UTILIZATION OF INTRAOPERATIVE ELECTRONEUROGRAPHY TO UNDERSTAND THE INNERVATION OF THE TRAPEZIUS MUSCLE

The radical neck dissection is an operation for the management of lymp h node metastases from primary sites involving the oral cavity, larynx , and other areas of the head and neck. In this procedure, the spinal accessory nerve is removed along with other structures. In modified ne ck dissection the spinal accessory nerve is preserved. Patients underg oing the modified neck dissection have had variable functional outcome s from little or no pain or disability, to significant muscle dysfunct ion. Our group hypothesized that patients with good functional outcome s following modified neck dissection may have had motor contributions from C2, C3, or C4 branches, while those with less favorable outcomes did not. To demonstrate the presence of motor input and its significan ce both from the spinal accessory nerve and the branches of the cervic al plexus, we utilized intraoperative electroneurography. We find that although there is motor contribution from C2, C3, and C4 to the trape zius muscle, it was not consistent or significant. (C) 1997 John Wiley & Sons, Inc.