Treatment of syncope in tongue cancer with palliative chemotherapy in the intensive care unit: A case report

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.

Meningeal Architecture of the Jugular Foramen: An Anatomic Study Using Plastinated Histologic Sections

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.

Glossopharyngeal Neuralgia with Syncope Caused by Recurrence of Esophageal Squamous Cell Carcinoma

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.

Relapse with Dysphagia in a Case of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

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.

[A post-styloid mass revealing a parapharyngeal schwannoma]

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.

Changes in number of water-filled vesicles of choroid plexus in early and late phase of experimental rabbit subarachnoid hemorrhage model: the role of petrous ganglion of glossopharyngeal nerve

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 and syncope]

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.

A ganglion cell cluster along the glossopharyngeal nerve near the human palatine tonsil

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.

Microvascular decompression for glossopharyngeal neuralgia: a long-term retrospectic review of the Milan-Bologna experience in 31 consecutive cases

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.

Neuromuscular specializations within human pharyngeal constrictor muscles

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 Role of Neuron Numbers of the Petrosal Ganglion in the Determination of Blood Pressure: An Experimental Study

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 survival of vagal and glossopharyngeal sensory neurons is dependent upon dystonin

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.

[Schwannoma of the hypoglossal nerve presenting as a syndrome of Collet-Sicard]

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.

[Visualization of the lower cranial nerves by 3D-FIESTA]

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.

Extraskeletal myxoid chondrosarcoma of the jugular foramen

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.

Preoperative visualization of microvascular compression of cranial nerve IX using constructive interference in steady state magnetic resonance imaging in glossopharyngeal neuralgia

We report a case of successfully treated glossopharyngeal neuralgia, in whom preoperative magnetic resonance imaging (MRI) with a sequence of constructive interference in steady-state (CISS) precisely delineated microvascular compression to the glossopharyngeal nerve at its cisternal portion. A 70-year old female experienced paroxysmal and excruciating pain, starting in the right ear and descending to the tongue and throat. The pain was brief, burning and triggered by swallowing food and drinks. Preoperative CISS-MRI delineated a small vascular loop compressing the glossopharyngeal nerve at its cisternal portion. The patient was diagnosed with glossopharyngeal neuralgia, and then, microvascular decompression surgery was performed. Intraoperative inspection revealed that the glossopharyngeal nerve root was in contact with a small arterial loop at its cisternal portion and was deformed as demonstrated by preoperative CISS-MRI. The glossopharyngeal nerve was displaced using a piece of Teflon felt, freeing it from the arterial loop compression. The patient's neuralgia resolved immediately after surgery. During a period of 2-years follow up, no recurrence of the neuralgia has occurred. The usefulness of CISS-MRI for the diagnosis of glossopharyngeal neuralgia is discussed.

Exophytic pilocytic astrocytoma of the brain stem in an adult with encasement of the caudal cranial nerve complex (IX?XII): presurgical anatomical neuroimaging using MRI

We describe a rare case of adult pilocytic astrocytoma in which exophytic growth from the brain stem presented as a right cerebellopontine angle mass. An initial MRI examination using T2- and T1-weighted images without and with contrast suggested the diagnosis of schwannoma. Subsequent use of 3D CISS (three-dimensional constructive interference in steady state) and T1-weighted contrast-enhanced 3D MP-RAGE (three-dimensional magnetization prepared rapid acquisition gradient echo) sequences led to the diagnosis of an exophytic brain stem tumor, documented the precise relationships of the tumor to cranial nerve VIII, revealed encasement of cranial nerves IX-XII (later confirmed intraoperatively), and provided the proper basis for planning surgical management.

Anatomic landmarks of the glossopharyngeal nerve: a microsurgical anatomic study

OBJECTIVE

Compared with other lower cranial nerves, the glossopharyngeal nerve (GPhN) is well hidden within the jugular foramen, at the infratemporal fossa, and in the deep layers of the neck. This study aims to disclose the course of the GPhN and point out landmarks to aid in its exposure.

