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The glossopharyngeal, vagus, and accessory nerves are discussed in this article, given their intimate anatomical and functional associations. Abnormalities of these lower cranial nerves may be intrinsic or extrinsic due to various disease processes. This article aims to review these nerves' anatomy and demonstrates the imaging aspect of the diseases which most commonly affect them., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Rationale: Syncope caused by head and neck cancer (HNC) is rare. However, syncope caused by tongue cancer (TC) is even rarer. In TC, syncope is caused by tumor-mediated compression of the carotid sinus and stimulation of the glossopharyngeal nerve., Patient Concerns: In this study, we report the case of a 48-year-old male patient who was diagnosed with advanced TC and bilateral cervical lymph node metastasis. On the third day of admission, the patient experienced recurrent syncope with hypotension and bradycardia., Diagnoses: The patient was diagnosed with a well-differentiated squamous cell carcinoma of the tongue along with massive cervical lymph node metastasis and carotid sinus syndrome., Interventions: Initially, symptomatic treatment of syncope boosted the blood pressure and increased the heart rate. Thereafter, a temporary pacemaker was implanted. Finally, chemotherapy was used to control the tumor and relieve syncope., Outcomes: After chemotherapy, the tongue ulcers and cervical lymph node reduced in size; syncope did not recur., Lessons: This case shows that chemotherapy may be a valid treatment option in patients with cancer-related syncope; however, the choice of chemotherapeutic drugs is critical. Intensive care provides life support to patients and creates opportunities for further treatment.

The carotid sinus nerve branches off the glossopharyngeal nerve just after its appearance from the jugular foramen, descends along the internal carotid artery, and enters the carotid sinus. There have been many studies of the pathway and the course of the carotid sinus nerve and its communications with surrounding nerves. The intercommunication is exceedingly complicated. Acknowledgment of its anatomic diversity can be important in specific operations dealing with this area. Herein we review the anatomy, variations, pathology, and clinical applications of the carotid sinus nerve., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: This 3-dimensional histologic study aimed to provide a precise description of the meningeal structures in the jugular foramen., Methods: 22 posterior skull base tissue blocks containing the jugular foramen region were obtained from 11 human cadaveric heads. These blocks were plastinated and cut into serial sections. After staining, these sections were examined under an optical microscope and used to reconstruct a 3-dimensional visualization model., Results: At the intracranial orifice of the jugular foramen, the meningeal dura formed 2 separate dural perforations: the glossopharyngeal meatus and the vagal meatus. The arachnoid extended into 2 dural meatuses and terminated at the inferior ganglion of the glossopharyngeal nerve in the glossopharyngeal meatus and the superior ganglion of the vagus nerve in the vagal meatus. At the intraforaminal part of the jugular foramen, the meningeal dura encased the glossopharyngeal nerve to form a dural sheath while encasing the vagus and accessory nerves to form a dural network. At the extracranial orifice of the jugular foramen, the dural wall of the jugular bulb extended downward to form a dense connective tissue sheath. The initial end of the internal jugular vein invaginated into this sheath and fused with the jugular bulb., Conclusions: Knowledge of the anatomy of the meningeal architecture of the jugular foramen can be helpful in avoiding surgical complications of the lower cranial nerves when this complex area is approached., (Copyright © 2019 Elsevier Inc. All rights reserved.)

We herein report a case of glossopharyngeal neuralgia with repeated syncope caused by the recurrence of esophageal carcinoma. The typical symptoms of glossopharyngeal neuralgia are paroxysmal, stabbing, electric shock-like pain in the pharynx and/or base of the tongue on swallowing and talking. In addition, syncope can also be caused by glossopharyngeal neuralgia. The diagnosis of glossopharyngeal neuralgia is not always easy because of its rarity. In the present case, we suspected that repeated syncope was caused by glossopharyngeal neuralgia due to the recurrence of esophageal carcinoma. Concurrent chemoradiation therapy was effective in reducing the tumor size, which resulted in the complete resolution of the symptoms.

Objective: Ramsay Hunt syndrome (RHS) and Bell palsy (BP) are typically known as facial nerve motor syndromes and are primarily unilateral. The aim of this study was to challenge this assertion, because both conditions are also known to be associated with viruses that typically affect several nerves., Methods: Ten participants with RHS, 12 with BP, all clinically unilateral, and 12 healthy controls were prospectively enrolled. Electrogustometric thresholds were measured bilaterally in the areas of the chorda tympani, the glossopharyngeal, and the major petrosal nerve. Also bilaterally, the taste function was tested using chemogustometry with different tastant concentrations. Again bilaterally, the morphology of the mucosa and the vessels of the anterior fungiform papillae were examined by contact endoscopy. Statistically, RHS and BP participants were compared with the healthy controls, and the paretic sides of RHS and BP were compared pairwise with their mobile sides., Results: Electrogustometrically, perception was reduced bilaterally in RHS (10-19dB, p < 0.001) and BP (3-5dB, p = 0.011-0.030) in all 3 innervation areas. Chemogustometrically, it was also reduced bilaterally in RHS (20-70%) and BP (8-50%). Papillary atrophies were increased 100% in RHS (p = 0.001) and BP (p < 0.001). They were more increased on the paretic side in RHS (30%, p = 0.078) and BP (83%, p < 0.001)., Interpretation: In these 2 clinically unilateral conditions, the gustatory perception and morphology are bilaterally affected, more in RHS and more on the paretic side. BP, known as an isolated motor condition, appears to be a cranial polyneuritis. A bilateral examination and therapeutic gustatory monitoring might follow these observations in evidence-based practice. Ann Neurol 2018;83:807-815., (© 2018 American Neurological Association.)

