Last updated:11-28-2009
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Definition and causes of Parkinson's disease - Parkinsons

Parkinson's disease is a common disease with an incidence of one in a thousand in developed countries. Parkinson's typically strikes the age group 50 to 70 years. The disease affects the brain, inhibits the body's movement and causes involuntary movement and tremors, hence the popular name "Jitters".


Parkinson's disease occurs because of a deterioration of neurons in an area of the brain, called the basal ganglia. The basal ganglia are very important for the body's movements. In the basal ganglia the balance between the two vital substances dopamine and acetylcholine is very important. If the balance is pushed towards too little acetylcholine, exaggerated movements occur resulting in Huntington's Chorea and if there is too little dopamine then movement is impaired resulting in Parkinson's.  
Parkinson's disease degrades the dopamine forming cells slowly, and as the dopamine levels decrease in the blood, the symptoms begin to emerge. This can take several years. It is not known why the degradation of cells starts. A few percent of cases stems from encephalitis (brain inflammation) and some cases are caused by drugs, but the vast majority of cases do not have any known or operative cause. There is a degree of inheritance (about 1 in 5 of cases), but upbringing, environment and chance also come into play.


Symptoms of Parkinson's disease

The three main symptoms of Parkinson's disease are:
  • Arms and legs are stiff, and it is hard to correct them.


  • Slow tremors (about 5 variations per second.). It is worst at rest, improves by movement and disappears during sleep.
  • Later symptoms are constant shaking of hands and fingers, called "pill-wheel shaking" because it looks like that you have a pill between your fingers, which is rubbed back and forth.
 Reduced movements: 
  • Slower movements than usual and as little as possible.
  • Facial muscles are affected with the patient unable to change facial expressions ("mask-face"). 
Besides this, there is a wide range of other symptoms: Small continuous steps, difficulty getting started with movements such as walking, only rare blinking of the eyes, deep and uniform voice, salivation (as normal swallowing and sinking is reduced) and a small cramped and finicky writing. Later memory and thinking is affected.


Progression and complications

Symptoms usually start on one side of the body and spread over the following years where the debilitation also becomes more apparent. Later in the cycle (this is due also in part to applied medication), there are periods of change between exaggerated movements and total rigidity. This is called on-off phenomena.


The disease is chronic and treatment does not cure but only delays the progression by some years. Parkinson's patients, however, have roughly the same life span as the rest of the population, although in the advanced stages as disabled.


Precautionary measures with Parkinson's disease

Many people 50-60 years of age experience slight tremors, especially in the hands. This is not Parkinson's disease. If you are experiencing other symptoms, or shake movements getting worse, you should consult a doctor.


It should be noted that some Parkinson's patients will suffer from depression, and it is important that both doctor and family are aware of this possibility, since the treatment of depression will give more energy and capacity to cope with the other effects of the disease.

Treatment of Parkinson's disease

Treatment varies somewhat depending on at which age the disease first appears. Patients under 60 years will usually start with drugs that increase cell production of dopamine. After a couple of years the treatment will change to substances which convert into dopamine in the body (L-DOPA). Patients over 60 years of age when diagnosed will usually start with L-DOPA. Additionally, there are some similar substances, which can complement or replace depending on the effect on symptoms. The side effects might be the above mentioned on-off phenomena.



If, after a few years, the medication is no longer effective, or if side effects are too severe, the next step might be surgery which remedies the vast majority of the symptoms. Implanted electrodes in the basal ganglia in the brain can be stimulated electrically and eliminate the symptoms.


Related articles:

ALS - Amyotrophic Lateral Sclerosis
Chorea (including Huntington's Chorea)
Dementia & Alzheimers disease
Neuromuscular diseases
Parkinsons disease (Paralysis agitans)



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