Jugular foramen schwannoma: analysis on its origin and location.

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.     

A rare case of jugular foramen schwannoma arising from Jacobson's nerve

The jugular foramen (JF) region is a complex area of the cranial base where venous structures such as the jugular bulb and the inferior petrosal sinuses are strictly related to the lower cranial nerves IX, X and XI. The most common tumours include glomus jugulare, schwannomas of the mixed cranial nerves (IX-XI) and meningiomas. Schwannomas involving the jugular foramen are rare neoplasms and in most of the cases are thought to originate from the X cranial nerve. We report a case of a schwannoma of the JF diagnosed at an early stage, allowing radiological and surgical evidence to support its origin from the tympanic branch of the IX cranial nerve. To our knowledge this is the first case reported in the literature of such a tumour.     

Schwannomas of the jugular foramen.

Schwannomas of the jugular foramen are relatively uncommon tumors. The growth and initial presentation of these tumors are variable and may not be associated with neuropathies of cranial nerves IX, X and XI. Seven patients with jugular fossa schwannomas are presented. Auditory brain stem response, electronystagmogram, computed cranial tomography, and carotid angiography arc helpful in diagnosis and preoperative evaluation. The surgical approach should be individualized to the lesion and may include transmastoid with extended facial recess, translabyrinthine, retrolabyrinthine, and infratemporal/cervical approaches.     

颈静脉孔区肿瘤术后后组脑神经损伤的评估和处理

目的：分析颈静脉孔区肿瘤术后后组脑神经损伤情况及其处理,以提高对后组脑神经损伤的认识并改进处理方法。方法：32例颈静脉孔区肿瘤患者中,颈静脉球体瘤12例,后组脑神经鞘膜瘤10例,脑膜瘤3例,胆脂瘤1例,颞骨巨细胞瘤2例,纤维瘤病1例,黏液软骨肉瘤1例,胚胎型横纹肌肉瘤1例,腺样囊性癌1例。均采取手术治疗,30例全切,1例近全切,1例大部切除。结果：除1例术后并发颅内出血死亡外,其余31例术后随访1-6年。术后后组脑神经功能仍正常者5例,新出现神经功能损伤者8例,原有神经功能损伤者18例术后出现不同程度的损伤加剧表现。手术前后行气管切开者8例,其中3例出院前拔管,5例带管出院。出院时后组脑神经损伤代偿者20例,失代偿者6例。失代偿者术后随访中3例代偿,2例部分代偿,1例未代偿。结论：颈静脉孔区肿瘤术后后组脑神经损伤是常见并发症,术前应根据患者年龄、神经功能等综合评估,术中应尽量保全神经,早期积极正确的功能锻炼是术后处理的关键。     

颈静脉孔神经鞘瘤的外科治疗

目的 探讨颈静脉孔神经鞘瘤的手术入路及治疗效果。方法 回顾性分析采用显微外科手术治疗颈静脉孔神经鞘瘤２４例,其中颅内型（Ａ型）：肿瘤主体位于桥小脑角（１２例）;骨内型（Ｂ型）：肿瘤主体位于颈静脉孔内,向颅内生长（５例）;颅外型（Ｃ型）：肿瘤主体位于颅外,并向颈静脉孔生长（１例）;混合型（Ｄ型）：肿瘤由颈静脉孔向颅内外生长,呈哑铃型（６例）。Ａ型采用枕下乙状窦后入路,Ｂ型采用远外侧入路,Ｃ型和Ｄ型采     

Parapharyngeal space schwannomas: preoperative imaging determination of the nerve of origin

