Advancing glenohumeral dysplasia treatment in brachial plexus birth injury: the end-to-side spinal accessory to suprascapular nerve transfer technique

PURPOSE

Brachial plexus birth injury (BPBI) is a common injury with the spectrum of disease prognosis ranging from spontaneous recovery to lifelong debilitating disability. A common sequela of BPBI is glenohumeral dysplasia (GHD) which, if not addressed early on, can lead to shoulder dysfunction as the child matures. However, there are no clear criteria for when to employ various surgical procedures for the correction of GHD.

METHODS

We describe our approach to correcting GDH in infants with BPBIs using a reverse end-to-side (ETS) transfer from the spinal accessory to the suprascapular nerve. This technique is employed in infants that present with GHD with poor external rotation (ER) function who would not necessitate a complete end-to-end transfer and are still too young for a tendon transfer. In this study, we present our outcomes in seven patients.

RESULTS

At presentation, all patients had persistent weakness of the upper trunk and functional limitations of the shoulder. Point-of-care ultrasounds confirmed GHD in each case. Five patients were male, and two patients were female, with a mean age of 3.3 months age (4 days-7 months) at presentation. Surgery was performed on average at 5.8 months of age (3-8.6 months). All seven patients treated with a reverse ETS approach had full recovery of ER according to active movement scores at the latest follow-up. Additionally, ultrasounds at the latest follow-up showed a complete resolution of GHD.

CONCLUSION

In infants with BPBI and evidence of GHD with poor ER, end-to-end nerve transfers, which initially downgrade function, or tendon transfers, that are not age-appropriate for the patient, are not recommended. Instead, we report seven successful cases of infants who underwent ETS spinal accessory to suprascapular nerve transfer for the treatment of GHD following BPBI.

A Randomised Control Trial Comparing the Outcomes of Anterior with Posterior Approach for Transfer of Spinal Accessory Nerve to Suprascapular Nerve in Brachial Plexus Injuries

Background: In brachial plexus surgery, a key focus is restoring shoulder abduction through spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer using either the anterior or posterior approach. However, no published randomised control trials have directly compared their outcomes to date. Therefore, our study aims to assess motor outcomes for both approaches. Methods: This study comprises two groups of patients. Group A: anterior approach (29 patients), Group B: Posterior approach (29 patients). Patients were allocated to both groups using selective randomisation with the sealed envelope technique. Functional outcome was assessed by grading the muscle power of shoulder abductors using the British Medical Research Council (MRC) scale. Results: Five patients who were operated on by posterior approach had ossified superior transverse suprascapular ligament. In these cases, the approach was changed from posterior to anterior to avoid injury to SSN. Due to this reason, the treatment analysis was done considering the distribution as: Group A: 34, Group B: 24. The mean duration of appearance of first clinical sign of shoulder abduction was 8.16 months in Group A, whereas in Group B, it was 6.85 months, which was significantly earlier (p < 0.05). At the 18-month follow-up, both intention-to-treat analysis and as-treated analysis were performed, and there was no statistical difference in the outcome of shoulder abduction between the approaches for SAN to SSN nerve transfer. Conclusions: Our study found no significant difference in the restoration of shoulder abduction power between both approaches; therefore, either approach can be used for patients presenting early for surgery. Since the appearance of first clinical sign of recovery is earlier in posterior approach, therefore, it can be preferred for cases presenting at a later stage. Also, the choice of approach is guided on a case to case basis depending on clavicular fractures and surgeon preference to the approach. Level of Evidence: Level II (Therapeutic).

Shoulder Dysfunction Post Spinal Accessory Nerve Preserving Neck Dissections: Our Experience

Apart from complete surgical clearance of the malignancy, reducing morbidity and improving quality of life of the patient is also considered. One of the morbidities linked with neck dissections is shoulder dysfunction. The aim of our study is to analyse the functional outcomes in patients operated for various neck dissections with preservation of the Spinal accessory nerve. A single centre prospective observational study was conducted in a total of 45 patients with oral cancers. These patients underwent Wide local excision of the primary tumour along with neck dissection. Tests for assessing spinal accessory nerve function was elicited in all these patients preoperatively and postoperatively. Patients were examined for shoulder pain and shoulder disability using Arm abduction test. All 45 patients underwent spinal accessory nerve preserving neck dissection. On post operative day 10, 89% of patients showed arm abduction test score of 1 and 47% of patients had a pain score of 6 whereas 13% had a pain score of 8. After 6 months of rehabilitation and regular follow up, 62% of the patients had improved arm abduction test score of 4 and above and all 45 patients had pain score improved to score of 4 and less. Variable amount of shoulder dysfunction is seen even in spinal accessory nerve preserving neck dissections. But active rehabilitation and regular follow up of these patients reduces the morbidity associated with shoulder syndrome.

