The comparison of intraoperative neuromonitorization results and postoperative shoulder functions in patients in which the spinal accessory nerve was preserved during neck dissection

Aim: Comparing the intraoperative neuromonitorization results with the postoperative shoulder functions in patients with preserved spinal accessory nerves during neck dissection.Method: Twenty necks of 17 patients who were operated by preserving the spinal accessory nerve were included in this study. The threshold results of the stimulus which generates visible electromyographic responses amplitude and the amplitudes of the EMG responses which occur in response to a one miliamper stimulus power were recorded when the spinal accessory nerve was identified for the first time and at the postoperatiferative period in all of the patients. The patients in whom the significant threshold and amplitude changes were obtained during the operation were established. The shoulder functions were evaluated neurophysiologically with EMG at the first postoperative month, also clinically with objective parameters at the first and second postoperative months were performed with Constant-Murley neck scoring and Groningen activity restriction scale in terms of subjective complaints.Results: Significant corruptions at shoulder functions were established in all of the patients with regard to Constant-Murley neck scoring and Groningen activity restriction scales at the first and second postoperative months compared to the preoperative period ( p<0.05). While normal EMG findings were determined at 5 % of the necks evaluated at the first postoperatiferative month, moderate neurogenic deficit in 30 %, partial axonal degeneration in 50 % and total axonal degeneration in 15 % of the patients were determined. Improvement was determined at the second month in the Groningen activity restriction scales in the groups at whom amplitude loss and threshold increase weren?t obtained at the evaluations which were made inside of the groups in which amplitude loss and threshold increase were established or not (p<0.05). It was determined that the objective corruptions of the shoulder functions which were documented by Constant-Murley shoulder scoring were significantly lower for the groups in whom the amplitude loss and threshold increase weren?t obtained in contrast to those in which the amplitude loss and threshold increase were obtained (p<0.05).Conclusion: Corruptions at shoulder functions were documented in all patients although spinal accessory nerve was preserved. It was determined that intraoperative neuromonitorization provides additional contribution to predict postoperative shoulder functions, however studies with long-term follow up periods are necessary.Key words: Accessory nerve, intraoperative neuromonitorization, neck dissection, shoulder functions.