OBJECTIVES: To determine if preoperative radiographic cross-sectional images can predict the nerve of origin of a parapharyngeal schwannoma and, specifically, whether it originates from the vagus nerve or the cervical sympathetic chain. DESIGN: A retrospective review. SETTING: Academic medical center. PATIENTS: The study population comprised 12 patients who underwent surgical resection of schwannomas of the parapharyngeal space. The nerve of origin was identified based on operative findings and postoperative physical examinations. Of the 12 patients, 11 underwent preoperative magnetic resonance imaging and 1 underwent preoperative contrast-enhanced computed tomography. A CAQ (Certificate of Added Qualification)-certified neuroradiologist reviewed the imaging studies, blinded to the surgically determined nerve of origin. For each case, it was predicted whether the tumor arose from the vagus nerve or sympathetic chain based on the location of the schwannoma with reference to the carotid sheath vessels. MAIN OUTCOME MEASURE: Identification of the nerves of origin using the displacement of vessels as a marker. RESULTS: At the time of operation, it was determined that 5 patients (42%) had schwannomas from the cervical sympathetic chain and 7 patients (58%) had schwannomas of the cervical vagus nerve. By imaging, the nerve of origin was successfully determined in 4 of 5 cases of sympathetic chain schwannoma (80%) and in 7 of 7 cases of vagal nerve schwannoma (100%). Schwannomas of the cervical sympathetic chain were found to displace both the carotid and jugular vessels without separating them. Vagal nerve schwannomas were found to separate the carotid arteries from the internal jugular vein. A vagal nerve schwannoma may also displace the sheath vessels posteriorly, without splaying them. CONCLUSIONS: Carotid and jugular vessel displacement, as determined by cross-sectional imaging, can predict the likely nerve of origin of a parapharyngeal space schwannoma. This determination allows for effective preoperative counseling regarding the expected sequelae of surgical resection.     

Intracanalicular schwannoma of the facial nerve: a manifestation of neurofibromatosis type 2

Primary facial nerve tumors, which are relatively uncommon, can present a diagnostic dilemma based on their location and variable pattern of symptoms. Of primary cranial nerve tumors, schwannomas of the facial nerve rank third in frequency after those of the eighth and fifth cranial nerves. We report an illustrative case of an intracanalicular schwannoma associated with several central nervous system tumors, consistent with neurofibromatosis type 2. Initially assumed to be an eighth cranial nerve tumor, the schwannoma was found intraoperatively to arise from the facial nerve. Early diagnosis and treatment enabled excision of the tumor without sacrifice of the facial nerve. Facial nerve schwannomas can resemble acoustic schwannomas in their clinical presentation. Only a heightened level of clinical vigilance will point to the correct diagnosis and result in an optimal therapeutic outcome for patients with these rare tumors.     

A study of tumors of the parapharyngeal space.

A retrospective study of patients with parapharyngeal tumors has been completed, and this report concerns 40 patients cared for during the years 1962–1973. The parapharyngeal space is a potential anatomical space with three rigid walls so that growth of a tumor proceeds either medially or inferiorly or both. This pattern of growth accounts for the distinct clinical appearance of a displaced palate and pharynx. As noted in this series of cases, Table I depicts the types of tumors which involved the parapharyngeal space. Eighty-two percent of the cases presented with benign tumors. On the other hand, 18 percent of the patients had malignant tumors. Benign mixed cell tumors and schwannomas are the most commonly noted benign tumors. Several cases presented with unusual tumors. In most patients the tumor was discovered on routine physical examination. Arteriography has become a valuable and safe diagnostic study. These procedures often help the surgeon to determine the extent of tumor, vessel displacement and the possibility of chemodectoma and even malignancy in some patients. An external surgical approach is recommended for surgical excision of the benign parapharyngeal tumor in most patients. Intraoral incisional biopsy in patients with benign tumors is to be avoided because of dangers of vessel and nerve injury as well as “seeding” of the biopsy site. On the other hand, malignancy may be diagnosed with incisional biopsy either performed externally or intraorally, depending on the judgment of the surgeon as to the anatomical location and site of the neoplasm. In final analysis the external surgical approach allows the surgeon systematically to identify tumor, important cranial nerves including the facial nerve and the great vessels. Every effort should be made by the surgeon not to violate the capsule of a benign mixed tumor during its removal. Removal of tumor is enhanced frequently by preliminary excision of the submandibular gland, vessel ligation and mandibulotomy. In the latter instance the patient must undergo tracheostomy. Postoperative cranial nerve palsies occurred for the most part in those patients who underwent surgical excision of schwannomas. These tumors originated from the vagus nerve or cervical sympathetic chain. Sacrifice of these nerves during removal caused little morbidity. Follow-up examinations in this series of patients revealed that if benign tumors are removed from the parapharyngeal space in a deliberately planned manner, recurrence rates are extremely low. In patients who are treated for malignant lesions, prognosis must be guarded, as mortality rates are high regardless of the type of therapy.     

