Computed tomographic features of canine intracranial and jugular foraminal masses involving the combined glossopharyngeal, vagus, and accessory nerve roots.

A chronic cough, gag, or retch is a common presenting clinical complaint in dogs. Those refractory to conservative management frequently undergo further diagnostic tests to investigate the cause, including CT examination of their head, neck, and thorax for detailed morphological assessment of their respiratory and upper gastrointestinal tract. This case series describes five patients with CT characteristics consistent with an intracranial and jugular foraminal mass of the combined glossopharyngeal (IX), vagus (X), and accessory (XI) cranial nerves and secondary features consistent with their paresis. The consistent primary CT characteristics included an intracranial, extra-axial, cerebellomedullary angle, and jugular foraminal soft tissue attenuating, strongly enhancing mass (5/5). Secondary characteristics included smooth widening of the bony jugular foramen (5/5), mild hyperostosis of the petrous temporal bone (3/5), isolated severe atrophy of the ipsilateral sternocephalic, cleidocephalic, and trapezius muscles (5/5), atrophy of the ipsilateral thyroarytenoideus and cricoarytenoideus muscles of the vocal fold (5/5), and an ipsilateral "dropped" shoulder (4/5). Positional variation of the patient in CT under general anesthesia made the "dropped" shoulder of equivocal significance. The reported clinical signs and secondary CT features reflect a unilateral paresis of the combined cranial nerves (IX, X, and XI) and are consistent with jugular foramen syndrome/Vernet's syndrome reported in humans. The authors believe this condition is likely chronically underdiagnosed without CT examination, and this case series should enable earlier CT diagnosis in future cases.

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.

Ultrasonic identification of internal jugular vein fenestration.

OBJECTIVE: Anatomic variations have curicial importance during neck surgery. We present a fenestrated internal jugular vein variation and the accessory nerve passing through it. Also, we discuss preoperative diagnosis of this variation using ultrasonography. METHOD: The possible recognition of this variation by ultrasonography is introduced. RESULTS: The accessory nerve in an internal jugular vein fenestration can be seen using ultrasonography. CONCLUSION: Preoperative identification of this rare variation may secure surgeon from potential complications.

Differential age-, gender-, and side-dependency of vagus, spinal accessory, and phrenic nerve calibers detected with precise ultrasonography measures.

INTRODUCTION: The standard ultrasonographic measurement tools (trace, ellipse) of cross-sectional areas (CSAs) of very small nerves typically yield rough measures in full square millimeters. METHODS: In 70 volunteers, the elliptically shaped CSAs of mid-cervical vagus, accessory, and phrenic nerves were estimated with three methods: 2 on-board tools (area tracing, ellipse fitting) and an off-line calculation of the CSA after on-board measuring of its long-axis and short-axis diameters both displayed with 1-2 digits following the decimal point. RESULTS: CSA measures of all mid-cervical nerves obtained with the precise approach were smaller than the two standard measures (each P < 0.001). Larger CSA of right compared to left vagus nerve was detected with all methods. However, decrease of accessory and phrenic nerve CSAs with increasing age and larger size of vagus nerve CSA in women vs. men were evident only with precise measures. DISCUSSION: Small nerve CSA should preferably be estimated with precise measures. Muscle Nerve 59:486-491, 2019.

Accessory nerve distribution for aesthetic botulinum toxin injections into the upper trapezius muscle: anatomical study and clinical trial : Reproducible BoNT injection sites for upper trapezius.

PURPOSE: The descending part of the trapezius muscle is clinically associated with neck pain and aesthetic applications. The innervation of the trapezius muscle is not well described in the medical literature for clinicians. The aim of study was to analyze the perforating branch pattern of the accessory nerve in the descending part of the trapezius muscle with the aim of describing the most efficient and reproducible BoNT injection sites for aesthetic treatment of shoulder contouring. METHODS: Twenty-six specimens (five male and eight female) from embalmed Korean cadavers were used in this study. The trapezius muscle was dissected scrupulously and then reflected to enable examination of the locations of the perforating points. The thickness of trapezius muscle was measured in 13 volunteers using a diagnostic ultrasonography system. BoNT was injected into the trapezius muscle bilaterally. Injections were performed at 6 points separated by 2 cm. The muscle thicknesses were measured three times using ultrasonography: before the injection and at 4 and 12 weeks after the injection. RESULTS: The dense arborization of the perforating accessory nerve branches was confined mostly to section b (66.7%, 54/81) and section c (33.3%, 27/81). The mean muscle thickness at 4 and 12 weeks consistently decreased 0.68-0.63 cm  in conventional method and 0.65-0.61 cm in new method (NDM) respectively (right and left). CONCLUSION: To optimize the outcome of BoNT injection, we recommended injecting into six points separated by 2 cm in sections b and c of the upper trapezius muscle. It is significant that it is easier to apply to anyone than to apply unstructured techniques.

