Hi, I had gone through your question and understand your concerns. The diagnosis of Parkinson disease is mainly clinical, in other words a group of symptoms and medical history observed by a specialist in a patient. Signs and symptoms include : Tremor mostly at rest ( shaking mainly of limbs), Slowness of movements, Speech and writing changes, Tightness (stiffness) of muscles, balance problems, loss of facial expressions. Other tests are performed to exclude diseases that may have similar symptoms and signs. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions.