Cervical and ocular vestibular evoked myogenic potentials in determining nerve division involvement in patients with a tumor located in the internal auditory canal

OBJECTIVES

The study aimed at the analysis of the parameters of acoustic cervical and ocular vestibular evoked myogenic potentials (AC-cVEMP and AC-oVEMP) response in patients with a confirmed tumor located in the internal auditory canal. It also aimed to assess to what degree a combination of these tests may be of benefit in the preoperative indication of the affected nerve division via preoperative determination whether the tumor originated from the superior or inferior division of the vestibular nerve, both divisions, or if it originated from a different nerve in the internal auditory canal.

METHODS

The study group included 50 patients. Preoperative MRI scans were used to measure tumor diameter. AC-cVEMP and AC-oVEMP testing were performed before tumor resection. The surgeon was asked for a detailed description of the tumor origin.

RESULTS

The corrected amplitude of cVEMP was significantly lower on the tumor side than on the non-affected side and in the control group. The corrected Asymmetry Ratio (AR) of cVEMPs in patients with the tumor was significantly elevated above the reference values with the mean being 58.29% and the mean AR of oVEMPs in patients the tumor was 71.78% which made both results significantly higher than in the control group. Neither cVEMP nor oVEMP latency was significantly correlated with tumor size. Data obtained from cVEMP and oVEMP tests was an effective indicator of tumor origin in 74% of patients showing which division (or both divisions) of the VIII^th nerve was affected in comparison with information obtained from the surgeon.

CONCLUSIONS

The combined use of AC-cVEMP and AC-oVEMP tests may be useful in surgical planning in patients the tumor located in the internal auditory canal, providing a highly probable determination of the division of the affected nerve. Such information is valuable for the surgeon as it offers additional knowledge about the tumor before the procedure. cVEMP and oVEMP results may not be used as the basis for the calculation of tumor size in patients.

Quality of life related to symptomatic outcomes in patients with vestibular schwannomas: A Canadian Centre perspective

Patients with vestibular schwannomas (VS) typically present with hearing loss and tinnitus as well as variable cranial nerve dysfunctions. Surgical resection, stereotactic radiotherapy and/or conservative management employing serial magnetic resonance or computed tomography imaging serve as the main treatment options. Quality of life (QoL) may be impacted by the extent of tumour burden and exacerbated or relieved by treatment. Subjective assessment and quality of life inventories provide valuable information in client centered approaches with important implications for treatment. The intention of QoL measurements affecting VS patients within a clinical setting is to facilitate discussions regarding treatment options and objectively evaluate patient- centered clinical outcomes in a naturalistic setting.

Prognostic Factors and Results of Radiation Therapy in Optic Pathway Tumors

Aims and Background

The role of radiotherapy in the management of patients with optic pathway tumors remains controversial. This study analyzes the outcome of patients treated with radiotherapy and attempts to identify the groups of patients that may require early therapy.

Methods

We retrospectively reviewed 36 patients with optic pathway tumors treated with radiotherapy alone (26 patients) or with postoperative radiotherapy (10 patients). Seven patients had optic nerve tumors and 29 patients had chiasmal tumors. The actuarial progression free survival and observed survival probabilities were calculated using the Kaplan-Meier method and differences between curves were evaluated by the Mantel-Cox test. The obtained significant variables in the univariate analysis were analyzed using the Cox proportional hazards model.

Results

The 10-year actuarial progression-free survival (10-y PFS) rate was 86% for patients with optic nerve gliomas and 47% for patients with chiasmal tumors. The 10-year actuarial observed survival (10-y OS) rate was 75% for patients with optic nerve gliomas and 53% for patients with chiasmal gliomas. In the group of patients with chiasmal tumors, progression-free survival and observed survival rates were significantly lower in infants (10-y PFS: 30%; 10-y OS: 37%), in patients with neurological deficits (10-y PFS and 10-y OS: 23%), in patients with signs of elevated intracranial pressure (10-y PFS and 10-y OS: 9%), with hydrocephalus (10-y PFS and 10-y OS: 0%), or with impairment of consciousness (10-y PFS and 10-y OS: 17%). Evaluation by computed tomography scanning was associated with a significantly higher probability of PFS. Radiation doses lower than 50 Gy were associated with significantly lower PFS and OS rates. In the Cox multivariate analysis, presence of neurological deficits and radiation dose significantly influenced observed survival. Presence of hydrocephalus significantly influenced progression-free survival.

