EMG test on Mestinon?
Hi,
I have been put on Mestinon 90mg every 4 hours during the day and 180 mg time release at night. Should I be on Mestinon while receiving an EMG test? So far, I've been told to stay on it, but I'm skeptical.
I appreciate your replies.
Thanks, Jennifer (serotonin negative/suspected generalized MG)
Thank you for your replies. I've asked for a retake of the EMG. I had taken 90mg of Mestinon that day, as I was having speech, swallow, walking, and breathing problems. I've had two EMGS in the past ten years but didn't remember about the Mestinon. It's hard for me to stop taking it at this point due to symptoms.
I am double seronegative. Is there research on how patients are diagnosed who respond well to Mestinon but don't show up on blood tests or the EMG?
Also, I noticed during this last EMG, the muscles I'm weak in were not tested. I asked the doctor performing the test if it were possible to test these muscles and he said not directly. Does testing the non-weak muscles result in a false negative?
History:
I began this journey over ten years ago with double vision. Doctors have always said it could be MG, neurologists have said it "sounded" like MG but they didn't see my symptoms. I've been prescribed Mestinon three times over the past ten years. Back then, Mestinon helped and eventually symptoms subsided or were mostly in the evenings. Blood tests and EMGs were negative then, too. Tens years of this turned into a disease I thought I knew like the back of my hand, even though I couldn't get a diagnosis, but I could manage with rest and careful planning.
Now, this current flare up - the worst it's ever been after starting a new and stressful job - has lasted for more than three months and includes the symptoms I wrote above. I am most concerned about this gagging, panting, cessation of breath symptom happening when I eat solid foods. So, I started with a speech and swallow therapist who put me on soft foods and recommended I rest. When my symptoms worsened, I went to a pulmonologist who said I have muscle weakness and needed more advanced medicine (IVIG and steriods) but for that I needed a neurologist. My primary consulted with a neurologist from the exchange (nonlocal) who also said I needed more advanced medicine because the Mestinon would eventually fail.
The bottom line is that I'm feeling stuck between a rock and a hard place. At this point, I'm waiting for my neurology appointment, which is very hard to come by as our metropolitan city only has one neurologist in private practice. The hospital ER says they don't have the facilities to test for a diagnosis, and can't help with more advanced medicine unless I'm unable to breath on my own. They won't admit me for inpatient treatment even upon the request of my primary and the pulmonologist. Personally, I'm feeling safe at home for now but anxious about what the neurologist is going to say in a few months. All of the neurologists I've been to in the past weren't certain it was MG without clinical evidence.
Kaye
, So glad you got Chloe's book (title is too long to type)
Really hope you have been keeping a journal of all activity, symptoms, how you slept, what you ate, any falls. Take it with you but know they won't look at it. Do write what symptoms you have had often, time they happen and what made it better or worse. make it as simple and clean as possible, make copy to leave with them. Again they may not acknowledge it during appt but hopefully they do read it. As an RN have thought about stuffing it up their nose but that is just extreme frustration. Please let me know how it goes on 19th and what you think of the book
Cheryl
Hey Kaye! I found these studies about double seronegative and seronegative MG and pyridostigmine (Mestinon): https://www.sciencedirect.com/science/article/abs/pii/S0960896613001156, https://www.sciencedirect.com/science/article/abs/pii/S0022510X14005929,
https://europepmc.org/article/med/15042294,
https://sciendo.com/article/10.2478/sjecr-2014-0007,
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1468-1331.2005.01137.x.
I am not finding studies specifically discussing an EMG test on muscles that are not weak at the time. I did find these studies that might be of interest though, https://pubmed.ncbi.nlm.nih.gov/19846306/,
https://teleemg.com/education/myasthenia-gravis/,
https://onlinelibrary.wiley.com/doi/abs/10.1002/mus.20568,
https://onlinelibrary.wiley.com/doi/abs/10.1002/mus.880150616.
- Jodi, Team Member
We were told not to take it for 48 hours. The neurologist who administers the test is the one that interprets the results, so that's whom you should ask. Juliana (Team Member)
Hey Kaye! I just read several studies and found this one of particular interest, https://pubmed.ncbi.nlm.nih.gov/31484280/. They looked at 111 gMG patients and had some discontinue Mestinon for 18 hours before their EMG and the others for 8 hours.
The findings suggest that in those who discontinued for 8 hours, "the positive rate of repetitive nerve stimulation in facial nerves and the extent of the amplitude decrease under different electrical stimulations (1 Hz, 3 Hz, and 5 Hz) were dramatically higher." "For gMG patients, the facial and accessory nerve detection can improve the positive rate of RNS. Different muscles had various sensitivity to PB" (Mestinon), "and orbicularis oculi muscle seemed the least sensitive muscle to PB" (Mestinon). "For suspect MG patients in severe condition, only discontinuing PB" (Mestinon) "medication for 8 h before low-frequency RNS testing can avoid the deterioration and also obtain similar positive rate."
This suggests discontinuing Mestinon to get an accurate reading, but 8 hours may be efficient. I would bring this up with your doctors.
How terrible are your symptoms without Mestinon, and are you on any other treatment? If you are solely on Mestinon, it may be riskier to discontinue it before the EMG as it could trigger a crisis. Has there ever been an instance you could receive a Mestinon dose on time? If so, how did your body react?
- Jodi, Team Member
