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Myasthenia Gravis

SFEMG - Asked to re-test?



I have been diagnosed with MG for a few years now.

However, my symptoms are sometimes called "atypical". One difference is that my ptosis looks somewhat "different" than some others with MG, but it does respond to Mestinon and to the non-clinical "ice test" (performed by my neuro-opthomolgist).

I had two neuros (treating neuro and one who performed regular EMG) tell me that I do NOT have MG.

Went for second opinion and then I had two neuros and neuro-opthomolgist confirm that I DO have MG.

The two neuros include treating neuro (with many, many years experience with MG), and the neurologist who did my SFEMG (highly regarded in well known training hospital).

DX now confirmed by symptoms, positive Tensilon, SFEMG and response to Mestinon. Have been on prednisone and now also azathioprine, trying to get off prednisone.

I have recently moved out of state to be near family because I had a crisis late last year (was in hospital) and not too soon after that I landed in the hospital with pneumonia.

My NEW neurologist now is suspicious of the MG diagnosis. Sending me for many tests, pulmonary, breathing and another SFEMG.

Questions: Do you think I need another SFEMG? The physician who performed my first SFEMG is regarded as an absolute expert in the state I used to live in. Test was VERY painful. He told me I would never have to take that test again. I am very stressed about taking the test again. Would it be within my "rights" to decline another SFEMG?

Also, new (less experienced with MG) neuro says to go off mestinon for 3 days before SFEMG.

However, I am still taking prednisone and azathioprine - will these drugs skew the SFEMG test?

The initial diagnosis for MG took a couple of years - now I am getting stressed about going through the process again.

Another question: if this is NOT MG - (I have almost all of the symptoms)- what other disease could possibly mimick MG?

Sorry for the long post. Hopefully my questions will benefit not only me, but others.

Thank you in advance for your answer.


Let me try to answer your questions, one-by-one:
  1. I would recommend that you go through the suggested tests by your new treating neurologist. The breathing tests are absolutely needed and the SFEMG will be helpful to your new neurologist in confirming that the disease is currently active. Having said that, you are always within your rights to refuse a test. Patient autonomy is a fundamental principle of medical ethics!
  2. If your current medications have been effective in inducing a remission, the SFEMG may be normal.
  3. There are many diseases that can imitate aspects of MG. It is for this reason that you need to continue to work with an experienced neurologist who can evaluate symptom by symptom.
It is always stressful for a patient to deal with an uncertain diagnosis or with physicians who question a diagnosis. I am afraid, however, that this is not uncommon in diagnosing and treating MG. The difficulty arises when you consider the risks of treating (and not treating) MG. Unfortunately, the medications have concerning side-effects with long-term use. And we physicians would hate to harm someone with drugs that are not warranted.

Take care!

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Response by:

John G Quinlan, MD John G Quinlan, MD
Professor of Neurology
College of Medicine
University of Cincinnati