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Background: Hearing response following an osteodural decompression of the internal auditory canal (IAC) is controversial., Objective: To evaluate the course of auditory brainstem responses (ABRs) and the early hearing response during the first year following IAC decompression for small to medium-sized vestibular schwannomas occurring in neurofibromatosis type 2 (NF2)., Methods: Retrospective chart review of middle fossa craniotomy for IAC osteodural decompression in NF2-related vestibular schwannomas., Results: Twelve NF2 patients were operated on from 2011 to 2016 for IAC decompression. All had NF2 according to the Manchester criteria. All had a progressive change of their ABRs documented from the diagnosis of NF2 over a mean period of 6.25 [0.36;10.9] yr. Treatment was proposed to stop hearing progression based on the speech discrimination scores (SDSs; n = 4) or for hearing maintenance (n = 8). In patients with prior hearing progression, hearing responses were observed in 3 of the 4 patients during the first year. One patient kept on progressing. In the hearing maintenance group, the SDSs remained stable. SDSs improved from 85% [20-100] to 92.5% [60-100] on average (n = 12) and from 55% [20-80] to 77.5% [50-100] in the hearing progression group (n = 4). ABRs improved in 4 patients following decompression., Conclusion: IAC decompression allows early objective hearing responses in select patients. We suggest that the procedure should be offered to patients with hearing progression based on their SDSs and/or associated progressive increases in their wave III and V latencies on ABRs., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: The vast majority of cerebellopontine angle tumors are benign with a favorable prognosis. Metastatic tumors occurring in the cerebellopontine angle are extremely rare. Herein, we report a case of colon carcinoma metastasis to the bilateral internal auditory canals., Case Description: A 59-year-old man presented with a 2-week history of binaural hearing loss. One year before admission, he was diagnosed with colon carcinoma and underwent surgical resection combined with chemotherapy. Physical examination showed complete hearing loss in bilateral ears and bilateral facial palsy. Magnetic resonance imaging of the brain revealed nodules in the bilateral internal auditory canals. Middle-ear computed tomography demonstrated soft-tissue masses extending into the bilateral internal auditory canals. A diagnosis of neurofibromatosis type II was suspected. A unilateral surgical resection of the cerebellopontine angle tumor was performed. Postoperatively, the hearing loss and facial palsy remained unchanged. Pathologic examination showed metastatic, poorly differentiated carcinoma. The patient was diagnosed with metastatic colon carcinoma in the bilateral internal auditory canals. The patient refused radiotherapy and chemotherapy. The tumor progressed rapidly, and the patient developed dysphagia and choking 1 month later. The patient died of respiratory and circulatory failure 2 months after the surgery., Conclusions: Clinicians should be aware of metastatic tumors in the internal auditory canals. Comprehensive clinicoradiologic evaluation should be highlighted. A history of malignancy and rapidly progressive hearing loss and facial palsy may suggest the diagnosis of metastasis to the internal auditory canal. The definitive diagnosis still depends on histopathologic examination., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: When vestibular schwannoma (VS) collides with meningioma at the cerebellopontine angle (CPA), a particular threat occurs. Sudden acceleration of tumor growth and unpredictable involvement of cranial nerves results in a special environment that aggravates management. The goal of this study was to analyze the extent of resection, postoperative facial and cochlear function, surgical strategy, and survival rates in patients with neurofibromatosis type 2 (NF2) with meningioma-vestibular schwannoma (M-VS) collision tumors., Methods: A total of 1284 VS, including 165 NF2 VS were operated at our department between January 2004 and May 2018. Out of these cases, a group of six NF2 patients with seven M-VS collision tumors was found following careful analysis of neuroradiological data and pathological and surgical reports. Patients were evaluated for extent of tumor resection and, furthermore, postoperative facial and hearing function., Results: Six patients with NF2 with seven M-VS collision tumors were included in this study. Mean age was 32 ± 8.2 years. A gross total resection (GTR) of both colliding tumors was achieved in only one case, a GTR of the meningioma and a subtotal resection (STR) of the VS in four cases and in two cases only, the meningioma was removed. In five of the cases, facial function was intact or good (House and Brackmann grades I-II) at long-term follow-up (mean follow-up 22 months). No mortality occurred during follow-up., Conclusions: Collision between M and VS at the CPA is a particular phenomenon in NF2 patients that may aggravate the situation with less favorable surgical outcome than NF-2 VS without meningioma.

Objective: To predict and optimize hearing outcomes with a cochlear implant (CI) in patients with intracochlear schwannoma and neurofibromatosis type 2 (NF2)., Patient: A patient with NF2 and bilateral deafness., Interventions: The intracochlear portion of a vestibular schwannoma was removed with a partial cochleoectomy. During the procedure, a CI was implanted., Main Outcome Measures: Perioperatively, electrically evoked auditory brainstem responses (eABRs) were recorded with a novel intracochlear, CI-evoked, broad band stimulus to support the decision to implant a CI., Results: We found positive eABR responses, with thresholds at around the 200 current level. The eV wave was discernible at all stimulated electrodes, with a prolonged latency of about 6.5 ms. The eIII wave was detected at electrodes 9 and 13, with a latency of 4.5 ms. The acoustic reflex was detectable at all stimulated electrodes. Subjective auditory perception could be achieved by stimulating 3 days after surgery. In open-set word recognition, the patient achieved 60% recognition of monosyllables after the first audio processor fitting and 100% 1 month later., Conclusions: After a partial cochleoectomy, this method may serve as a peri-operative, objective assessment of cochlear nerve integrity that could potentially impact the prediction of CI performance. Potential future applications might be assessments of cochlear nerve integrity in patients with inner ear malformations, radiologically suspected cochlear nerve deficiencies, and resected or irradiated spontaneous vestibular schwannomas or NF2.

Purpose: To describe a case of giant intercostal nerve schwannoma successfully resected in a patient with neurofibromatosis type 2., Methods: A 44-year-old woman, with a history of neurofibromatosis type 2, presented with chest discomfort and mild dyspnea. She had undergone a recent resection of a large frontal parasagittal benign meningioma. Radiologic examinations showed a large lesion (9×12×9 cm) of the left hemithorax causing a complete atelectasis of left upper lobe. Bronchoscopy did not show any endobronchial alterations, apart from an ab estriseco compression of the left upper bronchial tree. A transthoracic needle biopsy was then performed and microscopic examination revealed a mesenchymal tumor composed of spindle-like cells., Results: A video-assisted thoracoscopic surgery procedure was proposed. The tumor mass appeared to be tenaciously adherent to the parietal pleura in its anterolateral aspect, confirming the radiologic appearance. No invasion of the lung parenchyma or parietal pleural metastases were visible. Therefore, a left posterolateral thoracotomy at the fifth intercostal space was performed and a macroscopic complete resection was carried out. The recovery was uneventful and the patient was discharged on postoperative day 5. The histologic examination revealed a moderate cellular proliferation of spindle-shaped and oval to polygonal cells with frequent Verocay bodies; mitotic figures were rare. The tumor cells were strongly S-100 positive. The microscopic features were consistent with benign intercostal schwannoma. Eight years later, the patient is disease-free and asymptomatic., Conclusions: An unusual case of giant intercostal nerve schwannoma successfully resected in a patient with neurofibromatosis type 2 is described.

