Myasthenia Gravis Support Group

Myasthenia gravis (MG) is a neuromuscular disease leading to fluctuating muscle weakness and fatiguability. The hallmark of myasthenia gravis is muscle weakness that increases during periods of activity and improves after periods of rest. Although myasthenia gravis may affect any voluntary muscle, muscles that control eye and eyelid movement, facial expression, and...

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Another negative MG test

SREASON
SREASON

After all blood work and emg was neg now I've passed the SFEMG with flying colors also which they said it's very unlikely it's MG if that's normal. Has anyone else had MG with normal SFEMG. I'm so confused and feel so lost. The Mestinon is a God send and I don't understand why it's such a huge transformation with the meds if it's not MG. I'm sick of feeling crazy when I know I'm not. 

Rhanson
Rhanson
In one study 67% of people diagnosed with mg had a positive sfemg. https://www.ncbi.nlm.nih.gov/pubmed/24296278
So not a sure test for mg
Good luck
Russ
Meng
Meng
Single fiber EMG is only as good as the neuro who does it... I have had one that was negative. The room was ice cold and the neuro decided which muscles to test. When I asked why he did not test my forehead muscles - simply told we never test there. But there is where my facial weakness tends to be the worse. Did some research. Best practice is to test muscles in the forearm, forehead and eyes. Also there is a difference between when they stimulate your muscles and when you actually contract them. Room temp is important. Also testing weak muscles as reported by the individual is recommended. I have another test in June and plan on asking the neuro about what I have read.
LionJill
LionJill
I have had negatives on every test, yet mestinon seems to help me. I am scheduled for a SFEMG in a couple of months. I totally understand what you are saying. Today has been a great day - I have only had one mestinon. So now I go through the whole second guessing thing. Do I really have it? Is it the mestinon that causes the symptoms. oy vey this is so frustrating!
Rhanson
Rhanson
From the website www.myasthenia.org
"Sometimes all of these tests are negative or equivocal in someone whose story and examination still seem to point to a diagnosis of MG. A clinician skilled in recognizing MG and distinguishing MG from other conditions would need to determine if such a patient has MG or another disorder."
There is a test that you might have your doctor try -- The Tensilon test uses the drug Tensilon (edrophonium) to diagnose myasthenia gravis.Tensilon prevents the breaking down of the chemical acetylcholine, which then helps stimulate the muscles. A person tests positive for myasthenia gravis if their muscles get stronger after being injected with Tensilon.
This is essentially the same kind of medicine as Mestinon. If it works then most doctors will diagnose you with MG, and your thought that because mestinon works will be verified by a "test."
Good Luck Russ
Anushka_W
Anushka_W
I have been negative for all the blood tests that they normally do for MG and the SFEMG test. However, then a neurologist recommended that I had a very specific blood test done to test for MuSK Myasthenia Gravis, and it came out positive. MuSK MG is the rarer forms of Myasthenia Gravis, and as far as I understand it, not as easy to diagnose.
@LionJill, I found that the Mestinon (if you take too much) can mirror the Myasthenia symptoms. Also, my requirement of Mestinon vastly differs from day to day. It might be because I have absolutely zero routine with the job I have. I had similar feelings once I got diagnosed but in the end it really was Myasthenia.
Rhanson
Rhanson
http://www.prohealth.com/library/showarticle.cfm?libid=29084. Mestinon helps in another disease