pronounced, patients may have difficulty walking, talking, or completing other simple tasks. PD usually affects people over the age of 50. Early symptoms of PD are subtle and occur gradually. In some people the disease progresses more quickly than in others. As the disease progresses, the shaking, or tremor, which affects the majority of PD patients may begin to interfere with daily activities. Other symptoms may include depression and other emotional changes; difficulty in swallowing, chewing, and speaking; urinary problems or constipation; skin problems; and sleep disruptions. There are currently no blood or laboratory tests that have been proven to help in diagnosing sporadic PD. Therefore the diagnosis is based on medical history and a neurological examination. The disease can be difficult to diagnose accurately. Doctors may sometimes request brain scans or laboratory tests in order to rule out other diseases (nlm.nih.gov).

POSSIBLE CAUSES

The cause of Parkinson's disease is unknown. Many researchers believe that several factors