Neurofibromatosis type 2 (NF2) is a complex disease characterized by the development of multiple schwannomas, especially vestibular schwannomas, as well as other types of benign tumours including meningioma and spinal ependymoma. Due to its multisystem nature, the management of NF2 requires a multidisciplinary approach. In England, the delivery of care for NF2 patients has been centralized to four-"hub" centres in Manchester, Cambridge, Oxford and London each having associated "spoke" centres. Each centre has a core multidisciplinary team consisting of genetics, otolaryngology, neurosurgery, paediatrics, neurology, audiology, radiology, psychology, physiotherapy, specialist nurses and administrative staff. In addition, the core team has access to plastic surgery, ophthalmology, peripheral nerve surgery and adult and paediatric oncology. There are weekly multidisciplinary clinics each with six to eight patients. Each patient is discussed during a team meeting and the management decisions that are made are then discussed with the patients. All patients are reviewed at least annually and have annual head magnetic resonance imaging (MRI) and three yearly spinal MRI. Annual audiological assessment is performed. Cochlear implantation and auditory brainstem implantation are offered if indicated. Surgery, stereotactic radiosurgery and bevacizumab therapy are available for the management of intracranial and spinal tumours. The integration of the service in England has provided significant benefits to patient care and, in the long term, will provide robust patient outcome data that will provide an evidence base to assist in optimizing management of patients with NF2., (Copyright © 2016. Published by Elsevier Masson SAS.)

The understanding of the molecular pathways underlying tumor development in neurofibromatosis type 2 (NF2) is increasing. Thus, repositioning drugs, drug therapies that are already clinically available for various cancers, appear potentially promising for NF2 patients. Based on preclinical data from in vitro or animal models, five different treatments have been proposed for selected NF2 cases. Evaluation of bevacizumab, a monoclonal antibody against VEGF has mainly been reported in retrospective studies; it has been reported to induce hearing improvement and tumor shrinkage in more than 50% of progressive vestibular schwannomas (VS). In our experience with 16 patients, bevacizumab is associated with an increase of median time to tumor progression of VS from 5.6 months before bevacizumab onset, to more than 29.3 months. The need for intravenous injections and long term adverse events (hypertension, proteinuria, hemorrhage) are the main drawbacks. Lapatinib seemed promising in a single phase II trial with a volumetric response observed in 4/17 patients and a hearing response in 4/13, but is not currently used in clinical practice. Erlotinib has not been associated with radiographic or hearing responses in a phase II trial. Everolimus has been evaluated in 3 phase II trials. Everolimus did not induced tumor shrinkage, but seems to be able to increase time to tumor progression in selected cases. Currently, bevacizumab is the only drug proposed to selected NF2 patients., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

The main manifestation of neurofibromatosis type 2 (NF2) is the development of bilateral vestibular schwannomas (VS). Consequently, one of the most severe functional sequelae is bilateral sensorineural hearing loss, caused by spontaneous tumor progression and/or treatment-related damage (surgery or radiosurgery). Preserving or restoring hearing is still challenging in NF2 no matter the strategy applied to each individual based on the natural history of VS. In this review, the different strategies for hearing preservation or rehabilitation are discussed and illustrated by several cases. A decisional algorithm for NF2 patients with VS is proposed that takes into consideration the tumor size and hearing level., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Context and Objective: Bilateral vestibular schwannomas are the hallmark of neurofibromatosis 2 (NF2), occurring in 95% of patients. These tumors are associated with significant morbidity due to hearing loss, tinnitus, imbalance and facial weakness. As radiosurgery and chemotherapy have been recently introduced in the treatment armamentarium in addition to surgery, a thorough evaluation of vestibular schwannoma natural history is mandatory to determine the role and timing of each treatment modality., Methods: An exhaustive review of the literature was performed using the PubMed database concerning the natural history of tumor growth and hearing loss in NF2 patients with vestibular schwannomas., Results: Although some aspects of vestibular schwannoma natural history remain uncertain (pattern of tumor growth, mean tumor growth rate), factors influencing growth such as age at presentation and paracrine factors are well established. Studies focusing on the natural history of hearing have highlighted different patterns of hearing loss and the possible role of intralabyrinthine tumors. The polyclonality of vestibular schwannomas in NF2 was recently unveiled, giving a new perspective to their growth mechanisms., Conclusion: An uniform evaluation of tumor growth using volumetric evaluation and hearing with standard classifications will ensure the use of common endpoints and should improve the quality of clinical trials as well as foster comparison among studies while ensuring more consistency in decision-making., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Introduction: The aim of this study was to analyze the long-term results of Gamma-knife radiosurgery treatment of vestibular schwannomas in type 2 neurofibromatosis patients., Materials and Methods: A cohort of 129 treatments for vestibular schwannomas in 103 patients was selected from a prospectively-maintained clinical database. Tumor control was assessed by volumetric analysis of the tumor at the last follow-up. Any need of a further procedure such as microsurgical removal or second treatment was regarded as a failure of tumor control. Hearing function was assessed based on Gardner-Robertson classification. Progression-free survival and functional hearing preservation rates were estimated using the Kaplan-Meier method., Results: The median age at treatment was 34 years with no gender predominance. The median tumor volume was 1.5cm 3 . At a median clinical follow-up of 5.9 years, five patients had died, four underwent a second radiosurgical procedure and eight underwent microsurgical resection. Progression-free survival was 88 and 75% respectively at 5 and 10 years. Hearing was considered serviceable in 70 ears and remained functional in 28 ears. Kaplan-Meier estimates for 5 and 10 years functional hearing was 47 and 34%, respectively. Three patients developed new facial nerve palsy after radiosurgery at 15 days, 6 and 19 months respectively and only one partially recovered. Five patients complained of a subjective instability worsening. Four cases developed trigeminal neuropathy. No predictive factors were found to be statistically correlated with a better hearing outcome or an improved tumor growth control., Conclusion: Results prove less satisfying than in sporadic unilateral schwannomas. However, the lower rate of mortality and morbidity compared with microsurgical resection may support a proactive role of Gamma-knife in this pathology., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Introduction: Neurofibromatosis type 2 is characterized by the presence of bilateral vestibular schwannomas. However, other nervous system tumors may also occur. Therefore, the management of NF2 patients is complex and requires a multidisciplinary discussion in a specialized center., Materials and Methods: All recent articles concerning tumors other than vestibular schwannoma in NF2 disease were reviewed, using PubMed databases., Results: Intracranial meningiomas occur in 50% of NF2 patients, and are often multiple. Surgery remains the main treatment and should be performed in cases of growing tumors. The role of antiangiogenic therapy is currently under evaluation and the role of radiosurgery still remains to be defined in NF2 disease. Spinal tumors occur in about half of NF2 patients. Surgery should be discussed when radiological tumor progression is demonstrated, even if spinal tumors are asymptomatic, in order to preserve neurological function and good quality of life. As regards lower cranial nerve schwannomas, radiosurgery appears to be a more appropriate treatment for growing tumor with a small volume in order to avoid post-operative complications, especially swallowing disorders. Facial nerve schwannomas may appear, on MRI, like vestibular schwannomas. The diagnosis should be suspected when the facial palsy is an early symptom during cerebello-pontine tumor progression. Trigeminal schwannomas are frequent in NF2 disease and fortunately they are often asymptomatic. Among major neurofibromatosis types, peripheral nerve sheath schwannomas are only present in patients with NF2 disease and schwannomatosis. Surgical resection is required when the cutaneous schwannomas is painful or when tumor progression is observed and causes symptoms., Conclusion: Tumors other than vestibular schwannoma are also associated with a poor prognosis in NF2 patients. Surgery remains the main treatment in most cases. Each treatment decision in NF2 disease requires a complete evaluation of all cranial and spinal locations of the disease in order to establish surgical priorities and strategies., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Auditory brainstem implantation (ABI) is the only solution to restore hearing when cochlear nerves are disrupted together with the pathologies where bilateral cochleae do not provide a suitable location for cochlear implantation. We reported first two successful auditory brainstem implantation cases in patients with neurofibromatosis Type II (NF2) with bilateral acoustic neuroma causing bilateral profound sensorineural hearing loss in Malaysia. A good candidate selection, dedicated surgeons and rehabilitation team as well as strong family support are the crucial factors in achieving the best possible surgical, audiological and speech outcomes.

