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.

Microvascular Decompression Alone without Rhizotomy Is an Effective Way of Treating Glossopharyngeal Neuralgia: Clinical Analysis of 46 Cases.

BACKGROUND: Microvascular decompression (MVD) has been the right choice for glossopharyngeal neuralgia (GPN) patients. However, whether glossopharyngeal/vagal nerve root rhizotomy should be combined with MVD is still controversial. OBJECTIVE: To evaluate whether glossopharyngeal/vagal nerve root rhizotomy during MVD is necessary for the treatment of GPN. METHODS: We performed a retrospective study of 46 GPN patients who underwent MVD surgery alone in our hospital, and their patient demographics, clinical presentations, and intraoperative findings are shown. The immediate and long-term follow-up outcomes were investigated to show the treatment's efficiency and safety; the outcome was also compared with our previous study. The relevant literature was reviewed to show complications for GPN patients undergoing glossopharyngeal/vagal nerve root rhizotomy with MVD. RESULTS: The most common offending vessel was the posterior inferior cerebellar artery (60.9%). 100% of the patients were pain-free (score of I on the Barrow Neurological Institute pain intensity [BNI-P] scale) immediately after MVD surgery, while 1 patient relapsed with occasional pain 12 months after the operation (score of III on the BNI-P scale). Poor wound healing and hearing loss were found in 1 case each. No complications related to the glossopharyngeal nerve/vagal nerve were reported. Some surgical techniques, such as thorough exploration of the CN IX-X rootlets, full freeing from arachnoid adhesions, and usage of a moist gelatin sponge, can improve the success rate of the operation. CONCLUSIONS: MVD alone without rhizotomy is an effective and safe method for patients with GPN.

MRI Findings and Outcomes in Patients Undergoing Microvascular Decompression for Glossopharyngeal Neuralgia.

BACKGROUND AND PURPOSE: Glossopharyngeal neuralgia causes extreme paroxysmal pain in the posterior pharynx, tonsillar region, base of tongue, or deep ear, that is, the distribution of the glossopharyngeal nerve. Some cases of glossopharyngeal neuralgia are associated with neurovascular conflict, usually by the posterior inferior cerebellar artery. Such symptomatic compression occurs only in proximal, centrally myelinated portions of the glossopharyngeal nerve near the brainstem. Microvascular decompression provides effective and durable pain relief for properly selected patients with medically refractory glossopharyngeal neuralgia. The purpose of this study is to describe a tailored MRI evaluation of neurovascular conflict in glossopharyngeal neuralgia to improve candidate selection for microvascular decompression. METHODS: Our team developed a glossopharyngeal neuralgia imaging and evaluation protocol including a grading system for neurovascular conflict of the glossopharyngeal nerve and applied it to evaluate candidates for microvascular decompression. RESULTS: Our team grades neurovascular conflict as "contact" (vessel touching nerve without intervening cerebrospinal fluid) versus "deformation" (deviation or distortion of nerve from its normal course by the offending vessel). MRIs of patients with glossopharyngeal neuralgia demonstrate proximal neurovascular conflict. Postoperative MRI demonstrates separation of the glossopharyngeal nerve from the offending vessel. CONCLUSION: A tailored glossopharyngeal neuralgia imaging evaluation protocol is presented. We believe this approach has helped improve microvascular decompression outcomes and reduce unnecessary procedures at our institution. Further research may elucidate whether clinical and imaging features, including neurovascular conflict severity, predict surgical outcome for glossopharyngeal neuralgia.

Surgical Pitfalls in Carotid Endarterectomy: A New Step-By-Step Approach.