Rare Intraoperative Finding of the Spinal Accessory Nerve Piercing a Fenestration in the Internal Jugular Vein: A Case Report and Review of the Modern Literature

Variations in the anatomy of venous structures in the neck are not uncommon, but fenestrations are extremely unusual. Here, we report a rare case of the spinal accessory nerve piercing a fenestration in the internal jugular vein, found during elective neck dissection of a patient undergoing hemiglossectomy. Further, we present a literature review of recent previously published cases of this intraoperative finding. This paper is intended to provide readers with an appreciation for this particularly rare variation and to highlight its existence to surgeons who perform neck dissection. This knowledge is important in order to minimise the possibility of intraoperative damage.

Atypical meningioma originating from the spinal accessory nerve

Background

Atypical meningiomas rarely originate from the spinal accessory nerve at the C1-C2 level.

Case Description

A 57-year-old female presented with a 1-month history of headache. The cervical MR revealed a well-demarcated intradural/extramedullary tumor compressing the spinal cord at the C1-C2 level that measured 12 mm × 10 mm × 25 mm. She underwent microsurgical tumor resection. Intraoperatively, the tumor was adherent to the spinal accessory nerve, rather than the dura mater. Gross total tumor resection was performed, and the pathology was consistent with an atypical meningioma.

Conclusion

Atypical meningiomas rarely originate from the spinal accessory nerve. Gross total resection is the procedures of choice to mitigate the risk of tumor recurrence.

Preoperative ultrasound accurately characterizes surgically confirmed extracranial spinal accessory nerve injuries

OBJECTIVE

To determine the accuracy of preoperative ultrasound and MRI in surgically confirmed spinal accessory nerve injuries and present the benefits of a multimodality image review.

MATERIALS AND METHODS

A retrospective review of 38 consecutive patients referred to a peripheral nerve surgical practice at an academic teaching hospital with surgically confirmed spinal accessory nerve injuries. All cases were reviewed for patient demographics, date and cause of injury, preoperative EMG, and surgical diagnosis and management. Additionally, prospective interpretation of preoperative ultrasound and MRI reports were reviewed for concordance or discordance with the surgical diagnosis.

RESULTS

Iatrogenic injury was present in 37 (97%) cases and most commonly a result of an excisional lymph node biopsy (68%). Surgically confirmed spinal accessory nerve injury diagnoses consisted of 25 (66%) stump neuromas and 13 (34%) incomplete nerve injuries. Nine months was the average time from injury to surgery. Twenty-nine patients underwent preoperative ultrasound and/or MRI evaluation: 12 ultrasound only, 10 MRI only, and seven with both ultrasound and MRI. Eighteen (95%) preoperative ultrasound reports compared to four (24%) preoperative MRI reports were concordant with the surgical diagnosis. In the seven cases with both preoperative ultrasound and MRI, six had discordant ultrasound and MRI imaging diagnoses for which the ultrasound was concordant with the surgical diagnoses in all cases.

CONCLUSION

Preoperative ultrasound more accurately characterizes spinal accessory nerve injuries compared to MRI and should serve as the modality of choice when a spinal accessory nerve injury is suspected.

Comparison of ultrasound with electrodiagnosis of scapular winging: A prospective case control study

OBJECTIVE

Compare high-resolution ultrasound (HRUS) and electrodiagnostic examination (EDX) in the diagnostic workup of patients with scapulae alatae.

METHODS

27 patients with scapulae alatae and 41 healthy subjects (HS) and underwent a standardized clinical examination (CEX), EDX and HRUS. We measured the thickness of the serratus anterior (SER), rhomboid major and trapezius muscles and the diameter of the long thoracic (LTN), dorsal scapular and spinal accessory nerves (SAN).

RESULTS

Twenty patients showed medial winging and six patients showed lateral winging on CEX. One patient had both lateral and medial winging. In patients with medial winging, the SER muscle was thinner and the LTN diameter was larger on the symptomatic side compared with the asymptomatic side and with the dominant side in HS. In this group, both EDX and HRUS detected abnormalities of SER muscle/ LTN with sensitivity of 65%, and with specificity of 100% and 57%, respectively. EDX and HRUS detected abnormalities of the trapezius muscle/ SAN with sensitivity of 60% and 40%, and specificity of 91%, and 86 % a, respectively. There was no significant difference between the two methods.

CONCLUSION

HRUS can contribute to the diagnostic workup of scapulae alatae by demonstrating atrophy of muscles and enlargement in nerve diameter.

SIGNIFICANCE

HRUS supplements EDX in the diagnostic workup of scapulae alatae.

Intraoperative spinal accessory nerve monitoring in neck dissections

BACKGROUND

The identification and preservation of the spinal accessory nerve (SAN) is essential in neck surgeries due to possible complications. We report the technique to intraoperative neuromonitoring (IONM) of SAN in functional neck dissections.

METHOD

SAN was monitored by needle electrodes placed on the trapezius muscle. Preoperative and postoperative nerve mapping was performed.

