Great video, I'm getting an EMG tomorrow due to sciatica at the least that has lasted 5-6 months and tingling,right foot also turns outward about 45 degrees. Long time runner. Does the waveform show less activity and slower velocity?
How did your EMG go for your sciatica? I have piriformis syndrome which affects my sciatic nerve but never thought to get an EMG done on it (it's been hurting for a year, even with physical therapy and consistent yoga) Hope you're feeling better!
Hi Karan, if you stimulate distal to the conduction block (CB), the CMAP is normal. If you stimulate proximal to the CB, however, the action potential can't travel normally through the CB and there is a sudden drop in CMAP. Hope that helps.
@@bacolive Hi Brad. So basically the conduction block is a focal area of myelin damage right? If it's just damaging the myelin, only the velocity of conduction should be affected right? Why the amplitude (CMAP)?
Action potentials travel in trains. If you stimulate proximal to the CB, you will affect the rate at which APs in a train reach the muscle fibre (reduced rate, fewer APs/second). Some of these APs might not even make it through the CB. This causes fewer concurrent depolarizations of the muscle fibres. CMAP is reduced because it is dependent on how many times fibres depolarize simultaneously.
Amazing Video. Now I understand EMG. Sharing it with my other medical student colleagues! :) Thank you!
It's just really Amazing and very simple.. Really helpful video.. Thanx alot
Thank you for wonderful demonstration
Very helpful, thank you
clear and didactic
How to straighten an EMG curvy baseline, please? I have a green and a red electrode I place on the patient along with a concentric needle
Great video, I'm getting an EMG tomorrow due to sciatica at the least that has lasted 5-6 months and tingling,right foot also turns outward about 45 degrees. Long time runner. Does the waveform show less activity and slower velocity?
How did your EMG go for your sciatica? I have piriformis syndrome which affects my sciatic nerve but never thought to get an EMG done on it (it's been hurting for a year, even with physical therapy and consistent yoga) Hope you're feeling better!
Very useful!
Great video
Amazing
Why is the action potential (amplitude) affected in GBS if the problem is with myelin?
Hi Karan, if you stimulate distal to the conduction block (CB), the CMAP is normal. If you stimulate proximal to the CB, however, the action potential can't travel normally through the CB and there is a sudden drop in CMAP. Hope that helps.
@@bacolive Hi Brad. So basically the conduction block is a focal area of myelin damage right? If it's just damaging the myelin, only the velocity of conduction should be affected right? Why the amplitude (CMAP)?
@@karankalani4211 same question.
Action potentials travel in trains. If you stimulate proximal to the CB, you will affect the rate at which APs in a train reach the muscle fibre (reduced rate, fewer APs/second). Some of these APs might not even make it through the CB. This causes fewer concurrent depolarizations of the muscle fibres. CMAP is reduced because it is dependent on how many times fibres depolarize simultaneously.
@@EliHaynez in other words the amplitude reduce because of chronodispersion, right.
LF you know good neurology and anatomy no need to this.dr from Russia y of medical sciences.
thank you sir
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