How Parkinson’s Disease is Diagnosed
The diagnosis of Parkinson’s disease (PD) can be relatively straightforward by detecting particular clinical features, such as rest tremor, stiffness, and slowness on neurological exam. Typically, detecting these features leads to an accurate diagnosis, without any further testing needed.
In cases where the diagnosis remains uncertain, an imaging test called a DaTscan is available. However, this approach to PD diagnosis is rapidly evolving. Advances in the development of biomarkers is starting to change how PD is diagnosed and will potentially allow for diagnosis at an earlier stage than is possible now.
Understanding Parkinson’s Disease
Seeing a Movement Disorder Specialist
What is a movement disorder specialist?
A movement disorder specialist is a physician who has undergone additional, subspecialty training in the diagnosis and treatment of movement disorders, such as Parkinson’s, after training in general neurology. This type of specialist is best suited to evaluate your symptoms and determine whether additional testing is necessary to help with diagnosis. Depending on where you live, there may not be a movement disorder specialist near you, in which case, you should seek the advice of a general neurologist.
Learn more about movement disorder specialists
What to expect during your visit with a physician
When you or someone you know first visits a physician for the evaluation of potential Parkinson’s disease symptoms, it is helpful to know what to expect. During the first visit, the physician should take you through a series of physical tests and observations.
Parkinson’s Diagnosis Checklist
- Take a complete and careful medical history
- Review your current medications
- Take your blood pressure while you sit and stand
- Assess your thinking (or cognitive) skills
- Examine your facial expression
- Look for tremor in your face, hands, arms, or legs
- Examine whether there is stiffness in your arms, legs, torso, or shoulders
- Determine whether you can get up easily from a chair, especially without using your arms
- Examine your walking pattern
- Assess your balance as you stand
Typically, a trained physician will only consider the diagnosis of Parkinson’s disease if the person being examined has at least two of the core motor symptoms of Parkinson’s, including tremor, the characteristic bradykinesia (slowness of movement), or rigidity. At the end of your visit, the physician should discuss with you why you may or may not have Parkinson’s disease and the level of certainty about the diagnosis. This determination is based on your medical history and examination at this visit.
Helping Diagnose Parkinson’s with DaTscan and Other Tests
DaTscan
DaTscan is an imaging test which helps to visualize the dopamine system in the brain. It is most helpful when the diagnosis is uncertain, or your physician is trying to distinguish PD from certain other conditions that can mimic Parkinson’s. DaTscan will appear abnormal in any disease in which there is a loss of dopamine nerve endings in the area of the brain called the striatum. Therefore, DaTscan cannot distinguish PD from other related conditions that also have loss of dopamine nerves in this area, such as Progressive supranuclear palsy (PSP), Corticobasal ganglionic degeneration (CBGD) and Multiple system atrophy (MSA).
MRI
Magnetic resonance imaging (MRI), which examines the structure of the brain, may be utilized in certain situations to help with diagnosis.
Biomarker tests
There are two new tests for Parkinson’s disease that are commercially available. One is a test on the cerebral spinal fluid and the other requires a set of skin biopsies. Both of these tests are currently available but undergoing further evaluation to determine how best to utilize them in clinical practice. Your doctor will decide whether these tests are necessary to help in your diagnosis. Researchers are also actively trying to develop additional tests, including a biomarker in blood, that could help confirm the diagnosis.
Learn more about new biomarker tests
Determining diagnosis through response to Parkinson’s medication
If a person’s symptoms and neurologic examination are only suggestive of Parkinson’s disease or if the diagnosis is otherwise in doubt, the physician may prescribe a medication intended for Parkinson’s disease in order to gauge the response. In the case of typical Parkinson’s disease, there is a positive, predictable response to Parkinson’s disease medication; in the case of some related Parkinsonian syndromes, the response to medication may not be particularly robust, or it may be absent entirely.
If it’s not Parkinson’s disease, what else could it be?
There are several other conditions that might produce symptoms that can be mistaken for Parkinson’s disease. Here are some possibilities:
- Medication side effects: Certain drugs can produce or exacerbate symptoms. Because of this, your doctor should review all your medications with you to determine if any could contribute to PD-like symptoms.
- Essential tremor: This is a relatively common and benign cause of recurrent tremor and is often confused with the tremor of idiopathic Parkinson’s. A general neurologist or movement disorder specialist is the best physician to help differentiate between these two conditions.
- A Parkinsonian syndrome: The symptoms of several neurologic conditions are similar to those of idiopathic Parkinson’s, but they are often managed differently and may not respond to PD medication.
Remember: Only a general neurologist or movement disorder specialist can tell you with reasonable certainty if you have Parkinson’s. If for some reason you are not comfortable with the results your first physician provided, getting a second opinion from another general neurologist or movement disorder specialist is always an option, and is a common practice. It is important to feel comfortable with and confident in your physician to ensure the best possible outcome for you.
Once you or your loved one has a diagnosis of Parkinson’s disease, it is time to discuss treatment options with your physician.
Parkinson’s Disease: The Essentials
If you’re new to Parkinson’s disease and would like a good overview to help you better understand the disease, please view our Parkinson’s Disease: The Essentials presentation. It’s a great place to get started with reliable and concise information.