CONCLUSION

IONM for spinal accessory nerve in patients undergoing neck dissection is a useful technique that can be valuable for neck surgeries where spinal nerve injury is at risk.

Neuralgic amyotrophy and COVID-19 infection: 2 cases of spinal accessory nerve palsy

OBJECTIVE

Neuralgic amyotrophy (NA), also known as Parsonage-Turner syndrome is often triggered by mechanical stress or upper respiratory tract viral infections. We reported 2 cases of shoulder weakness and amyotrophy related to spinal accessory nerve (SAN) palsy due to neuralgic amyotrophy occurring after COVID-19 infection.

METHODS

For both patients, clinical history, clinical examination, electrodiagnostic (EDX), and imaging examinations invalidated other diagnoses but confirmed NA diagnosis.

RESULTS

The NA involved only the SAN in both cases. EDX revealed a characteristic axonal lesion found in NA. SAN conduction study revealed normal latencies and low compound motor action potential amplitude for trapezius muscle when needle examination demonstrated a neurogenic pattern and denervation signs in the trapezius muscle. Both patient's MRI revealed denervation T2 hypersignal in impaired muscles, and hypersignal of the involved roots, trunks, or nerves without any mass, cyst, injury, fibrous band, or tearing signs along SAN course.

CONCLUSIONS

The COVID-19 infection could be the trigger for NA as many other viruses, and as it is a possible trigger for Guillain-Barré syndrome.

Neuromuscular ultrasound of the scapular stabilisers in healthy subjects

•

HRUS can be used to visualise the muscles stabilizing the scapula and their corresponding nerves.

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We found acceptable intra- and inter-examiner agreements.

•

We present HRUS normative data using regression-based prediction formulas.

•

To our knowledge, we present the first-time normative data of diameter of the dorsal scapular nerve.

Objectives

To obtain normative high-resolution ultrasound (HRUS) data for thickness of the serratus anterior, the trapezius and the rhomboid major muscles and diameter of their corresponding nerves, the long thoracic, the spinal accessory and the dorsal scapular nerve. Moreover, we aimed to examine intra- and inter-examiner agreement of the HRUS measurements.

Methods

We included 41 healthy subjects. Muscle thickness and nerve diameter were measured bilaterally, resulting in 82 ultrasound measurements for each structure. Normative data were calculated using regression equations for the lower limit of muscle thickness and upper limit of nerve diameter, taking into account various variables. For intra- and inter-examiner agreement, ten subjects underwent two extra ultrasound examinations and Bland-Altman plots were calculated.

Results

This normative data set showed significant correlations between decreasing muscle thickness with increasing age and height and increasing muscle thickness with increasing weight and with male sex. Muscle thickness was larger on the dominant side compared to the non-dominant side for the trapezius and rhomboid muscles, whereas the opposite was found for the serratus anterior muscle. For all nerves, significant correlations were found between decreasing nerve diameter with increasing age and height. Intra-examiner agreement was acceptable in all sites. Inter-examiner agreement was acceptable for all sites but one site for the serratus anterior muscle and long thoracic nerve, and not acceptable for five out of six sites for the trapezius muscle.

Conclusion

This study provides HRUS normative data and intra- and inter-examiner agreement data for muscle thickness and nerve diameter for the muscles stabilizing the scapulae and their corresponding nerves.

Significance

The normative HRUS data reported may be useful in future studies investigating neuromuscular disorders.

The X-pointer: A forgotten anatomical relationship of spinal accessory nerve and great auricular nerve

INTRODUCTION

The preservation of the spinal accessory nerve cannot be overlooked in neck dissection. Injury to the nerve results in shoulder dysfunction and other related morbidities. In this article, we describe a unique constant relationship between spinal accessory nerve and great auricular nerve, at the junction of the anterior and posterior triangles of the neck, eponymously labelled the X- pointer.

METHODOLOGY

This was an observational study conducted at a tertiary care cancer centre that runs a comprehensive surgical training program. A 100 cases of modified radical neck dissection performed for oral cavity squamous cell carcinoma from January 2017 to January 2019 in were included. The relationship was analyzed in 100 cases of neck dissection for its constancy.

RESULT

In all the 100 cases, the X-pointer was demonstrated as a constant anatomical relationship between the spinal accessory nerve and great auricular nerve. The crossing over of the nerve on the undersurface of the sternocleidomastoid muscle is constant and independent of the patient's body proportions.

CONCLUSIONS

The relationship between the spinal accessory nerve and great auricular nerve remains constant irrespective of the technique of neck dissection and body habitus of the patient. In our view, this relationship can be used as an additional confirmatory landmark to prevent inadvertent injury to the spinal accessory nerve.

Shoulder function after neck dissection: Assessment via a shoulder-specific quality-of-life questionnaire and active shoulder abduction

OBJECTIVE

Neck dissection results in a high probability of postoperative shoulder functional impairment, even when the spinal accessory nerve is preserved. Therefore, surgeons must inform patients about the expected functional and qualitative recovery of shoulder function after surgery.

