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Competing Interests: The authors report no conflicts of interest.

Purpose of Review: Several neoplastic lesions may originate from facial nerves, including facial nerve schwannomas. These neoplastic lesions can cause various symptoms, such as facial nerve paralysis, and decrease the quality of life of patients. Therefore, knowledge of how to manage these diseases is important for otologists. However, the incidence of these diseases is extremely low, and universal management methods have not yet been established. This review summarizes recent advances in knowledge regarding these neoplastic lesions, especially facial nerve schwannomas., Recent Findings: Recent advances and the accumulation of knowledge regarding these benign facial nerve lesions have provided several preferable treatments and management methods, especially for facial nerve schwannomas. However, this still depends on the patient's symptoms and tumor localization., Summary: This review presents the optimal treatment protocol and differential diagnosis of benign facial nerve lesions. This may be useful for pretreatment differentiation and treatment decision-making., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Foster Kennedy syndrome refers to a finding of optic atrophy in one eye from direct compression of the optic nerve by a mass lesion and contralateral papilledema in the nonatrophic optic nerve caused by an increased intracranial pressure. When the fundoscopy finding is not due to a direct compressive mass, the term pseudo-Foster Kennedy syndrome is used; this can be caused by any process or processes that result in optic atrophy in one eye and optic disc edema in the other. Identifying Foster Kennedy syndrome in a patient calls for expedient neuroimaging looking for an intracranial mass lesion. In this article, we present the case of a patient presenting with vision loss and Foster Kennedy syndrome who was found to have a large trigeminal cystic schwannoma. While several other accompanying symptoms were not evident from the patient complaint, a careful history and physical examination revealed additional localizing clues: unilateral sensory changes in the face and pterygoid and masseter atrophy, unilateral cranial nerve VI palsy, and episodes of intense déjà vu sensation, which were presumed to represent temporal lobe-onset focal aware seizures. Trigeminal schwannomas are a rare entity, and they are even more rarely cystic. This case highlights an unusual scenario where a slow expansion of the tumor ultimately resulted in vision loss and presentation of the patient to medical attention., (© 2022 American Academy of Neurology.)

Background: An isolated oculomotor nerve (CN III) palsy is a diagnostic concern because of the potential for serious morbidity or life-threatening causes. We present 5 unusual causes of oculomotor nerve palsy that escaped initial diagnosis in order to raise awareness of their associated features that will facilitate correct diagnosis., Methods: This study consisted of a retrospective analysis of clinical features and imaging of 5 patients who were referred for neuro-ophthalmologic evaluation with presumed diagnosis of oculomotor nerve palsy of unknown reasons., Results: A complete CN III palsy and an inferior division CN III palsy were diagnosed with a schwannoma in the cavernous sinus and orbital apex portion, respectively; a middle-aged woman with aberrant regeneration was found to have a small meningioma; an adult man with ptosis was diagnosed with cyclic oculomotor paresis with spasms; and a patient after radiation was diagnosed with neuromyotonia., Conclusions: Localizing the lesion of oculomotor nerve palsy and careful examination of the imaging is crucial. Aberrant regeneration, cyclic pupil changes, and past medical history of amblyopia, strabismus, or radiation are also very helpful for diagnosis., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by North American Neuro-Ophthalmology Society.)

Abstract: A 78 year-old woman has experienced multiple episodes of transient right third nerve palsy over the course of 15 years and has undergone multiple imaging studies as well as investigations for myasthenia gravis and giant cell arteritis in search for the diagnosis. When seen after the most recent episode, MRI with contrast and Fast-Imaging Employing Steady-State Acquisition protocol revealed a subtle enlargement and enhancement of the cisternal and proximal cavernous portions of the right third cranial nerve. An empiric diagnosis of schwannoma intrinsic to third cranial nerve was made. All patients with cyclical third nerve palsies should have appropriate neuroimaging to rule out subtle structural lesions before other investigations are undertaken., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by North American Neuro-Ophthalmology Society.)

Trochlear schwannomas typically present with diplopia and are extremely rare benign intracranial neoplasms that require the combined expertise of neurotologists and neurosurgeons for surgical excision. A combined petrosal approach offers a surgical route for removal of growing and/or symptomatic tumors. A study of a trochlear nerve schwannoma that demonstrated rapid growth but was otherwise asymptomatic was presented in this study.

Objective: To present an unusual case of a temporal bone meningioma with intrafascicular spread throughout the temporal facial nerve from cerebellopontine angle (CPA) to stylomastoid foramen., Patient: Four-year-old female with progressive facial weakness and normal hearing., Main Outcome Measure: Clinical, radiological, and histopathological findings of temporal bone meningiomas., Results: A patient presented with progressive facial weakness and normal hearing. Imaging demonstrated a mass within the left internal auditory canal radiologically consistent with a schwannoma. Asymmetric enlargement with enhancement of the left facial nerve from CPA to the stylomastoid foramen suggested facial schwannoma. At surgery, gross tumor was noted in the internal auditory canal, the fallopian canal seemed expanded and the facial nerve was enlarged and had an irregular contour. Resection of the facial nerve from the CPA to just proximal to its exit at the stylomastoid foramen was necessary to achieve negative margins. Cable grafting was performed. The histopathologic diagnosis was transitional meningioma with intraneural growth throughout the length of the resected facial nerve segment., Conclusion: Meningiomas involving the temporal bone are exceedingly rare. We report a rare case of a child presenting with progressive facial weakness due to a presumed facial schwannoma spreading along the facial nerve throughout its intratemporal course that at surgery was found to be an intrafascicular CN VII meningioma.