Schwannomas of the parapharyngeal space and jugular foramen

Schwannomas or neurilemmomas are among the most common neoplasms occupying the parapharyngeal space, yet only 107 cases have been previously reported. Neurilemmomas involving the jugular foramen are extremely rare. Only 55 cases have been reported in the world literature. The neoplasm occurred in the parapharyngeal space in three of our patients and in the jugular foramen in another patient. Of the tumors located in the parapharyngeal space, the nerve of origin in one of them was the glossopharyngeal, which is extremely rare. Adequate exposure for complete excision of parapharyngeal space tumors is best obtained through an external incision and should not be attempted transorally. In the jugular foramen case, the neoplasm arose from the vagus nerve high in the neck and extended intracranially in a “dumbbell” shape into the posterior cranial fossa. Total removal was successfully accomplished in one stage, by using a subtotal temporal bone resection — upper neck — posterior cranial fossa approach. Surgical removal is the treatment of choice. Schwannomas rarely recur following complete excision.     

Facial nerve schwannoma: surgical excision versus conservative management.

Facial nerve schwannomas are slow-growing tumors that may involve any part of the facial nerve. When they present with moderate to total facial palsy, complete resection is clearly indicated. However, in cases with mild or no facial dysfunction, the best course of treatment is less obvious. A series of 22 patients with facial nerve schwannoma is presented, of whom 12 underwent definitive excision and 10 were managed more conservatively. The best postoperative facial function in the group who had tumor removal was a House-Brackmann grade III, while 8 of the conservatively treated group had normal facial function up to 10 years after presentation. As well, no significant tumor growth was noted on serial radiologic imaging of those being observed. Delaying surgical resection of facial nerve schwannomas may allow patients to retain normal facial function indefinitely.     

Transjugular craniotomy for the management of jugular foramen tumors with intracranial extension.

OBJECTIVES: To elucidate indications and outcomes with the transjugular craniotomy for resection of jugular foramen tumors with intracranial extension. The transjugular approach is a lateral craniotomy conducted through a partial petrosectomy traversing the jugular fossa combined with resection of the sigmoid sinus and jugular bulb, which often have been occluded by disease. STUDY DESIGN: Retrospective review. SETTING: University medical center. PATIENTS: Twenty-eight patients with intracranial jugular foramen tumors who underwent a total of 30 surgical procedures. MAIN OUTCOME MEASURES: Pathologic findings, surgical approach, extent of tumor resection, rate of facial nerve mobilization and ear canal closure, facial and lower cranial nerve outcomes, and hearing preservation. RESULTS: Tumors included schwannoma (37%), meningioma (33%), glomus jugulare (23%), and chordoma (7%). The surgical approaches were tailored to maximize functional preservation, and included the transjugular (53%), translabyrinthine (17%), retrosigmoid (10%), and far lateral (7%) craniotomies. Translabyrinthine (3%) or transcondylarfar lateral (3%) approaches were occasionally used in combination with the trans-jugular approach. Most procedures were managed in a single stage (90%), but three patients with massive tumor in the neck required two stages. Microsurgical gross total and near-total tumor removal (37% each) were commonly achieved, although subtotal resections (27%) were occasionally performed. In only a minority of cases was facial nerve mobilization (7%) or ear canal closure (21%) required. If present preoperatively, Grade I facial nerve function was usually maintained (22 of 24 [92%]) and Hearing Class A or B could always be maintained (9 of 9 [100%]). As expected, new lower cranial nerve dysfunction was common (8 of 30 [27%]), although over half of the patients had complete lower nerve palsy preoperatively (16 of 30 [53%]). CONCLUSION: Most patients with jugular foramen tumors with intracranial extension can be managed with a single-stage transjugular craniotomy. Facial nerve mobilization or ear canal closure is usually not required, permitting conservation of facial function and hearing, when present preoperatively.     

