Parkinson’s Disease Parkinson’s disease (PD) was first described in 1817 by Dr. James Parkinson, a British physician, for whom the disease was named. Parkinson's disease is a disorder that affects nerve cells in the part of the brain controlling muscle movement. It has four major features containing: Rest tremor of a limb, Slowness of movement, Rigidity and poor balance. PD, in simple terms, is the uncontrollable trembling of the hands, fingers, arms, jaws etc. Going in more depth, Parkinson's Disease belongs to a group of conditions called motor system disorders, which are the result of the loss of dopamine-producing brain cells. The four primary symptoms of PD are tremor, or trembling in 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