F waves & stuff

April 20, 2011 at 7:23 pm

Sharon- what little I know about F-waves is that they shouldn’t be latent, at least not too much.

However, to paraphrase others- the F-wave is apparently a ‘response’ to muscle stimulation that travels back up to the anterior horn cell. (yes, some people have what’s called anterior horn cell disease, ‘they’ accused me of it!)

Then, a measurement is made to determine the latency, or time lag of the responding signal. This, apparently gives an overall conduction velocity between the muscle and the spine.

The above from a little deeper within Laurel’s web site at-


Oh, the answer to your 1st question is that overall, my emg/ncv results ‘were mostly unchanged.’ The actual CMAP & SNAP should be higher not lower. I believe the lower aspect of the results are reflected in the dramatic drop from 10lbs to 7lbs in my right hand grip strength that I experienced during the time I was on 3 days IVIG every three weeks. I’m back up to about 9lbs now.

Laurel, thanks. You emg/ncv website will likely take days to read.