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Neuroimaging Clinics of North America Aug 2022The 12 cranial nerves (CNs) all have important functions. All, except the accessory nerve, arise solely within the cranial vault. We will discuss each CN function along... (Review)
Review
The 12 cranial nerves (CNs) all have important functions. All, except the accessory nerve, arise solely within the cranial vault. We will discuss each CN function along with its entire CN course. The modality of choice for evaluation of the CN itself is typically MRI, however, CT is very important to access the bony foramina and CN boundaries..
Topics: Accessory Nerve; Cranial Nerves; Humans; Magnetic Resonance Imaging
PubMed: 35843663
DOI: 10.1016/j.nic.2022.04.004 -
Anatomical Record (Hoboken, N.J. : 2007) Apr 2019The eleventh cranial nerve, the accessory nerve, has a complex and unique anatomy and has been the subject of much debate. Herein, we review the morphology, embryology,... (Review)
Review
INTRODUCTION
The eleventh cranial nerve, the accessory nerve, has a complex and unique anatomy and has been the subject of much debate. Herein, we review the morphology, embryology, surgical anatomy, and clinical manifestations of the accessory nerve. Included in this review, we mention variant anatomy, molecular development, histology, and imaging of the accessory nerve.
CONCLUSIONS
The accessory nerve continues to be a topic of much discussion regarding its exact function and in particular to its cranial roots. Recently, various surgical procedures have been devised that repurpose the accessory nerve (e.g., lengthening procedures, contralateral neurotization procedures). Currently, we continue to learn and have much to learn about this lower cranial nerve. Anat Rec, 302:620-629, 2019. © 2018 Wiley Periodicals, Inc.
Topics: Accessory Nerve; Accessory Nerve Injuries; Anatomic Landmarks; Anatomic Variation; Animals; Humans
PubMed: 29659160
DOI: 10.1002/ar.23823 -
Journal of Clinical Neurophysiology :... Jan 2018Multiple techniques have been developed for the electrodiagnostic evaluation of cranial nerves XI and XII. Each of these carries both benefits and limitations, with more... (Review)
Review
Multiple techniques have been developed for the electrodiagnostic evaluation of cranial nerves XI and XII. Each of these carries both benefits and limitations, with more techniques and data being available in the literature for spinal accessory than hypoglossal nerve evaluation. Spinal accessory and hypoglossal neuropathy are relatively uncommon cranial mononeuropathies that may be evaluated in the outpatient electrodiagnostic laboratory setting. A review of available literature using PubMed was conducted regarding electrodiagnostic technique in the evaluation of spinal accessory and hypoglossal nerves searching for both routine nerve conduction studies and repetitive nerve conduction studies. The review provided herein provides a resource by which clinical neurophysiologists may develop and implement clinical and research protocols for the evaluation of both of these lower cranial nerves in the outpatient setting.
Topics: Accessory Nerve; Electrodiagnosis; Humans; Hypoglossal Nerve
PubMed: 29298213
DOI: 10.1097/WNP.0000000000000439 -
Clinical Orthopaedics and Related... Nov 1999Injury to the spinal accessory nerve can lead to dysfunction of the trapezius. The trapezius is a major scapular stabilizer and is composed of three functional... (Review)
Review
Injury to the spinal accessory nerve can lead to dysfunction of the trapezius. The trapezius is a major scapular stabilizer and is composed of three functional components. It contributes to scapulothoracic rhythm by elevating, rotating, and retracting the scapula. The superficial course of the spinal accessory nerve in the posterior cervical triangle makes it susceptible to injury. Iatrogenic injury to the nerve after a surgical procedure is one of the most common causes of trapezius palsy. Dysfunction of the trapezius can be a painful and disabling condition. The shoulder droops as the scapula is translated laterally and rotated downward. Patients present with an asymmetric neckline, a drooping shoulder, winging of the scapula, and weakness of forward elevation. Evaluation should include a complete electrodiagnostic examination. If diagnosed within 1 year of the injury, microsurgical reconstruction of the nerve should be considered. Conservative treatment of chronic trapezius paralysis is appropriate for older patients who are sendentary. Active and healthy patients in whom 1 year of conservative treatment has failed are candidates for surgical reconstruction. Studies have shown the Eden-Lange procedure, in which the insertions of the levator scapulae, rhomboideus minor, and rhomboideus major muscles are transferred, relieves pain, corrects deformity, and improves function in patients with irreparable injury to the spinal accessory nerve.
