Parkinson disease is a progressively disabling disorder of the nervous system that causes marked tremor of the limbs, increased stiffness of the muscles, and impaired balance among other debilitating symptoms. At present there is no cure for the disease, but a variety of medications, known as antiparkinson drugs, provide dramatic relief from symptoms. Antiparkinson drugs restore the chemical dopamine in the brain or imitate dopamines actions. Hopefully in the new future there will be a cure as researches and scientists work on it.