Objective: The chemoreceptor network, consisting of the glossopharyngeal nerve and carotid body (GPN-CB), is essential for the regulation of blood pH. Its ischemic insults after subarachnoid hemorrhage (SAH), which may contribute to acidosis, have not been investigated., Methods: Twenty-three hybrid rabbits were used. They were divided into 3 groups: 5 as a control group, 5 as a sham group, and the remaining 13 as the study group. Injections included 1 cm 3 serum saline and 1 cm 3 autolog arterial blood into the cisterna magna in the sham and study group, respectively. Blood pH values of all animals were recorded. After 2 weeks, animals were euthanized. The number of normal and degenerated neurons of the carotid bodies (CBs) was counted by stereologic methods and analyzed statistically., Results: Two of 13 rabbits died within the second week. The mean blood pH values were measured as 7.35 ± 0.07 in the control group (n = 5), 7.33 ± 0.06 in the sham group (n = 5), 7.29 ± 0.05 in rabbits with slight acidosis (n = 6), and 7.23 ± 0.02 in rabbits with prominent acidosis (n = 7). In the control group, the average normal neuronal density of the CBs was 6432 ± 790/mm 3 and the degenerated neuron density was 11 ± 3/mm 3 , whereas the degenerated neuronal density in CBs was 35 ± 8/mm 3 in the sham group and 1034 ± 112/mm 3 in the slight acidosis-developed group (n = 6; P < 0.05). Conversely, degenerated neuron density of CBs was 2134 ± 251/mm 3 in the prominent acidosis-developed animals (n = 7; P < 0.005). Interestingly, in the rabbits who died, the degenerated neuron density of the CB was 3160 ± 840/mm 3 ., Conclusion: An inverse relationship between neurodegeneration in the CB and pH values secondary to the disruption of the GPN-CB network after SAH was found, which may contribute to developing acidosis., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Introduction: There are various communications between the superior cervical ganglion (SCG) and the vagus and glossopharyngeal nerves. However, little information exists concerning the origin of these sympathetic ganglion branches at the superior, middle, and inferior regions of the human SCG. The aim of this study was to describe the human SCG in a morphometric manner with the communication with cranial and cervical nerves and supply., Methods: This study characterized 72 SCG samples from 54 elderly Japanese human cadavers (30 males, 24 females; 65-100 years old). The SCG size (length, width, and thickness) and location were measured from the jugular foramen. We also defined the communication branches of the SCG to the vagus, glossopharyngeal, cervical, and accessory nerves at three regions (superior, middle, and inferior regions) of the SCG. Finally, we examined the arrangement and origin of the branch communications in detail and confirmed our observations, using histological sections of the SCG., Results: The SCG in all cadaver donors was detected at the C2 and C3 vertebra levels. The number of SCG branches supplied the communicating branches, such as the carotid branch, communicating branch of the vagus nerve, and glossopharyngeal nerve, were frequently detected in the superior region of the SCG (χ 2  = 587.72, df = 26, p  <   .001). The number of ganglion cells with a large number of neurons per unit area (1 mm 2 ) was most often found in the middle region with shrunken neurons of the SCG compared with other regions., Conclusion: The communication branches of the SCG are mainly connected to the vagus and glossopharyngeal nerves. Characterizing these branches can provide useful data for head and neck ganglion block and surgical treatments.

Glossopharyngeal neuralgia is a rare pain syndrome presenting with paroxysms of pain in the region of the glossopharyngeal nerve. Even more uncommon is the association between glossopharyngeal neuralgia and cardiac syncope. In these patients, the cardiovascular consequences may include bradycardia, hypotension and cardiac arrest. We describe the case of a 40-year-old patient who presented with this rare association of glossopharyngeal neuralgia and syncope. Multiple pauses including one lasting 14 s were noted on ambulatory ECG monitoring. In this case, the patient declined pharmacological treatment with carbamazepine or with permanent pacing and so far has been in remission from symptoms for 3 months., (2016 BMJ Publishing Group Ltd.)

Onset of epilepsy can occur at any age, but it is relatively rare in the elderly. Late onset epilepsy is usually secondary to stroke, tumour, trauma or neurodegenerative disorders. A 62-year-old Indian woman presented with frequent drop attacks sometimes leading to unconsciousness and, rarely, associated with seizure. Her epilepsy work up was unremarkable. As the disease progressed, she was diagnosed as having idiopathic epilepsy, syncope or pseudo-seizure, on different occasions, and was treated at length with no response. Finally, detailed history-taking revealed her as having glossopharyngeal neuralgia leading to syncope and seizures. She subsequently improved. In clinical practice, such rare entities should also be considered for proper management of patients' ailments., (2015 BMJ Publishing Group Ltd.)

Background: The neurologist is very familiar with the painful neuropathies of the trunk and extremities but, generally, to a lesser extent with those of the head and face. Of the latter, the neurologist is particularly familiar with ophthalmic zoster and trigeminal neuralgia., Review Summary: This review deals with neuropathic orofacial pain: (1) to highlight its presentation; and (2) to contrast it with that of neuropathic pain elsewhere in the body, including the head, from which it seems to differ significantly. The reason for the difference is also discussed as well as its implications for the diagnosis of orofacial pain as neuropathic. In the cases of neuropathic orofacial pain presented, the pain followed invasive dental procedures, making it relatively homogenous in terms of its etiology. The cases are contrasted with those of cranial nonorofacial and of noncranial painful neuropathy., Conclusions: It is suggested that the presence of abnormal sensory responses to touch, in the sense of paresthesia, dysesthesia, or allodynia, is a prerequisite for the diagnosis of neuropathic pain, when other, motor or sensory, signs of nerve injury ordinarily guiding the diagnosis are lacking, as is often the case in the face.