METHODS

The GPhN was studied in 10 cadaveric heads (20 sides) injected with colored latex for microsurgical dissection. The specimens were dissected under the surgical microscope.

RESULTS

The GPhN can be divided into three portions: cisternal, jugular foramen, and extracranial. The rootlets of the GPhN emerge from the postolivary sulcus and course ventral to the flocculus and choroid plexus of the lateral recess of the fourth ventricle. The nerve then enters the jugular foramen through the uppermost porus (pars nervosa) and is separated from the vagus and accessory nerves by a fibrous crest. The cochlear aqueduct opens to the roof of this porus. On four sides in the cadaver specimens (20%), the GPhN traversed a separate bony canal within the jugular foramen; no separate canal was found in the other cadavers. In all specimens, the Jacobson's (tympanic) nerve emerged from the inferior ganglion of the GPhN, and the Arnold's (auricular branch of the vagus) nerve also consisted of branches from the GPhN. The GPhN exits from the jugular foramen posteromedial to the styloid process and the styloid muscles. The last four cranial nerves and the internal jugular vein pass through a narrow space between the transverse process of the atlas (C1) and the styloid process. The styloid muscles are a pyramid shape, the tip of which is formed by the attachment of the styloid muscles to the styloid process. The GPhN crosses to the anterior side of the stylopharyngeus muscle at the junction of the stylopharyngeus, middle constrictor, and hyoglossal muscles, which are at the base of the pyramid. The middle constrictor muscle forms a wall between the GPhN and the hypoglossal nerve in this region. Then, the GPhN gives off a lingual branch and deepens to innervate the pharyngeal mucosa.

CONCLUSION

Two landmarks help to identify the GPhN in the subarachnoid space: the choroid plexus of the lateral recess of the fourth ventricle and the dural entrance porus of the jugular foramen. The opening of the cochlear aqueduct, the mastoid canaliculus, and the inferior tympanic canaliculus are three landmarks of the GPhN within the jugular foramen. Finally, the base of the styloid process, the base of the styloid pyramid, and the transverse process of the atlas serve as three landmarks of the GPhN at the extracranial region in the infratemporal fossa.

Unusual complication of tonsillectomy: taste disturbance and the lingual branch of the glossopharyngeal nerve

Taste disturbance is an unusual complication of tonsillectomy of which there are very few reports in the literature. The possible causes of this rare complication are: (1) direct or indirect damage to the glossopharyngeal nerve or its lingual branch (LBGN), (2) lack of dietary zinc, and (3) habitual drug intake. We report a 41-year-old man, who complained of taste disturbance following tonsillectomy that was performed for chronic tonsillitis and unilateral (left) tonsillar hypertrophy. During surgery, hypertrophic tonsils were found to be sited deeply into the tonsillar bed, especially at the lower pole of the left tonsil. Pathologic examination following tonsillectomy revealed a keratinous cyst and chronic infection at the left tonsil, and lymphoid hyperplasia and chronic infection at the right tonsil. Although his complaint had been getting better, qualitative examination of his taste function revealed bilateral impairment of the sense of sweet taste on the base of his tongue two months after the surgery, and a taste disturbance of sweet taste on the left side persisted the 10th month after the surgery. His serum zinc value was normal, and he did not take any drug that could affect his sense of taste. Depending on the literature data, possible indirect damage to the LBGN was suspected as the cause of the taste disturbance. This symptom may be reversible within two years after tonsillectomy, but it can also be irreversible. Therefore, tonsillectomy should be performed with minimal trauma to the tonsillar bed, especially when there is an additional pathology extending into the lower pole, and such a patient should be informed of the risk of post-operative taste disturbance after tonsillectomy as being one of the rare complications of this surgery.