Vernet syndrome resulting from varicella zoster virus infection-a very rare clinical presentation of a common viral infection.

Vernet syndrome is a unilateral palsy of glossopharyngeal, vagus, and accessory nerves. Varicella zoster virus (VZV) infection has rarely been described as a possible cause. A 76-year-old man presented with 1-week-long symptoms of dysphonia, dysphagia, and weakness of the right shoulder elevation, accompanied by a mild right temporal parietal headache with radiation to the ipsilateral ear. Physical examination showed signs compatible with a right XI, X, and XI cranial nerves involvement and also several vesicular lesions in the right ear's concha. He had a personal history of poliomyelitis and chickenpox. Laringoscopy demonstrated right vocal cord palsy. Brain MRI showed thickening and enhancement of right lower cranial nerves and an enhancing nodular lesion in the ipsilateral jugular foramen, in T1 weighted images with gadolinium. Cerebrospinal fluid (CSF) analysis disclosed a mild lymphocytic pleocytosis and absence of VZV-DNA by PCR analysis. Serum VZV IgM and IgG antibodies were positive. The patient had a noticeable clinical improvement after initiation of acyclovir and prednisolone therapy. The presentation of a VZV infection with isolated IX, X, and XI cranial nerves palsy is extremely rare. In our case, the diagnosis of Vernet syndrome as a result of VZV infection was made essentially from clinical findings and supported by analytical and imaging data.

Comparison of 2 Operative Methods for Treating Laterocollis and Torticollis Subtypes of Spasmodic Torticollis: Follow-Up of 121 Cases.

OBJECTIVE: The aim of this study was to compare the effects and complications of microvascular decompression (MVD) and neurectomy of spinal accessory nerve in the treatment of laterocollis and torticollis subtypes spasmodic torticollis (ST). METHODS: Clinical data were retrospectively collected from 121 patients with laterocollis and torticollis subtypes of ST from January 1, 2012 to January 1, 2016. Among all the patients, 80 were treated by MVD and 41 were treated by neurectomy of spinal accessory nerve. The effect of the surgery was evaluated by the reduction in the Toronto Western spasmodic torticollis rating scale total scores before and after the operation. The mean duration of the postoperative follow-up period was 18.7 months (range, 12-27 months). RESULTS: At the final follow-up, the Toronto Western spasmodic torticollis rating scale total score in the MVD group and in the neurectomy group was lowered by 50.43% ± 20.3% and 30.23% ± 19.4%, respectively, compared with the preoperative status (P < 0.05). In the MVD group, 25 (31.25%) patients achieved excellent relief, 44 (55%) patients improved moderate spasm, and 11 (13.75%) showed no relief. In the neurectomy group, 6 (14.63%) patients improved with excellent outcome, 7 (17.07%) had moderate relief, and 28 (68.29%) had no relief. There was no mortality or severe complication postoperatively, with the exception of hoarseness, shoulder numbness, and weakness. CONCLUSIONS: MVD for ST of laterocollis and torticollis subtypes can provide satisfactory and lasting improvements without nerve impairment. MVD is to be preferred to neurectomy of accessory nerve in treating ST of laterocollis and torticollis subtypes.

Spinal Accessory Nerve: Ultrasound Findings and Correlations with Neck Lymph Node Levels.