Trochlear nerve schwannoma is extremely rare, with only 35 pathologically confirmed patients being reported in the literature. Here, the authors report a patient of trochlear nerve schwannoma in the prepontine cistern manifesting as facial pain and double vision and presenting the image characteristics of repeated intratumoral hemorrhage, which has never been reported in the literature. Total tumor along with a portion of the trochlear nerve was removed by using a retrosigmoid approach. Facial pain disappeared after operation, and the diplopia remained. Follow-up studies have shown no tumor recurrence for 2 years and the simultaneous alleviation of diplopia. Information regarding the clinical presentation, radiological features and surgical outcomes of trochlear nerve schwannoma are discussed and reviewed in the paper.

Objective: To analyze facial nerve (FN) outcomes based on duration of FN palsy and surgical strategy in patients with geniculate ganglion hemangiomas (GGH)., Study Design: Case series and systematic review of the literature., Setting: Tertiary care center., Subjects and Methods: All patients undergoing surgical resection of GGH from 1992 to 2014 were studied and a review of the English literature was performed., Results: One hundred twenty unique patients (mean age 41.4 yrs, 44% female) were identified with GGH: 8 in the current series and 112 from the literature review. Of these patients, 94% presented with FN weakness, 18% reported hemifacial spasm, and 16% had hearing loss at presentation. Eleven patients underwent an initial period of observation, 6 of which experienced either growth or progression of FN dysfunction. One hundred fourteen subjects ultimately underwent surgical intervention. The average preoperative House-Brackmann (HB) score was 4.6 and the mean duration of preoperative FN palsy was 27 months (range, 1-132). The average postoperative HB score was 3.5 at the last follow-up. Anatomical FN preservation was reported in 44% of patients. Duration of FN palsy ≤12 months was associated with better pre- and postoperative FN outcome (HB 4.1 vs 5.1, p = 0.01 and 2.9 vs 4.0, p < 0.001, respectively). FN preservation was also associated with better postoperative FN outcome compared with interposition grafting (HB 2.6 vs 3.9, p < 0.001)., Conclusion: GGHs are rare benign vascular malformations that present with progressive FN palsy. In most patients, early surgical intervention should be considered since shorter duration of FN paralysis and anatomical preservation of the FN are significant predictors of final FN outcome.

Background: Cranial nerve schwannomas are radiologically characterized by nodular cranial nerve enhancement on magnetic resonance imaging (MRI). Schwannomas typically present with gradually progressive symptoms, but isolated reports have suggested that schwannomas may cause fluctuating symptoms as well., Methods: This is a report of ten cases of presumed cranial nerve schwannoma that presented with transient or recurring ocular motor nerve deficits., Results: Schwannomas of the third, fourth, and fifth nerves resulted in fluctuating deficits of all 3 ocular motor nerves. Persistent nodular cranial nerve enhancement was present on sequential MRI studies. Several episodes of transient oculomotor (III) deficts were associated with headaches, mimicking ophthalmoplegic migraine., Conclusions: Cranial nerve schwannomas may result in relapsing and remitting cranial nerve symptoms.

Objective: To present a series of patients with facial nerve schwannomas (FNSs) presenting as occluding external auditory canal (EAC) masses., Study Design: Retrospective case series., Patients: Four patients were identified with mastoid segment FNSs occluding the EAC. Three patients presented with conductive hearing loss (CHL), and the fourth presented with facial paralysis, later developing CHL., Intervention: One patient underwent conservative debulking, removing the EAC component only. Two patients were managed nonoperatively with periodic cleaning of entrapped keratin. The fourth patient received radiation therapy., Main Outcome Measures: Facial nerve function, canal cholesteatoma formation, and hearing., Results: Among the patients managed with serial cleaning of entrapped keratin, one maintained normal facial function and one worsened to House-Brackmann II/VI. Facial function worsened to House-Brackmann II/VI in the patient who underwent surgical debulking. The fourth patient, who received radiation, developed complete facial paralysis. All patients accumulated keratin medial to the tumor, and all had CHL., Conclusion: When evaluating an EAC tumor, it is important to obtain imaging before biopsy because biopsy of a schwannoma can result in paralysis. EAC occlusion by a schwannoma presents a challenging management issue, particularly when cholesteatoma forms between the tumor and the tympanic membrane. The primary goal is maintaining normal facial function as long as possible and avoiding secondary ear canal complications. The presence of canal occlusion limits the choice of stereotactic radiation because this leads to a month-long period of tumor swelling and cutaneous sloughing. Resection and grafting are indicated when substantial facial weakness or twitch develops.

Purpose of Review: A systematic approach to the history and examination allows the physician to diagnose the most common vestibular disorders of the brain or inner ear. However, some less common disorders require a specific familiarity so that they are not misdiagnosed as one of the more common disorders,treated inappropriately, or misattributed to a psychogenic etiology. This article describes four of the less common disorders that can present with a primary problem of dizziness and imbalance: (1) mal de débarquement syndrome, (2) bilateral vestibulopathy, (3) cerebellar ataxia, and (4) vestibular schwannomas (ie, acoustic neuromas)., Recent Findings: Associated clinical features of mal de débarquement syndrome have recently been investigated to clarify the spectrum of the syndrome. The combination of cerebellar ataxia, neuropathy, and vestibular areflexia (bilateral vestibulopathy) has been summated into a new syndrome. Further refinement of ocular motor features of cerebellar ataxia can narrow genetic testing requirements. Vestibular schwannomas remain an uncommon etiology for isolated dizziness; recent imaging studies have helped quantify the low yield of screening MRI protocols for the evaluation of undefined dizziness., Summary: A working knowledge of these less common disorders will help the physician make the diagnosis efficiently by gathering key elements of the history and fine-tuning diagnostic testing.