Glossopharyngeal and/or vagus nerve involvement is infrequent in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We herein report the case of a 69-year-old Japanese woman who presented with muscle weakness and numbness of the extremities with dysphagia. The serum anti-ganglioside GM1 immunoglobulin IgM antibody levels were elevated, and treatment with intravenous immunoglobulin (IVIg) resulted in a dramatic improvement; the weakness, numbness and dysphagia all resolved. However, relapse comprising dysphagia alone occurred on hospital day 26, and treatment with IVIg again proved extremely effective. IVIg therapy can be effective against cranial nerve involvement in cases of CIDP.

Introduction: The schwannoma of the glossopharyngeal nerve is a rare etiology among the tumor masses developed in the parapharyngeal space., Case Report: We report the case of a 33 years old woman in whom a large schwannoma of the left glossopharyngeal nerve was discovered incidentally on a brain MRI. Respiratory evolutionary prognosis imposed trans-oral surgical treatment., Discussion: We discuss the diagnostic and therapeutic strategy for the benign tumors of the parapharyngeal space., Conclusion: The schwannoma of the glossopharyngeal nerve is a benign rare lesion. The difficulty lies on the surgical strategy and the choice of the approach. The functional suites are marked by difficulty swallowing and require intensive speech therapy.

The patient is a 64-year-old woman who developed a sensation of right ear fullness and hearing loss in early November 2010. Physical examination revealed a painless reddish granular lesion filling in the right external auditory canal. Her right ear was deaf, and no facial palsy was noted. Computed tomography, magnetic resonance imaging and positron emission tomography revealed a middle ear mass extending to the external auditory canal with intracranial invasion causing temporal lobe retraction and inferiorly extending just anterior to the jugular bulb as well. A combination of transmastoid and middle cranial fossa approach along with anterior rerouting of the facial nerve was employed for a near-total removal of the tumor. Based upon the operative findings, it was deemed that the tumor could have arisen from the Jacobson's nerve., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: Cerebrospinal fluid (CSF) secretion may be increased in the early phases of subarachnoid hemorrhage (SAH), possibly via ischemic glossopharyngeal nerve discharges, and decreased due to glossopharyngeal nerve degeneration in the late phase of SAH; but this reflex pathway has not been definitively investigated. We studied the relationship between petrous ganglion of the glossopharyngeal nerve (GPN) and water vesicles of the choroid plexus (CP) in the early and late phases of SAH., Methods: This study was conducted on 30 rabbits, divided into four groups, with five rabbits in the control group (group I), five rabbits in the sham group (Group II), and 20 rabbits in the SAH group. In the SAH group, five of the animals were decapitated after 4 days of cisternal blood injections (Group III), and the other 15 animals were decapitated after 20 days of injections (Group IV). The Petrous Ganglia and CPs of lateral ventricles were removed and stained for stereological analysis., Results: The mean number of follicles per cubic millimeter was 5.3 ± 1.2 the in control group (Group I), 4.5 ± 0.9 in the sham group (Group II), 16.60 ± 3.77 the in early decapitated group (Group III), and 4.30 ± 0.84 in the late decapitated group (Group IV). The mean number of degenerated neuron density of petrous ganglions was 6 ± 2, 50 ± 6, 742 ± 96, and 2.420 ± 350 in the control (Group I), sham (Group II), early decapitated (Group III), and late decapitated group (Group IV), respectively. The mean number of water vesicles was statistically different after SAH between the early decapitated group (group III) and the late decapitated group (group IV) (P < 0.05)., Conclusions: We studied the relationship between petrous ganglion cells of the GPN and water vesicles of CP in the early and late phases of SAH, and found that CP vesicles are increased in the early phase of SAH due to irritation of GPN, and decreased in the late phase due to ischemic insult of the petrous ganglion and parasympathetic innervation of the CP.

Glossopharyngeal neuralgia is much less common in children and more difficult to relief its pain symptoms than the adults. We report an experience with peripheral glycerol injection for the control of pain in eight sick children with glossopharyngeal neuralgia. At the latest follow-up, 5 cases had a complete pain-free result after the treatment. There were two sick children who were recurred within three months, of which one child was respond to additional injections. It is concluded that the peripheral glycerol injection is safe and effective in the control of pain symptom among the children with glossopharyngeal neuralgia., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Object: The glossopharyngeal nerves (GPNs) and carotid bodies (CBs) have an important role in the continuation of the cerebral autoregulation and cardiorespiratory functions. The relationship between degenerative injury of CB and the GPN in subarachnoid hemorrhage (SAH) was studied., Methods: Twenty rabbits were included in this study. Five of them (n=5) were used as control group. The remaining animals (n=15) were exposed to experimental SAH. In the six animals of the SAH group, severe signs of illness were observed, and these six animals were killed in the first week after SAH. Others animals (n=9) were followed for 20 days and then sacrificed. GPNs and CBs were examined and, the live and degenerated GPN axon number, and of CB neuron numbers were stereologically estimated., Results: The mean number of live neurons in CBs was 4206.67±148.35 and live axons of GPNs were 1211.66±14.29 in the animals of the control group. The number of degenerated neurons of CBs was 2065±110.27 and the number of degenerated axons of GPNs was 530.83±43.48 in early killed animals with SAH. The number of degenerated neurons of CBs and the number of degenerated axons of GPNs were found as 1013.89±4184 and 2270.5±134.38 in the living animals with SAH, respectively., Conclusions: High number of degenerated axons of GPN and neurons of CBs of the early killed animals suggest that the mortality in early SAH might be due to GPNs injury secondary to compression of their axons or supplying vessels by the probably herniated brainstem, and secondary denervation injury of CBs, and lung., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Background: The causes of neuralgia are usually not known, but the condition can be caused by an underlying condition., Case Description: A 58-year-old man presented at the accident and emergency department with a 6-week history of continuous nagging pain in the region of his right ear, extending to the lower jaw and the right side of his neck; this worsened in progressive attacks, which were sometimes followed by non-rotatory dizziness and loss of consciousness. This clinical picture lead us to suspect glossopharyngeal neuralgia (GPN) because of the distribution of the pain and the secondary syncope, but the continuous nature of the pain was atypical and a reason for further investigation. This revealed metastatic parotid gland carcinoma with compression of the right glossopharyngeal nerve. Following palliative radiotherapy, the pain improved and there were no further episodes of loss of consciousness., Conclusion: When GPN is suspected and there is continuous pain, or neurological investigations reveal abnormalities, an underlying condition should be considered and additional investigations should be carried out.