Conclusions

The prognosis of patients with chiasmal gliomas presenting with neurologic deficits is poor and should be treated at diagnosis. A minimum tumor dose of 50 Gy is recommended.

Absent stapedial reflex: otosclerosis or middle ear tumor?

We present an unusual case in which a patient diagnosed as having otosclerosis on the basis of clinical and audiologic findings actually had a middle ear facial nerve schwannoma. To the best of our knowledge, this is the first reported case in English literature in which a facial nerve schwannoma presented with conductive deafness of gradual onset and absent stapedial reflex with a normally functioning facial nerve. We also include a review of the literature.

Intraparotid facial nerve schwannoma: clinician beware

Intraparotid facial nerve schwannomas are rare neoplasms that are challenging to diagnose and manage. Many patients present with a painless, palpable facial mass. The presence of facial paralysis is variable. Imaging studies and fine-needle aspiration cytology are not always helpful in preoperative diagnosis. With early diagnosis of facial nerve schwannoma, management of the patient can be planned and, ultimately, facial nerve function optimized. By reviewing the literature and 2 cases from a series of patients seen in our practice, we provide insight into the current diagnosis and treatment of a rare pathology.

Immunohistochemical analysis of the purinoceptor P2X7 in human lingual nerve neuromas

AIMS

Recent evidence suggests that the purinoceptor P2X7 may be involved in the development of dysesthesia following nerve injury, therefore, the aim of the present study was to investigate whether a correlation exists between the level of P2X7 receptor expression in damaged human lingual nerves and the severity of the patients' symptoms.

METHODS

Neuroma-in-continuity specimens were obtained from patients undergoing surgical repair of the damaged lingual nerve. Specimens were categorized preoperatively according to the presence or absence of dysesthesia, and visual analog scales scores were used to record the degree of pain, tingling, and discomfort. Indirect immunofluorescence using antibodies raised against S-100 (a Schwann cell marker) and P2X7 was employed to quantify the percentage area of S-100 positive cells that also expressed P2X7.

RESULTS

P2X7 was found to be expressed in Schwann cells of lingual nerve neuromas. No significant difference was found between the level of P2X7 expression in patients with or without symptoms of dysesthesia, and no relationship was observed between P2X7 expression and VAS scores for pain, tingling, or discomfort. No correlation was found between P2X7 expression and the time between initial injury and nerve repair.

CONCLUSION

These data show that P2X7 is expressed in human lingual nerve neuromas from patients with and without dysesthesia. It therefore appears that the level of P2X7 expression at the injury site may not be linked to the maintenance of neuropathic pain after lingual nerve injury.

Malignant orbital schwannoma with massive intracranial recurrence

BACKGROUND

A 62 year old male presented with progressive diplopia, left orbital pain and impairment of visual acuity.

METHOD AND FINDINGS

Neuroradiological investigation disclosed an orbital tumour. The lesion was totally excised. Histopathology examination revealed a malignant peripheral nerve sheath tumour (MPNST). The tumour recurred with intracranial extension. The patient died 13 months after the initial diagnosis.

CONCLUSIONS

To our knowledge, this is the first reported example of a massive intracranial recurrence of an orbital MPNST. The epidemiological features, clinical course and treatment of these lesions are discussed.

Isolated intraorbital schwannoma arising from the abducens nerve

CASE REPORT

A case of isolated schwannoma of the orbit, arising from the terminal branches of the abducens nerve to the lateral rectus muscle, is reported. The patient presented with a painless proptosis of the left eye.