Anatomy of the tonsillar bed: topographical relationship between the palatine tonsil and the lingual branch of the glossopharyngeal nerve

Taste disturbance may result from injury to the lingual branch of the glossopharyngeal nerve (LBGN) during tonsillectomy. Because an understanding of the anatomy of this nerve is required in order to avoid injuring it, a gross, histologic anatomic study was undertaken of the topographical relationship between the LBGN and the muscle layer of the palatine tonsillar bed. Evaluation of 107 sides of 83 Japanese adult cadavers (aged 27-88 years) confirmed that the muscular composition and lamination of the tonsillar bed do not change with age or pathological conditions such as inflammation. In about a quarter (23.4%) of cases, the LBGN traveled inferior to the styloglossus muscle and lateral to the superior constrictor pharyngeal muscle over its whole course to the base of the tongue, so that the palatine tonsil was clearly separated from the LBGN. In 55.1% of cases, however, the muscle lining of the tonsillar bed was discontinuous and thin muscle bundles, derived from the stylopharyngeus, palatopharyngeus or superior constrictor pharyngeal muscle, partially covered the tonsillar capsule externally. Moreover, in 21.5% of cases the LBGN was firmly adherent to the tonsillar capsule, due to the complete absence of muscles lining the tonsillar bed. In these cases, and also probably in a similar percentage of patients undergoing tonsillectomy, taste disturbance may occur on removal of the hypertrophic tonsillar capsule. Therefore, minimal disturbance of the tonsillar bed is recommended in all cases of tonsillectomy.

Gabapentin treatment of glossopharyngeal neuralgia: a follow-up of four years of a single case

Glossopharyngeal neuralgia causes intermittent, lancinanting pain, involving the posterior tongue and pharynx, with radiation to deep ear structures. There are different pharmacological therapies which are tried to treat the neuralgia: carbamazepin, phenytoin, diazepam, amytriptyline, phenobarbital, ketamine, and baclofen; there are also surgical treatment proposed in order to cure the neuralgia such as vascular decompression or electrical stimulation of the motor cortex controlateral to the pain area. We report a single case of a patient with glossopharyngeal neuralgia treated with Gabapentin, the first described, who was followed up for four years, who respond completely to the therapy and did not complain from side effects, reducing even the reminiscence of pain during the second cluster of crisis.

Cortical representation of Hering's nerve: a possible anatomical pathway for seizure cessation following electrical stimulation

OBJECTIVE

We recently found that Hering's nerve stimulation (HNS) effectively blunts seizure activity. This study characterizes the cortical areas that are activated by HNS.

METHODS

Hering's nerve (HN) was stimulated in 3 dogs and 6 pigs, and then the brains of the animals were removed. The insular and mesial temporal cortices were removed and evaluated for increased neuronal activity by examining Fos-like activity.

RESULTS

In both the dogs and pigs, Fos activity was elevated in the anterior insular and mesial temporal cortices. Increased cortical activity was not noted in adjacent areas such as the frontal cortex.

CONCLUSION

This study demonstrates that the mesial temporal and anterior insular cortices are selectively activated by stimulation of HN, thus suggesting cortical loci at which HNS might blunt seizure activity.

Imaging of the lower cranial nerves

Knowledge of the nuclear origins and the normal course of the cranial nerves, and their functional components, is important in any evaluation of cranial neuropathy. MR imaging allows detailed evaluation of cranial nerve anatomy and pathology. Newer MR sequences allow more sensitive methods of detecting pathology and determining the cause of cranial neuropathy. The correlation of clinical findings with MR images will allow for more definitive evaluation.

Eagle syndrome: entrapment of the glossopharyngeal nerve? Case report and review of the literature

Eagle syndrome is characterized by unilateral pain in the oropharynx, the side of the face, and the earlobe. It is caused by an elongated styloid process; resection of the elongated process eliminates the pain. Although quite rare, this syndrome is well represented in the oral, ear, nose, and throat surgery literature. In the neurosurgical literature, on the other hand, there is little if any mention of Eagle syndrome. The author presents a case of a woman who suffered from severe pain in the throat, the side of the face, and the ear. After the diagnosis of Eagle syndrome was made based on radiographic findings and was confirmed using a local anesthetic block, resection of the elongated styloid process was performed, resulting in complete and lasting pain relief. Eagle syndrome, which is caused by compression of the glossopharyngeal nerve as it passes the elongated styloid process, may be classified as an entrapment syndrome deserving of neurosurgical attention. The goal of this report is to familiarize neurosurgeons with Eagle syndrome and its diagnostic work up and treatment.