The lower cranial nerves innervate the pharynx and larynx by the glossopharyngeal (CN IX) and vagus (CN X) (mixed) nerves, and provide motor innervation of the muscles of the neck by the accessory nerve (CN XI) and the tongue by the hypoglossal nerve (CN XII). The symptomatology provoked by an anomaly is often discrete and rarely in the forefront. As with all cranial nerves, the context and clinical examinations, in case of suspicion of impairment of the lower cranial nerves, are determinant in guiding the imaging. In fact, the impairment may be located in the brain stem, in the peribulbar cisterns, in the foramens or even in the deep spaces of the face. The clinical localization of the probable seat of the lesion helps in choosing the adapted protocol in MRI and eventually completes it with a CT-scan. In the bulb, the intra-axial pathology is dominated by brain ischemia (in particular, with Wallenberg syndrome) and multiple sclerosis. Cisternal pathology is tumoral with two tumors, schwannoma and meningioma. The occurrence is much lower than in the cochleovestibular nerves as well as the leptomeningeal nerves (infectious, inflammatory or tumoral). Finally, foramen pathology is tumoral with, outside of the usual schwannomas and meningiomas, paragangliomas. For radiologists, fairly hesitant to explore these lower cranial pairs, it is necessary to be familiar with (or relearn) the anatomy, master the exploratory technique and be aware of the diagnostic possibilities., (Copyright © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.)

Dysphagia is very common in patients with Parkinson disease (PD) and often leads to aspiration pneumonia, the most common cause of death in PD. Current therapies are largely ineffective for dysphagia. Because pharyngeal sensation normally triggers the swallowing reflex, we examined pharyngeal sensory nerves in PD patients for Lewy pathology.Sensory nerves supplying the pharynx were excised from autopsied pharynges obtained from patients with clinically diagnosed and neuropathologically confirmed PD (n = 10) and healthy age-matched controls (n = 4). We examined the glossopharyngeal nerve (cranial nerve IX), the pharyngeal sensory branch of the vagus nerve (PSB-X), and the internal superior laryngeal nerve (ISLN) innervating the laryngopharynx. Immunohistochemistry for phosphorylated α-synuclein was used to detect Lewy pathology. Axonal α-synuclein aggregates in the pharyngeal sensory nerves were identified in all of the PD subjects but not in the controls. The density of α-synuclein-positive lesions was greater in PD patients with dysphagia versus those without dysphagia. In addition, α-synuclein-immunoreactive nerve fibers in the ISLN were much more abundant than those in cranial nerve IX and PSB-X. These findings suggest that pharyngeal sensory nerves are directly affected by pathologic processes in PD. These abnormalities may decrease pharyngeal sensation, thereby impairing swallowing and airway protective reflexes and contributing to dysphagia and aspiration.

Conclusion: The lingual branches of the glossopharyngeal nerve were most likely to bring not only gustatory nerves to the postsulcal part of the tongue but also autonomic nerves to the small glands and vessels. Tonsillectomy may injure the ganglion or reduce its function due to scar formation after surgery., Objectives: To determine the topographical anatomy of a suggested ganglion cluster along the lingual branches of the glossopharyngeal nerve and to identify the incidence., Methods: In the human pharynges of 12 donated cadavers, we studied the ganglia using routine procedures for paraffin-embedded histology and immunohistochemistry., Results: Near the palatine tonsil, the lingual branches of the glossopharyngeal nerve often contained ganglion cells (in 9 of 12 specimens). The ganglion cells, 20-40 µ in diameter, were sparsely distributed along a 0.5-3.0 mm length of the nerve course attached to the posterolateral aspect of the superior pharyngeal constrictor. Most of these cells were positive for neuronal nitric oxide synthase, while some were positive for tyrosine hydroxylase. Thus, the ganglion was composed of a mixed population of sympathetic and parasympathetic neurons.

Lower cranial nerve schwannomas are benign tumors of the neurolemmocytes of the cranial nerves. Among children, cranial nerve schwannomas are extremely rare and are predominantly associated with neurofibromatosis (NF) type 2. The purpose of the current case report is to describe a unique giant extra- and intracranial foramen jugular schwannoma in a young boy with lower cranial nerve deficits and glossopharyngeal neuralgia syncope syndrome and to review the pertinent literature. In the current case report, we illustrate the course of disease in a 14-year-old boy with a 4-month history of recurrent syncope and a big bulge on the left side of his neck. Audiometry showed deafness of the left ear. Magnetic resonance imaging (MRI) demonstrated a giant unilateral dumbbell-shaped intra- and extracranial foramen jugular schwannoma with a volume of 156 cm3 causing severe brain stem compression and obstructive hydrocephalus. The tumor was removed completely in a two-step surgery. The tumor was confirmed during surgery to originate from the glossopharyngeal nerve. The histological examination revealed the characteristic features of a schwannoma. The MRI 3 months after the second surgery confirmed complete tumor removal. The genetic examination for NF was negative. Review of literature showed that dumbbell-shaped lower cranial nerve schwannomas in the childhood population are rare., (Georg Thieme Verlag KG Stuttgart · New York.)

