The article was from 1974 and was a nerve stimulation test vs SFEMG if I understand the difference correctly. As I understand it though I think the results should still apply, at least generally.

At 31C the reduction was 9% which is near the bottom of normal. Warming the muscle 5 degrees to 36C resulted in a 44% reduction which is large. In another test they cooled a muscle from 34.2C to 30C and reduction in response improved from 25% to 4%. From that they conclude that false-negative diagnostic tests can happen due to unduly low temperatures.

Here's the full citation

S. Borenstein, JohnE. Desmedt,
TEMPERATURE AND WEATHER CORRELATES OF MYASTHENIC FATIGUE,
The Lancet,
Volume 304, Issue 7872,
1974,
Pages 63-66,
ISSN 0140-6736,

Grrrr! This makes me so angry! That room was freezing cold. I was freezing cold, even under a blanket they gave me. And the AC vent was straight overhead blowing an ice cold breeze directly down on me. Way to go, doc.

Every other EMG I've had, the room was really cold. What the heck???

Hydration plays a role as well. Subcutaneous fat (between the muscle and skin) of 9 mm can reduce an EMG signal by 80 percent. And men's muscles fatigue more quickly than women's do, which might be why the average time for a man to be diagnosed is 1 year, but the average for women is SEVEN years! Frankly, I think that's due to sexism! ;)

The best MG centers will make sure an MG patient is good and warm while having an EMG/SFEMG. In some places, they soak someone's legs in warm water first!

I hope the appt. on Monday goes well, Navario!

Annie

Thanks guys.

I have realised that coke can act as Mestinon.

I had some glasses of coke just before my last emg, the one which was negative

Can this have afected the repetitive emg?

My neurologist want me to try Prednisone since I have got thymic hyperplasia and one positive emg.

I feel much better since mestinon, but it doesnt work every day and sometimes i dont take it and im fine, other days i take it and im not, other days it helps some muscles but not others. It´s strange.

The point is that I am not sure if this is MG or not so I am scared of prednisone.

Thank you all for your replies. :hug:

Hi, Navario. So the neurologist believes you have MG. Then you probably do.

Not the coke, but the caffeine. There are no studies showing that caffeine can affect EMGS like Mestinon. But the science is technically sound.

I am not a doctor, so take what I say in that context. I do not think that Prednisone should be a first line drug for MG. But that's the algorithm they have. Mestinon is a helper drug. So the first drug they offer to suppress the immune system is Prednisone.

Steroids shut off the adrenals. That leaves a person open to adrenal issues if they become emotionally or physically stressed. Usually the adrenal glands adapt to those changes. A constant dose of Prednisone does not. The body becomes used to a particular dose as well. And when patients try to go off of Pred, no matter the dose they are on, it is near to impossible. They can also have signs of an adrenal crisis, which can be life-threateing and can make MG worse. MG can also become temporarily worse after first starting the drug.

Prednisone also causes a LOT of side effects and can cause diabetes. Sure, other immunosuppressants can also cause a risk of cancer, anemia, increase risk of infections, and lots of other issues. But no other drug is like steroids in what havoc it can wreak on the body.

A CT can't show a thymoma for sure. If you take immunosuppressants, that can increase the cancer risk.

Mestinon helps. But if you increase your activity, your muscles demand more acetylcholine. Mestinon might not be able to keep up with that demand. Our muscle receptors only allow for just so much acetylcholine to get through.

Mestinon kicks in after about 30 minutes. Two hours after that point, it wears off. How much are you taking and how often?

Only you can decide what kind of treatment option works for you. If you are wary of the diagnosis, Dr. Eymard is a great doctor for a 2nd opinion.

I really hope you will discuss more with your neuro, or another one. I wish I could do more to help you!

:grouphug:
Annie