DISCUSSION

Preoperative diagnosis of benign intraorbital neoplasm was made by means of CT and MR scans; the mass was radically excised through a microsurgical lateral orbitotomy and the pathological examination revealed a schwannoma. Features of orbital schwannoma are described, together with some details concerning the surgical strategy and the history of the evolution of the lateral orbitotomy.

Microsurgery for vestibular schwannoma after gamma knife radiosurgery

BACKGROUND

We evaluated the clinical characteristics of microsurgery for vestibular schwannoma (VS) after failed gamma knife radiosurgery (GKS).

METHOD

Twelve patients, 5 men and 7 women aged 19 to 70 years (mean 54.5 years), who underwent microsurgery after failed GKS for VS were studied retrospectively.

FINDINGS

The median interval between GKS and microsurgery was 28.8 months (range, 6.6-120 months) and 4 patients had undergone previous microsurgery. The mean volume of tumour at GKS was 6.9 cm(3) (range, 0.5-19.7 cm(3)) and the mean prescription dose to the tumour margin was 12.3 Gy. Microsurgery involved the lateral suboccipital approach in all patients. Tumour expansion involved solid enlargement in 7 patients, cystic enlargement in 3, and central necrosis in 2. Bleeding was slight in all patients except in one, probably because of the previous irradiation. Adhesion to the brain stem was severe in 7 patients. Identification of the facial nerve was easy in 5 operations and difficult in 7. Dissection of the tumour from the facial nerve was difficult in most interventions because of severe adhesions or colour change. Severe adhesions between the trigeminal nerve and the tumour was observed in 2 patients. The tumour was subtotally removed except around the internal auditory canal in most patients. Only one residual tumour increased in size and needed second GKS. The function of the facial nerve deteriorated in 3 patients, was unchanged in 7, and improved in 2. All patients had lost hearing on the affected side at the time of microsurgery.

CONCLUSIONS

Microsurgery for VS after failed GKS presents some technical difficulties. Dissection of the tumour from the facial nerve or brain stem is likely to be difficult. We recommend subtotal resection without dissection of the facial nerve and tumour, because growth of the residual tumour was rare in our series.

Retro-tympanic pulsatile mass originating from dumb-bell jugular foramen schwannoma

BACKGROUND

Jugular foramen (JF) tumours are uncommon with paraganglioma, schwannoma and meningioma occurring most commonly in this location. JF schwannoma with extension to the retro-tympanic area has been described only once.

METHODS

20-year-old man presented with headache, blurred vision, vomiting and diplopia.

FINDINGS

A left pulsatile retro-tympanic mass was seen at otoscopy. A jugular foramen tumour was found on CT and MR images. The intracranial portion of the tumour later diagnosed as schwannoma was removed. Control ENT examination confirmed that the residual retro-tympanic mass was no-longer pulsatile.

CONCLUSIONS

Jugular foramen schwannomas may also extend into the retro-tympanic area.

Management strategies for bilateral vestibular schwannomas

BACKGROUND

Bilateral vestibular schwannomas (VS) are rare. Most patients in India present late in the course of illness with large tumors and disabling deafness. Clinical presentation and management goals are different from that of unilateral VS.

AIMS

To highlight the differences in clinical presentations and surgical results of bilateral VS compared to unilateral VS; and, to propose a management strategy for these tumors with reference to tumor size, extent of growth and the presence or absence of hearing impairment.

METHOD

This is a retrospective study of 16 patients with bilateral VS treated over 10 years in a tertiary referral hospital. Assessment of VIIth and VIIIth cranial nerve function, tumor size, volume and extent of growth was performed in all patients. The management strategy was based on Samii's classification of tumor extent. All patients were operated using a retromastoid suboccipital approach. Postoperative results were analyzed and compared with those of unilateral VS.

