Electrophysiological Changes after Severance of the C7 Nerve Root

Abstract

Since 1986, contralateral C7 root transfer has been used to treat brachial plexus root avulsions in our hospital. We performed post-operative electrophysiological examinations of the healthy-side limb in the first 27 patients. Electromyography and nerve conduction studies on the healthy side demonstrated mild abnormalities only of individual limb muscles in a few cases. These changes mostly recovered during the follow-up period. In the measurement of radial nerve motor conduction, median nerve sensory conduction and somato-sensory evoked potentials, we found that the amplitude of the median nerve sensory conduction alone was slightly lower than that of the control group ( p < 0.05). The results showed that severance of C7 caused no permanent functional damage to the upper limb.