25% Denervation in Foot Common

[BandersnatchF]

Your foot wasn't tested because denervation in the foot is very common, showing up in as many of 25% of people tested. As a result, it's uncommon to do an EMG on foot muscles because any denervation they do find wouldn't be diagnostic. Instead, they test other muscles innervated by the nerves that lead to the foot. If it's a serious illness like ALS, denervation will show up anywhere along the affected nerve.

The difference between an EMG and NCS is that an EMG tests the interaction between your nerves and your muscles, and the NCS tests only the ability of your nerves to carry signals. Sensory nerves can be (and usually are) tested along with motor nerves on an NCS, but an EMG can only test motor nerves. They do both tests because, together, the tests are more diagnostic than either one alone. The NCS tests whether the "insulation" has been stripped from your nerves (among other things), and the EMG tests whether your muscles are responding properly to nerve signals.

 

[BandersnatchF]

Muscles don't have unreadable NCS; nerves do. The NCS has nothing to do with your muscles. The neuro puts electrodes at two places and measure the time it takes for a signal to travel from one electrode to the other via your nerve. The "shock" is the neuro putting a signal into your nerve with a small electric jolt.

In order for this to work, the neuro needs to place both electrodes on the same nerve. If they're on different nerves, the signal won't be detected. This is probably what happened to you. Assuming you can still use the muscle, there's at least some conductivity left. The neuro probably put the electrodes on different nerves because your body is wired differently, as described in my earlier link.

You should also remember that denervation of intrinsic foot muscles is very common, appearing in as many as one in four people. That's why they don't usually test foot muscles—denervation there has no diagnostic meaning.

 

[sarahandlifethelifem]

thanks again Bandersnatch_F... hey, perhaps if i take this helmet off - all of this info will begin to sink in

i've been getting a little irate that i still hadn't heard back from the neurophysiologist, and so today i called him and he said he hadn't received an email - so i checked it, and sure enough i'd sent it to the wrong address

so now i've just got home and logged on and there was a message from him... saying that he would be replying shortly after 'studying' my email... good heavens what on earth needs 'studying'

Will - has your neuro got back to you yet? is everything ok???

 

[Carrilicious]

Dearest Will,

That is news. And what makes it even better is that YOU feel good.

I am so happy for you.

Now go out and celebrate!!

Carri )