Electrophysiological study on nerve regeneration after second stage contralateral C 7 transfer

Objective To determine nerve regeneration after second stage transfer of contralateral C 7 to the recipient nerves by means of electrophysiological examination. Methods From March 1996 to September 1998, electrophysiological examination was done periodically in 28 cases after second stage contralateral C 7 transfer to the musculocutaneous nerve, radial nerve,and median nerve. Electromyography(EMG) and compound muscle action potentials(CMAP) of the muscles innervated by the recipient nerves were examined during follow up period. The latency, amplitude and motor nerve conduction velocity(MNCV) were measured. To record CMAP, the stimulation electrodes were put at the sternoclavicular joint, thoracic axillary zone, axilla, radial groove or elbow respectivelly. All patients were followed for 3 to 58 months, with an average of 15.4 months. Results After second stage contralateral C 7 transfer, nerve regeneration in the muscles innervated by the musculocutaneous, radial and median nerves could be first detected at postoperative month 4,6 and 12 respectively. Conclusions Among the recipient nerves after second stage contralateral C 7 transfer, regeneration potential was detected in the following order: musculocutaneous nerve, radial nerve,and median nerve.