Origin of ulnar compound muscle action potential investigated in patients with ulnar neuropathy at the wrist.
The compound muscle action potential from the abductor digiti minimi muscle is bi-lobed, and its second peak is formed by far-field potentials (FFPs). We investigated their origin in two patients with ulnar neuropathy at the wrist that spared the hypothenar muscles. FFPs were lost or distorted, which indicated that the deep motor branch-innervated muscles, such as the interossei, mainly contributed to the FFPs, especially to their initial N1 and steep following P1 components.
Higashihara
Mana
M
Department of Neurology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Sonoo
Masahiro
M
Imafuku
Ichiro
I
Ugawa
Yoshikazu
Y
Tsuji
Shoji
S
D000200:Action Potentials / Q000502:physiology*; D000328:Adult; D004566:Electrodes / Q000592:standards; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014459:Ulnar Nerve / Q000033:anatomy & histology / Q000503:physiopathology*; D017769:Ulnar Nerve Compression Syndromes / Q000175:diagnosis* / Q000503:physiopathology*