Chondrosarcomas of the jugular foramen

Objectives/Hypothesis: Chondrosarcomas of the jugular foramen are extremely rare tumors. Our review of the literature revealed eleven previously reported cases. The aim of this study is to describe the presenting symptoms, radiographic findings, operative procedures, and postoperative outcome of five histologically confirmed cases of chondrosarcomas arising from the jugular foramen. A review of the literature is also presented. Study Design: Retrospective study of an quaternary referral otology and skull base private center. Methods: Five cases of surgically treated and pathologically confirmed jugular foramen chondrosarcomas were identified. The follow‐up of the series ranged from 23 to 42 months (mean, 32.8 ± 7.7 months). Results: A single stage procedure was adopted in all the cases. Two patients underwent type A infratemporal approaches, one patient underwent a transotic approach extending to the neck with ligature of the internal jugular vein, one patient underwent a petro‐occipital transigmoid approach, and one patient underwent a combined petro‐occipital transigmoid–transotic approach. Gross total tumor removal was achieved in all patients. The most common complications were lower cranial nerve deficits. To date, no recurrence or residual tumors have been observed at radiological controls. Conclusions: We believe that the primary treatment for chondrosarcomas of the jugular foramen is gross total surgical resection of the tumor. It is our philosophy to reserve postoperative radiotherapy for patients with histologically aggressive tumors, as well as in cases with subtotal resection and recurrent tumors.     

Functional deficits of caudal cranial nerves after surgery of tumors in the foramen jugulare. A long-term follow-up study]

Jugular foramen tumors involve a critical area of the skull base. Usually they are characterized by palsy of the ninth, tenth, and eleventh cranial nerves. Depending on the extent of the tumor there are various approaches to the skull base and various surgical strategies to preserve the cranial nerves. The study is based on 31 patients who were operated on between 1982 and 1989 at the University ENT and Neurosurgery Departments in Freiburg and Mainz. The neurological findings were analyzed on admission, on discharge, and in the follow-up. While there was partial or complete dysfunction of the lower cranial nerves on discharge, long-term compensation was excellent. All patients were able to breath normally and maintain their weight by oral diet. Rerouting of the facial nerve endangers its postoperative function. Nevertheless, the long-term follow-up demonstrated excellent recovery and good functional and cosmetic results.     

Computed tomography in the diagnosis of primary tumors of the petrous bone

This paper constitutes an evaluation of 23 patients with signs and symptoms of 4 types of tumors: 6 congenital epidermoids, 3 cases of meningiomas presenting within the temporal bone, 2 cases of jugular fossa schwannomns, 3 cases of glomus tympanicum, and 9 selected cases of glomus jugulare tumors. Since these tumors occur insidiously and are located in an inaccessible region of the skull, they are usually not diagnosed until they reach considerable size and cause multiple cranial nerve deficits or intracranial complications. Assessment of these tumors and subsequent surgical management depend primarily on the preoperative radiographic findings. CT and dynamic CT study have proven to be extremely valuable and accurate in the diagnosis of these lesions. Epidermoids have a characteristic CT appearance. Dynamic CT is often helpful in differentiating glomus tumors from meningiomas and schwannomas. Involvement of the middle ear, labyrinth, intracranial, and extracranial components of these tumors can be best evaluated by CT. This paper places special emphasis on congenital cholcsteatoma (epidermoid) and draws relevant conclusions about the diagnostic work-up.     