Background: Resection of a vestibular schwannoma may result in facial paralysis and hearing loss on the side of the tumor. We evaluated clinical, audiologic, and intraoperative events and radiologic parameters in a case of contralateral side sensorineural hearing loss. We also performed a literature search using PubMed., Case Description: A 25-year-old woman with neurofibromatosis 2 developed contralateral side sensorineural hearing loss immediately after resection of vestibular schwannoma. The patient regained partial hearing with a short course (2 months) of steroid therapy over 6 months., Conclusions: Literature search yielded 20 cases. We evaluated possible etiology, pattern, extent, recovery, and final outcome in these patients with management options. Several etiologies have been proposed, including development of endolymphatic hydrops, vascular phenomenon, mechanical injury, barotrauma, and autoimmune cochleolabyrinthitis. Sudden release of cerebrospinal fluid seemed to be the most likely explanation in the present case. There is no way to predict this complication beforehand. Operating in supine position, slow release of cerebrospinal fluid, irrigation of the operating field, maintenance of normotension, and judicious use of the drill may help in prevention. A short course of corticosteroids and vasodilators helped in spontaneous recovery in most of the cases., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: Auditory brainstem implant (ABI), a standard technique in treatment of profound sensorineural hearing loss in patients with neurofibromatosis 2, is now being increasingly employed in children with congenital bilateral sensorineural hearing loss, as in Michele's deformity. A detailed knowledge of the relevant surgical anatomy of the lateral recess and its anatomical landmarks including the flocculus, the choroid plexus and the root entry zones of facial-vestibulocochlear and glossopharyngeal-vagus nerve complexes and their anatomical variants is mandatory, as it is the conduit for electrode array placement. The placement of electrode may be eased or impeded by these variations., Materials and Methods: Thirty-two children with congenital bilateral hearing loss underwent surgery through retromastoid suboccipital approach for placement of auditory brainstem implant. The preoperative anatomy was reviewed in detail during procedure and again later in the operative videos., Results: The flocculus was classified into four grades based on its anatomy and relations. Among these, grade II (11 children) was the commonest while grade IV (five children) was least common. Choroid plexus was variable in size across grades of flocculus. Difficulty in defining the anatomy was significantly more (p value = 0.003) in the group with higher grade flocculus (grade III and IV) than in lower grade flocculus (grade I and II)., Conclusion: The flocculus in these patients is classifiable into one of the four grades and the surgical nuances such as difficulty in defining the anatomy for placement of ABI are dependent on the characteristics exhibited by the floccular anatomy and relations.

Surgical treatment of vestibular schwannoma (VS) in patients with neurofibromatosis type 2 (NF2) along with functional preservation of cranial nerves is challenging. The aim of this study was to analyze the outcomes of hearing and facial nerve function in patients with NF2 who underwent large-size VS (> 2 cm) surgery. From 2006 to 2016, one hundred and forty NF2 patients were included with 149 large-size VS resections using retrosigmoid approach. Hearing function was classified according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria. Preoperative and one-year postoperative facial nerve function were both assessed using the House-Brackmann (H-B) grading scale. A multivariate logistic regression was performed to identify preoperative predictors for facial function outcomes. No operative death we noted. Total tumor removal was achieved in 82.6% of the operated VSs. The anatomical integrity of the facial nerve was preserved in 67.8% of surgeries. Good facial nerve function (H-B Grades I-III) was maintained in 49.6% of patients at 12 months after surgery. Tumor size larger than 3 cm and preoperative facial weakness related with worse outcome of facial nerve function (P < 0.001; for both). Hearing preservation surgeries were attempted in 31 ears. Class B or C hearing according to the AAO-HNS criteria was maintained in 7 ears (22.5%), and measurable hearing was maintained 11 ears (35.5%). It is challenging to maintain hearing and facial nerve function in NF2 patients with large VSs. Early surgical intervention is an appropriate choice to decrease the risk of neurological functions deficit.

Objectives: Auditory brainstem implants (ABIs) may be the only opportunity for patients with NF2 to regain some sense of hearing sensation. However, only a very small number of individuals achieved open-set speech understanding and high sentence scores. Suboptimal placement of the ABI electrode array over the cochlear nucleus may be one of main factors for poor auditory performance. In the current study, we present a method of awake craniotomy to assist with ABI placement., Methods: Awake surgery and hearing test via the retrosigmoid approach were performed for vestibular schwannoma resections and auditory brainstem implantations in four patients with NF2. Auditory outcomes and complications were assessed postoperatively., Results: Three of 4 patients who underwent awake craniotomy during ABI surgery received reproducible auditory sensations intraoperatively. Satisfactory numbers of effective electrodes, threshold levels and distinct pitches were achieved in the wake-up hearing test. In addition, relatively few electrodes produced non-auditory percepts. There was no serious complication attributable to the ABI or awake craniotomy., Conclusions: It is safe and well tolerated for neurofibromatosis type 2 (NF2) patients using awake craniotomy during auditory brainstem implantation. This method can potentially improve the localization accuracy of the cochlear nucleus during surgery.

Most patients diagnosed with neurofibromatosis type 2 (NF2) have bilateral vestibular schwannomas (VS). Through reviewing surgical method and clinical outcomes, we tried to find out a strategy for treatments in NF2 patients with VS.We retrospectively reviewed patients diagnosed pathological NF2 and have had microsurgery (MS) for VS in the PLA Army General Hospital. Seventeen patients were included from January 2000 to December 2016. Fifteen patients had progressive hearing impairment, and 7 ears were totally deaf. Computed tomography and magnetic resonance imaging were used for preoperative and postoperative evaluation. House-Brackmann (H-B) classification was used to evaluate facial function, and the hearing outcome was classified according to American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification system. The outcomes included functional hearing, facial function, and complications.In the 17 patients, 9 were men, and the mean age was 27.2 years old. The mean duration of disease was 38.4 months. Twenty-six VS were excised. Nine patients with bilateral VS and unilateral surgery had repeated surgery for the contralateral tumor after 3 to 12 months. The hearing preservation rate was 41.6%. In the 26 excisions for VS, 24 had intact facial nerve. In the other 2 tumor excision, damaged facial nerves had head-to-head adhesion using biological fibrin glue. The rate of facial nerve function preservation was 60%. No mortality or major complication was reported. The follow-up time ranged from 11 to 78 months with a mean value of 39 months.MS is an effective treatment for NF2 patients with VS. The operation for bilateral VS should be staged according to tumor size and bilateral hearing function. However, methods on how to preserve functional hearing and facial function remain the issue. Further randomized controlled studies are needed to find out a better treatment for NF2 patients with VS according to the overall condition.