Objective: Posteroinferior cerebellar artery (PICA) aneurysms are uncommon and have not been well investigated previously. We report our series of 29 ruptured PICA aneurysms with surgical treatment along with the description of the surgical anatomy of the PICA to the lower cranial nerves in cadaveric specimen., Methods: All patients with ruptured PICA aneurysms who were surgically treated at the First Affiliated Hospital of Soochow University during the period from January 1995 to December 2008 were reviewed retrospectively. Data relating to clinical, radiological, and intraoperative findings were analyzed. Forty formalin-fixed cerebellar hemispheres provided the material for the study of describing the detailed surgical anatomic relationship of the PICA to the lower cranial nerves., Results: In our series, ruptured PICA aneurysms reached an incidence of 2.35% of all ruptured intracranial aneurysms. There were 13 aneurysms (44.8%) located in the proximal segment, and 16 (55.2%) located in the distal segment. Of these, 89.7% were saccular, 6.9% fusiform, and 3.4% dissecting aneurysms. Usually, the surgical outcome was influenced by Poor admission grade, the presence of obstructive hydrocephalus and associated distal AVM. In cadaveric specimen, 17.5% of PICAs passed between the glossopharyngeal and vagus nerves, 7.5% between the vagus and accessory nerves, and 62.5% through the rootlets of the accessory nerve., Conclusion: This report summarizes the presentation and outcome of a large series of 29 patients with ruptured PICA aneurysms, and we conclude that ruptured PICA with surgical treatment usually gets well recovered. The study does, however, also demonstrate that the anatomic relationship of the PICA and lower cranial nerves is somehow variable and irregular. Recognition of the findings in cadaveric dissection is essential in treating lesions of this region., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Previously we demonstrated that chronic hypoxia (CH) induces an inflammatory condition characterized by immune cell invasion and increased expression of inflammatory cytokines in rat carotid body. It is well established that chronic inflammatory pain induces the expression of acid-sensitive ion channels (ASIC) in primary sensory neurons, where they contribute to hyperalgesia and allodynia. The present study examines the effect of CH on ASIC expression in petrosal ganglion (PG), which contains chemoafferent neurons that innervate oxygen-sensitive type I cells in the carotid body. Five isoforms of ASIC transcript were increased ∼1.5-2.5-fold in PG following exposure of rats to 1, 3, or 7 days of hypobaric hypoxia (380 Torr). ASIC transcript was not increased in the sympathetic superior cervical ganglion (SCG). In the PG, CH also increased the expression of channel-interacting PDZ domain protein, a scaffolding protein known to enhance the surface expression and the low pH-induced current density mediated by ASIC3. Western immunoblot analysis showed that CH elevated ASIC3 protein in PG, but not in SCG or the (sensory) nodose ganglion. ASIC3 transcript was likewise elevated in PG neurons cultured in the presence of inflammatory cytokines. Increased ASIC expression was blocked in CH rats concurrently treated with the nonsteroidal anti-inflammatory drug ibuprofen (4 mg·kg(-1)·day(-1)). Electrophysiological recording of carotid sinus nerve (CSN) activity in vitro showed that the specific ASIC antagonist A-317567 (100 μM) did not significantly alter hypoxia-evoked activity in normal preparations but blocked ∼50% of the hypoxic response following CH. Likewise, a high concentration of ibuprofen, which is known to block ASIC1a, reduced hypoxia-evoked CSN activity by ∼50% in CH preparations. Our findings indicate that CH induces inflammation-dependent phenotypic adjustments in chemoafferent neurons. Following CH, ASIC are important participants in chemotransmission between type I cells and chemoafferent nerve terminals, and these proton-gated channels appear to enhance chemoreceptor sensitivity.

Purpose: To assess the most effective magnetic resonance imaging (MRI) sequence for the visualization of the 9th, 10th, and 11th cranial nerves (glossopharyngeal, vagus, and accessory nerves, respectively) in their intraforaminal/canalicular courses., Materials and Methods: Balanced fast-field echo (b-FFE), 3D-T2W DRIVE, T2W 2D TSE and post-contrast T1W MRI sequences were all applied and we tried to get the best sequence for the exact assessment of the 9th, 10th, and 11th cranial nerves. Six hundred nerves of 100 patients without symptoms of neurovascular compression were examined using the above sequences. Imaging analysis was graded as: a) nerves analyzed by certainty (score of 2), b) nerves analyzed partially (score of 1), and c) nerves not identified (score of 0)., Results: In all three nerves, the best sequence for the visualization of the cisternal and intraforaminal course was b-FFE, with 58%, 73%, 62%, and all together 64.3% success in showing the fascicles of the 9th-11th nerves. This sequence with a very short time of repetition, symmetrical and balanced gradient around the echo time allowed very fast imaging and a high signal to noise ratio. T2W TSE sequence was superior to the DRIVE T2W sequence in assessing the cisternal and intraforaminal part of all three nerves. Post-contrast T1W sequence was probably the worst sequence in showing all three nerves., Conclusion: b-FFE gradient echo MRI sequence with high spatial resolution is the optimal sequence for determining the courses of 9th-11th cranial nerves.

