Parkinson’s disease is a slow progressing, degenerative disorder of the nervous system that has several distinguishing characteristics including tremors when at rest, sluggish initiation of movements and muscle rigidity. This disease is caused by degeneration of or damage to nerve cells within the basal ganglia in the brain causing a lack of dopamine within this part of brain. The cause of the nerve cell degeneration and dopamine loss is usually unknown although genetics does not appear to play a major role.
In cases where the cause is known it is believed to be a late complication of viral encephalitis, which is a rare but severe flu like infection. This in turn prevents the basal ganglia from modifying the nerve pathways that control muscle contractions. As a result of this the muscles are overly tense, causing tremors, joint rigidity and slow movement. In most cases drug treatments increase the level of dopamine in the brain or oppose the action of acetylcholine. Parkinson's disease will usually begin as a slight tremor of one hand, arm or leg. During the early stages the tremor is worse when the limb that is affected is at rest.
When the limb is used the shaking will virtually stop. As the disease progresses it affects both sides of the body and causes stiffness, weakness and trembling of the muscles. Symptoms may include a stiff shuffling, over balancing walk that can break into uncontrollable, tiny, running steps, a constant trembling of the hands that is more marked at rest and is sometimes accompanied by a shaking of the head, a permanent rigid stoop and an unblinking, fixed expression. Intellect is unaffected by this disease until later, although the speech may become slow and hesitant, handwriting is usually very small and depression is common.
Even though there is no cure for Parkinson's disease there is much that can be done for the sufferers to improve their mobility and morale through exercise, special aids in the home and encouragement. There are organizations that exist to provide help and advice for sufferers and their families. In the early stages this is often all that is needed. As the disease progresses treatment with drugs will minimize the symptoms but cannot halt the degeneration of brain cells.
Treatments are usually complex since several different drugs may need to be administered in various different combinations. Levodopa-carbidopa, which is a drug the body converts into dopamine is usually the most effective. Other drugs that are given in conjunction with or as a substitute for levodopa include selegiline, bromocriptine or pergolide, amantadine and anticholinergic drugs that provide an effective relief for specific symptoms such as tremors.
If Parkinson's disease is left untreated it will progress over 10 to 15 years to severe weakness and incapacity. But with modern drug treatments considerable relief from the illness can be obtained, as well as a much-improved quality of life. In about one third of the sufferers of Parkinson's disease signs of dementia will eventually develop. Researchers are now experimenting with the transplantation of dopamine secreting adrenal tissue in an attempt to find a cure for this disease.