Search

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.)

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 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.

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.)

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.

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.

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.

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.

The substantia nigra is not the induction site in the brain of the neurodegenerative process underlying Parkinson disease (PD). Instead, the results of this semi-quantitative study of 30 autopsy cases with incidental Lewy body pathology indicate that PD in the brain commences with the formation of the very first immunoreactive Lewy neurites and Lewy bodies in non-catecholaminergic neurons of the dorsal glossopharyngeus-vagus complex, in projection neurons of the intermediate reticular zone, and in specific nerve cell types of the gain setting system (coeruleus-subcoeruleus complex, caudal raphe nuclei, gigantocellular reticular nucleus), olfactory bulb, olfactory tract, and/or anterior olfactory nucleus in the absence of nigral involvement. The topographical parcellation of the nuclear grays described here is based upon known architectonic analyses of the human brainstem and takes into consideration the pigmentation properties of a few highly susceptible nerve cell types involved in PD. In this sample and in all 58 age- and gender-matched controls, Lewy bodies and Lewy neurites do not occur in any of the known prosencephalic predilection sites (i.e. hippocampal formation, temporal mesocortex, proneocortical cingulate areas, amygdala, basal nucleus of Meynert, interstitial nucleus of the diagonal band of Broca, hypothalamic tuberomamillary nucleus).

It has been proposed that Sudden Infant Death Syndrome (SIDS) might occur as a consequence of a developmental deficit associated with the cardiorespiratory and arousal control centers located within the brainstem. In this study 1.1' dioctadecyl-3,3,3',3-tetramethylindocarbocyanine perchlorate (DiI) was used to investigate the trajectories of the glossopharyngeal and vagus nerves which carry essential afferent and efferent fiber tracts associated with cardiac and respiratory control and of the hypoglossal nerve which innervates the tongue, in SIDS (n = 14) and control (n = 7) infants. The postnatal development of the trajectories of these nerves was examined in non-SIDS brains and comparisons were then made with age-matched SIDS brains. The mean profile area of hypoglossal and dorsal motor neurons were also assessed. In controls, no major alterations were observed in the trajectories of axon bundles with increasing age (7 wk to 2 yr) in each of the nerves investigated although axon bundles appeared to increase in thickness with age. In SIDS cases (2 wk to 44 wk), the trajectories of the cranial nerves were not different from those seen in age-matched control cases. The mean profile area of hypoglossal and dorsal motor neurons was not significantly different between control and SIDS infants. We conclude that the DiI tracing technique can be used successfully to trace the pathways of cranial nerves in human infant fixed-tissue. Furthermore, if functional differences exist between SIDS and non-SIDS brains in the control of respiration, circulation, or arousal they do not appear to be related to markedly reduced or aberrant projections of the glossopharyngeal, vagus, or hypoglossal nerves.

Clinical studies by Jannetta and others implicated that arterial compression of the root entry zone (REZ) of cranial nerves IX and X at the left ventrolateral medulla may represent an etiological factor for arterial hypertension. Positive therapeutic outcomes with reduction of hypertension in 42 of Jannetta's patients by microsurgical decompression initiated further studies. Experience of our group points in the same direction. Four patients treated by microvascular decompression showed lasting reduction of severe hypertension postoperatively. In our previous comparing postmortem explorations and angiographic studies essential hypertensive patients displayed signs of left sided neurovascular compression in opposition to normotone controls or renal hypertensive patients. By using MR-imaging we are currently developing a method of detecting neurovascular compression syndromes in hypertensive patients suitable for surgical management.

Cranial nerves IX (glossopharyngeal), X (vagus), and XI (spinal accessory) are intimately related. Therefore, for imaging purposes they are best considered as a unit rather than as individual structures. The XIth nerves are not considered true cranial nerves because they are formed by cephalic (bulbar) and caudal (spinal) divisions. The XIIth (hypoglossal) nerves arise inferiorly to the above mentioned cranial nerves and exit the skull via a different set of foramina. Because the course of these four pairs of cranial nerves extends from the base of the skull to the upper thorax, a combination of both magnetic resonance imaging (MRI) and computed tomography is needed for optimal evaluation. This article will emphasize the use of MRI when appropriate.

Purpose: To determine the clinical usefulness of MR imaging to screen for vascular compression of the lateral medulla, considered by some to be responsible for neurogenic hypertension., Methods: MR images and clinical records of 120 adults who had received brain MR imaging for any reason were divided into two groups: group 1 (n = 60) consisted of patients with essential hypertension and group 2 (n = 60) included patients who lacked a diagnosis of hypertension. No patient manifested symptomatic cranial neuralgias. The root entry zone of cranial nerves IX and X into the left lateral medulla was examined by MR imaging for proximity to the ipsilateral vertebral artery or its branches. Images lacking any contact between visible vascular structures and the root entry zone were recorded as normal. Vascular compression was graded according to the degree of proximity to the root entry zone. Lateral medullary contact only (grade I), contact and depression (grade II), or lower brain stem displacement or rotation (grade III) of the root entry zone were recorded in both hypertensive and normotensive patients. Among hypertensive patients, additional data were gathered from electrocardiographic, echocardiographic, and urinary protein reports., Results: We found compression in 34 (57%) of the patients from group 1 and in 33 (55%) of the patients from group 2. Compressions in group 1 were grade I in 22 (37%) of the patients, grade II in 8 (45%), grade II in 4 (7%), and grade III in 2 (3%). There were no statistically significant differences in MR findings between the two groups. Among group 1 patients, MR grading did not predict end-organ changes in the heart (left axis deviation and left ventricular hypertrophy) or kidneys (proteinuria)., Conclusion: Vascular compression of the root entry zone of cranial nerves IX and X into the left lateral medulla is not an adequate lesion to produce systemic hypertension. This finding is as common among normotensive patients as among hypertensive populations. Neither the presence nor the severity of changes in the root entry zone on MR images increases the occurrence of common end-organ responses in the heart or kidneys among hypertensive patients. MR screening is not warranted among hypertensive patients lacking symptomatic cranial neuralgias.

Microsurgical resection is the primary management approach for patients with intracranial schwannomas. Recent studies have demonstrated that stereotactic radiosurgery is an effective therapeutic modality for patients with acoustic schwannomas. To define the role of radiosurgery in the management of patients with nonacoustic schwannomas, we reviewed the results of gamma unit stereotactic radiosurgery in six patients with trigeminal and five patients with jugular foramen region schwannomas. No patient with a trigeminal schwannoma demonstrated tumor growth during a mean follow-up of 21 months (range, 7-35 mo), whereas one patient with a jugular foramen region schwannoma had an increase in tumor size 7 months after radiosurgery. No new cranial nerve or brain stem deficits were noted in either patient group after radiosurgery. In this early experience, radiosurgery proved an effective primary or adjuvant technique for selected patients with schwannomas of the trigeminal, glossopharyngeal, or vagus nerves. Using our described method, the safety of radiosurgery was demonstrated on the brain stem, regional cranial nerves, and especially those cranial nerves intimately associated with the tumor.