Gout affecting the axial joints is uncommon; however, its involvement may be complicated by neurological symptoms associated with spinal compression at the affected level. Specific involvement of the odontoid process is even rarer. We report the first case of gout involving the odontoid process with resultant glossopharyngeal (CN IX), vagus (CN X) and hypoglossal (CN XII) nerve palsies., (© 2010 The Authors. International Journal of Rheumatic Diseases © 2010 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd.)

Aim: The aim of this study was to determine the relationship between ischemic neurodegeneration, of the petrosal ganglion of the glossopharyngeal nerve, and BP fluctuations, after subarachnoid hemorrhage (SAH)., Material and Methods: Twenty-four rabbits had their blood pressure and heart rhythms studied daily over 20 days. Then, the histopathology of the petrosal ganglion was examined in all animals. Normal and apoptotic neuron density of the petrosal ganglion and blood pressure values were compared statistically., Results: Mean total volume of the petrosal ganglia was calculated as 0.9 ± 0.34/mm3. BP level of control group was 96.1 ± 2.1 mmHg; 116.5 ± 4 mmHg of mild hypertension (HT) group and 128.1 ± 3.6mmHg in the severe HT group. When the groups were compared to each other they were significantly different. The level of normal-apoptotic neuron in control group was 11,240 ± 802/mm³ -40 ± 6.3/mm³; 9730 ± 148.7/mm³ - 1560 ± 256.2/mm³ in the mild HT group and 6870 ± 378.8/mm³-4240 ± 628.2/mm³ in the severe HT group. When the groups were compared to each other there was significantly difference., Conclusion: Blood pressure variability observed in this study may be explained by ischemic neurodegeneration of petrosal ganglia caused by SAH. The results of this study suggest that petrosal ganglion ischemia has potential implications for the development of hypertension. These findings suggest that new treatment strategies should be considered for the treatment of SAH.

Background: The lower cranial nerves must be identified to avoid iatrogenic injury during skull base and high cervical approaches. Prompt recognition of these structures using basic landmarks could reduce surgical time and morbidity., Methods: The anterior triangle of the neck was dissected in 30 cadaveric head sides. The most superficial segments of the glossopharyngeal, vagus and its superior laryngeal nerves, accessory, and hypoglossal nerves were exposed and designated into smaller anatomic triangles. The midpoint of each nerve segment inside the triangles was correlated to the angle of the mandible (AM), mastoid tip (MT), and bifurcation of the common carotid artery., Results: A triangle bounded by the styloglossus muscle, external carotid artery, and facial artery housed the glossopharyngeal nerve. This nerve segment was 0.06 ± 0.71 cm posterior to the AM and 2.50 ± 0.59 cm inferior to the MT. The vagus nerve ran inside the carotid sheath posterior to internal carotid artery and common carotid artery bifurcation in 48.3% of specimens. A triangle formed by the posterior belly of digastric muscle, sternocleidomastoid muscle, and internal jugular vein housed the accessory nerve, 1.90 ± 0.60 cm posterior to the AM and 2.30 ± 0.57 cm inferior to the MT. A triangle outlined by the posterior belly of digastric muscle, internal jugular vein, and common facial vein housed the hypoglossal nerve, which was 0.82 ± 0.84 cm posterior to the AM and 3.64 ± 0.70 cm inferior to the MT., Conclusions: Comprehensible landmarks can be defined to help expose the lower cranial nerves to avoid injury to this complex region., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Objective: Our surgical results were reviewed to clarify the cause of glossopharyngeal neuralgia (GPN) and the effects of the microvascular decompression (MVD) procedure., Methods: Fourteen cases of idiopathic GPN were operated on through the transcondylar fossa (supracondylar transjugular tubercle) approach. Their clinical data and operative records were retrospectively reviewed., Results: In every case, vascular compression on the glossopharyngeal nerve was found and MVD was performed without any major complications. In 13 of the 14 cases the neuralgia completely disappeared postoperatively. Recurrence of pain was found in 1 case. Offending vessels were the posterior inferior cerebellar artery (PICA) in 10 cases, the anterior inferior cerebellar artery (AICA) in 2 cases, and both arteries in 2 cases. In 10 of the 14 cases, the high-origin PICA formed an upward loop between the glossopharyngeal and vagus nerves, compressing the glossopharyngeal nerve upward. In those cases, the PICA was transposed and fixed to the dura mater by the stitched sling retraction technique, and MVD was very effective., Conclusion: The offending artery was the PICA in most cases. MVD is expected to be very effective, especially when the radiological images show the following 3 findings: 1) high-origin PICA, 2) the PICA making an upward loop, and 3) the PICA coursing the supraolivary fossette. The transcondylar fossa approach is suitable for transposing the PICA by the stitched sling retraction technique, and provides sufficient surgical results.

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., (Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.)

High exposure of the internal carotid artery is a challenging procedure even for experienced surgeons. Access to the distal internal carotid artery is impeded by progressive encroachment of the mastoid process and the angle of the mandible and furthermore at this level the artery is intimately associated with the hypoglossal and glossopharyngeal nerves. If high exposure is needed we prefer preparation of the distal internal carotid artery by dissection of the venter posterior of the digastric muscle and the styloid process including the stylohyoid and stylopharyngeus muscles. This procedure can be advantageously carried out without additional preoperative requirements. The need for high access to the internal carotid artery depends strongly on the underlying pathology: in atherosclerotic disease the rate of high access in our patients is approximately 4.4%, whereas in carotid aneurysms the rate is considerably higher and averages about 15%.