Purpose: Full-thickness macular holes affect 0.3% of the population, worldwide. This condition has a predilection for females in their sixth to seventh decade. Patients can present with severe impairment of their central vision or can be relatively asymptomatic. We believe that an optic disc hemangioblastoma adhered to the vitreous, causing an anterior displacement of the hyaloid membrane that resulted in a form of vitreomacular traction that pulled the macular hole nasally, toward the optic nerve., Case Report: A 66-year-old white male presented to our clinic with decreased vision. He had a previously stable, longstanding optic disc hemangioblastoma. On presentation, an early developing full-thickness macular hole was noted. The outcome was a full-thickness macular hole that was disproportionately more detached on the nasal side of the macula. Treatment regimen included repeated intravitreal off-label injections with bevacizumab, followed by external beam radiation therapy, ultimately followed by surgery., Conclusions: Treatment in this case was especially complicated because of the presence of the macular hole in addition to the hemangioblastoma. The plan was to decrease vascular activity of the hemangioblastoma before proceeding with macular hole repair. First, off-label bevacizumab injections were administered, followed by external beam radiation therapy, and finally combined surgery. Surgery was successful, and to date, the macula is flat and intact.

Objective: To describe the management of traumatic neuroma of the facial nerve in a child and literature review., Patient: Sixteen-month-old male subject., Intervention: Radiological imaging and surgery., Main Outcome Measures: Facial nerve function., Results: The patient presented at 16 months with a right facial palsy and was found to have a right facial nerve traumatic neuroma. A transmastoid, middle fossa resection of the right facial nerve lesion was undertaken with a successful facial nerve-to-hypoglossal nerve anastomosis. The facial palsy improved postoperatively., Conclusion: A traumatic neuroma should be considered in an infant who presents with facial palsy, even in the absence of an obvious history of trauma. The treatment of such lesion is complex in any age group but especially in young children. Symptoms, age, lesion size, growth rate, and facial nerve function determine the appropriate management.

Hypoglossal schwannoma is a rarely encountered skull base lesion that has generally both intracranial and extracranial parts. This article reports a case of hypoglossal schwannoma that is purely extracranial and presents itself only with persistent headache. Magnetic resonance imaging delineated a mass at the skull base that consisted of both cystic and solid components, consistent with a nerve sheath tumor. Cervical approach was chosen, and the mass was completely removed. Postoperatively, the patient developed hypoglossal nerve palsy because the hypoglossal nerve was sacrificed. Hypoglossal schwannomas are briefly discussed with a literature review.

Objective: To examine the relationship between the amount of change in size and associated hearing in bilateral vestibular schwannomas (VSs) in persons with neurofibromatosis 2 (NF2)., Study Design: Annual magnetic resonance imaging and audiological examinations were conducted on NF2 patients., Subjects: Fifty-two patients enrolled in the NF2 Natural History Consortium in whom both VSs were untreated. Magnetic resonance imaging and hearing exams were available for at least 2 time points 1 year apart. The 32 males and 20 females had a mean age at diagnosis of 26 years (SD = 18). In 19 (37%) subjects, the NF2 germline mutation could not be identified in the blood (mosaic)., Outcome Measures: Greatest diameter change in tumor size for each of the 2 tumors from first to second evaluation was determined. Differences in amounts of change between the 2 sides and in hearing (4-frequency pure-tone average) were evaluated using multivariate analysis of variance., Results: Overall, the VSs demonstrated significant average growth (p < 0.001), and hearing worsened significantly (p < 0.001) over 1 year. The amount of change in the bigger tumors was not associated with the amount of change in the smaller tumors within each patient. Vestibular schwannoma size changes were not associated with the corresponding hearing changes (Kendall's tau, p = not significant [n.s.])., Conclusion: A significant 1-year change in VS size and hearing occurred in NF2 patients. Clinically, tumor change or hearing deterioration on one VS cannot be used to predict changes in the other VS. This suggests that, although NF2 is a Mendelian disease, the germline genotype-phenotype relationship may resemble that of complex disorders.

Objective: To report 4 patients who have developed a conductive and/or mixed hearing loss due to dehiscence of the inner ear after retrosigmoid approach for removal of acoustic neuroma., Patients: Four patients who presented with conductive and/or mixed hearing loss after retrosigmoid approach for removal of acoustic neuroma., Main Outcome Measure: Evidence of inner ear dehiscence on postoperative computed tomographic scan of the temporal bones., Conclusion: The occurrence of conductive hearing loss after the surgical removal of an acoustic neuroma has not previously been documented. Computed tomographic scan of the temporal bones showing inner ear dehiscence may explain this finding. Formal documentation of such cases may allow techniques to be developed to reduce its occurrence or reconstruction of the defect at the time of primary surgery.