Topics: Accessory Nerve; Accessory Nerve Injuries; Humans; Muscle, Skeletal; Paresis; Peripheral Nervous System Diseases; Physical Examination; Shoulder
PubMed: 10613148
DOI: No ID Found -
The Journal of Laryngology and Otology Dec 2007The XIth cranial nerve or accessory nerve provides the motor supply to the sternocleidomastoid and trapezius muscles. It is frequently encountered during neck surgery,... (Review)
Review
The XIth cranial nerve or accessory nerve provides the motor supply to the sternocleidomastoid and trapezius muscles. It is frequently encountered during neck surgery, and as such is at risk of iatrogenic injury, resulting in the 'shoulder syndrome'. Historically, the nerve was sacrificed on oncological grounds during radical neck dissection. However, the basis for sacrifice is unfounded in the majority of cases, and accessory nerve sparing selective neck dissection has equal oncological efficacy. The path of the nerve in the neck is very variable, and there is not a wholly reliable landmark for its identification. However, there are a number of methods described in the literature to guide the surgeon in its identification. This paper provides a systematic review of all the methods available for identification of the accessory nerve, and comments on the reliability of each. In doing so, the detailed anatomy of the accessory nerve is also described.
Topics: Accessory Nerve; Accessory Nerve Injuries; Humans; Neck; Neck Dissection; Neck Muscles; Postoperative Complications
PubMed: 17892604
DOI: 10.1017/S0022215107000461 -
Seminars in Neurology Feb 2009The spinal accessory nerve, primarily a motor nerve, innervates the sternocleidomastoid and trapezius muscles. Proximally, lesions can occur intracranially at the skull... (Review)
Review
The spinal accessory nerve, primarily a motor nerve, innervates the sternocleidomastoid and trapezius muscles. Proximally, lesions can occur intracranially at the skull base or just outside the jugular foramen producing ipsilateral weakness of trapezius and sternocleidomastoid muscles; or distally, in the posterior neck triangle causing trapezius muscle weakness.
Topics: Accessory Nerve; Accessory Nerve Diseases; Humans; Magnetic Resonance Imaging; Muscle Weakness; Neck Muscles; Tomography, X-Ray Computed
PubMed: 19214936
DOI: 10.1055/s-0028-1124026 -
Clinical Anatomy (New York, N.Y.) Jan 2024This study aimed to investigate the anatomy of the spinal accessory nerve (SAN) in the posterior cervical triangle, especially in relation to adjacent anatomical... (Meta-Analysis)
Meta-Analysis Review
This study aimed to investigate the anatomy of the spinal accessory nerve (SAN) in the posterior cervical triangle, especially in relation to adjacent anatomical landmarks, along with a systematic review of the current literature with a meta-analysis of the data. Overall, 22 cadaveric and three prospective intraoperative studies, with a total of 1346 heminecks, were included in the analysis. The major landmarks relevant to the entry of the SAN at the posterior border of the SCM muscle (PBSCM) were found to be the mastoid apex, the great auricular point (GAP), the nerve point (NP), and the point where the PBSCM meets the upper border of the clavicle. The SAN was reported to enter the posterior cervical triangle above GAP in 100% of cases and above NP in most cases (97.5%). The mean length of the SAN along its course from the entry point to its exit point from the posterior triangle of the neck was 4.07 ± 1.13 cm. The SAN mainly gave off 1 or 2 branches (32.5% and 31%, respectively) and received either no branches or one branch in most cases (58% and 23%, respectively) from the cervical plexus during its course in the posterior cervical triangle. The major landmarks relevant to the entry of the SAN at the anterior border of the TPZ muscle (ABTPZ) were found to be the point where the ABTPZ meets the upper border of the clavicle and the midpoint of the clavicle, along with the mastoid apex, the acromion, and the transverse distance of the SAN exit point to the PBSCM. The results of the present meta-analysis will be helpful to surgeons operating in the posterior cervical triangle, aiding the avoidance of the iatrogenic injury of the SAN.