Background: For treating a patient with multiple falcine and parasagittal lesions, we believe that it is beneficial to resect the maximum possible number of lesions during one operation, even if some lesions are asymptomatic. This practice can potentially reduce the total number of operations during a patient's lifetime., Methods: We provide an introduction of a concurrent endoscopic approach via the interhemispheric fissure., Conclusions: Applying this endoscopic approach concurrently with conventional microscopic surgery can enable the safe resection of as many lesions as possible during one operation.

Objective: Patients with neurofibromatosis type 2 (NF2) are prone to develop multiple intracranial neoplasms, such as schwannomas of the cranial nerves and meningiomas. The aim of our study was to investigate 1) the median growth rate per year, 2) the growth-free interval, and 3) the growth patterns of NF2-associated intracranial tumors., Methods: All available magnetic resonance (MR) images of patients from the regional neurofibromatosis center were collected. The depicted tumors' volumes were then calculated if the tumors met the following inclusion criteria: contrast enhanced T1-weighted MRI datasets had to be available from at least two investigations and tumors had to be measurable on at least two slices., Results: One-hundred and eighty-eight tumors from 52 patients (20 male, 32 female) met the inclusion criteria for volumetric analysis. Overall, the median follow-up time was 76.5 months per patient (range 13-199 months). After 5 years, the median tumor size was 196% ± 338% for vestibular schwannomas (VS), 204% ± 702% meningiomas (M), 128% ± 64.9% for non-vestibular schwannomas (NVS) and 139% ± 270% for pre-operated tumors of the cerebellopontine angle (TX), respectively. The median time to 20% tumor progression was 21 months for VS, NVS and TX, and 17 months for M. Overall, saltatory growth was the most common growth pattern (46.9%)., Conclusions: Most NF2-associated tumors display a saltatory growth pattern. Meningiomas and untreated vestibular schwannomas grow rapidly and overall at similar rates. Tumors of the CPA that have been operated on and non-vestibular schwannomas show less relative growth per year., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To report the preliminary outcomes of auditory brainstem implantation (ABI) under a compassionate use protocol for two ABI devices that are not approved by the US Food and Drug Administration., Methods: A retrospective review was performed of neurofibromatosis type 2 (NF2) patients who underwent microsurgery for vestibular schwannoma (VS) and placement of either the Cochlear ABI541 or Med-El Synchrony ABIs. Peri-operative and device- related complications were reviewed. Audiometric performance was also evaluated., Results: Seven patients received either the Cochlear ABI541 (6) or the Med-El Synchrony ABI (1) after the resection of VS. No device or patient-related complications occurred to date. Surgical times and early audiological performance are similar to our previous experience with the Cochlear ABI24 device., Conclusions: Early experience with the Cochlear ABI541 and Med-El Synchrony ABI devices under a compassionate use protocol suggest that both devices are safe with comparable utility to the Cochlear ABI24 device.

The article addresses the issue of a combination and relationship between intramedullary spinal cord tumors (IMSCTs) and neurofibromatosis (NF)., Aim: To study, based on large clinical material, features of the prevalence and biological nature of intramedullary spinal cord tumors in neurofibromatosis patients in different age groups., Material and Methods: We analyzed the data of the largest series of patients from all age groups who underwent surgery for spinal cord intramedullary tumors (541 patients; 586 surgeries; age, 2 months to 72 years)., Results: Our findings support a potential pathogenetic relationship between intramedullary tumors and neurofibromatosis. Astrocytoma was a predominant intramedullary tumor in patients with NF-1, while ependymoma predominated in patients with NF-2. IMSCTs combined with NF-1 occur predominantly in children and adolescents, while a combination with NF-2 is typical of young adults. Our findings confirm the fact that IMSCT surgery is required for a small number of NF patients.

Objective: To evaluate whether an auditory brainstem implant (ABI) can impact levels of tinnitus in neurofibromatosis type-2 (NF2) patients who have undergone translabyrinthine craniotomy for vestibular schwannoma (VS) removal and to evaluate the burden of tinnitus in these patients., Study Design: A retrospective case series and patient survey., Setting: Tertiary neurotologic referral center., Patients: NF2 patients who underwent translabyrinthine removal of VS and ABI placement between 1994 and 2015., Interventions: A survey, retrospective review and two validated tinnitus handicap questionnaires (tinnitus handicap inventory [THI] and tinnitus visual analogue scale [VAS]) were used to characterize the degree of tinnitus in NF2 patients and whether an ABI can alter tinnitus levels., Main Outcome Measures(s): Survey results, THI and VAS scores., Results: One hundred twelve ABI users were contacted and 43 patients (38.3)% responded to our survey. Tinnitus was reported in 83.7% of patients. The THI score for responders was 17.8 ± 20.5 standard deviation (SD). For survey participants, the ABI reduced tinnitus levels (mean VAS: Off = 3.5; On 1-h = 2.1; p = 0.048). For patients who subjectively reported that the ABI reduced tinnitus loudness, tinnitus levels were immediately reduced on ABI activation and after 1 hour of use (mean VAS: Off = 4.8; On = 2.4; On 1-h = 1.8; p < 0.01). Suppression did not continue after the device was turned off. Audiological performance with the ABI did not correlate with tinnitus suppression., Conclusion: NF2 patients who have undergone removal of VS have a significant tinnitus handicap and benefit from tinnitus suppression through utilization of an ABI possibly through masking or electrical stimulation of the auditory brainstem.

Objective: This study aimed to (1) characterize morphological characteristics of the electrically evoked cortical auditory event-related potentials (eERPs) and explore the potential association between onset eERP morphology and auditory versus nonauditory stimulation; (2) assess test-retest reliability of onset eERPs; (3) investigate effects of stimulation level on onset eERPs; and (4) explore the feasibility of using the onset eERP to estimate the lowest stimulation level that can be detected for individual stimulating electrodes in patients with auditory brainstem implants (ABIs)., Design: Study participants included 5 children (S1 to S5) and 2 adults (S6 to S7) with unilateral Cochlear Nucleus 24M ABIs. Pediatric ABI recipients ranged in age from 2.6 to 10.2 years (mean: 5.2 years) at the time of testing. S6 and S7 were 21.2 and 24.6 years of age at the time of testing, respectively. S6 and S7 were diagnosed with neurofibromatosis II (NF2) and implanted with an ABI after a surgical removal of the tumors. All pediatric subjects received ABIs after being diagnosed with cochlear nerve deficiency. The lowest stimulation level that could be detected (behavioral T level) and the estimated maximum comfortable level (C level) was measured for individual electrodes using clinical procedures. For electrophysiological measures, the stimulus was a 100-msec biphasic pulse train that was delivered to individual electrodes in a monopolar-coupled stimulation mode at stimulation levels ranging from subthreshold to C levels. Electrophysiological recordings of the onset eERP were obtained in all subjects. For studies evaluating the test-retest reliability of the onset eERP, responses were measured using the same set of parameters in two test sessions. The time interval between test sessions ranged from 2 to 6 months. The lowest stimulation level that could evoke the onset eERP was defined as the objective T level., Results: Onset eERPs were recorded in all subjects tested in this study. Inter- and intrasubject variations in morphological characteristics of onset eERPs were observed. Onset eERPs with complex waveforms were recorded for electrodes that evoked nonauditory sensations, based on feedback from subjects, as well as for electrodes without any indications of nonauditory stimulations. Onset eERPs in patients with ABIs demonstrated good test-retest reliability. Increasing stimulation levels resulted in increased eERP amplitudes but showed inconsistent effects on response latencies in patients with ABIs. Objective and behavioral T levels were correlated., Conclusions: eERPs could be recorded in both non-NF2 and NF2 patients with ABIs. eERPs in both ABI patient groups show inter- and intrasubject variations in morphological characteristics. However, onset eERPs measured within the same subject in this study tended to be stable across study sessions. The onset eERP can potentially be used to estimate behavioral T levels in patients with ABIs. Further studies with more adult ABI recipients are warranted to investigate whether the onset eERP can be used to identify electrodes with nonauditory stimulations.