Objective: To describe and analyze a series of intracochlear schwannomas., Methods: From 1987 to 2005, 19 patients with schwannomas involving the cochlea were included in this series. Clinical, audiovestibular, and imaging data concerning initial and follow-up visits were collected., Results: The mean age was 54 years (range, 25-71 yr). The series comprised 10 women and 9 men, 18 solitary tumors and 1 neurofibromatosis Type 2 patient. The mean diagnosis delay was 11 years (range, 1-31 yr). At diagnosis, a total or profound hearing loss (Class D of American Academy of Otolaryngology-Head and Neck Surgery classification) was noted in 17 patients (89%), and a severe loss (Class C) was reported in 2 patients (11%). Facial paresis was reported in 2 patients (11%; Grades 2 and 4 of House and Brackmann classification). Magnetic resonance imaging showed an involvement of the posterior labyrinth in 8 patients (37%), an extension of the schwannoma to the internal auditory meatus in 8 patients (37%), and a cerebellopontine angle extension in 7 patients (32%). In 11 patients (58%), the schwannoma was removed through a transotic route. In the 8 remaining patients, a watch-and-rescan policy was decided. The postoperative course was uneventful. Postoperative follow-up period was 27 months (range, 6-88 mo). Postoperative facial function was assessed as Grade 1 in 7 patients, as Grade 2 in 4, and as Grade 4 in 1 patient., Conclusion: The diagnosis of intracochlear schwannomas can be difficult on magnetic resonance imaging. The diagnosis should be considered in all unilateral hearing losses.

Objective: To calculate cerebrospinal fluid (CSF) leak rates for translabyrinthine (TL), middle cranial fossa (MCF), and retrosigmoid/suboccipital (SO) craniotomies performed for removal of vestibular schwannoma (VS) and analyze whether packing the eustachian tube (ET) in TL VS resections impacts CSF rhinorrhea rates., Study Design: Retrospective., Setting: Tertiary care center., Methods: Chart review., Results: Three hundred fifty-nine VS resections were reviewed in 356 patients ranging from 10 to 86 years of age. Two hundred thirty-one TL, 70 MCF, 53 SO, and 5 combined TL/SO procedures were analyzed. Total CSF leak rates (incisional, otorrhea, and rhinorrhea) were 14.2% for TL, 11.4% for MCF, and 13.2% for SO approaches. Differences in overall CSF leak rates were not statistically significant. For those who underwent TL craniotomies, 2 groups of patients were identified based on whether their ETs were packed during surgery. In 1 group, the incus was removed, the aditus enlarged, the ET packed, and the middle ear filled with muscle. In the second group, the aditus, epitympanum and middle ear were packed without removing the incus, and the ET was not packed. Of 148 patients who had their ET packed, 12 developed CSF rhinorrhea (8.1%). The CSF rhinorrhea rate for patients who did not have ET packing was 5.9% (3 of 51 patients). This difference was not statistically significant (p = 0.80). When Proplast was used to pack the ET (121 patients), the CSF rhinorrhea rate was 5.8%. Unfortunately, this material extruded in 4 of 121 patients (3.3%) and presented clinically as delayed purulent otorrhea., Conclusion: Cerebrospinal fluid leak rates were similar in patients undergoing TL, SO, and MCF approaches, and CSF rhinorrhea was not decreased by ET packing. Patients whose ETs are packed with Proplast are at risk for extrusion and otorrhea years after their initial VS resection.

Objective: The aim of this study was to assess the incidence of balance problems after acoustic neuroma surgery, evaluating whether disequilibrium is disabling., Study Design: Retrospective observational study., Setting: Rehabilitation center., Patients: A group of 386 patients who underwent acoustic neuroma surgery., Interventions: Patients were selected from a population of 459 subjects who had undergone surgery for acoustic neuroma., Mean Outcome Measures: The Dizziness Handicap Inventory, The Activities-specific Balance Confidence Scale (ABC), and a specific questionnaire on oscillopsia., Results: The specific questionnaire emphasized that 39 patients (10.10%) perceived disequilibrium as disabling, and the oscillopsia handicap score result was moderate in 73.32% of the sample, mild in 21.50%, and severe in 5.18% of patients. The Dizziness Handicap Inventory and ABC scales revealed the presence of handicap and disability due to disequilibrium and the influence of some variables such as sex and a higher oscillopsia handicap score. Dizziness Handicap Inventory and ABC scores were higher in symptomatic patients., Conclusion: Disequilibrium influences handicap and disability after acoustic neuroma surgery. This symptom is also present after several years since surgery, and some patients perceived disequilibrium as disabling.

A 17-year-old woman developed a sixth cranial nerve palsy from a malignant peripheral nerve sheath tumor of the trigeminal nerve. This case is unusual in that the principal symptom was diplopia stemming from a sixth cranial nerve palsy. Pain was mild, and trigeminal function was preserved. Imaging evidence of rapid growth of the cavernous sinus mass gave rise to an initial impression that the cause might be inflammatory. Treatment with gamma knife stereotactic radiosurgery produced some improvement in sixth cranial nerve function and reduction in tumor size over a follow-up period of 9 months.

