PMA DIAGNOSIS – Fact or Fiction?

So, you have received a PMA Diagnosis? How can you be sure that this diagnosis is correct or at least the most likely candidate among a sea of unpleasant alternatives?

This conundrum is at the heart of my own situation. I have spent the better part of 2 years trying to either confirm or disprove my own diagnosis of Progressive Muscular Atrophy. During this time since PMA diagnosis, I have tried to keep an open mind while researching an area that is fraught with partial or misinformation.

What are the Chances?

One of the best articles that I have read on the variants that can mimic ALS can be found at: “Mimics and Chameleons in Motor Neurone Disease“. The graphic above that shows the typical process that leads to a definitive PMA diagnosis, mimics my own journey almost exactly. According to this article, variants with pure LMN (lower motor neuron) symptoms are the hardest to pin down and the most likely to be misdiagnosed.

This article offers some interesting statistics about MND and the diagnostic process. Apparently, 85% of suspected ALS patients present with clear upper AND lower motor neuron symptoms. In addition, studies have shown that approximately 1 in 10 pALS are incorrectly diagnosed, (I am using the terms ALS and MND interchangeably here). Those with lower motor neuron symptoms only represent about 10% of all cases. A final PMA Diagnosis occurs in only about 1  in 20 or 5% of pALS.

One of the most interesting insights that I discovered here is that there is a correlation between the period between the original onset of symptoms and final diagnosis and the eventual prognosis. The longer the symptoms were present, the longer the patient can be expected to survive. I suppose that this makes intuitive sense but be aware that this is not necessarily a hard and fast rule. However, just yesterday, as I was being assessed by my physiotherapist and OT for a power wheelchair, she opined that presentation history is the best predictor of future progression.

Why is the correct diagnosis critical?

Most of us are aware that there is currently no cure for ANY variant of Motor Neuron Disease and there are only a couple of approved and accepted prescription drugs available: Rilutek/Riluzole and Edaravone. Both of these drugs are controversial, expensive and come with some gnarly side-effects. What is more, the proof of effectiveness is tenuous at best. That being the case, one ought to be as confident as possible of the final diagnosis before embarking upon such a course of treatment.

If you are personally unconvinced with your own current diagnosis, you owe it to yourself to demand a second (or as in my case a third) neurological consult.