RESULTS

The mean age of presentation was 25.7 years. Hearing impairment was the commonest symptom. Headache with features of raised intracranial pressure were present in 10 (62.5%) patients. Giant tumors were present in seven (43.7%) patients; large tumors in eight (50%) and a medium-sized tumor in one (6.3%). Total tumor resection was achieved in 13 patients and subtotal resection in two. One patient was managed conservatively and followed up with serial CT scans. On the contralateral side, one large tumor required total excision. One medium sized tumor underwent sub-capsular excision in an attempt to preserve hearing. The facial nerve was anatomically preserved in seven (46.7%) patients and in one, the cochlear nerve was anatomically preserved. There was no peri-operative mortality.

CONCLUSIONS

Patients with bilateral schwannomas are younger, have larger lesions, poorer preoperative hearing and are more likely to lose either auditory and/or facial nerve function during attempted total resection of the tumor. Classifying the tumors into two groups by extent, that is, tumors extending to the cerebellopontine angle cistern (T1-T3a) and, tumors extending to or compressing the brainstem (T3b to T4b), allows the surgical strategy to be defined.

Characterizing the auditory changes in tumor metastasis to the bilateral internal auditory canals

We report the changes in auditory function in a patient with tumor metastasis to the bilateral internal auditory canals (IAC). The hearing gradually deteriorated at frequencies below 1 kHz and above 4 kHz, with the auditory brainstem response (ABR) eventually becoming absent in both ears. However, distortion product otoacoustic emissions (DPOAE) were present at low frequencies, which suggests that the organ of Corti in its upper turn remained unaffected by tumor invasion. Metastatic tumors in the bilateral IAC have been reported to mimic neurofibromatosis type 2, and radiological differentiation from acoustic schwannoma is difficult. We characterize the hearing deterioration caused by metastasis of malignant tumors in the IAC.

Ocular neuromyotonia with spastic lid closure

Ocular neuromyotonia is characterized by tonic spasms of extraocular muscles evoked by eccentric gaze that induces transient strabismus and diplopia. We report the case of a 70-year-old woman who initially presented with unilateral deficits in fifth and sixth cranial nerve functions attributed to a fifth cranial nerve schwannoma. After radiation treatment, she developed neuromyotonia and synkinesis of the ipsilateral third cranial nerve. During the attacks of neuromyotonia, the left eyelids were often spastically closed, a phenomenon not previously reported. The ocular neuromyotonia regressed spontaneously within 3 years, but components of the synkinesis persisted. Ephaptic transmission in a damaged third cranial nerve may be responsible for the neuromyotonia and synkinesis. Synkinesis is a more enduring manifestation.

Dura-Based Giant Intracranial Schwannoma in the Middle Fossa -Case Report-

A 49-year-old female presented with a rare giant schwannoma arising from the dura mater of the middle fossa manifesting as loss of left visual acuity. Magnetic resonance imaging revealed a heterogeneously enhanced giant mass in the left middle fossa. Surgery via the transsylvian approach confirmed the origin of the tumor between the left internal carotid artery and the trigeminal nerve in the lateral wall of the cavernous sinus. Elongated abducens nerve was confirmed, but no tumor adhesion to the abducens nerve was found. The tumor was closely attached to the dura mater of the middle fossa and the lateral wall of the cavernous sinus. The histological diagnosis was schwannoma. Both left oculomotor and abducens nerve pareses occurred immediately after the operation but gradually resolved over 3 months. The operative findings indicated that this schwannoma may have arisen from the meningeal branch of the trigeminal nerve in the dura mater of the middle fossa.

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.

Percutaneous radio-frequency mandibular nerve rhizotomy guided by CT fluoroscopy

We describe a new method for radio-frequency mandibular nerve rhizotomy under CT fluoroscopy. A patient with cancer had severe intractable and drug-resistant pain in his left mandibular region. Because he had an anatomic deformity due to cancer invasion and radiation therapy, we planned a mandibular nerve rhizotomy under CT fluoroscopic imaging. The needle was advanced to the mandibular nerve just caudal to the foramen ovale under real-time CT fluoroscopy, avoiding the cancer region. Pain scores of the patient were reduced after the nerve rhizotomy, without any complications.