Purpose: To evaluate the ultrasound characteristics of the spinal accessory nerve (SAN) and correlate nerve location with neck lymph node level. Materials and Methods: 50 participants with 100 SANs were enrolled in this study. The SAN was traced from the trapezius muscle to the upper neck and was identified by a hypoechoic linear structure without color Doppler flow. The ultrasound characteristics of the SAN, such as visibility, diameter, relationship with adjacent structures, and its correlation with lymph node levels, were evaluated. Results: The SAN was identified in 96 %-100 % of segments. The mean diameter of the SAN was 0.54 ±â€Š0.09 mm. The SANs was located between the trapezius and levator scapulae muscles and 90.8 % were traced into the trapezius muscle. In the upper neck, the SAN passed deep into the sternocleidomastoid (SCM) muscle in 38 % of cases and between the two heads of the SCM muscle in 62 % of cases. The SAN was found at neck lymph node levels II, III, IV, and V, but not I or VI. Conclusion: Continuous ultrasound monitoring of the SAN and its correlation with lymph node levels is possible in most patients. Our current findings may assist in the future prevention of SAN injury during ultrasound-guided procedures.

ANATOMICAL STUDY OF CRANIAL NERVE EMERGENCE AND SKULL FORAMINA IN THE HORSE USING MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY.

For accurate interpretation of magnetic resonance (MR) images of the equine brain, knowledge of the normal cross-sectional anatomy of the brain and associated structures (such as the cranial nerves) is essential. The purpose of this prospective cadaver study was to describe and compare MRI and computed tomography (CT) anatomy of cranial nerves' origins and associated skull foramina in a sample of five horses. All horses were presented for euthanasia for reasons unrelated to the head. Heads were collected posteuthanasia and T2-weighted MR images were obtained in the transverse, sagittal, and dorsal planes. Thin-slice MR sequences were also acquired using transverse 3D-CISS sequences that allowed mutliplanar reformatting. Transverse thin-slice CT images were acquired and multiplanar reformatting was used to create comparative images. Magnetic resonance imaging consistently allowed visualization of cranial nerves II, V, VII, VIII, and XII in all horses. The cranial nerves III, IV, and VI were identifiable as a group despite difficulties in identification of individual nerves. The group of cranial nerves IX, X, and XI were identified in 4/5 horses although the region where they exited the skull was identified in all cases. The course of nerves II and V could be followed on several slices and the main divisions of cranial nerve V could be distinguished in all cases. In conclusion, CT allowed clear visualization of the skull foramina and occasionally the nerves themselves, facilitating identification of the nerves for comparison with MRI images.

Anatomical study of spinal accessory nerve using ultrasonography.

OBJECTIVE: The purpose of our study was to demonstrate that ultrasonography may allow a precise assessment of the course and relationships of the spinal accessory nerve (SAN). MATERIAL AND METHODS: This study, initially undertaken in 7 cadavers, was followed by high-resolution ultrasonographic study in 15 volunteers (30 nerves) by two radiologists in consensus. The location, course and relations to the adjacent anatomic structures of the SAN were analyzed. RESULTS: The precise course of the SAN between the lateroposterior border of the sternocleidomastoid muscle and the anterior border of the trapezius muscle could be identified by high-resolution ultrasonography. In contrast, clinical bone landmarks were not found helpful for the identification of the nerve. CONCLUSION: The SAN can be clearly depicted by means of ultrasonography. Knowledge of the nerve's precise location, which may evidence individual variations, may have useful clinical applications.

Ultrasound visualization of the spinal accessory nerve in vivo.

BACKGROUND: Inadvertent injury of the spinal accessory nerve during surgical procedures is a cause of significant morbidity with medicolegal repercussions. Surface anatomy is an unreliable guide to the nerve's location. We suggest that ultrasound can be used to map the course of the nerve in the posterior triangle of the neck. MATERIALS AND METHODS: Fifty healthy subjects (28 females, mean age 37 y) were scanned using a VF13-5 linear probe and a Siemens Sonoline Antares ultrasound machine (Siemens Medical Solutions USA Inc., Malvern, PA). The caliber, course, and distribution of the nerve in the posterior triangle of the neck were recorded. RESULTS: The nerve was visualized bilaterally in all subjects, running superficially across the posterior triangle with either a straight (56%) or tortuous (44%) course at a depth of about 3 mm beneath the skin surface. It had a mean caliber of 0.76 ± 0.12 mm. It exited the posterior border of sternocleidomastoid at a mean of 6.7 (4.0-9.4) cm below the mastoid process and 1.1 (0.1-2.1) cm above the great auricular point and penetrated the anterior border of trapezius 5.4 (2.1-9.2) cm above the clavicle. Importantly, 58% of nerves divided into 2-4 branches before penetrating trapezius; the nerve branched on at least one side in 49 of 50 individuals. CONCLUSIONS: The spinal accessory nerve and its anatomical variants can be consistently and reliably demonstrated by ultrasound in normal individuals. Surface anatomical landmarks are not a reliable guide to the position and course of the nerve in the posterior triangle. Preoperative mapping of the nerve with ultrasound may reduce the risk of iatrogenic injury.