METHODS

The present study included a prospective cohort of 66 patients (85 neck dissection sides) who underwent neck dissection between December 2015 and July 2017 at a single institution. The active shoulder abduction angles of the affected side and the patient-reported shoulder-specific quality-of-life recovery score of the Western Ontario Rotator Cuff (WORC) questionnaire were examined at 1, 3, 6, 9, and 12 months postoperatively. Additionally, the association between these outcomes and risk factors for shoulder impairment were investigated.

RESULTS

The average active shoulder abduction angles were significantly improved at 3 and 6 months postoperatively compared with 1 month postoperatively (96.5 ± 4.3° at 1 month versus 110.1 ± 4.7° at 3 months, p = 0.035, and versus 142.0 ± 4.6° at 6 months, p < 0.0001). The proportion of patients who were unable to abduct their shoulders by 150° or more was significantly lower at 6 months postoperatively (41.5%) compared with 1 month postoperatively (82.4%, p < 0.0001). The WORC score significantly improved from 60.4 ± 2.4% at 1 month postoperatively to 67.9 ± 2.6% at 6 months postoperatively (p = 0.036). Multivariate analysis revealed that postoperative radiotherapy was a significant risk factor for shoulder impairment at 3 and 6 months postoperatively (p = 0.003 and p = 0.027, respectively), and that level V dissection and head and neck irradiation were significant risk factors for a worse shoulder outcome at 6 and 9 months postoperatively (respective p values for level V dissection and head and neck irradiation were p = 0.049 and p = 0.030 at 6 months postoperatively, and p = 0.016 and p = 0.013 at 9 months postoperatively).

CONCLUSION

Satisfactory functional and qualitative recovery of shoulder function was achieved at 6 months after neck dissection. Postoperative radiotherapy was a predictor of poor shoulder function in the early postoperative period; both level V dissection and head and neck irradiation were predictors of poor shoulder function at 6 and 9 months after neck dissection.

Evaluation of a high-signal lesion posterior to the intracranial vertebral artery using 3D balanced fast-field echo imaging

Previous reports have identified a small, benign, high-signal lesion (HSL) posterior to the intracranial vertebral artery and associated with the ipsilateral spinal accessory nerve (SAN) using 3D fluid-attenuated inversion recovery (3D FLAIR) imaging as an emerging new entity. To elucidate the relationship between HSLs and SAN, 76 patients with 86 HSLs were evaluated using 3D FLAIR and 3D balanced fast-field echo (3D bFFE imaging). All HSLs showed contact with ipsilateral SAN on both the sequences. 3D bFFE imaging clearly distinguished between the two structures unlike 3D FLAIR. Moreover, SAN was surrounded by HSLs on 3D bFFE images, which may be a characteristic of this entity.

Clinical neurophysiology of cranial nerve disorders

Electrophysiologic techniques are available to measure many of the cranial nerves. The procedures can be done using equipment available in standard clinical neurophysiology laboratories. These studies can aid in localization of cranial nerve lesions as well help identify the underlying pathology and possibly aid in prognosis. The trigeminal pathways can be measured using the blink and masseter responses. The facial nerve is measured by the blink response and by direct facial stimulation; techniques such as lateral spread can identify specific abnormalities. The spinal accessory nerve is measured using nerve conduction techniques. Needle examination can be routinely performed on muscles innervated by cranial nerves V, VII, X, XI and XII. These studies reliably measure the functional integrity of cranial nerves and their central pathways. Intraoperative monitoring of the cranial nerves is useful in certain surgeries. This chapter reviews current techniques used to evaluate cranial nerves, emphasizing the methods available in most clinical neurophysiology laboratories.

Spinal Accessory Nerve Meningioma at the Foramen Magnum with Medullar Compression: A Case Report and Literature Review

BACKGROUND

Meningiomas that arise from the cranial nerve are rare. We present a case with an intradural extramedullary tumor at the foramen magnum originating from the spinal accessory nerve.

CASE DESCRIPTION

The patient was a 69-year-old woman with dizziness and pain in the bilateral shoulder for 2 years. Neurologic examination revealed spinal accessory nerve palsy (difficult in raising the shoulder, deficit of 3/5) on the left side without further deficits. Magnetic resonance imaging showed medullar compression because of a left intradural extramedullary foramen magnum lesion dorsolateral to the medulla. Surgical exposure via a midline suboccipital approach with C1 laminectomy revealed that the lesion arises from the left accessory nerve without dural attachment. The tumor was resected without injury to the spinal accessory nerve, and histologic examination revealed that it was a meningothelial meningioma. The spinal accessory nerve palsy improved to 4 of 5 after 3 months after surgery.

CONCLUSIONS

To our knowledge, this is the first report of an accessory nerve meningioma at the foramen magnum in which the spinal accessory nerve palsy appeared before operation and improved after tumor resection.