Objective: To evaluate the surgical results in primary facial nerve (FN) tumors., Study Design: Retrospective case review., Setting: Private neuro-otological and skull-base tertiary referral center., Patients: Twenty eight consecutive patients affected by primary FN tumors that underwent surgery between December 1990 and February 2001., Interventions: The lesions were removed through a variety of surgical approaches, depending on tumor location and extension, as well as preoperative hearing. In one case, partial removal was performed., Main Outcome Measures: Preoperative and postoperative FN function; preoperative and postoperative hearing level; and postoperative complications., Results: Based on histologic examination, tumors were distributed as follows: 18 schwannomas, six hemangiomas, two meningiomas, and two neurofibromas. Tumor location varied, with lesions distributed along the entire length of the nerve. Facial dysfunction was the most frequently recorded symptom, followed by hearing loss. Only five patients presented a preoperative grade 1 facial function. In the remaining patients of the group, the facial deficit lasted from 2 to 120 months, with a mean of 31.2 months. Anatomic integrity of the nerve was preserved in 4 cases; all others required a nerve interruption followed by reconstruction using a sural nerve graft. The complications recorded were: one cerebrospinal fluid leak, one postoperative retraction pocket, and one external auditory canal wall resorption requiring a surgical revision. Preoperative hearing remained unchanged in 8 out of the 15 patients in whom a hearing preservation procedure was attempted. In 25 cases, a follow-up of equal to or longer than 1 year was available, with the FN functions: two grade 1, eight grade 3, nine grade 4, three grade 5, and three grade 6. Patients with a preoperative deficit lasting more than 1 year demonstrated the worst recovery., Conclusions: Primary FN tumors are rare lesions that include different histologic types. FN deficit represents the most common symptom, but it is not present in all cases. A conservative strategy is often adopted in presence of a normal preoperative facial function. When surgical management is selected, the decision on surgical approach to use depends on tumor size and location, as well as on preoperative hearing. FN integrity may be spared in rare occasions, but more frequently nerve reconstruction is required. Final facial function recovery is mainly dependent on the preoperative presence of FN deficit and its duration.

Objective: To evaluate the results of facial nerve reconstruction by means of grafting and to determine the influence of different variables on final functional recovery., Study Design: Retrospective case review., Setting: Tertiary otologic and skull base referral center., Patients: Sixty nine patients underwent facial nerve grafting. Facial nerve tumors (24) or vestibular schwannomas (18) affected most of them. Preoperatively, 47 patients had a clinical facial nerve deficit lasting from 1 to 120 months, with a mean of 20.2 months., Main Outcome Measures: Final facial nerve motor function., Results: Among the 56 patients with a follow-up time equal to or longer than 1 year, 26 recovered to a Grade III (46.4%), 14 to a Grade IV (25%), while 16 remained at Grade V or Grade VI according to the House-Brackmann scale. Patients with a preoperative facial nerve deficit for more than 1 year showed the lowest rate of recovery, with only 3 cases (19%) reaching Grade III., Conclusions: Duration of the preoperative facial nerve deficit emerged as the most important factor influencing final results. According to the authors' data, the 1-year period after the occurrence of the preoperative clinical deficit seemed to be the cutoff point in achieving a high rate of good postoperative recovery. Among the other factors that might have influenced the final outcome, only the underlying cause of the lesion played a significant role.

Objective: To assess facial nerve function after fascicle preservation surgery in cases of facial nerve neuroma involving the cerebellopontine angle., Study Design: Retrospective case series and literature review., Setting: Tertiary referral center., Patients: Seven patients with facial nerve neuroma involving the posterior cranial fossa were reviewed from a single neurotologist's practice and combined with a review of 648 cases reported in the literature., Interventions: Translabyrinthine resection was used in all patients for complete tumor removal. Nerve reconstruction was accomplished with fascicle preservation (three cases), cable nerve interposition grafting (three cases, one of which involved using cranial nerve VIII as the graft), or direct anastomosis (one case)., Main Outcome Measure: Facial nerve function as measured by the House-Brackmann grading system. RESULTS A postoperative facial nerve (House-Brackmann) grade of II/VI was obtained in two of our three patients who underwent fascicle preservation reconstruction and in two of eight cases reported by other authors. One case reported elsewhere resulted in grade I/VI, and four other cases reported elsewhere achieved grade III/VI; only two cases were grade V/VI. There were no tumor recurrences at 5 to 19 years of follow-up., Conclusion: Most cases of facial nerve neuroma require facial nerve resection. In rare cases, these tumors can be dissected away from the nerve fascicles, allowing the surgeon to preserve the facial nerve. This method resulted in better long-term postoperative facial nerve function (House-Brackmann grade II/VI vs. grade III/VI) compared with other techniques for patients in this small series, and no tumor recurrence.

Objective: The aim of this study was to report a series of 18 facial nerve schwannomas, including 2 infantile cases., Study Design: Retrospective case review., Setting: Tertiary referral center., Patients: Eighteen patients with facial nerve schwannoma, operated on between 1980 and 2000., Intervention: Surgical treatments were performed in all cases., Main Outcome Measures: The presenting symptoms and facial nerve function were graded using the House-Brackmann scale and eye closure. RESULTS Facial nerve paralysis was the most common symptom, presenting in 94% of cases, followed by hearing loss and mass lesion. In one case, the tumor was shaved, leaving the facial nerve intact. In the other cases, the facial nerve reconstruction with hypoglossal-facial anastomosis or interposition graft was performed. The postoperative facial function was House-Brackmann grade IV in most cases (88.2%). In terms of the functional recovery classified by complete or incomplete eye closure, the moderate preoperative facial nerve palsy group showed a better functional outcome than severe group., Conclusion: In cases with good facial nerve function, it would be better to consider an alternative method for preserving the facial nerve. Furthermore, when facial nerve paralysis has developed to more than House-Brackmann grade III, an immediate operation is recommended to obtain a good postoperative facial functional recovery.

