If they are caused by motor neuron damage, spasticity and cramping are UMN symptoms. If they are the only symptoms the EMG may be normal/clean. However, there are certain types of neuromuscular activity that may not be felt, that an EMG can pick up. I will defer to someone more knowledgeable than me to explain in greater detail.
The upper and lower designation of motor neurons does not describe what parts of the body they contol, but the level of refinement or order of movement. Upper motor neurons govern fine motor control (although exactly how is a bit of a mystery).
Think in terms of an infant, and the level of control they have over their bodies. An infant can move their arms and legs, but lack the motor control to thread a needle or write their name. When UMN damage occurs the body loses its coordination and fine motor control. This is why "primitive" reflexes (similiar to those you see in an infant like the startle response and Babinski's sign) remerge with significant UMN damage.
I hope this helps, and someone certainly can explain it better than I,
Planning. That is a good explaination. Too bad it only enhances my concerns.
I guess now, since my most recent Neuro exams haven't shown any Hoffman or Babinski, and my EMG was clean but I'm still having cramps in hands, forearms, and sometime thighs I just have to wait for the impending doom of getting a positive Hoffman and/or Babinski in the near future which will of course will send them down the Bulbar path. This of course really scares me and depresses me like never before.
Robert- That was an excellent explanation! [Maybe I will even add some points to your reputation] LOL.
I don't know if you read the post about the new format on the forum but that little white thing in the left corner is for people to vote on your reputation. We were trying to figure it out on another thread.
Jules- and if you do get a postive hoffman/and or babinski how will that lead you to the bulbar path. they are symtoms of alot of things.
30% of the normal population has a positve hoffman, it does mean much.
ok here is a dilema about cramping i have,i have tried not to get too worried about.
in all the 9yrs i have had mnd (umn for 7yrs then slight lmn past 2yrs) i never had cramping untill about a year ago.
i only had it in my left lower leg/foot that has hypotonia and atrophy so the cramping must be something to do with these.
however the other week i had a day were i had cramping in my right calf that has fassics that were never there before,i only had them in my left calf and foot.
then the other day i had cramping in the muscle just down from the thumb on the palm side(dont know what its called)this really freaked me out.
One example is that this morning I was pumping gas into my truck and the hand (palm near pinkie_ I was using to hold the pump started to feel a little pain and "cramp" some while holding the handle pumping gas in the cold weather. I had to take my hand off the handle shake it out then rub it and put it back on the handle. Additionally, when I squeeze my fist really, really tight for 10-20 seconds my hands start aching and are a little stiff when I unfold my fingers.
Another example is that I have a low level aching in my thighs occasionally when sitting at my desk, in bed, or on the couch. I've having a hard time telling if it's because I've read here that so many people here who have ALS/Bulbar started with cramping in thighs or if I'm just moving into the next steps of Bulbar/ALS.
as for the hand thing I get that all the time now. I was mopping and my hand (more so on the pinkie side of palm) aches really bad and so do my thumbs. I have this im both hands. I dont describe as a cramp (that would move your fingers or hand) but a deep ache that hurts and I have to rub out. I have this in feet and hands and I call it a crampy feeling because it feels like it could cramp but never does. Just aches or hurts or feels weak.