Diagnosing someone with MG is not that hard. Why doctors make it hard is beyond me.


Annie,

I think the problem lies in the fact that they are not able to differentiate between-diagnosing a clinical myasthenic picture (which is fairly easy and in most patients, even those that have a less typical course, quite clear to the extent that a first year medical student can recognize it) and verifying autoimmune MG.

And then they start confusing everything, questioning what they clearly see, questioning their patient's reliability etc.

I think my own story exemplifies it beautifully.

20 years ago, when I was a young medical student, one of my peers noticed that I had difficulty holding the book (when we studied in the evening) and left eye ptosis. she consulted a bright young neurology resident (without me knowing) and he approached me one day after school, looked at my eyes, and asked me to come with him to his office.
after a 10 minute interview (in which I admitted noticing that I was losing my strength in the evening and not able to tell my son a bed-time story for the last few months, etc.) , a quick neurological examination and a tensilon test he did on the spot, he told me that I have MG and gave me my first bottle of mestinon pills. he said that just in case he needs to do some more tests.

when my tests came back normal, he consulted an expert. even this expert agreed that I have at least ocular MG. ( I didn't know then that it is acceptable to have normal tests in ocular, but not so in generalized).

but, when I started having more significant generalized symptoms, including episodes of shortness of breath (one which prompted hospital admission by this resident), it became obvious that I could not possibly have MG.
the expert came to the hospital (after the resident gave orders for plasmapheresis and steroids to be started that evening), told them to stop all treatment (including mestinon) and when I had some improvement with bed-rest, he concluded that I have "nothing", can continue taking mestinon as placebo (if I wish to do so) and discharged me home.

every abnormal test that I had, was attributed to deconditioning, anxiety, or what ever explanation you could think of.

so, paradoxically, as my symptoms became much more severe and more clearly evident, it made them question the diagnosis, instead of the exact opposite.

and why? because in their opinion it was "impossible" to have such severe symptoms with normal ancillary tests.

you would think that this was 20 years ago, and now things have changed, but not really.

this is taken from a letter written by a world leading expert, in one of the best MG centers, only 2 years ago.

"...You have continued to have symptoms and perhaps the most striking element is the recurring episodes of profound weakness with breathing difficulties. However, I was encouraged by the fact that in the fortnight before we met you felt that there had been some improvement.

On clinical examination I was not convinced of the presence of any specific weakness. Your eye movements were normal and the eyelids did not show fatiguability. (to this a good friend of mine, who is a neurologist, asked if he himself had bilateral ptosis or was he blind?)

The neurophysiological studies were essentially within normal limits. There was one very minor abnormality on single fibre studies but that is non-specific and certainly the electrical test did not show the changes that we would normally expect to see in somebody with substantial myasthenic weakness.

I promise you, this is real. I just did "copy and paste" from his original letter.
he also wrote an e-mail to my GP at the same time, suggesting that "all involved will be positive" and explaining that it would be advisable for me to receive "emotional support", as many patients with MG will continue to have such "symptoms" even when their illness is fully under control ( such as mine obviously was).

I can promise you that if my EMG did show "the changes they would normally expect to see in somebody with substantial myasthenic weakness", the approach would have been completely different. quite likely, I would have been admitted to the ICU with the (correct) diagnosis of myasthenic crisis. what other name would you give a situation in which someone has recurring and almost continuous episodes of profound weakness with breathing difficulties, unmeasurable vital capacity, requiring respiratory support, and on examination does not have any "specific weakness" because she can hardly move and has shortness of breath (anxiety?) just being examined briefly? and has to use her respirator in the middle of the electrophysiological examination, that "did not show the changes we would normally expect to see"?

their need to have so-called "objective" evidence (eg-seeing a graph, as opposed to seeing their patient), blocks their ability to see, hear or think clearly.

This is why it is so hard for them to diagnose this illness. This is why every physician (including most neurologists that saw me, before they had results of tests) had no doubt that I had MG (despite my "unusual" symptoms and clinical course) and most neurologists doubted this diagnosis, once they received the results of their tests.

I think and hope that this is now starting to change, as there is a gradual better understanding of the complexity of this illness, and the limitations of the currently used diagnostic tests, even among the neurology community.

And I am doing what ever I can to facilitate this change.

I think that patients should be aware, that at least some neurologists will not treat them seriously regardless of the severity of their symptoms, once they have normal test results, and they have to seek someone else, who does understand the limitations of those tests.

should such patients be treated with immunomodulatory treatment with all its possible side-effects is a harder question, because some of them may have a genetic abnormality and not an autoimmune disease, and I do hope that within the next few years, the developments in the field of genetic testing will make it possible to screen such patients for possible mutations effecting the NMJ and down-stream related proteins.

like you say- it should not be that hard to diagnose a patient with clearly evident myasthenic symptoms, and figure out if he/she has a genetic problem, autoimmune disease (or possibly both) and decide within a reasonable time period regarding the optimal management approach.

it should not take 20 years, and not even 2 years...