Post-traumatic glomus tumor of the left anterior supraclavicular nerve: a case report.

OBJECTIVES: Peripheral nerve glomus tumors are extremely rare and occur with typical symptoms of peripheral neuropathic pain. Clinicians hardly consider this entity when faced with the swelling of a peripheral nerve and the diagnosis is reached only with histological examination. Nerves of limbs are usually affected and the solid glomus tumor is the most frequent histological variant. CASE DESCRIPTION: A 55-year-old man presented with a glomus tumor of the anterior supraclavicular nerve of the left cervical plexus, misdiagnosed clinically and radiologically as neuroma. Despite the preoperative suspicion and the intraoperative appearance, the histological examination revealed a glomus tumor with a prevalent muscular component, a glomangiomyoma. Once the tumor was removed, pain regressed completely. CONCLUSIONS: Because of its rarity, pre-operative diagnosis of glomus tumors is still a challenge, especially when arising from peripheral nerves. In the presence of chronic localized neuroma-type pain and sensitivity, glomus tumors should be considered in the pool of differential diagnosis, even if the imaging is not conclusive.

Nerve block as neuropathic pain treatment for the great auricular nerve neuropathy: A case report.

OBJECTIVE/BACKGROUND: The great auricular nerve (GAN) is a major sensory branch of the cervical plexus. Painful great auricular neuropathy causes pain circumscribed to the inferior preauricular region, the jaw angle, the ventral pinna, and the mastoid region. METHODS: We present a 46-year-old woman experiencing facial pain in the bilateral preauricular and infra-auricular region, constant, of abrasive quality without any other associated symptomatology that is triggered or aggravated with cephalic movements, cervical turn, mandibular movement, and palpation on the affected area. RESULTS: Symptomatic treatment with analgesics, anti-inflammatories, and neuropathic preventive medications was ineffective. However, nerve block anesthetic treatment resulted in complete pain remission. CONCLUSION: Great auricular neuropathy is an uncommon cause of facial pain; our case report is the first bilateral occurrence reported to date. It should be suspected in patients with circumscribed shooting or lancinating paroxysmal pain in the territory of the GAN. It is characterized by the aggravation of pain with cervical movements and complete relief after anesthetic blockade.

Schwannoma del plexo cervical en una mujer de 76 años / Schwannoma of the cervical plexus in a 76-year-old woman

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Report of a non-looped variant of ansa cervicalis with omohyoid innervation from accessory nerve branch and omohyoid attachment to mastoid process.

INTRODUCTION: A variant of the innervation of the infrahyoid neck musculature is reported in which the typical looped ansa cervicalis structure is absent. In this variant, the infrahyoid muscles (sternohyoid, sternothyroid omohyoid and thyrohyoid) were innervated by a presumptive superior root of "ansa cervicalis" traveling with vagus nerve (CN X) and not branching from hypoglossal nerve (CN XII). The omohyoid muscle, typically innervated by the inferior root of ansa cervicalis, is instead innervated by nerve fibers branching from the accessory nerve (CN XI). This formation created a non-looping variant of ansa cervicalis. Furthermore, the omohyoid muscle did not attach to the hyoid bone but instead attached to the mastoid process of the temporal bone by merging its fibers superiorly and posteriorly with the clavicular portion of the sternocleidomastoid muscle, creating a "sternocleidoomomastoid" muscle innervated by a branch of accessory nerve. MATERIALS AND METHODS: This variation was found in one black male cadaver from a cohort of 25 male and female cadavers. RESULTS: Only one variation of ansa cervicalis was observed. CONCLUSIONS: As neck dissections and surgical procedures of this region are performed for a variety of conditions-including coronary artery bypass grafting and metastatic neck disease-variations of this type are of broad clinical surgical importance.

Perineural Spread of Melanoma to the Brachial Plexus: Identifying the Anatomic Pathway(s).

BACKGROUND: Perineural spread of melanoma is a well-known mechanism of metastasis in cases involving cranial nerves. Brachial plexus involvement is rare, and the pathway is unknown. METHODS: A retrospective review of the Mayo Clinic database was performed to identify patients with a history of melanoma and brachial plexus compromise treated between 1994 and 2017. Inclusion criteria were a history of melanoma, a clinical diagnosis of brachial plexopathy, radiologic features consistent with perineural spread, and biopsy of melanoma within nerves. RESULTS: We identified 42 patients (24 men and 18 women; median age, 61 years; range, 37-84 years) with a history of melanoma and brachial plexopathy. On a review of clinical information, 2 cases met our inclusion criteria. Both patients presented with progressive brachial plexopathy, and imaging studies revealed features consistent with perineural spread. In 40 excluded patients, brachial plexopathy was caused by metastasis to axillary lymph nodes (n = 11), trauma (n = 8), post-surgical sequelae (n = 7), tumors other than melanoma (n = 5), inflammation (n = 5), radiation (n = 2), a combination of radiation and postsurgical changes (n = 1), and radiculopathy (n = 1). CONCLUSIONS: The 2 patients identified had similar clinical and radiologic features. We believe that there is a pattern of perineural spread to the brachial plexus through the cervical plexus. A literature review identified several recently published cases demonstrating an analogous mechanism of melanoma spread involving upper cervical nerves, supporting our proposed pathway.

