Spinal accessory nerve function after neck dissections

Abstract

The aim of this study was to evaluate spinal accessory nerve function after functional neck dissection (FND) and radical neck dissection (RND) by monitoring the nerve with electromyographic (EMG) examinations. A prospective, double-blind, clinical study was undertaken in 21 patients (42 neck side dissections) operated on for head and neck malignant diseases, separated into two groups: 10 neck sides in the RND group and 32 neck sides in the FND group. Electromyographic examinations were performed pre-operatively and post-operatively in the third week and third and ninth months. Additionally, a questionnaire, modified from the neck dissection impairment index, was applied to all the patients in order to assess shoulder function in the ninth post-operative month. All patients had maximum EMG scores pre-operatively. Following the operation, motor amplitudes decreased in both groups. At the third post-operative month, amplitudes decreased to their lowest values. As expected, the decreases in amplitude and EMG score were more prominent in the RND group. Following reinnervation, the amplitudes of the trapezius motor response increased in the FND group but never reached pre-operative values (during the time of follow up). The FND group scores for pain, neck and shoulder stiffness, and disability in heavy object lifting, light object lifting and reaching overhead were significantly lower than those of the RND group. In FND, one aims to preserve anatomically the spinal accessory nerve, and it is presumed to be intact after the procedure. However, using EMG nerve function monitoring, our study revealed that profound spinal nerve injury was detected immediately after FND surgery, which tended to improve over subsequent months but had not regained its original function by the end of the ninth post-operative month.

Spinal accessory nerve neuropathy following neck dissection

“…These findings are in agreement with those from our study 15 . We have noticed that Snd causes better shoulder function when compared to other types of dissections; this difference has been explained by less level V manipulation during the surgical procedure, resulting in less damage to the accessory nerve and the neck plexus 1,7,[12][13][14]17,18 . The shoulder syndrome is an important sequela of nd.…”

“…electrophysiological evaluations have shown that, despite the nerve's anatomical integrity, the risk is even greater whenever the neck's posterior triangle is involved (level V) 1,[15][16][17] . The muscles' denervation potentials become characteristic after two to three weeks of the lesion, first on the proximal muscles, later on the distal ones.…”

“…1 However, this procedure may cause severe morbidity. One of the most common complications stemming from nd is shoulder dysfunction caused by manipulation of the spinal accessory nerve (Xi cranial nerve) -which causes atrophy of the trapezium muscle.…”

Spinal Accessory Nerve Palsy: Associated Signs and Symptoms

“…Functional outcomes following RND are inferior to spinal accessory nerve-sparing procedures due to the resultant chronic trapezius dysfunction. 7,9,13,33,43,50,53 The MRND and SND procedures were developed to spare the spinal accessory nerve, thus limit trapezius dysfunction; however, significant incidence of spinal accessory nerve injury has been reported 6,10,13,14,52,53 that might have resulted from nerve manipulation. 6,29,43,50,52 The MRND requires lymph node dissection at all levels, but the spinal accessory nerve is usually spared.…”

“…40 Spinal accessory nerve injury commonly occurs during neck dissection surgery. 2,6,9,11,[13][14][15][27][28][29]31,43,46,48,49,52,53 Neck dissection surgery is performed to treat head and neck carcinoma and is categorized into 3 different procedures: radical S pinal accessory nerve palsy (SANP) is common following neck dissection surgery or lymph node excision, 2,6,9,11,[13][14][15][27][28][29]31,43,46,48,49,52,53 blunt or penetrating trauma to the lateral neck region, 2,11 and cervical stretch injuries. 32 Spinal accessory nerve injury results in trapezius paralysis or dysfunction and a diagnostic cluster of signs and symptoms, including shoulder girdle depression, trapezius atrophy, scapular dyskinesis, loss of shoulder STUDY DESIGN: Retrospective case series.…”