Parkinson's disease results from a gradual degeneration of nerve cells in the portion of the mid-brain that controls body movements. The first signs of the onset of the disease are a feeling of weakness or stiffness in one limb, and/or a fine trembling of one hand when it is at rest (activity causes the tremor to disappear). Eventually, the shaking will worsen and spread, muscles will tend to stiffen, and balance and coordination will deteriorate. Depression and other mental or emotional problems are common.
The four primary symptoms of Parkinson's Disease are tremor or trembling in the hands, arms, legs, jaw, and face; rigidity or stiffness of the limbs and trunk; bradykinesia or slowness of movement; and postural instability or impaired balance and coordination. As these symptoms become more pronounced, patients may have difficulty walking, talking, or completing other simple tasks. Over 40% of patients develop a dementia syndrome that is largely distinct from Alzheimer's disease. Depression is common, also occurring in more than 40% of patients with Parkinson's Disease. Careful evaluation is necessary to help distinguish Parkinson's disease from second causes of parkinsonism.
The disease is both chronic, (it persists over a long period of time) and progressive (its symptoms grow worse over time). It is not contagious nor is it usually inherited-that is, it does not pass directly from one family member or generation to the next.
Parkinson's Disease affects about 1 in every 250 people over 40 years old and about 1 in every 100 people over 65 years old. It is slightly more common in men than in women. Medication can treat its symptoms, and the disorder is not directly life-threatening. Mostly it is a quality of life issue. About half of all patients treated with drugs have no major disabilities 10 years after the onset of the disease.
National Parkinson Foundation estimates that the total cost from Parkinson's Disease exceeds $5.6 billion annually in USA alone.