Investigations using magnetic resonance imaging: is neurovascular compression present in patients with essential hypertension?

OBJECT

A possible relationship between neurovascular compression of the rostral ventrolateral medulla oblongata (RVLM) and essential hypertension is investigated using a specifically designed magnetic resonance (MR) imaging method. In conjunction with the ninth and 10th cranial nerves, baroreceptor afferents enter the RVLM, which represents a crucial relay for regulation of autonomic blood pressure. In 1985 Jannetta and coworkers proposed a causal relationship between essential hypertension and intraoperatively observed neurovascular compression of the left RVLM.

METHODS

Currently, MR imaging is the method of choice for the assessment of neurovascular relationships at the brainstem. By obtaining axial images of a thin-slice turbo inversion-recovery sequence and three-dimensional time-of-flight MR angiograms (fast imaging with steady-state precision), the authors documented the occurrence of neurovascular contacts with the RVLM at the level of the root entry zones (REZs) of the ninth and 10th cranial nerves in 25 patients with essential hypertension, 30 normotensive volunteers, and 10 patients with renal hypertension. Neurovascular contacts with the REZ at the left RVLM were found in 32% of patients with essential hypertension, 37% of normotensive volunteers, and 20% of patients with renal hypertension. In total, neurovascular contacts on either side of the RVLM were documented in 68% of patients with essential hypertension, 53% of normotensive volunteers, and 50% of patients with renal hypertension.

CONCLUSIONS

The results do not support the theory of neurovascular compression in cases of essential hypertension. Findings of neurovascular contacts on MR images are not indications for decompression surgery. For further clarification, however, prospective MR imaging studies should be considered in young patients with essential hypertension in whom the history of high blood pressure is short.

Imaging of the glossopharyngeal, vagus, and accessory nerves

The origination and course of the glossopharyngeal, vagus and accessory cranial nerves explains their function and localizes pathology. Abnormalities of these lower cranial nerves may be intrinsic or extrinsic and is due to a multiplicity of disease processes. The clinical presentation of the involved cranial nerve helps to guide imaging evaluation. Magnetic resonance imaging without and with contrast is the mainstay of imaging of cranial nerves IX, X and XI pathology, but computed tomography provides substantial information as well.

Where does parkinson disease pathology begin in the brain?

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).

Cranial root injury in glossopharyngeal neuralgia: electron microscopic observations. Case report

Optical and electron microscopic examinations were made of a biopsy sample of the ninth and 10th cranial nerves obtained during posterior fossa surgery for the relief of pain in a patient suffering from glossopharyngeal neuralgia (GN). Pathological findings, which were restricted to a small fraction of fascicles in the nerves, included large patches of demyelinated axons in close membrane-to-membrane apposition to one another and zones of less severe myelin damage (dysmyelination). These observations, in the light of similar morphological changes observed in biopsy samples excised from patients with trigeminal neuralgia, and new information on the pathophysiological characteristics of injured peripheral nerve axons, can account for much of the symptomatology of GN.

Tracing cranial nerve pathways (glossopharyngeal, vagus, and hypoglossal) in SIDS and control infants: a DiI study

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.

Jugular foramen syndrome caused by varicella zoster virus infection in a patient with ipsilateral hypoplasia of the jugular foramen

We report a patient with acute cranial polyneuropathy with unilateral involvement of the ninth, tenth, and eleventh cranial nerves. Although this patient lacked a typical cutaneous herpetic manifestation, elevated levels of IgM and IgG antibodies to varicella zoster virus (VZV) in both the serum and cerebrospinal fluid confirmed the clinical diagnosis of VZV infection and zoster sine herpete. Coexisting hypoplasia of the ipsilateral jugular foramen was detected using three-dimensional, surface-rendering displays reconstructed from the cranial helical CT scan. The patient recovered almost completely following treatment with an anti-inflammatory corticosteroid. Anatomical narrowing of the jugular foramen in this patient may have contributed to entrapment of the affected nerves at their passage through the foramen.

