The purpose of this study is to quantitatively compariso of the influence of different reference electrode position on the amplitude, surface area, latency and duration of CMAP during routine NCV studies in radial, ulnar and median nerves. All of these CMAP signals were sent to computer for analysis. The data revealed;(1)In median nerve examination, the surface area and amplitude decreased markedly (p<0.05 & p<0.02) when the reference electrode was shifted from MP joint to IP joint of the thumb. (2)In radial nerve study, reference electrode in wrist position has the largest surface area & amplitude, while 1/2 between wrist and active recording showed the smallest surface area and amplitude, (p<0.01) and duration(p<0.02). (3)Inulnar verve, there was no significant statistical difference in amplitude, surface area, latency & duration with the reference electrode at MP joint and DIP joint of the little finger.
The purpose of this study is to quantitatively compariso of the influence of different reference electrode position on the amplitude, surface area, latency and duration of CMAP during routine NCV studies in radial, ulnar and median nerves. All of these CMAP signals were sent to computer for analysis. The data revealed;(1)In median nerve examination, the surface area and amplitude decreased markedly (p<0.05 & p<0.02) when the reference electrode was shifted from MP joint to IP joint of the thumb. (2)In radial nerve study, reference electrode in wrist position has the largest surface area & amplitude, while 1/2 between wrist and active recording showed the smallest surface area and amplitude, (p<0.01) and duration(p<0.02). (3)Inulnar verve, there was no significant statistical difference in amplitude, surface area, latency & duration with the reference electrode at MP joint and DIP joint of the little finger.