Objective: Evaluation of the ability of screening high-resolution, nonenhanced, fast spin echo (FSE) T2-weighted magnetic resonance imaging (MRI) of the internal auditory canal (IAC) and cerebellopontine angle (CPA) to detect nonacoustic schwannoma causes of unilateral sensorineural hearing loss (SNHL). FSE-MRI is equally sensitive in detecting acoustic (vestibular) schwannoma as gadolinium-enhanced MRI, but sensitivity to other causes of hearing loss is unknown., Study Design: Retrospective review of screening FSE-MRI studies., Setting: Academic otology/neurotology and neuroradiology practices., Patients: There were 1,070 patients with unilateral SNHL who underwent radiologic screening for retrocochlear pathology., Results: Normal findings were found in 944 cases. Typical (acoustic) vestibular schwannoma were found in 56 patients. Seventy additional lesions were identified: 27 CPA lesions, 29 inner ear lesions, and 12 intraaxial lesions including 9 infarctions, 1 multiple sclerosis case, 1 mesial temporal lobe sclerosis, and 1 colloid cyst., Conclusions: High-resolution T2 FSE-MRI of the IAC and CPA is a highly sensitive screening tool for unilateral SNHL, which can detect a variety of lesions in addition to vestibular schwannomas. To our knowledge in 2 years of follow-up in these patients screened for IAC/CPA lesions, no other lesions causing SNHL have been found. High-resolution FSE screening technique, used in conjunction with appropriate clinical prescreening and referral, can provide an equally sensitive method of evaluating unilateral SNHL compared to gadolinium-enhanced T1 MRI while reducing costs and providing distinct advantages in evaluating nonacoustic schwannoma causes of SNHL.

Objective: To determine the risk of loss of useful hearing in the absence of tumor growth among patients undergoing conventional management of acoustic neuroma., Setting: Tertiary referral center., Study Design: Retrospective case review., Patients: Ten patients (12 ears) were identified having a period of no tumor growth of at least 6 months (19.0+/-12.8 months), and for whom at least two audiograms were available in this period., Interventions: None., Main Outcome Measures: Loss of useful hearing defined using 70% speech discrimination score (SDS) and 30 dB pure tone average (PTA) (70/30), or 50% SD and 50 dB PTA (50/50) criteria., Results: Three of seven (43%) ears with useful hearing using the 70/30 rule and two of eight ears (25%) using the 50/50 rule lost this useful hearing., Conclusions: There is a significant risk of useful hearing loss with conservative management of nongrowing acoustic neuromas.

Objectives: To assess facial nerve injury caused by vestibular Schwannoma compression and the adaptive ability of the nerve/muscle complex to maintain normal clinical facial function., Study Design: Prospective study., Setting: Tertiary referral centre., Patients: Thirty-four patients undergoing translabyrinthine resection of vestibular schwannoma., Intervention: Diagnostic., Main Outcome Measures: Facial nerve action potential (FNAP) amplitude recorded at the second genu enables direct assessment of motoneuron function. Comparison of FNAP amplitudes to stimulation proximal and distal to tumor compression allows calculation of motoneuron conduction block across the site of tumor compression. Recordings performed before tumor dissection from the facial nerve reflects nerve injury caused by vestibular Schwannoma compression alone. Comparison of compound muscle action potential (CMAP) amplitudes to stimulation proximal and distal to tumor compression measures motoneuron conduction block and compensatory collateral sprouting at the nerve/muscle interface. Comparison of FNAP and CMAP data demonstrates the extent of collateral sprouting, which helps maintain normal clinical facial function., Results: Normal clinical facial function is maintained when only 10% of functioning motoneurons are active. The facial nerve is highly susceptible to tumor compression with significant motoneuron injury occurring with all sizes of tumors. Motoneuron injury correlates with tumor size but with exceptions. Collateral sprouting maintains muscle function despite severe motoneuron injury. There is a significant decrease in muscle function when >80% of functioning motoneurons are in conduction block., Conclusions: The facial nerve is highly susceptible to vestibular Schwannoma compression. Collateral sprouting of active functioning motoneurons reinnervate denervated muscle fibers so maintaining muscle function and therefore clinical facial function.

The authors describe the clinical and electrophysiologic findings in a patient with synkinesis between muscles innervated by the facial and trigeminal nerves after resection of a trigeminal schwannoma. Conventional facial nerve conduction and blink reflex studies were normal. Stimulation of the supraorbital and facial nerves elicited reproducible responses in the masseter and pterygoid muscles, confirming a peripheral site of aberrant regeneration of the facial and trigeminal nerves.

Objective: This study aimed to clarify the pathophysiology involved in the cause of hearing impairment due to acoustic neuromas (AN) with electrocochleograph (ECoG)., Study Design: The study design was a retrospective case study., Setting: This study was conducted in a tertiary referral center., Patient: Thirty-four patients diagnosed as having AN by magnetic resonance imaging between 1988 and 1995., Intervention: Diagnostic., Main Outcome Measures: The authors made a comparison between the patients' ECoG findings and the size of their tumors as determined by magnetic resonance imaging and a pure-tone audiometry (PTA). The disparity between the threshold of PTA and the detective threshold of compound action potential (CAP) or that of the cochlear microphonics (CM) was calculated. When the threshold of the PTA was worse than the detective threshold of the CAP or the CM, the disparity was regarded as indicating a hearing loss of retrocochlear origin., Results: There was no correlation found between tumor size and the detective threshold of CAP or CM. Disparity was found to correlate with tumor size., Conclusions: These findings seem to indicate that retrocochlear damage in AN increases parallel to the growth of the tumor and that retrocochlear damage can be detected by the ECoG before surgery.