Neurogenic hypertension. A new MRI protocol for the evaluation of neurovascular compression of the cranial nerves IX and X root-entry zone

OBJECTIVE

Neurovascular compression of the rostral ventrolateral medulla (RVLM) has been implicated in the pathogenesis of essential hypertension. Although MRI has been widely used to evaluate the morphologic relation of structures in this region, spatial resolution of the previously used techniques was limited. This article describes the use of a new MRI protocol that combines two sequences with improved spatial resolution and complementary image information as well as a set of defined criteria for image analysis.

METHODS

MRI of the brain stem was performed in 60 hypertensive and 50 normotensive subjects using a 3D-CISS and a 3D-FISP-MRA sequence. Neurovascular contact in the RVLM was independently assessed by four readers using predefined criteria and compared with a consensus finding. Agreement was expressed by kappa statistics on a 0 to 1 scale.

RESULTS

Left-sided neurovascular contact within the RVLM was found in 13 (22%) hypertensive and 6 (12%) control subjects. The inter-reader agreement for positive and negative findings ranged from 0.47 to 0.79; agreement to the consensus finding ranged from 0.65 to 0.90.

CONCLUSIONS

The combination of 3D-CISS and arterial flow-sensitive 3D-FISP, together with the evaluation criteria defined in this study, can be used for describing the finer anatomic features of the brain stem, and in particular for investigation of neurovascular contact of the IX/X cranial nerve root-entry zone. The high quality of images and the substantial or almost perfect reader-consensus agreement should make this protocol useful for future investigations of the neurovascular compression syndrome in patients with essential hypertension and possibly in other neurovascular compression syndromes, such as trigeminal neuralgia and hemifacial spasm.

The glossopharyngeal nerve, glossopharyngeal neuralgia and the Eagle's syndrome--current concepts and management

Glossopharyngeal neuralgia is not just a painful condition. At times, it may be life-threatening as a result of associated cardiovascular consequences. Even in the absence of life-threatening consequences, it can be a severe debilitating disease with depression, suicidal tendencies, fear of swallowing, loss of weight and under-nutrition. The treatment for glossopharyngeal neuralgia and Eagle's syndrome has evolved over time. This review summarises the scientific evidence and philosophy about current management and therapy. Emphasis is placed on the importance of excluding secondary causes of glossopharyngeal neuralgia before embarking on nerve section through the posterior cranial fossa approach. The Eagle's syndrome due to an elongated styloid process is the most important cause of secondary glossopharyngeal neuralgia. Stylectomy is effective and should be considered before embarking on any neurosurgical procedure. Peripheral cervical and trans-tonsillar approaches to the glossopharyngeal nerve are also discussed.

Chemoafferent degeneration and carotid body hypoplasia following chronic hyperoxia in newborn rats

1. To define the role of environmental oxygen in regulating postnatal maturation of the carotid body afferent pathway, light and electron microscopic methods were used to compare chemoafferent neurone survival and carotid body development in newborn rats reared from birth in normoxia (21 % O2) or chronic hyperoxia (60 % O2). 2. Four weeks of chronic hyperoxia resulted in a significant 41 % decrease in the number of unmyelinated axons in the carotid sinus nerve, compared with age-matched normoxic controls. In contrast, the number of myelinated axons was unaffected by hyperoxic exposure. 3. Chemoafferent neurones, located in the glossopharyngeal petrosal ganglion, already exhibited degenerative changes following 1 week of hyperoxia from birth, indicating that even a relatively short hyperoxic exposure was sufficient to derange normal chemoafferent development. In contrast, no such changes were observed in the vagal nodose ganglion, demonstrating that the effect of high oxygen levels was specific to sensory neurones in the carotid body afferent pathway. Moreover, petrosal ganglion neurones were sensitive to hyperoxic exposure only during the early postnatal period. 4. Chemoafferent degeneration in chronically hyperoxic animals was accompanied by marked hypoplasia of the carotid body. In view of previous findings from our laboratory that chemoafferent neurones require trophic support from the carotid body for survival after birth, we propose that chemoafferent degeneration following chronic hyperoxia is due specifically to the loss of target tissue in the carotid body.