Objective: To describe the experience of auditory brainstem implantation (ABI) in patients with Neurofibromatosis type 2 (NF2)., Study Design: Retrospective case review., Setting: Tertiary referral centre., Patients: Implanted with a Cochlear ABI22 or ABI24M between 1994 and 2009 because of NF2 disease., Intervention(s): Rehabilitative., Main Outcome Measure(s): Surgical complication rate; audiological outcomes., Results: There were 50 primary ABI insertions in 49 patients, including 16 inserted at the time of first side tumor removal as a sleeper, and two revision repositionings which failed to improve outcome. Postoperatively three patients had cerebrospinal fluid leaks which did not require reoperation, one patient had meningitis, and eleven patients suffered either temporary or permanent lower cranial nerve dysfunction. Twenty-nine patients became full time users; a further 12 patients became non-users. Three patients died while their device was inactive. Five patients retain serviceable contralateral hearing. Audiological open set testing of users showed means of: environmental sounds discrimination 51%; phoneme discrimination: with ABI alone 22%/lip reading (LR) 45%/ABI with LR 65%; sentence testing: with ABI alone 13%/LR 19%/ABI with LR 54%., Conclusions: The majority of patients with NF2 implanted with an ABI find the device a useful aid to communication in conjunction with LR and in recognizing common environmental sounds. A small proportion gain open set discrimination. Almost a third of patients may end up as non-users. There is probably an increased risk of postoperative lower cranial nerve dysfunction so careful preoperative assessment is advised.

To discuss the appropriate treatment strategy for NF2-related vestibular schwannoma (VS) according to our experiences, we analyzed long-term clinical and radiological data focusing on NF2-related VS patients. Seventeen NF2-related VS patients were included. Based on their first management modality for VS, we classified these patients into the following four groups: microsurgery (MS), fractionated gamma knife radiosurgery (f-GKS), single session gamma knife radiosurgery (s-GKS), and conservative management (CM). Each patient was assessed for each separate ear. Changes of tumor volume and hearing status for 32 ears in 17 patients according to their first treatment modality were evaluated. The mean follow-up duration and tumor volume of the MS (4 ears, 4 patients), f-GKS (12 ears, 10 patients), s-GKS (8 ears, 7 patients), and CM (8 ears, 7 patients) groups were 3.9 years and 1.6 mL; 5.1 years and 11.1 mL; 8.4 years and 5.6 mL; and 6.1 years and 1.6 mL, respectively. Relatively lower local control rates were observed in the MS and the CM group (0 and 12.5 %, respectively). On the other hand, better local control rates for follow-up periods of 5.1 and 8.4 years were achieved in the f-GKS and the s-GKS groups (75 and 50 %, respectively). However, hearing preservation in all treatment modalities could not be achieved effectively. Long-term preservation of hearing in at least one serviceable ear as well as tumor control should be considered for each patient. Therefore, a proper treatment option should be selected at the appropriate time according to clinical characteristics of individual patients.

Objective: To describe our experience and outcomes of auditory brainstem implantation (ABI) in Chinese patients with Neurofibromatosis Type II (NF2)., Study Design: Retrospective case review., Setting: Tertiary referral center., Patients: Patients with NF2 who received ABIs., Results: Between 1997 and 2014, eight patients with NF2 received 9 ABIs after translabyrinthine removal of their vestibular schwannomas. One patient did not have auditory response using the ABI after activation. Environmental sounds could be differentiated by six (75%) patients after 6 months of ABI use (mean score 46% [range 28-60%]), and by five (63%) patients after 1 year (mean score 57% [range 36-76%]) and 2 years of ABI use (mean score 48% [range 24-76%]). Closed-set word identification was possible in four (50%) patients after 6 months (mean score 39% [range 12-72%]), 1 year (mean score 68% [range 48-92%]), and 2 years of ABI use (mean score 62% [range 28-100%]). No patient demonstrated open-set sentence recognition in quiet in the ABI-only condition. However, the use of ABI together with lip-reading conferred an improvement over lip-reading alone in open-set sentence recognition scores in two (25%) patients after 6 months of ABI use (mean improvement 46%), and five (63%) patients after 1 year (mean improvement 25%) and 2 years of ABI use (mean improvement 28%). At 2 years postoperatively, three (38%) patients remained ABI users., Conclusion: This is the only published study to date examining ABI outcomes in Cantonese-speaking Chinese NF2 patients and the data seems to show poorer outcomes compared with English-speaking and other nontonal language-speaking NF2 patients. Environmental sound awareness and lip-reading enhancement are the main benefits observed in our patients. More work is needed to improve auditory implant speech-processing strategies for tonal languages and these advancements may yield better speech perception outcomes in the future.

In neurofibromatosis type 2 (NF2) bilateral vestibular schwannomas (VS) or their treatment usually results in bilateral hearing loss. Cochlear implantation (CI) was traditionally not used in these patients due to concern that retrocochlear disease would render the implant ineffective. This paper describes the auditory outcomes of CI in 13 patients with NF2 and includes patients with untreated VS and patients undergoing VS removal with cochlear nerve preservation. The non-user rate was 7.7%. Of the active users, median CUNY score was 98%, median BKB score in quiet was 90% and median BKB score in noise was 68%. CI is a viable option in selected patients with NF2.

