In this era of genuinely marvelous, high-tech, medical devices, it is sometimes surprising that certain diseases are still diagnosed "clinically," meaning that the clinician makes the call based on just the story of symptoms and the physical exam. Parkinson's disease is one such disease. There is no "Parkinson scan" or "Parkinson blood-test" to rely upon. MRI scans, CT scans and blood tests are usually normal in people with this disease.

Of course, once upon a time