Parkinsons disease. Illustration of the brain, depicting the neurological disorder of Parkinsons disease. In the foreground is a crosssection through the upper brainstem. Parkinsons disease is caused by a degeneration of nerve tissue within the brains basal ganglia, particularly the substantia nigra (black). These areas are involved in controlling motor functions. Degeneration of these nerve pathways prevents contracted muscle from relaxing causing tremor, joint rigidity and slow movement. Parkinsons disease affects the elderly, progressing from a slight hand tremor, to an unbalanced, bentover, shuffling walk. Treat ment includes dopamine drugs. There is no cure.