Carotid endarterectomy (CEA) is a surgical intervention that may prevent stroke in asymptomatic and symptomatic patients. Our aim was to examine the microsurgical anatomy of carotid artery and other related neurovascular structures to summarize the CEA that is currently applied in ideal conditions. The upper necks of 2 adult cadavers (4 sides) were dissected using ×3 to ×40 magnification. The common carotid artery, external carotid artery (ECA), and internal carotid artery were exposed and examined. The surgical steps of CEA were described using 3-D cadaveric photos and computed tomography angiographic pictures obtained with help of OsiriX imaging software program. Segregating certain neurovascular and muscular structures in the course of CEA significantly increased the exposure. The division of facial vein allowed for internal jugular vein to be mobilized more laterally and dividing the posterior belly of digastric muscle resulted in an additional dorsal exposure of almost 2 cm. Isolating the ansa cervicalis that pulls hypoglossal nerve inferiorly allowed hypoglossal nerve to be released safely medially. The locations of the ECA branches alter depending on their anatomical variations. The hypoglossal nerve, glossopharyngeal nerve, and accessory nerve pierce the fascia of the upper part of the carotid sheath and they are vulnerable to injury because of their distinct courses along the surgical route. Surgical exposure in CEA requires meticulous dissection and detailed knowledge of microsurgical anatomy of the neck region to avoid neurovascular injuries and to determine the necessary surgical maneuvers in cases with neurovascular variations.

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.

Magnetic Resonance Imaging Evidence of Varicella Zoster Virus Polyneuropathy: Involvement of the Glossopharyngeal and Vagus Nerves Associated With Ramsay Hunt Syndrome.

The involvement of lower cranial nerve palsies is less frequent in Ramsay Hunt syndrome caused by varicella zoster virus (VZV). The authors report 1 of extremely rare patients of radiologically proven polyneuropathy of VZV infection with magnetic resonance imaging findings of VII, IX, and X cranial nerve involvement is a 62-year-old female patient, who initially presented with Ramsay Hunt syndrome. Varicella zoster virus infection should be considered even in patients who show unilateral palsy of the lower cranial nerves associated with laryngeal paralysis. Thin-section T2W and T1W images with a contrast agent should be added to the imaging protocol to show the subtle involvement.

Glossopharyngeal nerve block using ultrasound guidance: a case report of a new technique.

A new technique for blocking the glossopharyngeal nerve is described using ultrasound guidance. It is felt this technique will decrease the incidence of complications and increase the efficacy of this block for pain relief in cancer patients. The pertinent anatomic and technical considerations are discussed.

Intracranial glossopharyngeal neurinomas. Report of two cases with special emphasis on computed tomography and magnetic resonance imaging findings.

Two patients with intracranial glossopharyngeal neurinoma are described. In both patients, neurologic signs and findings of conventional radiologic and computed tomography examinations suggested a diagnosis of acoustic neurinoma. Magnetic resonance imaging, however, definitely indicated that the mass had actually arisen from the lower cranial nerves. This was confirmed at operation. The superb sensitivity and specificity of magnetic resonance imaging in the diagnosis of posterior fossa extraaxial mass are emphasized.

Intracranial glossopharyngeal schwannoma, a tumour imitating an acoustic schwannoma.

Neurinomas originating from the ninth cranial nerve are rarely observed. The early signs and symptoms of a glossopharyngeal neurinoma are rather discrete, and it can happen that a tumour here will often first be recognised with the signs and symptoms of an expanding posterior fossa lesion--thus often closely resembling an acousticus neurinoma.

High-resolution CT of the jugular foramen: anatomy and vascular variants and anomalies.

In high-resolution computed tomographic (HRCT) images of dry skulls and patients, the anatomy of the jugular foramen and its neighboring structures was demonstrated to excellent advantage. Among those structures visualized were the cortical margins of the jugular compartments, which are important in evaluating tumor involvement, the anatomic relationship between the jugular fossa and the hypotympanum, and the adjacent basal foramina. The inferior tympanic canaliculus, which transmits the inferior tympanic artery and nerve and houses one fifth of the glomus formation, thereby playing a role in arterial anomalies as well as glomus tumors, was occasionally recognizable. In addition, subtle bone findings associated with vascular anomalies in and around the jugular foramen, critically important in the differential diagnosis of glomus tumors, were visualized. Examples of these findings are presented.