Hi ksm3327 -

Parkinson's Disease is a degenerative disorder of the central nervous system characterized by tremor and impaired muscular coordination.  To put it simply, Parkinson?s Disease (or PD) is progressive.  It will eventually get worse with time.  It can and commonly does affect the central nervous system - the whole body.  It can be identified by several factors, one being tremors, another being the patients lack of coordination in moving, due to their muscles being affected.

Basically, a healthy brain will produce the correct amount of dopamine needed for the brain to function properly.  A person who has Parkinson?s doesn?t produce enough dopamine, having a lack of control over their movements. 

Dopamine is the brain?s oil, causing it to work effectively, much like oil is to a car engine.  When the oil gets low, you begin to experience a lot of problems. 

I?m not sure if that?s what you?re looking for ? let me know.  Good luck!