Topics: Humans; Accessory Nerve; Prospective Studies; Cadaver; Neck; Neck Muscles
PubMed: 37767816
DOI: 10.1002/ca.24119 -
Anatomical Science International Jun 2024The spinal accessory nerve, considered part of the eleventh cranial nerve, provides motor innervation to sternocleidomastoid and trapezius. A comprehensive literature... (Review)
Review
The spinal accessory nerve, considered part of the eleventh cranial nerve, provides motor innervation to sternocleidomastoid and trapezius. A comprehensive literature review and two cadaveric dissections were undertaken. The spinal accessory nerve originates from the spinal accessory nucleus. Its rootlets unite and ascend between the denticulate ligament and dorsal spinal rootlets. Thereafter, it can anastomose with spinal roots, such as the McKenzie branch, and/or cranial roots. The spinal accessory nerve courses intracranially via foramen magnum and exits via jugular foramen, within which it usually lies anteriorly. Extracranially, it usually crosses anterior to the internal jugular vein and lies lateral to internal jugular vein deep to posterior belly of digastric. The spinal accessory nerve innervates sternocleidomastoid, receives numerous contributions in the posterior triangle and terminates within trapezius. Its posterior triangle course approximates a perpendicular bisection of the mastoid-mandibular angle line. The spinal accessory nerve contains sensory nociceptive fibres. Its cranial nerve classification is debated due to occasional non-fusion with the cranial root. Surgeons should familiarize themselves with the variable course of the spinal accessory nerve to minimize risk of injury. Patients with spinal accessory nerve injuries might require specialist pain management.
Topics: Humans; Accessory Nerve; Cadaver; Anatomic Variation
PubMed: 38696101
DOI: 10.1007/s12565-024-00770-w -
Clinical Anatomy (New York, N.Y.) Mar 2021The classification of the accessory nerve (CN XI) remains a source of debate; its exact function has not been fully elucidated having also an atypical morphology for a... (Review)
Review
INTRODUCTION
The classification of the accessory nerve (CN XI) remains a source of debate; its exact function has not been fully elucidated having also an atypical morphology for a cranial nerve. A better insight into its anatomical and physiological features is of clinical relevance. The aim was to conduct a review of 18th and 19th century books from the Royal Medical/Surgical Colleges in Scotland, United Kingdom. A contextual historical analysis of the depictions and descriptions of the accessory nerve could provide insight into the disparity in the current descriptions.
MATERIALS AND METHODS
Online archive catalogues were systematically searched and, during site visits, resources were formally and contextually analyzed, with the information then thematically analyzed. The themes were discussed against a widely known reference textbook of the era.
RESULTS
Based on the thematic analysis, the resources were categorized either as practical anatomy books or field-specific anatomy books including neuroanatomy atlases. This intended use, along with the target audience, influenced the scope and detail of information, typically with general anatomy for students in the practical resources, and specialist information in the field-specific resources. The authors' professional background also influenced the way the accessory nerve was described and/or depicted, with surgeons/physicians placing emphasis on the clinical aspects. Content variations could also be attributed to communication restrictions of the era, and associated purchasing costs.
CONCLUSIONS
Although scientific advances are nowadays disseminated at a faster pace, actively bridging the gap between anatomical sciences and clinical research is still needed when considering the accessory nerve to further elucidate the mysteries of this structure.
Topics: Accessory Nerve; Anatomy; Books; History, 18th Century; History, 19th Century; Humans; Scotland
PubMed: 32239537
DOI: 10.1002/ca.23593 -
British Journal of Neurosurgery Dec 2019We present a case of the spinal accessory nerve traversing a fenestrated internal jugular vein. Awareness of this variant may be important in neurosurgical procedures... (Review)
Review
We present a case of the spinal accessory nerve traversing a fenestrated internal jugular vein. Awareness of this variant may be important in neurosurgical procedures that involve upper cervical exposures.
Topics: Accessory Nerve; Cadaver; Humans; Jugular Veins; Spinal Nerves
PubMed: 31502482
DOI: 10.1080/02688697.2019.1661969