Objective: To examine surgical findings and results of microvascular decompression (MVD) for glossopharyngeal neuralgia (GN)., Methods: Between 1990 and 2007, 31 consecutive patients affected by drug-resistant GN underwent MVD through a retromastoid keyhole in the supine position with the head rotated to the opposite side. A retrospective analysis was performed that paid particular attention to the relationship among surgical technique, pain control and side effects., Results: A vascular compression of the glossopharyngeal nerve was found in all cases. Twenty-eight out of 31 patients (90.3%) were found to be pain free without medication at long-term follow-up (1-17 years, mean 7.5 years). Three patients (9.7%) were found to require medication to control pain paroxysms that were less frequent and less severe than those observed preoperatively. Two patients required repeated surgery for a drug-resistant recurrence of pain for a total of 33 MVDs. We observed no mortality and did not find any long-term surgical morbidity. Cranial nerve impairment, when observed, always resolved in the following months., Conclusions: MVD is a safe and effective treatment for GN in patients of all ages.

Objective: Neurophysiological intraoperative monitoring of the glossopharyngeal nerve has been performed only with needle electrodes inserted into the pharyngeal muscles or soft palate. We describe a noninvasive method of monitoring this cranial nerve., Methods: A 30-year-old man who presented with headache, as well as speech and swallowing difficulty, underwent surgical resection of a right vagus nerve schwannoma. Neurophysiological intraoperative monitoring of multiple lower cranial nerves, including the glossopharyngeal and vagus nerves, was performed., Results: The glossopharyngeal nerve was monitored with an adhesive surface electrode mounted on the cuff of a laryngeal mask airway, and the vagus nerve was monitored with a similar electrode mounted on the endotracheal tube. Successful monitoring allowed separation of the glossopharyngeal nerve from the tumor, and there was no postoperative swallowing deficit., Conclusion: Monitoring of the glossopharyngeal nerve with surface electrodes is possible and reliable, but it must be combined with vagus nerve monitoring.

A 36-year-old woman presented with glossopharyngeal and vagus nerve palsy, which proved to be herpes zoster based on the high titers of Varicella zoster virus antibody in her serum. Thin-section T1-weighted images with contrast media demonstrated swelling and distinct contrast enhancement of the glossopharyngeal and vagus complex, mimicking a tumor. Following MR imaging, the size of the nerve complex returned to normal; however, the contrast enhancement remained longer than the symptoms.

Objective: To examine the microsurgical anatomy of the jugular foramen and correlate anatomical findings to clinical manifestations of jugular foramen schwannomas concerning tumor origin and location., Study Design: Anatomical analysis of jugular foramen was performed by dissection of 25 cadavers (50 sides). By retrospective review of 9 cases of jugular foramen schwannomas surgically treated, the origin and location of tumor were studied., Setting: Tertiary referral center., Main Outcome Measures: The anatomical characteristics of jugular foramen, lower cranial nerves, and inferior petrosal sinus were correlated with the origin and growth pattern of jugular foramen schwannomas., Results: The superior and inferior ganglions of the glossopharyngeal nerve and the superior ganglion of the vagus nerve were located within the jugular foramen. The superior ganglions of the glossopharyngeal and vagus nerves were located superiorly, whereas the inferior ganglion of the glossopharyngeal nerve was found inferiorly in relation to the inferior petrosal sinus orifice. In our series of 9 cases of jugular foramen schwannoma, the most common nerve of origin was the vagus nerve, followed by the glossopharyngeal nerve., Conclusion: The reason for the predilection of the jugular foramen schwannoma for the glossopharyngeal and vagus nerves may be associated with the presence of their ganglions within the jugular foramen. Also, the inferior petrosal sinus may act as a barrier to tumor growth, and the location of the ganglion of tumor origination within the jugular foramen in relation to the inferior petrosal sinus may be correlated to the predominant direction of tumor extension.

Objectives: At present it is believed that the pharyngeal constrictor (PC) muscles are innervated by the vagus (X) nerve and are homogeneous in muscle fiber content. This study tested the hypothesis that adult human PCs are divided into 2 distinct and specialized layers: a slow inner layer (SIL), innervated by the glossopharyngeal (IX) nerve, and a fast outer layer (FOL), innervated by nerve X., Methods: Eight normal adult human pharynges (16 sides) obtained from autopsies were studied to determine 1) their gross motor innervation by use of Sihler's stain; 2) their terminal axonal branching by use of acetylcholinesterase (AChE) and silver stain; and 3) their myosin heavy chain (MHC) expression in PC muscle fibers by use of immunocytochemical and immunoblotting techniques. In addition, the specialized nature of the 2 PC layers was also studied in developmental (newborn, neonate, and senescent humans), pathological (adult humans with idiopathic Parkinson's disease [IPD]), and comparative (nonhuman primate [adult macaque monkey]) specimens., Results: When nerves IX and X were traced from their cranial roots to their intramuscular termination in Sihler's-stained specimens, it was seen that nerve IX supplied the SIL, whereas branches of nerve X innervated the FOL in the adult human PCs. Use of AChE and silver stain confirmed that nerve IX branches supplying the SIL contained motor axons and innervated motor end plates. In addition to distinct motor innervation, the SIL contained muscle fibers expressing slow-tonic and alpha-cardiac MHC isoforms, whereas the FOL contained muscle fibers expressing developmental MHC isoforms. In contrast, the FOL became obscured in the elderly and in the adult humans with IPD because of an increased proportion of slow muscle fibers. Notably, distinct muscle fiber layers were not found in the human newborn and nonhuman primate (monkey), but were identified in the 2-year-old human., Conclusions: Human PCs appear to be organized into functional fiber layers, as indicated by distinct motor innervation and specialized muscle fibers. The SIL appears to be a specialized layer unique to normal humans. The presence of the highly specialized slow-tonic and alpha-cardiac MHC isoforms, together with their absence in human newborns and nonhuman primates, suggests that the specialization of the SIL maybe related to speech and respiration. This specialization may reflect the sustained contraction needed in humans to maintain stiffness of the pharyngeal walls during respiration and to shape the walls for speech articulation. In contrast, the FOL is adapted for rapid movement as seen during swallowing. Senescent humans and patients with IPD are known to be susceptible to dysphagia; and this susceptibility may be related to the observed shift in muscle fiber content.