Objective: Since 1991, three separate reports have shown how hearing may be salvaged after translabyrinthine excision of small acoustic tumors. The authors submit yet another report of a complete translabyrinthine excision of a 1.4-cm intracanalicular acoustic tumor with modest hearing preservation. An attempt is made to retrace the steps of the operation and recognize and discuss what particular events may have safeguarded the viability of the cochlea. With the availability of cochlear implantation, there should be added incentive to preserve the cochlear neurones if hair cells cannot be saved., Study Design: The study design was a retrospective case review., Setting: The study was conducted at a primary care hospital., Intervention: Therapeutic and rehabilitative measures were performed., Main Outcome Measures: Hearing preservation was measured., Case Report: A 55-year-old woman presented with a left-sided hearing loss and a 1.4-cm left acoustic tumor completely filling the internal auditory canal (speech reception threshold [SRT] 30 dB, discrimination [Pb] 28%). A successful translabyrinthine excision of the tumor was performed in November 1995. A 1-year postoperative audiogram showed a mixed hearing loss in the left ear with SRT 85 dB and Pb 0%. Average pure-tone threshold for 500 Hz, 1 kHz, and 3 kHz was 50 dB and aided SRT 40 dB with Pb 64%. Postoperative magnetic resonance imaging confirmed complete excision of the tumor., Conclusion: An exceptional case of hearing preservation after translabyrinthine excision of a small acoustic tumor illustrates how it may be possible to preserve cochlear hair cells and neurones simultaneously in certain selected cases. A review of the surgical events shows the value of sealing the cochlear duct with bone wax, selectively removing the vestibular nerves with the tumor by sharp dissection, and safeguarding the meatal segment of the anterior inferior cerebellar artery by a limited dural incision.

Objective: The aim of the study was to provide a clinical review of the middle fossa approach for hearing preservation in patients with neurofibromatosis type 2 (NF2)., Study Design: The study design was a prospective case review., Setting: The study was conducted at a private practice tertiary neurotologic referral center., Patients: Eighteen patients diagnosed with NF2 underwent 23 middle fossa procedures between 1992 and 1996 for removal of an acoustic neuroma. The nine males and nine females ranged in age from 11-73 years with a mean age of 28 years. Tumor size ranged from 0.5-2.5 cm with a mean of 1.1 cm., Main Outcome Measures: House-Brackmann facial nerve grade was measured. In addition, hearing level was classified both by the American Academy of Otolaryngology-Head and Neck Surgery criteria for reporting results of hearing preservation surgery and by comparison with preoperative level (15 dB/15%)., Results: Measurable hearing was preserved in 65%, 48% within 15 dB of preoperative pure-tone average (PTA) and within 15% of preoperative speech discrimination. Bilateral hearing preservation occurred in five patients. Excellent facial nerve function (House-Brackmann grades I-II) was obtained in all patients with normal preoperative facial nerve function., Conclusions: In this series of patients with NF2, outcomes in hearing and preservation of preoperative facial nerve function are similar to results seen in patients suffering a sporadic unilateral acoustic neuroma. However, early intervention is crucial in obtaining such favorable outcomes.

Objective: This study aimed to identify preoperative signs or symptoms that correlate with poor postoperative vestibular compensation after acoustic neuroma removal., Study Design: The study design was a retrospective chart review., Setting: The study was conducted at a tertiary care center., Patients: A total of 210 patients who had acoustic neuromas removed via the retrosigmoid approach from January 1, 1990, to July 1, 1995, participated., Main Outcome Measures: Persistent dysequilibrium for > 3 months after surgery was measured., Results: Age (p = 0.002), gender (p = 0.007), presence of preoperative dysequilibrium (p = 0.005), duration of preoperative dysequilibrium > 3.5 months (p = 0.003), and central findings on electronystagmography ( p < 0.001) were related to poor outcome., Conclusions: The authors found 31% of patients to have dysequilibrium lasting > 3 months after surgical removal of an acoustic neuroma. Age > 55.5 years, female gender, constant preoperative dysequilibrium present for > 3.5 months, and central findings on electronystagmography were associated with a worse outcome.

An interesting case is reported of an 11-year-old girl who experienced a sudden, profound right-sided hearing loss at the age of 5 years after hearing a "pop" and the sound of rushing water in her right ear. At that time the patient was thought to have Mondini's deformity, and a perilymphatic fistula of the oval window in the right ear. Six years later she was diagnosed with a juvenile pilocytic astrocytoma of the pons with an exophytic component extending into the cerebellopontine angle. Of particular interest in this case is the presence of evoked otoacoustic emissions in the right ear with a profound neural hearing loss. The presence of transient evoked and distortion product otoacoustic emissions confirmed normal sensory outer hair cell function and an intact peripheral auditory system in a clinically deaf ear, thus indicating hearing loss due to a neural component instead of a sensory component, which was previously assumed.

