Myasthenia Gravis For support and discussions on Myasthenia Gravis, Congenital Myasthenic Syndromes and LEMS.


advertisement
 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 07-08-2011, 08:36 PM #1
AnnieB3 AnnieB3 is offline
Grand Magnate
 
Join Date: Feb 2009
Posts: 3,306
15 yr Member
AnnieB3 AnnieB3 is offline
Grand Magnate
 
Join Date: Feb 2009
Posts: 3,306
15 yr Member
Lightbulb SFEMG - Why are they negative?

This topic has been annoying me for years. Why do some MG patients, who obviously have MG, have negative SFEMG's? Is it as simple as too much fat?

http://www.smpp.northwestern.edu/~sm...2005POIntl.pdf

Quote:
With a ‘typical’ fat layer thickness of 9 mm above the biceps muscle (Durnin and Wormersley, 1974) the amplitude of the surface EMG fell by 80.2%.
A SFEMG needle has to go through the skin first, then subcutaneous fat and then the muscle. This article clearly shows that fat does indeed lower the frequency of the reading. I knew that this can happen when doing an EKG of the heart, so I figured it had to happen during a SFEMG. Or an RNS.

We all know about hydration, warmth of muscles, Mestinon and other drugs and things like technician experience, etc. effecting a SFEMG. But fat?

Women inherently have more fat than men. It's for a reason! But what if that does indeed interfere with the SFEMG results?

I am just putting this out there in a continued effort to understand why the medical community keeps saying that the SFEMG is the "gold standard" for diagnosing MG (instead of a clinical exam and common sense and antibodies and Tensilon tests and . . . ).

Any thoughts on this? Last year I did find a bunch of information that says that men's muscles fatigue more quickly than women's do. It seems that this issue is a lot more complex than what neuros say about it. Thanks for any input or sharing your own experiences.

If we're the "weaker" sex, it sure seems a lot harder to prove it.

Annie

Last edited by AnnieB3; 07-09-2011 at 12:10 AM.
AnnieB3 is offline   Reply With QuoteReply With Quote
"Thanks for this!" says:
rach73 (07-10-2011)
 


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Negative SFEMG but still have MG? jana Myasthenia Gravis 37 01-26-2018 09:50 AM
SFEMG on face n8swife Myasthenia Gravis 10 03-21-2011 01:26 PM
SFEMG pain Stellatum Myasthenia Gravis 0 01-13-2011 08:41 PM
SFEMG yesterday MomYaYa Myasthenia Gravis 2 01-13-2011 05:12 PM
Sfemg ? scrubbs Myasthenia Gravis 2 01-09-2011 10:20 AM


All times are GMT -5. The time now is 05:34 PM.

Powered by vBulletin • Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.

vBulletin Optimisation provided by vB Optimise v2.7.1 (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.
 

NeuroTalk Forums

Helping support those with neurological and related conditions.

 

The material on this site is for informational purposes only,
and is not a substitute for medical advice, diagnosis or treatment
provided by a qualified health care provider.


Always consult your doctor before trying anything you read here.