Background: Baroreceptor reflexes are regulated by nerve terminals of the glossopharyngeal and vagal nerves. The body of pressure-sensitive neurons of these nerves is located in the petrosal ganglion of both nerves. We examined whether there is a relationship between the neuron numbers of the inferior ganglion of the glossopharyngeal nerve and blood pressure values., Methods: Petrosal ganglions were examined in 18 male hybrid rabbits divided into three equal groups: Group A normotensive (TA=90-100 mmHg), Group B hypertensive (TA>100 mmHg); and Group C hypotensive (TA<90 mmHg). After examination of blood pressure for one week, all animals were sacrificed, and the petrosal ganglions extracted bilaterally and examined histopathologically using the physical dissector method., Results: The mean (+/-SD) neuronal density was: Group A 8700+/-200, Group B 7800+/-250 and Group C 9800+/-300, respectively. The difference between the groups B and C as compared to A was significant (p<0.01) while the difference between Groups B and C was highly significant (p<0.001)., Conclusions: An inverse relationship was noticed between the neuronal density in the petrosal ganglion and blood pressure values with potential implications in the study of the etiology of hypertension.

The vagal and glossopharyngeal sensory ganglia and their peripheral tissues were examined in wild type and dystonia musculorum mice to assess the effect of dystonin loss of function on chemoreceptive neurons. In the mutant mouse, the number of vagal and glossopharyngeal sensory neurons was severely decreased (70% reduction) when compared with wild type littermates. The mutation also reduced the size of the circumvallate papilla (45% reduction) and the number of taste buds (89% reduction). In addition, immunohistochemical analysis demonstrated that the dystonin mutation reduced the number of PGP 9.5-, calcitonin gene-related peptide-, P2X3 receptor- and tyrosine hydroxylase-containing neurons. Their peripheral endings also decreased in the taste bud and epithelium of circumvallate papillae. These data together suggest that the survival of vagal and glossopharyngeal sensory neurons is dependent upon dystonin.

Collet-Sicard is a rare syndrome that consists of the palsy of all the lower four cranial nerves. We describe this entity in relation with a schwannoma of the hypoglossal nerve. A 45 year-old-patient was admitted to the hospital referring hoarseness and difficulty in swallowing for two weeks. On neurological examination, the patient exhibited palsy of the ninth, tenth, eleventh and twelfth nerves. This is a syndrome of Collet-Sicard. The cranial MRI revealed a small intracranial and extracranial tumor adjacent to the hypoglossal foramen. The tumor involved the jugular foramen and was moderately enhanced with gadolinium The patient underwent surgical removal. The pathologic examination of the surgical specimen confirmed the diagnosis of a schwannoma of the hypoglossal nerve. We have carried out a research of the Collet-Sicard syndrome and of its aetiology. Although schwannoma the hypoglossal nerve is a rare disorder we consider that this entity should be included in the differential diagnosis of the Collet-Sicard syndrome.

MR cisternography has been introduced for use in neuroradiology. This method is capable of visualizing tiny structures such as blood vessels and cranial nerves in the cerebrospinal fluid (CSF) space because of its superior contrast resolution. The cranial nerves and small vessels are shown as structures of low intensity surrounded by marked hyperintensity of the CSF. In the present study, we evaluated visualization of the lower cranial nerves (glossopharyngeal, vagus, and accessory) by the three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequence and multiplanar reformation (MPR) technique. The subjects were 8 men and 3 women, ranging in age from 21 to 76 years (average, 54 years). We examined the visualization of a total of 66 nerves in 11 subjects by 3D-FIESTA. The results were classified into four categories ranging from good visualization to non-visualization. In all cases, all glossopharyngeal and vagus nerves were identified to some extent, while accessory nerves were visualized either partially or entirely in only 16 cases. The total visualization rate was about 91%. In conclusion, 3D-FIESTA may be a useful method for visualization of the lower cranial nerves.

Objective: To report a case of an extraskeletal myxoid chondrosarcoma (EMC) arising from the jugular foramen. EMCs are tumors usually seen in the deep soft tissues of the extremities and are rarely seen within the intracranial cavity. The histological differential diagnosis includes chordoma, conventional chondrosarcoma and chordoid meningioma, among others. A distinguishing feature of EMC is their characteristic reciprocal translocation t(9;22)(q22;q12)., Material: A 63-year-old man presented with progressive hearing loss and gait imbalance. Magnetic resonance imaging showed a heterogeneously enhancing 2.4 cm mass in the cerebellopontine angle. A right far lateral transcondylar skull base approach with gross total removal of the tumor was performed. Intraoperative findings showed that the mass appeared to arise from the glossopharyngeal nerve within the jugular foramen., Method: Histology, immunohistochemistry, and fluorescence in situ hybridization studies were performed., Results: Histological and immunohistochemical studies were compatible with the diagnosis of EMC. Fluorescence in situ hybridization studies showed disruption of the EWS gene locus at 22q12 and added further support to the diagnosis., Conclusions: We report a rare case of EMC arising from the jugular foramen, and the diagnosis of EMC can be supported by confirmation of disruption of the EWS gene locus.