James Parkinson was not aware of the importance of his medical discovery in 1817 when describing what is now known as Parkinson's Disease. What is Parkinson's Disease (PD)? Parkinson's Disease is a neurological illness that slowly but progressively affects a small area of cells in the middle of the brain known as the substantia nigra. These cells gradually degenerate which causes a lack of production of the vital chemical, dopamine, which helps the nervous system control muscle activity (www.parkinson.org/pdedu.htm). Due to the reduction of dopamine, symptoms of the disease begin to occur. .
There are four major symptoms which are key to be aware of when diagnosing the disease. There are also many other symptoms which have been observed in persons with Parkinson's disease. The most common of all the symptoms is the tremor. The classic PD tremor is a rhythmic back and forth movement of the thumb and forefinger, sometimes referred to as "pill rolling". However, trembling can also affect the arms, legs, face and jaw. Approximately seventy-five percent of PD patients develop tremor, particularly in the earliest of stages. Tremors tend to affect only one side of the body, which therefore may cause a feeling of unbalance. Although tremor is so common, about twenty-five percent never develop significant tremor (Cram 5). .
Another common symptom is stiffness and rigidity, or better known as "freezing". In order for the body to maneuver smoothly, opposing sets of muscles must relax and contract alternately. In a person who has been diagnosed with PD, the muscles may remain constantly tense and contracted, forcing the person to freeze, literally (Cram 6). In the early stages, rigidity is often a symptom that patients are not to aware of. The problem is usually detected through a medical examination. When the doctor moves the joints in order to stretch the affected muscles, he or she finds there to be increased resistance to the movement.