It is a diagnosis based partly on exclusion, and it can only be confirmed by a pathological test. Based on symptoms, patients are given a diagnosis of possible, or probable, depending on the displayed symptoms. Occasionally, an MRI will show a typical pattern (hot cross bun).
A significan percentage are diagnosed with Parkinson’s Disease until it becomes obvious that Dopamine is not effective or that the progression of the disease is not following the expected course. There are a number of other “Parkinson’s Plus” diseases as well as Autonomic Failure, MS, ALS, normal presdure Hydrocephalus that will be ruled out prior to making the diagnosis.