Four cases of spinal accessory nerve passing through the fenestrated internal jugular vein.

PURPOSE: Neck dissection (ND) is an important technique for the treatment of cervical lymph node metastasis in patients with head and neck cancer. Since the introduction of functional ND (FND), various modifications have been made to reduce the adverse effects of radical ND. Recently, many investigators have documented cases of FND with preservation of the spinal accessory nerve (SAN) and/or the sternocleidomastoid muscle, which have contributed to improve the quality of life following ND. For this type of ND, special attention must be paid to identify the SAN and the internal jugular vein (IJV). METHODS: We performed 123 NDs over 2 years at the Department of Otolaryngology, Head and Neck Surgery, Kobe University Hospital. We collected data of all patients who underwent NDs by retrospectively reviewing the relevant hospital medical records and operative notes. RESULTS: In 4 out of 123 NDs (3.3%), an anomaly of the SAN passing through the fenestrated IJV was observed. CONCLUSION: Although this anomaly is rare, head and neck surgeons should be aware of this anomalous relationship between the SAN and the IJV in order to avoid accidental injury to these structures during ND.

Ultrasound-guided spinal accessory nerve blockade in the diagnosis and management of trapezius muscle-related myofascial pain.

We report the first description of ultrasound-guided spinal accessory nerve blockade using single-shot and subsequently continuous infusion (via a perineural catheter) local anaesthetic techniques, for the diagnosis and treatment of myofascial pain affecting the trapezius muscle. A 38-year-old man presented with a two-year history of incapacitating left suprascapular pain after a fall onto his outstretched hand. The history and clinical examination was suggestive of myofascial pain affecting the trapezius muscle. This had been unresponsive to pharmacological therapy, physiotherapy or suprascapular nerve blockade. Following identification of the spinal accessory nerve in the posterior triangle of the neck, we performed ultrasound-guided nerve blocks, first using a single injection of local anaesthetic and subsequently using a continuous infusion via a perineural catheter, to block the nerve and temporarily relieve the patient's pain. We have demonstrated that the spinal accessory nerve is identifiable in the posterior triangle of the neck and can be blocked successfully using ultrasound guidance. This technique can aid the diagnosis and treatment of myofascial pain originating from the trapezius muscle.

The glossopharyngeal, vagus and spinal accessory nerves.

The glossopharyngeal, vagus and spinal accessory nerves are closely related anatomically, and to a certain extent, functionally. We present an overview of their anatomy, highlighting the important clinical and imaging implications. The main pathologic lesions arising from these nerves are also discussed and the imaging features reviewed.

Ultrasonography of the accessory nerve: normal and pathologic findings in cadavers and patients with iatrogenic accessory nerve palsy.

OBJECTIVE: To determine feasibility of ultrasonography in detecting the normal accessory nerve as well as pathologic changes in cases of accessory nerve palsy. METHODS: Four patients with accessory nerve palsy were investigated by ultrasonography. Three cases of accessory nerve palsy after lymph node biopsy and neck dissection were primarily diagnosed on the basis of ultrasonography using a 5- to 12-MHz linear transducer. In addition, we performed ultrasonography in 3 cadaveric specimens to show the feasibility of detecting the accessory nerve. RESULT: Nerve transection (n = 2), scar tissue (n = 1), and atrophy of the trapezius muscle (n = 4) were confirmed by electroneurographic testing and surgical nerve inspection. In 1 case in which a patient had a whiplash injury with accessory nerve palsy, ultrasonography showed atrophy of the trapezius muscle with a normal nerve appearance. CONCLUSIONS: Ultrasonography allows visualization of the normal accessory nerve as well as changes after accessory nerve palsy.