The purpose of this report is to detail three rare cases of neurofibromatosis type 2 (NF2) with symptomatic extracranial extension of intracranial meningioma. We present ocular findings, imaging techniques applied, pathological findings of the space-occupying lesions, and therapy. One of these patients, the daughter of one of the other individuals, presented with a large neck mass, but no surgically treatable findings associated with the external growth of the meningioma. The patients complained of symptoms associated with the extracranial portion of the intracranial meningioma, rather than of the intracranial primaries. However, facial and neck surgical care is very limited in patients with such advanced-stage tumours. The prolongation of life was unquestionably predominantly determined by the behaviour of the intracranial tumour. Head and neck surgeons should be aware of the rare possibility that solid tumours of this region could be extracranial-extending meningioma in an inherited disease., (Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Objective: The aim of this study was to evaluate the clinical features of spinal schwannomas in patients with schwannomatosis and compare them with a large cohort of patients with solitary schwannomas and neurofibromatosis Type 2 (NF2)., Methods: The study was a retrospective review of 831 patients with solitary schwannomas, 65 with schwannomatosis, and 102 with NF2. The clinical, radiographic, and pathological data were extracted with specific attention to the age at onset, location of tumors, initial symptoms, family history, and treatment outcome., Results: The male-to-female ratio of patients with schwannomatosis (72.3% vs 27.7%) was significantly higher than that of patients with solitary schwannomas (53.3% vs 46.7%) and NF2 (54.0% vs 46.0%), respectively (chi-square test, p = 0.012). The mean age at the first spinal schwannoma operation of patients with NF2 (24.7 ± 10.2 years) was significantly younger than that of patients with solitary schwannomas (44.8 ± 13.2 years) and schwannomatosis (44.4 ± 14.1 years; 1-way ANOVA, p < 0.001). The initial symptoms were similar among the 3 groups, with pain being the most common. The distribution of spinal tumors among the 3 groups was significantly different. The peak locations of spinal schwannomas in patients with solitary schwannomas were at C1-3 and T12-L3; in schwannomatosis, the peak location was at T12-L5. A preferred spinal location was not evident for intradural-extramedullary tumors in NF2. Only a slight prominence in the lumbar area could be observed. The patients in the 3 groups obtained similar benefits from the operation; the recovery rates in the patients with solitary schwannomas, NF2, and schwannomatosis were 50.1%, 38.0%, and 53.9%, respectively. The prognosis varied among spinal schwannomas in the patients with schwannomatosis. Up until the last date of follow-up, most patients with schwannomatosis (81.5%) had undergone a single spinal operation, but 12 patients (18.5%) had undergone multiple spinal operations. Patients with nonsegmental schwannomatosis or those with early onset disease seemed to have a poor prognosis; they were more likely to undergo multiple spinal operations. Small cauda equina nodules were common in patients with schwannomatosis (46.7%) and NF2 (86.9%); these small schwannomas appeared to have relatively static behavior. Two patients suspicious for schwannomatosis were diagnosed with NF2 with the detection of constitutional NF2 mutations; 1 had unilateral vestibular schwannoma, and the other had suspicious bilateral trigeminal schwannomas., Conclusions: The clinical features of spinal schwannomas vary among patients with solitary schwannomas, NF2, and schwannomatosis. Spinal schwannomas of patients with NF2 appear to be more aggressive than those in patients with solitary schwannomas and schwannomatosis. Spinal schwannomas of schwannomatosis predominate in the lumbar area, and most of them can be treated successfully with surgery. The prognosis varies among spinal schwannomas of schwannomatosis; some patients may need multiple operations due to newly developed schwannomas. Sometimes, it is difficult to differentiate schwannomatosis from NF2 based on clinical manifestations. It is prudent to perform close follow-up examinations in patients with undetermined schwannomatosis and their offspring.

Objective: We sought to determine clinical characteristics of NF2 patients with spinal lesions and to define when and like the spinal tumors are a major problem in the treatment of patients with NF2., Methods: The authors retrospectively reviewed the clinical records, neuroimaging studies, and follow-up data of the 34 patients with neurofibromatosis type 2, who were treated at our institution between 1998 and 2014. 23 patients harbored one or multiple spinal tumors., Results: Patients with spinal tumors had a lower age at first symptoms of the disease, a higher number of intracranial meningiomas and non-vestibular schwannomas. 11 patients had one or more intramedullary tumors with MRI characteristics of spinal ependymomas. 22 patients had intradural extramedullary tumors. 7 patients presented with symptomatic spinal tumors on admission or developed symptoms during the follow-up. Only two intramedullary and four extramedullary tumors demonstrated growth in the mean radiological follow-up period of over 6 years. It was found that symptomatic both intra- and extramedullary tumors were associated with younger age at the onset of NF2-related symptoms. 2 patients with intramedullary tumors and 12 patients with extramedullary tumors underwent their tumors resection. In case of symptomatic tumors partial recovery was observed in two patients., Conclusion: It seems that close surveillance with MR imaging is a reasonable option for asymptomatic spinal tumors. Nevertheless, intramedullary tumor removal in non-growing and asymptomatic cases may be an option when ABI implantation is considered. Symptomatic tumors and those of documented growth should be eligible for surgical intervention., (Copyright © 2015 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.)

Objective: Treatment of meningiomas in neurofibromatosis type II (NF2) patients is challenging because the natural history of these tumors is unclear. More insight in tumor growth and factors predicting growth may contribute to a better clinical management. In this study, growth characteristics of supratentorial NF-related meningiomas were examined and the association between tumor growth rate and location was evaluated., Methods: In all NF2 patients followed up at the VU University Medical Center, who underwent a minimum of 3 consecutive scans, tumor volumes were assessed by using 3D volumetric measurement (Brainlab, Feldkirchen, Germany). Growth patterns were visually analyzed. To assess the association between tumor growth rate and tumor location, the meningiomas were divided in 3 groups on the basis of their location: skull base, convexity, and "other." Univariable and multivariable logistic regression models were built., Results: Twenty-one patients (13 females) with a mean (standard deviation) follow-up period of 5.55 (2.48) years and a total of 210 meningiomas were included in the analyses. Tumors followed different growth patterns and did not increase in size simultaneously within 1 patient. Skull base meningiomas had a significantly higher absolute growth rate compared with convexity (β = 0.91, 95% confidence interval [CI] 0.08-1.73) and "other" (β = 1.07, 95% CI 0.27-1.86) and a significantly higher relative growth rate on both linear and geometric growth rate compared with "other" (β = 90.73, 95% CI 5.50-175.95 and β = 18.63, 95% CI 2.94-34.31, respectively) on multivariable logistic regression., Conclusion: Within a single patient, NF2-related meningiomas follow different growth patterns. Skull base meningiomas grow faster compared with other locations. Yearly magnetic resonance imaging scans and timely treatment of skull base meningiomas should be considered., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Patients with neurofibromatosis type 2 (NF2) are an important subgroup of patients undergoing peripheral nerve schwannoma excision, however data on their outcomes are lacking. Co-existing peripheral neuropathy can complicate the clinical presentation and recovery in NF2. We designed a study to compare outcomes of peripheral nerve schwannoma excision in NF2 patients with excision of isolated, sporadic schwannomas in non-NF2 patients., Methods: 30 peripheral nerve schwannoma excisions from 15 NF2 patients were compared to 30 excised isolated schwannomas. These were matched for age, size, nerve and level of involvement. Final outcomes were scored on a scale of 0 (no improvement) to 3 (complete symptom resolution). Data were analysed by McNemars test and Wilcoxen matched pairs test., Results: NF2 patients had multiple lesions and more pre-operative weakness (p = 0.041) and sensory loss (p = 0.133) compared to controls. Post-operative neurological morbidity occurred in both groups after schwannoma excision. Final outcome scores of 2.4 in NF2 and 2.2 in controls indicate great improvement or complete resolution in the majority., Conclusions: Outcomes in the NF2 group are not different to controls, despite NF2 patients having more significant pre-operative deficit and co-existing neuropathology. These findings suggest that surgical intervention should be offered to NF2 patients with peripheral nerve schwannomas., (Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objectives: The aim of this study was to determine the prevalence of cochlear obliteration after labyrinthectomy., Study Design: Retrospective review of medical records., Setting: Tertiary referral center., Patients: Sixty-five patients who had previously undergone resection of an acoustic neuroma through a translabyrinthine approach., Intervention: The magnetic resonance studies were analyzed as part of the routine surveillance after tumor resection., Main Outcome Measure: To determine whether the cochlear lumen remained fluid filled., Results: Sixty-five cochleas were examined. Forty-four cochleas were patent and, of the remaining 21, 9 were obliterated and 12 were partially obliterated. The average length of follow-up for the patent, partially obliterated, and obliterated cochlea groups was 47, 29, and 77 months, respectively., Conclusion: Obliteration of the cochlea, either partially or completely, occurs in approximately one-third of patients. Time elapsed after labyrinthectomy did not seem to be a predictor of cochlear obliteration.