Compression of the Rostral Ventrolateral Medulla by a Vagal Schwannoma of the Cerebellomedullary Cistern Presenting with Refractory Neurogenic Hypertension: Case Report

OBJECTIVE:

The rostral ventrolateral medulla is thought to serve as a final common pathway for the integration of central cardiovascular information and to be important for the mediation of central pressor responses. An association between essential hypertension and neurovascular compression of the rostral ventrolateral medulla has been reported. This may be mediated by an increase in sympathetic tone.

CLINICAL PRESENTATION:

Schwannomas arising from the lower cranial nerves (Cranial Nerves IX-XI) are rare, constituting only 3% of all intracranial schwannomas unassociated with neurofibromatosis. The majority of these tumors present as jugular foramen lesions and, less commonly, they occur along the extracranial course of these nerves. An intracisternal location is extremely rare. Fewer than 15 cases of pathologically proven intracisternal vagal schwannomas in the absence of neurofibromatosis have been reported.

INTERVENTION:

We report a case of vagal schwannoma in the cerebellomedullary cistern causing distortion of the vagal root entry zone and presenting with refractory neurogenic hypertension. Total microsurgical excision of this tumor, arising from one of the rootlets of the vagus nerve, was achieved. Immediately postoperatively, blood pressure decreased markedly, and despite our effort to maintain the blood pressure with fluids, the patient developed a cerebral infarction in the watershed zone.

CONCLUSION:

We discuss the proposed mechanism of hypertension, and the perioperative management, stressing blood pressure control. A review of the literature regarding vagal schwannomas is also presented. To the best of our knowledge, this is the first case report of a cerebellomedullary cistern vagal schwannoma presenting with neurogenic hypertension.

April 2002: 35-year-old healthy man with enlarging right parotid mass

The April 2002 Case of the Month (COM). 35-year-old healthy man developed a mass in the right parotid gland. A superifical parotidectomy was performed for a 4.5 x 1.5 x 1.5 cm mass involving the intraparotid facial nerve. Grossly the tumor was multinodular, smooth and yellow with normal surrounding salivary gland. Microscopically, the tumor showed expanding nodules composed of proliferating fibroblasts, Schwann cells, and perineural-like cells in a myxoid stroma. Normal peripheral nerve twigs were identified in the periphery of the tumor. There was no increased mitotic activity, cellularity or nuclear pleomorphism. S-100 immunohistochemical stain was positive. The tumor was diagnosed as a solitary plexiform neurofibroma. Plexiform neurofibromas in this area have been described in children with von Recklinghausen's disease or neurofibromatosis 1 (NF 1). Plexiform neurofibromas typically involve deep seated nerve trunks and is considered pathognomonic for NF 1. This unusual case represents a solitary variant of plexiform neurofibroma presenting as a parotid mass in an adult patient without a personal stigmata or family history of NF 1.

Usefulness of transcervical approach for surgical treatment of hypoglossal schwannoma with paraspinal extension: case report

BACKGROUND

Usefulness of transcervical approach to hypoglossal schwannoma with paraspinal extension is described herein.

CASE DESCRIPTION

A 54-year-old woman presented with gradually worsening left hypoglossal nerve palsy. The findings were of a tumor lying in the left hypoglossal canal and paraspinal region and were consistent with hypoglossal schwannoma. Subtotal intracapsular removal of the tumor was performed via transcervical approach. The symptoms improved, and no additional symptoms were noted.

CONCLUSION

The transcervical approach and intracapsular removal of the tumor under electrophysiological monitoring provided for successful minimally invasive surgery in this case of hypoglossal schwannoma.