We report three patients with gangliogliomas involving the optic chiasm via distinct mechanisms. The ganglioglioma in one patient likely originated in the temporal lobe and spread medially to involve the chiasm, and diffuse spinal cord dissemination also occurred. Chiasmal involvement in this manner and dissemination at presentation are unusual for gangliogliomas. The tumor in a second patient was intrinsic to the hypothalmus and chiasm, while in the third patient, it involved both optic tracts, and a cyst compressed the chiasm laterally. Two patients developed severe bilateral visual loss, while the other had a stable bitemporal hemianopsia. Two patients received radiotherapy, but one continued to lose vision. Although gangliogliomas rarely involve chiasm, the mechanisms by which they produce chiasmal visual loss may be diverse, and the long-term visual prognosis is variable.

Techniques to repair cerebrospinal fluid (CSF) leak through the eustachian tube (ET) include temporary or permanent CSF diversion; middle fossa craniotomy and packing of the ET from above; and packing of the ET from behind, through the middle ear. We report a case of endoscopic closure of the ET in the nasopharynx (the front). A 26-year-old woman underwent a translabyrinthine removal of a 4.5-cm vestibular schwannoma. One year later, she developed CSF rhinorrhea and meningitis. Attempts at control of this leak included traditional approaches mentioned previously (shunting, middle fossa, middle ear packing). The leak recurred 2-3 months after each procedure. An endoscope was used transnasally to expose the ET orifice, which was incised, inverted, and cauterized. She has remained free of leak for 1 year. Our success in this difficult case suggests that this is a useful procedure for treatment of CSF rhinorrhea originating in the posterior fossa. Greater experience is needed to verify its long-term effectiveness and utility as a primary procedure for the treatment of CSF rhinorrhea.

High-resolution computed tomography (CT) has long been the method of choice in the visualization of the petrous bone, the internal auditory canal, and the cerebellopontine angle. The introduction of magnetic resonance imaging (MRI), especially of the three-dimensional Fourier transformation constructive interference in steady state (3DFT-CISS), has proved to be superior in the detection of soft-tissue lesions in the inner ear. The aim of this study was to visualize small anatomic structures of the inner ear and cerebellopontine angle. The examinations were performed with a standard head coil on a 1.5-T Magnetom ("Vision"; Siemens, Erlangen, Germany). The three-dimensional reconstruction of the cochlea, semicircular canals, and vestibulum allowed detailed visualization, as well as the imaging of cranial nerves VII and VIII. Our results indicate that 3DFT-CISS MRI is a valuable diagnostic tool in the evaluation of inner ear anatomy and pathology; in most cases, however, it must be supplemented by HR-CT.

The advent of magnetic resonance imaging (MRI) has significantly increased the clinician's ability to detect small vestibular schwannomas. This had led to controversy in the evaluation of patients with asymmetric sensorineural hearing loss, as some recent studies have suggested that the auditory brainstem response (ABR) does not adequately detect small tumors of the internal auditory canal and cerebellopontine angle. As these studies evaluated ABR results in patients already diagnosed with vestibular schwannomas, they could not determine the epidemiologic accuracy (validity) of the ABR as a screening test for retrocochlear pathology. We report on the preliminary results of an ongoing prospective study on the evaluation of patients with asymmetric sensorineural hearing loss. All patients with asymmetry in two or more pure-tone thresholds of > or = 15 decibels or asymmetry in speech discrimination scores of > or 15% or both entered the study and underwent both an ABR examination and an enhanced MRI scan. Based on preliminary results obtained from the first 47 patients entered in this study, the ABR screening test for retrocochlear pathology was determined to have a sensitivity of 63%, a specificity of 64%, a positive predictive value of 26%, and a negative predictive value of 89%. All patients in whom ABR failed to diagnose a vestibular schwannoma had unilateral hearing los. These results bring into question the validity of ABR as a screening test for retrocochlear pathology, particularly in cases of unilateral hearing loss. Continued patient enrollment in this study will allow the confirmation of these results.

A retrospective analysis was performed of puretone audiograms, speech-discrimination scores, and gadolinium-enhanced magnetic resonance imaging scans of 75 patients with vestibular schwannomas (acoustic neuroma). Sensorineural hearing loss was analyzed for low frequencies (250-500 Hz), midfrequencies (1,000-2,000 Hz), and high frequencies (4,000-8,000 Hz). The largest tumor diameter in the cerebellopontine angle and the lateral extent of invasion by tumor into the internal auditory canal were calculated from magnetic resonance images. There were statistically significant correlations between the largest tumor diameter and the severity of low-frequency sensorineural hearing loss (p = 0.001). However, no significant correlations were found between the following: largest tumor diameter and the severity of mid-frequency or high-frequency sensorineural hearing loss or speech-discrimination scores and lateral extent of invasion of the internal auditory canal and sensorineural hearing loss at all frequencies or speech-discrimination scores (p > or = 0.05). The findings suggest that nerve compression is not the only cause of hearing loss in vestibular schwannoma.

A 54-year-old man developed an acquired monocular elevation paresis. Forced lid closure or oculocephalic reflexes failed to elevate the affected eye in contrast to the contralateral eye, which turned fully upward using either maneuver. A mass lesion compressing the lateral aspect of the right oculomotor nerve at the exit of the brainstem was found. The monocular elevation paresis in this patient reflects damage of the oculomotor nerve fascicles that supply the inferior oblique and superior rectus muscles. This case supports the accepted topographical fascicular arrangement of the oculomotor nerve, with the inferior oblique and superior rectus being the most lateral and caudal, and the pupilloconstrictor fibers and the inferior rectus being most medial and rostral.