One of a group of conditions called motor system disorders which result from loss of dopamine-producing brain cells. Symptoms of PD include tremor (trembling in hands, arms, legs, jaw, and face), rigidity (stiffness of the limbs and trunk); bradykinesia (slowness of movement) and postural instability (impaired balance and coordination). As these symptoms become more pronounced, patients may have difficulty walking, talking, or completing other simple tasks. The disease usually affects people over the age of 50, can be difficult to diagnose accurately and may require brain scans or laboratory tests to rule out other conditions.
The above terms and definitions are part of the Taxonomy of Human Services, used here by permission of INFO LINE of Los Angeles.