乙状窦后入路切除颈静脉孔区哑铃形肿瘤

目的 探讨颈静脉孔区哑铃型肿瘤的手术入路及治疗效果。方法 回顾性分析采用枕下乙状窦后入路切除4例颈静脉孔区哑铃型肿瘤的临床资料。结果 肿瘤全切除3例，大部切除1例，无手术死亡及严重并发症。结论 经乙状窦后入路可以安全切除哑铃型颈静脉孔区肿瘤。术中应注意保护好后组颅神经。     

Conservative facial nerve management in jugular foramen schwannomas

OBJECTIVE: Although transposition of the facial nerve is crucial in infiltrative vascular lesions involving the jugular foramen, the objective was to show that a conservative approach to management of the facial nerve is sufficient with jugular foramen neuromas because of their noninfiltrative, less vascular nature and medial location in the jugular foramen. STUDY DESIGN: Retrospective case review. SETTING: Tertiary, private, multiphysician, otologic practice. PATIENTS: Sixteen patients with jugular foramen schwannoma (18 procedures) treated between January 1975 and October 1995. The 8 male and 8 female patients ranged in age from 13 to 66 years (mean age 47.7 years). INTERVENTION: One-stage, total jugular foramen neuroma removal without transposition of the facial nerve, using a variety of surgical approaches. MAIN OUTCOME MEASURES: Facial nerve transposition (yes or no), House-Brackmann facial nerve grade, lower cranial nerve status, complications. RESULTS: One-stage total tumor removal was accomplished in all the cases. In 13 (72%) of the neuromas, removal was accomplished without facial nerve transposition. Transposition was performed in 2 revision cases in which scar tissue from a previous operation prevented complete control of the carotid artery and safe removal, 2 cases with large tumor extension anteriorly to the petrous apex, and 1 case with extensive involvement of the middle ear. A House-Brackmann facial nerve Grade I or II was obtained in 16 of the 18 procedures, with 1 Grade III and 1 case that remained Grade V, as it was preoperatively. CONCLUSIONS: One-stage, total tumor removal can be achieved with excellent control of the important vascular structures and without transposition of the facial nerve in a majority of jugular foramen schwannomas.     

A Hearing Preservation Technique for the Resection of Extensive Jugular Foramen Tumors

Objective To describe a modified surgical approach for patients who maintain hearing function with jugular foramen tumors that extend to the posterior cranial fossa and the neck. Study Design A retrospective review of 6 patients with jugular foramen tumors that were resected by a combined suboccipital and infralabyrinthine–transcervicomastoid approach. Methods A combined suboccipital and infralabyrinthine–transcervicomastoid approach is characterized as follows: 1) There is no ablation of ear structures except the infralabyrinthine mastoid bone; the auricle is retracted anteriorly while preserving the bony wall and skin of the ear canal. 2) After superficial parotidectomy, a limited length of nerve VII from the intratemporal vertical segment is rerouted to divisions of the parotid portion. 3) The tumor is removed along with the internal jugular vein and sigmoid sinus, then the extended intracranial mass is resected through an additional suboccipital approach. Results Five of the 6 patients had complete removal of all gross tumors. There were no major complications or mortalities. The preoperative levels of hearing were preserved in 5 of the 6 patients. Favorable facial function in the immediate postoperative period was noted in 4 of the 6 patients. Incomplete paralysis of 2 patients recovered eventually. Conclusion We propose that a combined suboccipital and infralabyrinthine–transcervicomastoid approach to the jugular foramen can provide sufficient exposure to resect most dumbbell‐shaped tumors, and it could be the initial treatment of choice for patients with remnant hearing.     

