Parkinson's disease. Conceptual image of a brain in a profile view of a silhouetted human head, with the red glow representing the effects of Parkinson's disease. This condition is caused by a degeneration of nerve tissue within the basal ganglia of the brain. This degeneration leads to loss of muscle control, and tremors and a shuffling walk. Treatment for the symptoms includes dopamine drugs and deep brain stimulation. There is no cure.