Making an accurate diagnosis of Parkinson’s — particularly in its early stages — is difficult, but a skilled practitioner can come to a reasoned conclusion that it is PD. You may have experienced this frustration. Perhaps it took years for you to receive a diagnosis. Perhaps you have been diagnosed, but with Parkinsonism, not Parkinson's, and are confused about the implications.
How is Parkinson’s Diagnosed?
Often, the diagnosis of Parkinson’s is first made by an internist or family physician. Many people seek an additional opinion from a neurologist with experience and specific training in the assessment and treatment of Parkinson’s disease — referred to as a movement disorder specialist.
To diagnose Parkinson’s, the physician takes a careful neurological history and performs an examination. There are no standard diagnostic tests for Parkinson’s, so the diagnosis rests on the clinical information provided by the person with Parkinson’s and the findings of the neurological exam.
The doctor looks to see if your expression is animated.
Your arms are observed for tremor, which is present either when they are at rest, or extended
Is there stiffness in your limbs or neck?
Can you rise from a chair easily?
Do you walk normally or with short steps, and do your arms swing symmetrically? The doctor will pull you backwards.
How quickly are you able to regain your balance?
The main role of any additional testing is to exclude other diseases that imitate Parkinson’s disease, such as stroke or hydrocephalus. Very mild cases of PD can be difficult to confirm, even by an experienced neurologist. This is in part because there are many neurological conditions that mimic the appearance of Parkinson’s.
A person’s good response to levodopa (which temporarily restores dopamineaction in the brain) may support the diagnosis. But this is not relevant if your doctor thinks you do not need any medication at this time. If you are in doubt of your diagnosis or if you need further information, you may want to seek a second opinion.
Why Aren’t There Tests to Diagnose Parkinson’s?
There is no standard diagnostic test for Parkinson’s. Researchers are working to develop an accurate “biological marker,” such as a blood test or an imaging scan. To date, the best objective testing for PD consists of specialized brain scanning techniques that can measure the dopamine system and brain metabolism. But these tests are performed only in specialized imaging centers and can be very expensive.
Pimavanserin (Nuplazid™)has been approved by the US Food and Drug Administration (FDA) for the treatment of hallucinations and delusions associated with Parkinson’s disease psychosis. The drug’s manufacturer, Acadia Pharmaceuticals Inc., announced the approval on April 29. Pimavanserin is the first drug indicated specifically to treat symptoms of psychosis in Parkinson’s.
Parkinson's Disease Research & Education Institute