Spinal Accessory Nerve Injury Induced by Manipulation Therapy: A Case Report

Spinal accessory nerve (SAN) injury mostly occurs during surgical procedures. SAN injury caused by manipulation therapy has been rarely reported. We present a rare case of SAN injury associated with manipulation therapy showing scapular winging and droopy shoulder. A 42-year-old woman visited our outpatient clinic complaining of pain and limited active range of motion (ROM) in right shoulder and scapular winging after manipulation therapy. Needle electromyography and nerve conduction study suggested SAN injury. Physical therapy (PT) three times a week for 2 weeks were prescribed. After a total of 6 sessions of PT and modality, the patient reported that the pain was gradually relieved during shoulder flexion and abduction with improved active ROM of shoulder. Over the course of 2 months follow-up, the patient reported almost recovered shoulder ROM and strength as before. She did not complain of shoulder pain any more.

Spinal accessory nerve preservation in modified neck dissections: surgical and functional outcomes

The spinal accessory nerve (SAN) or XI cranial nerve is frequently encountered during neck surgery, and as such is at risk of iatrogenic injury, resulting in "shoulder syndrome". Modified neck dissection (MND) with preservation of the SAN is based on desire to minimise the functional deformity associated with section of the eleventh nerve. The aim of this study was to analyse the intra-operative variations of the spinal accessory nerve pathway and to evaluate shoulder dysfunction postoperatively. The cross-sectional demonstration analysis was created through the medical records retrospectively of 165 consecutive patients who underwent neck dissections at our institution in the past 5 years with attention to ultrasound and MRI preoperative findings, type of neck dissection, type of identification and dissection of SAN, postoperative morbidity and survival rate. The safest identification of SAN is in the posterior neck triangle where it may be recognised exiting from the posterior border of the sternocleidomastoid muscle (SCM) at Erb's point. For exact preoperative planning, ultrasound and MRI are superior to determine the position of the eleventh nerve. The mean distance between the greater auricular point and the SAN was 0.90 cm. Average length of the trunk from Erb's point until the penetration in the trapezius muscle was around 5.1 cm, ranging from 4.8 to 5.4 cm. The diversity in the course from the posterior border of the SCM and posterior neck triangle was confirmed in 9 cases (15%), predominantly at the level of entering the posterior neck triangle. The frequency of postoperative morbidity of SAN was 46.7% for radical neck dissections, 42.5% for selective neck dissections and 25% for MND. For each separate type of dissection, different subtypes were included. Identification of the SAN over established landmarks is unconditionally reliant on the exact preoperative mapping of the nerve with imaging diagnostics. MND has similar regional control rates to more comprehensive operations in appropriately selected patients and significantly reduces the risk of functional disability.

The course of lower cranial nerves within the neck: a cadaveric dissection study

PURPOSE

To evaluate the course of lower cranial nerves (CNs) within the neck in relation to surrounding structures and anatomic landmarks via a cadaveric dissection study.

METHODS

A total of 70 neck dissections (31 bilateral, 8 unilateral) were performed on 39 adult fresh cadavers [mean (SD) age: 38.5 (11.2) years, 29 male, 10 female] to identify the course of lower CNs [spinal accessory nerve (SAN), vagus nerve and hypoglossal nerve] within the neck in relation to surrounding structures [internal jugular vein (IJV), common carotid artery (CCA)] and distance to anatomical landmarks (cricoid cartilage, hyoid bone, digastric muscle).

RESULTS

SAN travelled most commonly anterior to IJV (51.4%) at the level of jugular foramen, while travelling lateral to IJV at the post belly of digastric (55.7%) and inferior to digastric muscle (90%) in most neck dissections. Vagus nerve travelled lateral to CCA in majority (94.3%) of dissections, while medial (2.9%), posterolateral (1.4%) and posterior (1.4%) positions were also noted. Average distance of hypoglossal nerve was 27.7 (9.7) mm to carotid bifurcation, 9.3 (3.9) mm to hyoid bone, and 54.7 (18.0) mm to the inferior border of cricoid cartilage.

CONCLUSION

In conclusion, our findings indicate that anatomic variations are not rare in the course of lower CNs within the neck in relation to adjacent structures, and awareness of these variations together with knowledge of distance to certain anatomic landmarks may help the surgeon to identify lower CNs during neck surgery and prevent potential nerve injuries.

Spinal accessory nerve repair using a direct nerve transfer from the upper trunk: results with 2 years follow-up

Spinal accessory nerve grafting requires identification of both nerve stumps in the scar tissue, which is sometimes difficult. We propose a direct nerve transfer using a fascicle from the posterior division of the upper trunk. We retrospectively reviewed 11 patients with trapezius palsy due to an iatrogenic injury of the spinal accessory nerve in nine cases. The mean age was 38 years (range 21-59). Preoperatively, patients showed shoulder weakness and limited range of motion. At a mean follow-up of 25 months, active shoulder abduction improvement averaged 57°. Trapezius muscle strength graded M4 or M5 in 10 cases and M3 in one case. No deltoid or triceps impairment was reported. Scapula kinematics was considered normal in seven patients. This technique gave satisfactory functional results and may be an alternative to spinal accessory nerve grafting for the management of trapezius palsies if direct repair is not feasible.

