Clinical and electrophysiological evaluation of shoulder functions in spinal accessory nerve-preserving neck dissection

Abstract

The aim of this study was to evaluate shoulder functions after neck dissection with preservation of the spinal accessory nerve by objective physical examination, electromyographic findings, and subjective patient complaints, and also to investigate the effect of the type of neck dissection. Materials and methods: The present study included 29 patients on whom unilateral selective or modified radical neck dissection was performed for head and neck cancer and/or metastasis to the neck. Electromyographical findings, range of motion, and pain scores of the shoulder joint were determined for the operated and nonoperated (control) sides. Results: An electromyographic examination of the trapezius and sternocleidomastoid muscle with superficial and pin electrodes showed a statistically significant difference when comparing the latency and amplitude values of the operated and nonoperated sides (P < 0.05). Flexion, abduction, and external rotation of the shoulder joint were found to be significantly affected on the operated side (P < 0.05). Electrophysiological differences were not found with regards to neck dissection types. Mild or moderate pain was observed at the early stage with a visual pain scale. Conclusion: Despite spinal accessory nerve preservation during neck dissection, electrophysiological changes and alterations in clinical functions might be seen in all areas of the nerve that innerves the shoulder muscles.