Neurofibromatosis type 2 (NF2) is a dominantly inherited genetic condition. Bilateral vestibular schwannoma, which are benign tumors, composed of neoplastic Schwann cells that arise from the eighth cranial nerve, are the hallmark of NF2. Standard approaches for treatment of growing vestibular schwannoma include observation, surgical removal and radiation therapy. Molecular targeted therapies also present great prosperity in recent years. In this review, we summarize the latest progresses on the treatment of NF2-associated vestibular schwannoma.

Objective: Guidelines for appropriate management of vestibular schwannomas in NF2 patients are controversial. In this paper we reviewed our experience with patients with NF2 for the results of surgical treatment with particular reference to hearing and facial nerve preservation., Methods: We included in the study 30 patients (16 women and 14 men) with the diagnosis of NF2 treated in our department between 1998 and 2014 who underwent surgery for vestibular schwannoma removal with a follow-up for at least 1 year. In 3 cases, the vestibular schwannomas were unilateral. Six patients with bilateral vestibular schwannomas underwent unilateral procedure. Therefore, 51 acoustic tumors were studied in 30 patients., Results: No operative death we noted. Significant deterioration to the non-functional level occurred in 19 out of 22 cases with well-preserved preoperative hearing. Only three ears maintained their preoperative good hearing. Hearing was preserved in cases of small schwannoma not exceeding 2 cm. Among 21 patients who underwent bilateral operations hearing was preserved in 3 out of 7 cases when smaller tumor or better hearing level side was attempted at first surgery. In contrary none of the 14 patients retained hearing when the first operation concerned the worse-hearing ear. Among 14 tumors up to 2 cm there was only one case of moderately severe facial nerve dysfunction (House-Brackmann Grade IV) in the long follow-up., Conclusion: Early surgical intervention for vestibular schwannoma in NF2 patient is a viable management strategy to maintain hearing function and preserve facial nerve function., (Copyright © 2015 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.)

Object: The aim of this study was to evaluate long-term clinical outcomes after Gamma Knife surgery (GKS) for patients with neurofibromatosis Type 2 (NF2) and the role of GKS in the management of NF2., Methods: From December 1994 through December 2008, a total of 46 patients (21 male, 25 female) with NF2 underwent GKS and follow-up evaluation for at least 5 years at the Gamma Knife Center of the Beijing Neurosurgical Institute. GKS was performed using the Leksell Gamma Knife Models B and C. The mean age of the patients was 30 years (range 13-59 years). A family history of NF2 was found for 9 (20%) patients. The NF2 phenotype was thought to be Wishart for 20 (44%) and Feiling-Gardner for 26 (56%) patients. Among these 46 patients, GKS was performed to treat 195 tumors (73 vestibular schwannomas and 122 other tumors including other schwannomas and meningiomas). For vestibular schwannomas, the mean volume was 5.1 cm(3) (median 3.6 cm(3), range 0.3-27.3 cm(3)), the mean margin dose was 12.9 Gy (range 10-14 Gy), and the mean maximum dose was 27.3 Gy (range 16.2-40 Gy). For other tumors, the mean volume was 1.7 cm(3) (range 0.3-5.5 cm(3)), the mean margin dose was 13.3 Gy (range 11-14 Gy), and the mean maximum dose was 26.0 Gy (range 18.0-30.4 Gy). The median duration of follow-up was 109 months (range 8-195 months)., Results: For the 73 vestibular schwannomas that underwent GKS, the latest follow-up MR images demonstrated regression of 30 (41%) tumors, stable size for 31 (43%) tumors, and enlargement of 12 (16%) tumors. The total rate of tumor control for bilateral vestibular schwannomas in patients with NF2 was 84%. Of the 122 other types of tumors that underwent GKS, 103 (85%) showed no tumor enlargement. The rate of serviceable hearing preservation after GKS was 31.9% (15/47). The actuarial rates for hearing preservation at 3 years, 5 years, 10 years, and 15 years were 98%, 93%, 44%, and 17%, respectively. Of the 46 patients, 22 (48%) became completely bilaterally deaf, 17 (37%) retained unilateral serviceable hearing, and 7 (15%) retained bilateral serviceable hearing. The mean history of the disease course was 12 years (range 5-38 years)., Conclusions: GKS was confirmed to provide long-term local tumor control for small- to medium-sized vestibular schwannomas and other types of tumors, although vestibular schwannomas in patients with NF2 responded less well than did unilateral sporadic vestibular schwannomas. Phenotype is the most strongly predictive factor of final outcome after GKS for patients with NF2. The risk for loss of hearing is high, whereas the risk for other cranial nerve complications is low.

Objective: To determine factors related to high levels of speech recognition in patients with the auditory brainstem implant (ABI)., Study Design: Retrospective case review., Setting: International multicenter data from hospitals and tertiary referral facilities., Patients: Patients with neurofibromatosis type 2 (NF2) and bilateral vestibular schwannomas., Intervention: ABIs were placed after the removal of vestibular schwannomas., Main Outcome Measures: Demographic and surgical data were collected from 26 patients with ABIs who achieved scores of better than 30% correct identification of sentences presented in quiet listening conditions and without lipreading cues., Results: Scores better than 30% speech recognition of standard sentence test materials (HINT or equivalent) in quiet listening conditions were obtained in 26 of the 84 NF2 patients (31%). ABI speech recognition was correlated with surgical position, length of deafness, the number of distinct pitch electrodes, perceptual levels, and ABI stimulation rate, but not correlated with tumor size, tumor stage, the number of electrodes used, or electrophysiological recordings. This paper presents the consensus opinion from a meeting of surgeons to compare outcomes across ABI surgical centers., Conclusions: The consensus opinion was that brainstem trauma is a primary factor in the variability of outcomes in NF2 patients. The significant co-factors in outcomes implied that ABI surgery should be accomplished with great care to minimize physical and venous trauma to the brainstem. It is clear that high levels of speech recognition, including high levels of open-set speech recognition, are possible with the ABI even in patients with NF2 and large tumors.

Conclusions: Even though sound perception may be limited after treatment with an auditory brainstem implant (ABI), it provides benefits and should be selectively offered to patients. Importantly the patients must be motivated, given reasonable expectations of outcome and offered long-term rehabilitation with a considerable 'learn to listen' period with the implant device., Objectives: To describe the clinical experiences and results of 24 ABI surgeries performed in Uppsala University Hospital between 1993 and 2013., Methods: Most patients (n = 20) suffered from neurofibromatosis type 2 (NF2); a few patients (n = 4) were paediatric non-NF2 patients. The files were searched for information on the presurgery size of the vestibular schwannoma, whether the patient had undergone gamma knife treatment, the surgical approach, the side effects of the surgery and of the use of the implant, the electrode activation pattern and implant use, and categories of auditory performance (CAP) score., Results: Our results show that many patients greatly benefited from an ABI, and most of the patients used their implants even though the hearing improvements usually consisted of awareness of surrounding sounds and improved lip-reading. No severe side effects were observed from implant stimulation.