LEVEL OF EVIDENCE

IV.

Single-incision Eden-Lange procedure in trapezius muscle paralysis: A report of 11 cases

OBJECTIVE

The aim of this study was to evaluate the outcome of single-incision Eden-Lange procedure in trapezius muscle paralysis.

METHODS

The medical records of 11 patients (3 females and 8 males); mean age: 41 (25-59) years with trapezius muscle paralysis who underwent Eden-Lange procedure in our Center, between February 2009 and April 2013, were retrospectively analyzed. The clinical outcomes were evaluated with the American Shoulder and Elbow Surgeons Shoulder (ASES) score and visual analogue scale (VAS).

RESULTS

The mean duration of symptoms before surgery was 10.18 months. The average duration of follow-up was 33.5 (24-48) months. The mean VAS score improved from 7.8 to 1.6 points (p < 0.05). The total ASES improved from 32.8 to 82.1 points (p < 0.05). The mean range of motion in forward elevation and abduction increased significantly from 121.80 to 154.40 (p < 0.05) and 80.00 to 148.18° (p < 0.05), respectively.

CONCLUSION

Single incision Eden-Lange procedure appears to be a safe and effective treatment option for the patients with trapezius muscle paralysis.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Intraoperative Brief Electrical Stimulation of the Spinal Accessory Nerve (BEST SPIN) for prevention of shoulder dysfunction after oncologic neck dissection: a double-blinded, randomized controlled trial

Background

Shoulder dysfunction is common after neck dissection for head and neck cancer (HNC). Brief electrical stimulation (BES) is a novel technique that has been shown to enhance neuronal regeneration after nerve injury by modulating the brain-derived neurotrophic growth factor (BDNF) pathways. The objective of this study was to evaluate the effect of BES on postoperative shoulder function following oncologic neck dissection.

Methods

Adult participants with a new diagnosis of HNC undergoing Level IIb +/− V neck dissection were recruited. Those in the treatment group received intraoperative BES applied to the spinal accessory nerve (SAN) after completion of neck dissection for 60 min of continuous 20 Hz stimulation at 3-5 V of 0.1 msec balanced biphasic pulses, while those in the control group received no stimulation (NS). The primary outcome measured was the Constant-Murley Shoulder (CMS) Score, comparing changes from baseline to 12 months post-neck dissection. Secondary outcomes included the change in the Neck Dissection Impairment Index (ΔNDII) score and the change in compound muscle action potential amplitude (ΔCMAP) over the same period.

Results

Fifty-four patients were randomized to the treatment or control group with a 1:1 allocation scheme. No differences in demographics, tumor characteristics, or neck dissection types were found between groups. Significantly lower ΔCMS scores were observed in the BES group at 12 months, indicating better preservation of shoulder function (p = 0.007). Only four in the BES group compared to 17 patients in the NS groups saw decreases greater than the minimally important clinical difference (MICD) of the CMS (p = 0.023). However, NDII scores (p = 0.089) and CMAP amplitudes (p = 0.067) between the groups did not reach statistical significance at 12 months. BES participants with Level IIb + V neck dissections had significantly better ΔCMS and ΔCMAP scores at 12 months (p = 0.048 and p = 0.025, respectively).

Conclusions

Application of BES to the SAN may help reduce impaired shoulder function in patients undergoing oncologic neck dissection, and may be considered a viable adjunct to functional rehabilitation therapies.

Trial registration

Clinicaltrials.gov (NCT02268344, October 17, 2014).

High-resolution Imaging of Neural Anatomy and Pathology of the Neck

The neck has intricately connected neural structures, including cervical and brachial plexi, the sympathetic system, lower cranial nerves, and their branches. Except for brachial plexus, there has been little research regarding the normal imaging appearance or corresponding pathologies of neural structures in the neck. The development in imaging techniques with better spatial resolution and signal-to-noise ratio has made it possible to see many tiny nerves to predict complications related to image-guided procedures and to better assess treatment response, especially in the management of oncology patients. The purposes of this review is to present imaging-based anatomy of major nerves in the neck and explain their relevant clinical significance according to representative pathologies of regarded nerves in the neck.

Topographic anatomy of the great auricular point: landmarks for its localization and classification

PURPOSE

The great auricular point (GAP) marks the exit of the great auricular nerve at the posterior border of the sternocleidomastoid muscle (SCM). It is a key landmark for the identification of the spinal accessory nerve, and its intraoperative localization is vital to avoid neurological sequelae. This study delineates the topography and surface anatomy landmarks that used to localize the GAP.