Stereotactic Radiosurgery for Vestibular Schwannomas: Analysis of 317 Patients Followed More Than 5 Years

OBJECTIVE:

Many investigators have reported successful treatment of vestibular schwannomas with gamma knife radiosurgery (GKRS). However, long-term outcomes should be evaluated before concluding that GKRS is truly safe and effective for the treatment of vestibular schwannomas.

METHODS:

Between May 1991 and December 1998, 346 consecutive patients (excluding those presenting with neurofibromatosis Type 2) were treated with GKRS. Of these, 317 patients were assessed. Twenty-nine patients were lost to follow-up within 5 years.

RESULTS:

The median follow-up period was 7.8 years. Of 301 patients who underwent serial follow-up imaging, two (1%) experienced complete remission, 184 (61%) experienced partial remission, 93 (31%) had stable tumors, and 22 (7%) experienced treatment failure. The actuarial 5- or 10-year progression-free survival (PFS) rate was 93 and 92%, respectively. Tumors less than 15 cm3 in volume (10-yr PFS, 96%; P < 0.001) or which did not compress the brainstem and deviate the fourth ventricle (10-yr PFS, 97%; P = 0.008) resulted in significantly better PFS rates. Failure of treatment usually occurred within 3 years. When the tumor was treated with a marginal dose of 13 Gy or less, the hearing preservation rate was 68%, transient facial palsy developed at a rate of 1%, and facial numbness developed at a rate of 2%.

CONCLUSION:

GKRS proved to be a safe and effective treatment for patients followed longer than 5 years who presented with tumors with a volume of less than 15 cm3 and who did not have significant fourth ventricle deviation. Good functional outcomes were observed in this group of patients.

Localized Transcranial Electrical Motor Evoked Potentials for Monitoring Cranial Nerves in Cranial Base Surgery

OBJECTIVE:

To describe a novel monitoring technique that allows “functional” assessment of cranial nerve continuity during cranial base surgery.

METHODS:

Facial motor evoked potentials (MEP) in 71 consecutive patients were obtained by localized transcranial electrical stimulation in all patients requiring facial nerve monitoring during the period from November 2002 to August 2004. With transcranial electrical stimulation localized to the contralateral cortex, facial nerve MEPs are obtained through stimulation of more proximal intracranial structures.

RESULTS:

Logistic regression revealed that the final-to-baseline facial MEP ratio predicted satisfactory (House-Brackmann Grade 1 and 2 function) immediate postoperative facial function (0.005 > P > 0.0005). Contingency table analysis showed high correlation (χ2, P ≤ 2 × 108) and acceptable test characteristics using a 50% final-to-baseline MEP ratio.

CONCLUSION:

Facial nerve MEPs recorded intraoperatively during cranial base surgery using the proposed technique predicts immediate postoperative facial nerve outcome. This technique can also be used to monitor other motor cranial nerves in cranial base surgery.

Management of vagal paraganglioma: Is operative resection really the best option?

BACKGROUND

Vagal paragangliomas cannot be resected without sacrifice of the vagal nerve. The risk of bilateral vocal cord palsy has been reason to postpone treatment of this benign and slow growing neoplasm in hereditary cases. Postponement could be considered for solitary cases as well.

METHODS

An institute-based review of 48 patients with vagal paragangliomas over the past 30 years was performed.

RESULTS

Forty-eight patients with 58 vagal paragangliomas were studied. All but 4 patients had multiple paragangliomas and should be considered hereditary cases. The 10 patients that underwent an operation lost the vagal nerve; 60% of them had additional cranial nerve palsy postoperatively. In the group of patients who were followed for an average period of 8.5 years, 3 patients (8%) developed cranial nerve palsy.

CONCLUSIONS

Aggressive treatment of vagal paragangliomas leads to unnecessary early loss of vagal nerve function. A period of clinical and radiologic follow-up preceding an operation may lead to prolonged preservation of voice and swallowing functions in these patients, without grave consequences for other lower cranial nerves.