Here, we describe an extremely rare case of angiosarcoma arising in schwannoma of the cerebellopontine angle and later associating with meningioma in a patient with neurofibromatosis type 2. A 33-year-old disabled Japanese man with right drop foot after surgery for an unspecified tumor demonstrated multiple tumors, suspected to be schwannoma, in the bilateral cerebellopontine angles, the cervical and lumbar spinal cord, and on the right nuchal skin. Also present were several tumors in the medulla and thoracic spinal cord suspected to be ependymoma or astrocytoma. The patient was diagnosed with neurofibromatosis type 2 according to the diagnostic criteria by the U.S. National Institutes of Health. The bilateral tumors in the cerebellopontine angle were resected to reduce symptoms and brain stem compression. Histopathological analysis revealed angiosarcoma arising in schwannoma of the bilateral tumors, and angiosarcoma was proportionally larger in the right tumor than in the left. At age 36, the patient underwent a second resection of the regrown tumor in the left cerebellopontine angle, and histopathology demonstrated mixed angiosarcoma and meningioma. That angiosarcoma arises in schwannoma is a pathogenesis within the realm of conjecture, especially that the phenomenon of mixed meningioma and angiosarcoma has not been reported to date.

Objective: Review the useful hearing preservation and tumor control outcomes of microsurgery (MS), stereotactic radiation (SR), conservative management (CM), and chemotherapy (ChT) for Neurofibromatosis type 2 vestibular schwannomas., Data Sources: Ovid MEDLINE was used to conduct a thorough search of English-language publications dating from 1948 to February 2013., Study Selection: Patients must have had useful hearing at diagnosis and treated with one of the 4 treatments as their primary therapy. All sporadic vestibular schwannoma cases were excluded., Data Extraction: A total of 19 articles were reviewed. Hearing preservation was defined as unchanged or improved useful hearing. Tumor control was defined as no change in size or tumor regression for SR, CM, and ChT-treated cases, and as no recurrence for MS treated cases., Conclusion: Microsurgery seems to have the worse overall results, while SR has very good tumor control with poor useful hearing preservation. If a patient qualifies for CM, he is likely to show the most satisfactory results with the least treatment available. A close follow-up on ChT clinical trials and possible side-effects is warranted as preliminary short-term results are quite favorable. Additional long-term studies are required for a better understanding of this disease.

Background: The Novalis linear accelerator system, a well developed modality, can be used for stereotactic radiosurgery (SRS). The aim of this study was to clarify the efficiency and safety of Novalis SRS in treating vestibular schwannomas., Materials and Methods: This 4-year retrospective study enrolled 23 patients with 26 vestibular schwannomas (3 patients suffered from neurofibromatosis Type II). Five patients had undergone tumor resection. All 26 tumors were treated using Novalis SRS, with a prescription dose that varied between 10 and 16Gy (mean, 11.8±1.7Gy). The average follow-up period was 56.5±22.1 months (range, 17-87 months)., Results: There were 9 men and 14 women. Their mean age at the time of treatment was 54.0±14.6 years (range, 27-84 years). On average, the original size of the tumor was 19.0±7.2mm in maximal diameter (range, 4.6-39.9mm). At the last follow-up, 20 tumors had regressed (76.9%), and there was no observed change in the size of 3 tumors (11.5%). Three of 26 tumors (11.5%) enlarged more than 2mm in one direction. Thus the ultimate radiological tumor control rate was 88.5% (23/26). In addition, 20 (87.0%) patients retained their pre-irradiation hearing function. Facial and trigeminal nerve function were both preserved in all patients. No death occurred during the follow-up, and no patient was treated with a second SRS or converted to tumor resection., Conclusion: Novalis SRS is a reliable treatment option for vestibular schwannomas. With an optimal radiation dose, satisfactory tumor control can be achieved while preserving cranial nerve function., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Purpose: Vestibular schwannomas (VS) are often followed without initial therapeutic intervention because many tumors do not grow and radiation therapy is associated with potential adverse effects. In an effort to determine whether maximizing initial surveillance predicts for later treatment response, the predictive value of preirradiation growth rate of VS on response to radiation therapy was assessed., Methods and Materials: Sixty-four patients with 65 VS were treated with single-fraction stereotactic radiation surgery or fractionated stereotactic radiation therapy. Pre- and postirradiation linear expansion rates were estimated using volumetric measurements on sequential magnetic resonance images (MRIs). In addition, postirradiation tumor volume change was classified as demonstrating shrinkage (ratio of volume on last follow-up MRI to MRI immediately preceding irradiation <80%), stability (ratio 80%-120%), or expansion (ratio >120%). The median pre- and postirradiation follow-up was 20.0 and 27.5 months, respectively. Seven tumors from neurofibromatosis type 2 (NF2) patients were excluded from statistical analyses., Results: In the 58 non-NF2 patients, there was a trend of correlation between pre- and postirradiation volume change rates (slope on linear regression, 0.29; P=.06). Tumors demonstrating postirradiation expansion had a median preirradiation growth rate of 89%/year, and those without postirradiation expansion had a median preirradiation growth rate of 41%/year (P=.02). As the preirradiation growth rate increased, the probability of postirradiation expansion also increased. Overall, 24.1% of tumors were stable, 53.4% experienced shrinkage, and 22.5% experienced expansion. Predictors of no postirradiation tumor expansion included no prior surgery (P=.01) and slower tumor growth rate (P=.02). The control of tumors in NF2 patients was only 43%., Conclusions: Radiation therapy is an effective treatment for VS, but tumors that grow quickly preirradiation may be more likely to increase in size. Clinicians should take into account tumor growth rate when counseling patients about treatment options., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Aims and Background: To evaluate the long-term outcome of patients with vestibular schwannoma (VS) and neurofibromatosis type 2 (NF2) treated with fractionated stereotactic radiotherapy (FSRT) or stereotactic radiosurgery (SRS)., Patients and Methods: Sixteen VS in 14 patients with NF2 were treated with FSRT (n = 14) and SRS (n = 2). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. For patients treated with FSRT a median total dose of 57.6 Gy was prescribed with a median fractionation of 5 × 1.8 Gy per week. For patients who underwent SRS a median single dose of 17 Gy was prescribed to the 80% isodose., Results: FSRT and SRS were well tolerated. Local control rate was 94% for a median follow-up time of 131 months; 2- and 5-year progression-free survival were 100%. The probability of maintaining the pretreatment hearing level was 44%. Useful hearing preservation was 33%. Cranial nerve toxicity was moderate. Trigeminal nerve function worsened in 2 patients (12%) and facial nerve function in 3 patients (19%). One patient developed a new tinnitus., Conclusion: FSRT and SRS are both safe and effective noninvasive and minimally invasive treatment options for patients with VS in the setting of NF2. The long-term local control rates are excellent. Functional hearing preservation is worse in patients with VS and NF2 than in patients with sporadic VS.