METHODS

Thirty cadaveric heminecks were dissected on a layer-by-layer approach. The topography of the GAP was examined relative to the insertion point of the SCM at the clavicle, tip of the mastoid process, and angle of the mandible. The GAP and its relation to the SCM were determined as a ratio of the total length of the SCM.

RESULTS

The GAP was demonstrated to be in a predictable location. The mean length of the SCM was 131.4 ± 22 mm, and the mean distance between the GAP and the mastoid process was found to be 60.4 ± 13.76 mm. The ratio of the GAP location to the total SCM length ranged between 0.33-0.57. The mean distance between the angle of the mandible and the GAP was determined to be 57 ± 22.2 mm. Based on the midpoint of the SCM, the GAP was above it in 66.7 % of subjects and classified to Type A, and below it in 33.3 % of subjects appointed to Type B.

CONCLUSIONS

The anatomical landmarks utilized in this study are helpful in predicting the location of the GAP relative to the midpoint of the SCM and can reduce neural injuries within the posterior triangle of the neck.

Long-term clinical outcomes of spinal accessory nerve transfer to the suprascapular nerve in patients with brachial plexus palsy

BACKGROUND

For the reconstruction of brachial plexus lesions, restoration of elbow flexion and shoulder function is fundamental and is achieved by dual nerve transfers. Shoulder stabilization and movement are crucial in freedom of motion of the upper extremity. In patients with C5-C6 brachial plexus injury, spinal accessory nerve transfer to the suprascapular nerve and a fascicle of ulnar nerve to musculocutaneous nerve (dual nerve transfer) are carried out for restoration of shoulder abduction and elbow flexion, respectively. In the present study, we evaluated the long-term clinical outcomes of spinal accessory nerve transfer to the suprascapular nerve for restoration of shoulder abduction in patients with brachial plexus palsy undergoing a dual nerve transfer.

PATIENTS AND METHODS

In the present retrospective review, 22 consecutive subjects with upper brachial plexus palsy were assessed. All of the subjects underwent spinal accessory nerve transfer to the suprascapular nerve and a dual nerve transfer from the ulnar nerve to the biceps branch and from the median nerve to the brachialis branch of the musculocutaneous nerve simultaneously. All of the subjects were followed up for 18 to 24 months (average, 21.7 months) for assessing the recovery of the shoulder abduction and motor function.

RESULTS

Spinal accessory nerve transfer to the suprascapular nerve showed a motor function recovery of M3 and M4 in 13.6 and 63.6% of the subjects, respectively. However, 22.7 % of the subjects remained with a motor function of M2. The mean of shoulder abduction reached 55.55 ± 9.95° (range, 40-72°). Altogether, good functional results regained in 17 out of 22 the subjects (77.2 %). Linear regression analysis showed that advanced age was a predictor of low motor functional grade.

CONCLUSIONS

The evidence from the present study suggests that transferring spinal accessory nerve to the suprascapular nerve for restoring shoulder abduction is an effective and reliable treatment with high success rate in patients with brachial plexus palsy, especially in young patients.

Division of the spinal accessory nerve in the anterior triangle: a prospective clinical study

The anatomical relation between the spinal accessory nerve and internal jugular vein is well documented, but other variants of the nerve, including the contributions of the cervical plexus to supply motor fibres to the trapezius, are less well known. We have previously described an anatomical variant in which the spinal accessory nerve divided before entering the sternocleidomastoid, and the inferior trunk passed directly under it to supply the trapezius. We now present a prospective study of 133 neck dissections (excluding radical dissections) in which a meticulous search was made for the variant in the anterior triangle of the neck during operation. We found it in 3 necks (2%). One of the 3 patients had a bilateral neck dissection but it was found on one side only, and in 2 cases it communicated with the cervical plexus. In all 3, stimulation of the inferior division resulted in contraction of the trapezius while the upper division was found to supply the sternocleidomastoid only. The finding of this variant, which was more common than first thought, highlights the need for meticulous dissection of the nerve before it enters the sternocleidomastoid to ensure that, when present, the inferior branch is preserved to minimise potential postoperative shoulder dysfunction. Further research including a cadaveric study is needed to understand this important variant more fully.

Expanding what is known of the anatomy of the spinal accessory nerve

The spinal accessory nerve (SAN) is classically considered a motor nerve innervating the sternocleidomastoid and trapezius muscles. Its anatomical relevance derives from the high prevalence of lesions following head and neck surgeries. As expected, trapezius weakness and atrophy are the most common findings; however, it is also commonly accompanied by pain and other sensory deficits that have no clear explanation, suggesting other functions. We have recently seen two patients presenting with an unrecognized sign, that is, subclavicular/pectoral asymmetry secondary to the SAN lesion. Retrospectively, we reviewed other patients with similar findings in our case series and in the literature. We discuss the anatomical connections of the SAN with the superficial cervical plexus and propose an explanation for this finding. Of the 41 patients in our series, we identified this sign in all who had preoperative photographs. New insights on the anatomy and connections of the SAN may account for the diversity of symptoms and signs presented following an operative intervention as well as the variability of its severity.

