The Laryngoscope Lippincott Williams & Wilkins, Inc. © 2007 The American Laryngological, Rhinological and Otological Society, Inc. Spinal Accessory Nerve Monitoring in Selective and Modified Neck Dissection Robert Lee Witt, MD; Lidia Rejto, PhD Objectives: To determine whether a threshold in- crease in current is required to stimulate the spinal accessory nerve (SAN), comparing current on initial identification of the SAN and after completion of the dissection and before closure for selective neck dis- section (SND), zones 1, 2, and 3, and modified radical neck dissection (MRND), zones 1, 2, 3, 4, and 5, and compare clinical outcome measures for “shoulder syndrome” for SND and MRND. Study Design: Pro- spective study of 22 consecutive patients receiving SND or MRND by one surgeon at one institution. Methods: Electrophysiologic recording of current on initial identification of the SAN was compared with the current recorded at the completion of the procedure and before closure for SND and MRND. Clinical correlation measured and compared pa- rameters of “shoulder syndrome” (shrug, flexion, abduction, winging, and pain) for SND and MRND at 2 months. Results: Zero of 11 (0%) patients with SND and 3 of 11 (27%) patients with MRND had significant threshold increases (>0.4 mAmp) on completion of the dissection. One of 11 (9%) pa- tients with SND and 3 of 11 (27%) with MRND had less than 90 degrees of shoulder abduction, scap- ular winging, or significant pain. Conclusions: Electrophysiologic integrity of the SAN does not completely correlate with clinical outcome mea- sures for “shoulder syndrome.” It is significant that 17 of 19 (89%) patients without an electro- physiologic threshold increase did not develop “shoulder syndrome.” This study demonstrated less electrophysiologic threshold shift and “shoulder syn- drome” with SND compared with MRND. Key Words: Spinal accessory nerve, nerve monitoring. Laryngoscope, 117:776 –780, 2007 INTRODUCTION The feasibility of monitoring the spinal accessory nerve (SAN) during modified radical neck dissection (MRND) has been previously demonstrated. An electro- physiologic threshold increase was not found in more than 70% of patients undergoing MRND. Although this data did not completely correlate with clinical outcome mea- sures of “shoulder syndrome,” it did demonstrate that in the patients without an electrophysiologic threshold in- crease, 90% did not develop “shoulder syndrome.” 1 The purpose of this paper is to determine 1) whether a threshold increase in current is required to stimulate the SAN, comparing current on initial identification of the SAN and after completion of the dissection and before closure for selective neck dissection (SND), zones 1, 2, and 3, and MRND, zones 1, 2, 3, 4, and 5, and 2) to compare threshold increase in current with clinical outcome mea- sures for “shoulder syndrome” for SND and MRND. A similar study has not before been published. METHODS This was a prospective study of 22 consecutive patients receiving SND (zones 1, 2, 3) or MRND (zones 1–5 with preser- vation of the SAN but sacrifice of the sternocleidomastoid muscle and jugular vein) by one surgeon at one institution. Other SNDs and radical neck dissection were excluded. Institutional review board approval was obtained for this study. Electrophysiologic recording of current on initial identifica- tion of the SAN was compared with the current recorded at the completion of the procedure and before closure for SND and MRND. Clinical correlation measured and compared parameters of “shoulder syndrome” (shrug, flexion, abduction, winging, and pain) for SND and MRND at 2 months. Patients in the study group had no formal physical therapy program instruction between the initial and follow-up evalua- tions. All were instructed to limit reach to no higher than shoul- der height and avoid carrying more than 5 pounds with the affected arm. Gentle neck range of motion, pectoral stretches performed in supine or reclined position with the arm abducted less than 90 degrees, and scapular retraction exercises were included in the postoperative discharge instructions. The functional evaluation was performed at 2 months post- operatively. The evaluation included a subjective pain rating using a 0 to 10 description, with 0 representing “no pain” and 10 meaning “the worst pain I can imagine.” Patients were asked specifically to describe the pain in the affected shoulder along the superior border of the scapula. From the Department of Otolaryngology (R.L.W.), Christiana Care Health Systems, Wilmington, Delaware, U.S.A.; Jefferson Medical College (R.L.W.), Philadelphia, Pennsylvania, U.S.A.; and the Department of Sta- tistics (L.R.), University of Delaware, Newark, Delaware, U.S.A. Editor’s Note: This Manuscript was accepted for publication January 12, 2007. Poster Presentation at the Triological Society Combined Sections Meeting, Marco Island, Florida, U.S.A., February 14 –18, 2007. Send correspondence to Robert L. Witt, MD, 2401 Pennsylvania Ave., #112, Wilmington DE 19806. E-mail: RobertLWitt@aol.com DOI: 10.1097/MLG.0b013e3180341a0c Laryngoscope 117: May 2007 Witt and Rejto: Spinal Accessory Nerve Monitoring 776