颈静脉孔的显微外科解剖研究

目的研究颈静脉孔的硬脑膜结构和孔内神经、血管结构的行程及形态特征。方法显微镜下模拟枕下极外侧入路、颈-乳突入路和Fisch颞下窝入路的手术操作，研究10例福尔马林及乳胶灌注头颈标本颈静脉孔的显微解剖特征。结果在颈静脉孔的颅内开口，舌咽神经与迷走、副神经间被纤维或骨性结构隔开。在颈静脉孔内，脑神经行于颈静脉球上方的内侧，舌咽神经位于最前方，所有神经束均可用显微外科技术分开，副神经的脑根同脊髓根一起进入颈静脉孔后又加入迷走神经。颈静脉球及临近颈内静脉接受来自乙状窦、岩下窦、椎静脉丛、舌下神经管静脉丛、髁导静脉及岩斜下静脉的静脉回流。结论颈静脉孔的颅内开口可分为岩部、颈内部(或神经部)和乙状窦部．颈静脉孔内脑神经的不同神经纤维束在整个行程中彼此独立，副神经仅由脊髓根构成。     

Surgical management of jugular foramen schwannomas with hearing and facial nerve function preservation: a series of 23 cases and review of the literature

OBJECTIVE: Schwannomas of the jugular foramen are rare lesions and controversy regarding their management still exists. The objective of this retrospective study was to analyze the management and outcome in a series of 23 cases collected at a single center. SETTING: This study was conducted at a quaternary private otology and skull base center. METHODS: Charts belonging to patients with a diagnosis of jugular foramen schwannoma attending our center between May 1988 and April 2006 were examined retrospectively. RESULTS: The study group consisted of 23 patients. One patient (a 73-year-old woman) with normal lower cranial nerves function was managed with watchful expectancy and regular clinical and radiologic follow ups. The infratemporal fossa approach-type A (IFTA-A) was performed in 3 cases. One patient underwent a transcochlear-transjugular approach. Of the 22 patients surgically treated, 12 patients were operated on by the petrooccipital transsigmoid approach (POTS). In one patient with a preoperative dead ear, a combined POTS-translabyrinthine approach was adopted. Two patients were operated on through the POTS approach combined with the transotic approach. In another case (a 67-year-old woman), a subtotal tumor removal through a transcervical approach was planned to resect a 10-cm mass in the neck. One patient underwent a first-stage combined transcervical-subtotal petrosectomy approach to remove a huge tumor in the neck; the second-stage intradural removal of the tumor was accomplished through a translabyrinthine-transsigmoid-transjugular approach. The last patient underwent a first-stage combined transcervical-subtotal petrosectomy approach to remove the neck tumor component; this patient is now waiting for the second-stage intradural removal of the tumor. Complete tumor removal was accomplished in 21 cases and in one case, a residual schwannoma was left in place in the area of the jugular foramen. The 3 patients who were operated on by IFTA-A underwent permanent anterior transposition of the facial nerve. At 1-year follow up, 2 of these patients had House-Brackmann grade I and 1 reached grade IV. The patient who underwent a transcochlear-transjugular approach had a permanent posterior transposition of the facial nerve. At 1-year follow up, he had grade III facial nerve function. Postoperative facial nerve function was normal (House-Brackmann grade I) in all patients operated on by the POTS approach. Twelve patients had hearing-preserving surgery using the POTS approach. Good hearing was preserved in 10 cases (83.3%), the majority of whom (58.3%) maintained their preoperative hearing level. There was no perioperative mortality. One patient (4.5%) experienced a postoperative cerebrospinal fluid leak. After surgery, all patients did not recover the function of the preoperatively paralyzed lower cranial nerves. A new deficit of one or more of the lower cranial nerves was recorded in 50% of cases. So far, no patient has experienced recurrence during the follow-up period as ascertained by computed tomography or magnetic resonance imaging. CONCLUSIONS: Surgical resection is the treatment of choice for jugular foramen schwannomas. The POTS approach allowed single-stage, total tumor removal with preservation of the facial nerve and of the middle and inner ear functions in the majority of cases. Despite the advances in skull base surgery, new postoperative lower cranial nerve deficits still represent a challenge.     

颈静脉孔神经鞘瘤（附5例报告）

本文报告了经手术治疗的颈静脉孔神经鞘瘤５例，其临床表现与波及的颅神经有关，但多有听神经受损症状，术前易误诊。ＭＲＩ对诊断有助，该肿瘤为良性，及时手术全切疗效满意。