High division of the spinal accessory nerve and communication with a C2 branch of the cervical plexus: a previously unreported anatomical variant

Anatomical variations of the spinal accessory nerve are well known. We describe a previously unreported variant in which the nerve divided high in level II after crossing the internal jugular vein and before entering the sternomastoid muscle. Both branches were joined by a communication from the C2 cervical root. We discuss the clinical implications of this finding.

An Anatomical Variation of the Lesser Occipital Nerve in the "Carefree part" of the Posterior Triangle

The occurrence of the lesser occipital nerve (LON) at an anomalous location in the "carefree part" within the posterior triangle has been seldom reported in the literature. We are reporting a rare case of location of the LON in the "carefree part" of the posterior triangle, in a 55-year-old formalin embalmed male cadaver. LON, after emerging from the posterior margin of the sternomastoid muscle (SM), ran obliquely towards the trapezius muscle. Here, it hooked around the unusual separated muscle fasciculus of the trapezius, 7.5 cm below the superior nuchal line. Further, LON gave contributions to spinal accessory nerve (SAN); one deep into the SM and another one in the posterior triangle. The knowledge on the unusual location and course of the LON and its contribution to the SAN is significantly important while an anaesthetic blockade is being performed for the management of a cervicogenic headache and a super selective radical neck dissection.

Specific scapular kinematic patterns to differentiate two forms of dynamic scapular winging

BACKGROUND

Dynamic scapular winging (DSW) is a rare and misdiagnosed disorder causing considerable disability due to reduced scapular stability and abnormal motion. Two common causes are long thoracic nerve lesions resulting in serratus anterior muscle palsy and spinal accessory nerve lesions resulting in trapezius muscle palsy. The aim of this study was to analyse 3D scapular kinematic patterns in patients with DSW due to long thoracic (LTNL) or spinal accessory nerve lesions (SANL).

METHODS

3D scapular kinematics were assessed using a non invasive method involving an electromagnetic device during arm elevation in the frontal and sagittal planes in 9 patients (4 with SANL and 5 with LTNL) with unilateral DSW confirmed by electrical evidence. Within subject affected-unaffected differences were measured and compared between pathological groups (Mann-Whitney).

FINDINGS

Differences between affected and unaffected shoulders were significantly greater for scapular posterior tilt (at rest and 30° for sagittal arm elevation, at rest, 30° and 60° for frontal arm elevation) in the LTNL compared to the SANL group. Differences between affected and unaffected shoulders were significantly greater for scapular protraction (at rest and 60° of sagittal arm elevation, at rest, 30° and 60° of frontal arm elevation) and scapular lateral rotation at 60° for frontal arm elevation in the SANL compared to the LTNL group.

INTERPRETATIONS

These kinematic findings show two different scapular patterns that are specific to the neurological lesion. Moreover our kinematic data relate to specific clinical signs and the functional roles of the muscles involved.

Minimizing shoulder syndrome with intra-operative spinal accessory nerve monitoring for neck dissection

The objective of this study was to analyze the safety and results of intra-operative SAN (spinal accessary nerve) monitoring during selective neck dissection, with emphasis on shoulder syndrome. Twenty-five consecutive patients with head and neck cancer were studied. Selective neck dissection was performed by a single clinical fellow under the supervision of the department chief using an intra-operative SAN monitor. Electrophysiological data were recorded after initial identification of the SAN and continued until just before closure. Electromyographic evaluation was carried out to assess SAN function one month postoperatively. Shoulder disability was also evaluated at this time using a questionnaire for shoulder syndrome (shrug, flexion, abduction, winging, and pain). No patients had postoperative shoulder syndrome involving shrug, flexion, abduction, or winging. Twenty-two of the 25 (88%) patients had shoulder pain, but the average pain score was low (2.3 ± 1.3). No patients had neck recurrence during at least 1 year of follow up. By using nerve monitoring during selective neck dissection, no patient developed significant "shoulder syndrome", with the exception of slight pain.

Preservation of Spinal Accessory Nerve during Radical Neck Dissection

BACKGROUND

Radical Neck Dissection done in cases of squamous carcinoma of the head and neck with cervical metastases leads to significant morbidity due to the 'shoulder syndrome' arising from denervation and atrophy of the trapezius muscle supplied by the Spinal Accessory Nerve (SAN). Preservation of the SAN (described as Modified RND Type 1) has been described by various workers.

METHODS

We present our experience with 24 patients of squamous carcinoma of the head and neck with cervical metastases. MRND Type 1 was performed in those cases where the SAN was not involved by metastatic disease.

RESULTS

The SAN could be preserved in all the patients who were cN0, cN1 and cN2. Only one patient who was cN3 required sacrifice of SAN as the nerve was infiltrated by metastatic disease. Shoulder function was good where SAN was preserved. Conclusion : This procedure is oncologically safe and morbidity associated with the "Shoulder Syndrome" was prevented.