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.

Quantification of Trapezius Muscle Innervation During Neck Dissections: Cervical Plexus Versus the Spinal Accessory Nerve.

OBJECTIVES: Despite increasing use of selective, nerve-sparing surgical techniques during neck dissections, the reported rate of postoperative paralysis of the trapezius muscle is still high. The aim of the study is to measure and compare motor inflow to the trapezius muscle, in order to better understand the peripheral neuroanatomy. METHODS: Intraoperative nerve monitoring (electroneurography) in patients undergoing routine neck dissection (n=18). The innervation of the 3 functional parts of the trapezius muscle was mapped and quantified through compound muscle action potentials. RESULTS: In 18/18 (100%) of the patients, the spinal accessory nerve (SAN) innervated all parts of the trapezius muscle. In 7/18 (39%) of the patients, an active motor branch from the cervical plexus was detected, equally distributed to all functional parts of the trapezius muscle, at levels comparable to the SAN. CONCLUSIONS: Compared to the SAN, branches from cervical plexus provide a significant amount of neural input to all parts of the trapezius muscle. Intraoperative nerve monitoring can be used in routine neck dissections to detect these branches, which may be important following surgical injury to the SAN.

High-Resolution Ultrasound for Diagnostic Assessment of the Great Auricular Nerve--Normal and First Pathologic Findings.

PURPOSE: The great auricular nerve (GAN) is a sensory branch of the superficial cervical plexus. While its blockade is an established procedure, little is known about the ultrasound appearance of pathologic conditions of the GAN itself. We, therefore, aimed to evaluate the possibility of the visualization and diagnostic assessment of the GAN along its entire course by means of high-resolution ultrasound (HRUS). MATERIALS AND METHODS: To assess the feasibility of visualization, we performed HRUS with an 18 MHz probe, HRUS-guided, fine-needle ink markings and consecutive dissection in six anatomical specimens. Then, we measured the diameter of the GAN in healthy volunteers and finally performed a retrospective review of patients referred for HRUS examinations because of pain within GAN territory between August 1, 2012 and August 1, 2013. RESULTS: The GAN was clearly visible with HRUS from its formation to the final branches, and was marked successfully on both sides in all anatomical specimens (n = 12). The mean average in-vivo was 0.14 cm ± 0.03 (range 0.08-0.2). Seven cases of patients with GAN pathologies of various origins (idiopathic, traumatic, tumorous and iatrogenic) were identified, of which 6 were visible on HRUS and all of which could be confirmed by complete resolution of symptoms after selective HRUS-guided GAN block. CONCLUSION: This study confirms the reliable ability to visualize the GAN with HRUS throughout its course, both in anatomical specimens and in vivo. The provided cases show that pathologies of the GAN seem to have a variety of causes and may not be rare. We, therefore, encourage the use of HRUS in patients with unclear pain in the auricular, periauricular and posterior-lateral head.

Malignant peripheral nerve sheath tumor of the superficial cervical plexus with parotid extension.

INTRODUCTION: Cervical locations of malignant peripheral nerve sheath tumor (MPNST) are rare, at less than 1% of malignant tumors of this region. CASE REPORT: A 53-year-old woman presented with a lateral cervical swelling involving the parotid region. Histology was in favor of MPNST. Adjuvant radiotherapy was indicated because of the infiltrating nature of the tumor. At 2 years' follow-up, there was no recurrence. DISCUSSION: Clinical diagnosis is difficult in cervical MPNST. Only histology with immunohistochemistry can establish the correct diagnosis. Treatment requires complete surgical resection and regular clinical follow-up.

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.

Communication of the transverse cervical nerve with the marginal mandibular nerve: a previously unreported anatomical variant.

Communications between the transverse cervical nerve (C2 and 3) and the cervical branch of the facial nerve have been reported. We describe a case in which the transverse cervical nerve joined the marginal mandibular branch of the facial nerve. It was found during a selective neck dissection and to our knowledge is the first report of such a communication. We discuss the clinical relevance particularly in relation to confusion with the marginal mandibular branch of the facial nerve when operating in the submandibular region.

Sympathetic nerve fibers and ganglia in canine cervical vagus nerves: localization and quantitation.

