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...
I have almost completely bulbar symptoms, no ptosis. My symptoms are relieved with Mestinon. I am seronegative. They are doing a single fiber, I am told, on my eye. Will it show anything if I don't have ptosis?
http://www.ncbi.nlm.nih.gov/pubmed/12140000 says that sfemg on the tongue (hypoglossal nerve) was slightly better for bulbar MG if I read it right. It found 3 more than other muscles, but also missed a couple too.
Good Luck
She said a muscle biopsy is my next step as she doesn't think it is MG. But she can't explain why the mestinon works and refused to order the muscle biopsy. Still waiting (a year now) for a second opinion in case it is something else, like mitochondrial disease.
I have had bulbar symptoms, worse at some times than others. During my respiratory testing while off Mestinon for 60 hrs I couldn't swallow water when my throat was frozen with lidocaine - that fits with MG. But during the test with Mestinon I could swallow the water while frozen.
I'm sure there will be more antibodies discovered in the future for those of us who are seronegative and have negative SFEMG tests.
Flutebell
Technically any muscle could be used by using a conversion factor to find the normative values for sitmulation jitter. They normally use the eye first. In my case there was some abnormality in how mine was located so they used my arm instead just above the wrist.
Not everyone has ptoses but they still routinely use these two muscles consistently so I am thinking jitter shows up regardless.
I would just mention to the tester about the location of your symptoms. Technically if there was another muscle they wanted to use they could. I am thinking it won't matter whcih they use but I would go ahead and ask the tester but go ahead with the testing.
Mine was abnormal and enough to justify the use of pyridostigmine but not classic. I had a phenomenal tester. He had years of practice in this type of test and a personality that meant he looked for rather hard to find signals. He manipulated the needle when needed and my test was unusual in that it was three hours long. It was done at a teaching university and in a warm room.
Not all testers are equal. Not all have the same background or pay attention to the same concerns like room temperature. I do think it matters. Most textbooks say it should only be done by a very experienced tester in this test. You have every right to ask the background including number of tests given or years of experience and defer to another tester if needed. I drove 7 hours to mine.
My daughter's was done on the eye muscle. Her's was positive.
That said my next step due to the complexity of my presentation is to get genetic testing. It is not covered by insurance in my case.
Hopefully it gives clues that lead to clarification and a clearer tx plan.
I noted in reading about different genetic tests that they do have ones now that give some information on the area of the neurojuncton. Mine will be more general in nature but I hope to report more on this later.
I am thinking that with the slowness of identifying antibodies that genetic testing might be the next step for those of us who are seronegative. We really are on the cusp of some amazing medical tests who's costs will come down dramatically in the next five years. At some point soon they will be routine in doctor's offices. Not so yet tho and costly.
Let us know how the testing goes and if you get a clear answer to your question.