Once again the enigmatic oracle Viartis has emerged from the mists of the Web with disturbing Parkinson's news, this time about misdiagnosis. Citing a finding that "Initial diagnoses of Parkinson's Disease made by general neurologists were only infrequently changed, yet were incorrect in 24% to 35% of cases". The Viartis item goes on to report that "This means that many people have been treated for Parkinson's Disease for the rest of their lives without ever having had Parkinson's Disease. In people taking Parkinson's Disease drugs, Parkinsonism was confirmed in only 74% of cases and only 53% of them had probable Parkinson's Disease". You can find the article with links to supporting material here.
What else could your disorder be? Benign essential tremor, Wilson's Disease, perhaps a brain tumor. These conditions call for radically different approaches than PD. If a general practice neurologist comes up with the wrong diagnosis up to 35% of the time how do you think people outside the neurology field are doing with their diagnosis accuracy? What's a potential Parkie to do?
This is why it is useful to either get your diagnosis or a second opinion from a movement disorders specialist. Your chances of a correct diagnosis are best with a specialist with extensive training and practical experience in the area, hence the value of the neurological sub-specialty of movement disorders. Unfortunately, even with this training it can be tough to sort the differences in types of Parkinsonism.
So we find yet another question underneath the surface here, which could be phrased this way: "Aughhhhhhh! You always tell me that I need to trust my doctor, then you tell me that I can't trust my doctor? What's the point? I hate you! I hate you!" The point is that you have to be involved in your care. You must seek out the most high-quality information you can find from a variety of trustworthy sources, then listen to your own body to confirm that whatever they tell you squares with what you are experiencing as a patient. In a perfect world we wouldn't have to ask these questions. In our imperfect one we must answer them the best we can.