What's Parkinson's Disease (PD)?
Parkinson's disease (PD) is a progressive neuro- degenerative brain disorder [3]. PD occurs when certain neurons in a part of the brain called the substantia nigra die or become impaired [5]. It has been proved that these cells produce dopamine which allows smooth, coordinated function of the body's muscles and movement [5]. The symptoms of Parkinson disease such as tremor, slowed movement, rigidity and difficulty with balance appear when about 80% of cells producing dopamine are damaged [5]. The symptoms of PD may include small cramped handwriting, stiff facial expression, shuffling walk, muffled speech, and depression [5]. Based on the UK Parkinson's Disease Society Brain Bank criteria for clinical diagnosis [3], PD can be characterized as follows:
1. Bradykinesia plus one of rigidity, tremor, or postural instability.
2. At least three of rest tremor, progressive symptoms, unilateral onset, early response to levodopa, revodopa-induced dyskinesia.
3. No identifiable cause for the parkinsonism.
