1. Health
Send to a Friend via Email

Mistaken PD Diagnosis


Updated May 05, 2009

Mistaken PD Diagnosis
© 2001-2008 HAAP Media Ltd

Parkinson's Disease Is Difficult to Diagnose

In its early stages, Parkinson's disease is difficult to diagnose. Early symptoms may come and go. You may write them off as temporary cramps or stiffness. Or you may say to yourself “I’m just getting old!” But they keep returning, and you visit your doctor who then tells you that it will take time before a definitive diagnosis can be made. You become anxious and impatient.

Here are some things to consider when you think you may have PD but neither you nor your doctor is sure about the diagnosis: Diagnosing PD may be difficult even for a neurologist familiar with the disease.

  • There are no blood or lab tests than can definitively diagnose PD. It is typically diagnosed on the basis of the history and variety of symptoms and a clinical examination.

  • The four classic symptoms of PD are tremors, rigidity, slowness of movement, and postural instability. If you have these symptoms and they are persistent and they started on one side of your body, your doctor may be more likely to diagnose PD.

Response to Drug Therapy

Even if you have the three classic symptoms of PD, you may still not have PD. To decrease the chances of making an inaccurate diagnosis, your doctor will very likely suggest a trial of antiparkinsonism drugs, usually levodopa.

  • If your symptoms improve with the drug, PD is likely the diagnosis.

  • If after a fair trial with the drug you still do not get better, the tremor, slowness and rigidity may be due to some other problem besides PD.

At this point your doctor may order further tests such as scans of your brain. Here are some things to remember about these tests:

  • Computed tomography (CT) and magnetic resonance imaging (MRI) cannot diagnose PD, but they can help to rule out other diseases that may produce PD-like symptoms.

  • Positron emission tomography (PET scans) or single photon emission tomography (SPECT scans) using specialized isotopes can visualize dopamine levels in the brain and can therefore help diagnose PD and distinguish PD from other PD-like disorders. However, these tests are expensive and not widely available. They may be unnecessary if simpler diagnostic tests can do the job.

PD versus Progressive Supranuclear Palsy (PSP)

The three cardinal symptoms of PD (tremor, rigidity and slowness of movement) are collectively called “parkinsonism,” but not all people with parkinsonism have PD. In fact, all three of these cardinal signs of PD may be present in other diseases, the pathology, course and causes of which are different from PD. As mentioned above one way to decrease the likelihood of making an inaccurate diagnosis is to begin a trial of levodopa. If you improve on levodopa, there is an increased likelihood that you have parkinsonism. If your symptoms do not improve after levodopa, then other diagnoses should be considered:

Progressive Supranuclear Palsy (PSP)

The most common mistaken diagnosis when PD is a possibility is progressive supranuclear palsy (PSP) -- an akinetic-rigid syndrome. For every 100 people with PD, there are five with PSP.

  • The most distinguishing characteristic of PSP is that you become unable to move your eyes. Upward gaze in particular becomes difficult.

  • If you have PSP you will very likely also have major problems with balance -- even early in the disease, so you may find yourself literally falling down.

  • Unlike PD, PSP begins on both sides of the body at the same time, occurs without tremor, and responds poorly or not at all to levodopa.

  • PSP progresses more rapidly than PD.

  • You may also find that your ability to focus and be attentive fluctuates throughout the day. Sometimes it’s fine, while other times it’s impossible to stay focused.

When Struggling With Potential Diagnoses

It’s always hard on you and your loved ones when you are struggling to find out what’s causing those troublesome movement problems. Be persistent in that struggle -- no matter how upsetting and trying it may be. The earlier you find out what’s wrong, the more effective the treatments will be for whatever problem you have.

Here are some things to consider when struggling with potential diagnoses:

  • Take control of the situation. Make a list of all the symptoms you have noticed and when you first noticed them. Then read the list over. Do you have any of the “classic” PD symptoms: tremor, slowness of movement, or stiffness?

  • Ask friends and family for their opinions. Ask them when they first noticed any troubles. In addition to the motor symptoms, ask them about whether they think your personality and mood have changed. Share all this information with your doctor.

  • Get a second and even third opinion, if needed. Once you have a certain diagnosis you may even feel a certain relief. At least you now know what you are dealing with. Remember, you are not your disease. Do not let it dictate to you. There are many effective treatments available. You can learn more about these treatments from your doctor and from this website.


R. Pahwa and K.E. Lyons (Editors),Handbook of Parkinson’s Disease; 4th Edition, New York, Informa Healthcare Publishers, 2007.

Shobha, S. Rao, SM.D., Laura A. Hofmann, M.D., and Amer Shakil, M.D. "Parkinson's Disease: Diagnosis and Treatment." American Family Physician December 15, 2006. http://www.aafp.org/afp/20061215/2046.html

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.