BACKGROUND: Cervical vagal nerve (CVN) stimulation may improve left ventricular ejection fraction in patients with heart failure. OBJECTIVES: To test the hypothesis that sympathetic structures are present in the CVN and to describe the location and quantitate these sympathetic components of the CVN. METHODS: We performed immunohistochemical studies of the CVN from 11 normal dogs and simultaneously recorded stellate ganglion nerve activity, left thoracic vagal nerve activity, and subcutaneous electrocardiogram in 2 additional dogs. RESULTS: A total of 28 individual nerve bundles were present in the CVNs of the first 11 dogs, with an average of 1.87±1.06 per dog. All CVNs contain tyrosine hydroxylase-positive (sympathetic) nerves, with a total cross-sectional area of 0.97±0.38 mm(2). The sympathetic nerves were nonmyelinated, typically located at the periphery of the nerve bundles and occupied 0.03%-2.80% of the CVN cross-sectional area. Cholineacetyltransferase-positive nerve fibers occupied 12.90%-42.86% of the CVN cross-sectional areas. Ten of 11 CVNs showed tyrosine hydroxylase and cholineacetyltransferase colocalization. In 2 dogs with nerve recordings, we documented heart rate acceleration during spontaneous vagal nerve activity in the absence of stellate ganglion nerve activity. CONCLUSIONS: Sympathetic nerve fibers are invariably present in the CVNs of normal dogs and occupy in average up to 2.8% of the cross-sectional area. Because sympathetic nerve fibers are present in the periphery of the CVNs, they may be susceptible to activation by electrical stimulation. Spontaneous activation of the sympathetic component of the vagal nerve may accelerate the heart rate.

Diabetic cervical radiculoplexus neuropathy: a distinct syndrome expanding the spectrum of diabetic radiculoplexus neuropathies.

Diabetic lumbosacral radiculoplexus neuropathy is a subacute painful, asymmetrical lower limb neuropathy due to ischaemic injury and microvasculitis. The occurrence of a cervical diabetic radiculoplexus neuropathy has been postulated. Our objective was to characterize the clinical features and pathological alterations of diabetic cervical radiculoplexus neuropathy, to see if they are similar to diabetic lumbosacral radiculoplexus neuropathy and due to ischaemic injury and microvasculitis. We identified patients with diabetic cervical radiculoplexus neuropathy by review of the Mayo Clinic database from 1996 to 2008. We systematically reviewed the clinical features, laboratory studies, neurophysiological findings, neuroimaging and pathological features and compared the findings with a previously published diabetic lumbosacral radiculoplexus neuropathy cohort. Eighty-five patients (56 males, 67 with Type 2 diabetes mellitus) were identified. The median age was 62 years (range 32-83). The main presenting symptom was pain (53/85). At evaluation, weakness was the most common symptom (84/85), followed by pain (69/85) and numbness (56/85). Neuropathic deficits were moderate (median motor neuropathy impairment score 10.0 points) and improved at follow-up. Upper, middle and lower brachial plexus segments were involved equally and pan-plexopathy was not unusual (25/85). Over half of patients (44/85) had at least one additional body region affected (30 contralateral cervical, 20 lumbosacral and 16 thoracic) as is found in diabetic lumbosacral radiculoplexus neuropathy. Recurrent disease occurred in 18/85. Neurophysiology showed axonal neuropathy (80/80) with paraspinal denervation (21/65), and abnormal autonomic (23/24) and sensory testing (10/13). Cerebrospinal fluid protein was elevated (median 70 mg/dl). Magnetic resonance imaging showed brachial plexus abnormality in all (38/38). Nerve biopsies (11 upper and 11 lower limbs) showed ischaemic injury (axonal degeneration, multifocal fibre loss 15/22, focal perineurial thickening 16/22, injury neuroma 5/22) and increased inflammation (epineural perivascular inflammation 22/22, haemosiderin deposition 6/22, vessel wall inflammation 14/22 and microvasculitis 5/22). We therefore conclude that (i) diabetic cervical radiculoplexus neuropathy is a predominantly monophasic, upper limb diabetic neuropathy with pain followed by weakness and involves motor, sensory and autonomic fibres; (ii) the neuropathy begins focally and often evolves into a multifocal or bilateral condition; (iii) the pathology of diabetic cervical radiculoplexus neuropathy demonstrates ischaemic injury often from microvasculitis; and (iv) diabetic cervical radiculoplexus neuropathy shares many of the clinical and pathological features of diabetic lumbosacral radiculoplexus neuropathy, providing evidence that these conditions are best categorized together within the spectrum of diabetic radiculoplexus neuropathies.

Perineural tumor spread - Interconnection between spinal and cranial nerves.

The secondary neoplastic involvement of the cervical plexus in patients with head and neck malignancies is extremely rare. MR examination of the neck revealed the diffuse neoplastic infiltration of the right C2 root, in a 57-year-old patient with several months long pain in the right ear region and a history of the tongue squamous cell carcinoma. Associated perineural tumor spread and consequent distal involvement of great auricular nerve and vagus nerve were evident. Best of our knowledge, this is the first reported involvement of the cervical plexus in patients with head and neck cancers, associated with the clearly documented interconnection between the cervical plexus and cranial nerves via great auricular nerve.