[Via the submandible: cervical glossopharyngeal neurectomy and histomorphology findings]

Three cases of serious idiopathic glossopharyngeal neuralgia are reported. They were treated with cervical glossopharyngeal neurectomy via the submandible. The resected nerve tissue was detected under light and microscope. The pathological change was found in the form of myelinoclasis. The present article is intended to introduce a method via the submandible, comparing the intracranial and extracranial approach. We think the procedure via the submandible is a method more safe, simple and therefore, worthy to be recommended.

The jugular foramen: microsurgical anatomy and operative approaches

The jugular foramen, based on these studies of microsurgical anatomy, is divided into three compartments: two venous and a neural or intrajugular compartment. The venous compartments consist of a larger posterolateral venous channel, the sigmoid part, which receives the flow of the sigmoid sinus, and a smaller anteromedial venous channel, the petrosal part, which receives the drainage of the inferior petrosal sinus. The petrosal part forms a characteristic venous confluens by also receiving tributaries from the hypoglossal canal, petroclival fissure, and vertebral venous plexus. The petrosal part empties into the sigmoid part through an opening in the medial wall of the jugular bulb between the glossopharyngeal nerve anteriorly and the vagus and accessory nerves posteriorly. The intrajugular or neural part, through which the glossopharyngeal, vagus, and accessory nerves course, is located between the sigmoid and petrosal parts at the site of the intrajugular processes of the temporal and occipital bones, which are joined by a fibrous or osseous bridge. The glossopharyngeal, vagus, and accessory nerves penetrate the dura on the medial margin of the intrajugular process of the temporal bone to reach the medial wall of the internal jugular vein. The operative approaches, which access the foramen and adjacent areas and are demonstrated in a stepwise manner, are the postauricular transtemporal, retrosigmoid, extreme lateral transcondylar, and preauricular subtemporal-infratemporal approaches.

Neurovascular compression at the left ventrolateral medulla as an etiological factor for arterial hypertension

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.

Magnetic resonance imaging of cranial nerves IX, X, XI, and XII

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.

MR screening for brain stem compression in hypertension

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.

Resolution of obstructive sleep apnea after microvascular brainstem decompression

Lesions of the brainstem have been associated with obstructive sleep apnea in previous reports. We now report a case in which retromastoid craniectomy with microvascular decompression of the medulla and ninth and tenth cranial nerves resulted in the complete resolution of severe obstructive sleep apnea. Possible mechanisms for this observation are discussed.

Preservation of cranial nerve function after radiosurgery for nonacoustic schwannomas

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.

Radical removal of a large glossopharyngeal neurinoma with preservation of cranial nerve functions

A 51-year-old man is reported who was suffering from an extensive right-sided glossopharyngeal neurinoma (4.6 x 3.4 cm). The patient was admitted with a history of headache for six to seven years and vomiting for two years accompanied by a progressive hearing loss, tinnitus and dizziness during the last year. Audiometry indicated a perceptive deafness in the whole frequency range up to 70 dB HL, while electronystagmography (ENG) showed a loss of vestibular function of the right side, but there were no signs of a jugular foramen syndrome. Magnetic resonance imaging (MRI) revealed a large tumor portion in the right cerebello-pontine angle with only a small part in the jugular foramen. The neurinoma was completely removed by microsurgery through a suboccipital approach with preservation of nerves VII-XII. The postoperative course was uneventful and normal function of facial and caudal cranial nerves (Nn IX-XII) were proven by electromyography and magnetic stimulation, with exception of a transitory hypesthesia in the palatine region which completely normalized within a few months. The right-sided hearing loss was unchanged, but vertigo improved. In comparison with literature review the lack of temporary or permanent postoperative dysfunctions of caudal cranial nerves as well as of the facial nerve was extraordinary in the reported case.