Preview
In its early stages, Parkinson's disease is easily mistaken for essential tremor. As the disease progresses, additional signs accumulate that help in identification, such as the muscle rigidity and expressionless appearance that typify the disorder. However, its differentiation from the many disorders with similar signs as early as possible is desirable because correct treatment to enhance quality of life can then be instituted. In this article, the authors describe diagnosis of primary and secondary Parkinson's disease.