| چکیده انگلیسی مقاله |
Introduction: The Martin-Gruber Anastomosis (MGA) is probably the most well known of anomalies that occur at various levels between the median and ulnar nerves. It is formed by motor axons from the median nerve that join the ulnar nerve, and innervate the muscles that normally are ulnar-innervated. The purpose of this study was to establish the relative frequency of MGA and its subtypes in healthy subjects and to draw the attention of clinicians working in the neurophysiological laboratory to the presence of this anstomosis, and thus to avoid possible misinterpretations of data from nerve conduction studies (NCS) and needle electromyography (EMG). Materials and methods: In this study that performed in a descriptive method, 130 persons (60 men and 70 women) were selected and we did NCS on their both hands. Surface recording electrodes were placed on the thenar, hypothenar and first dorsal interosseous (FDI) muscles. Both median and ulnar nerves were stimulated supramaximally at the wrist (distal) and the elbow (proximal) ,and compound muscle action potentials (CMAPs) were recorded and their amplitudes evaluated. Chi-square test was used for data analysis. Results: MGA was found in 34 persons (26.15%) and in 47 hands (18.07%). The most frequent type of anastomosis was type II (61.7%). Type I, III and IV anastomosis were observed in 2, 3 and 13 (27.66%) hands respectively. Conclusions: It can thus be concluded that MGA is frequently encountered and it should be borne in mind that anomalous innervation models may influence the electrophysiological findings and thus give rise to faulty interpretations, especially in the case of median and ulnar nerve lesions. Keyword: Martin-Gruber Anastomosis, Nerve Conduction Study, Electromyography, Median Nerve, Ulnar Nerve |
