Three montages for Transcranial electric stimulation in predicting the early post-surgery outcome of the facial nerve functioning.

OBJECTIVE: We assessed the Transcranial Electrical Stimulation (TES)-induced Corticobulbar-Motor Evoked Potentials (Cb-MEPs) evoked from Orbicularis Oculi (Oc) and Orbicularis Oris (Or) muscles with FCC5h/FCC6h-Mz, C3/C4-Cz and C5/C6/-Cz stimulation, during IntraOperative NeuroMonitoring (IONM) in 30 patients who underwent skull-base surgery. METHODS: before (T0) and after (T1) the surgery, we compared the peak-to-peak amplitudes of Cb-MEPs obtained from TES with C3/C4-Cz, C5/C6-Cz and FCC5h/FCC6h-Mz. Then, we compared the response category (present, absent and peripheral) related to different montages. Finally, we classified the Cb-MEPs data from each patient for concordance with clinical outcome and we assessed the diagnostic measures for Cb-MEPs data obtained from FCC5h/FCC6h-Mz, C3/C4-Cz and C5/C6-Cz TES stimulation. RESULTS: Both at T0 and T1, FCC5h/FCC6h-Mz stimulation evoked larger Cb-MEPs than C3/C4-Cz, less peripheral responses from direct activation of facial nerve than C5/C6-Cz. FCC5h/FCC6h-Mz stimulation showed the best accuracy and specificity of Cb-MEPs for clinical outcomes. CONCLUSIONS: FCC5h/FCC6h-Mz stimulation showed the best performances for monitoring the facial nerve functioning, maintaining excellent diagnostic measures even at low stimulus voltages. SIGNIFICANCE: We demonstrated that FCC5h/FCC6h-Mz TES montage for Cb-MEPs in IONM has good accuracy in predicting the post-surgery outcome of facial nerve functioning.

Age, preoperative tumor volume and widening of the internal acoustic meatus are independent factors associated with poor preoperative hearing in vestibular schwannoma patients - results of a single-center retrospective analysis.

Preoperative hearing function shows wide variations among patients diagnosed with vestibular schwannoma. Besides the preoperative tumor size there are other factors that influence the preoperative hearing function that are frequently discussed. A comprehensive analysis of a large cohort of vestibular schwannomas has the potential to describe new insights and influence the preoperative management. We analyzed clinical factors, imaging data and the expression of the proliferation marker MIB1 as potential influencing factors on the preoperative hearing function in a retrospective cohort of 523 primary sporadic vestibular schwannomas. The results of the preoperative audiometry were quantified using the Gardner-Robertson Score. Uni- and multivariate analyses were performed. Serviceable hearing (Gardner-Robertson class 1 or 2) was documented in 391 patients (74.8%). Factors associated with non-serviceable hearing (Gardner-Robertson class 3-5) were patients of older age (p < 0.0001), larger preoperative tumor volume (p = 0.0013) and widening of the internal acoustic meatus compared to the healthy side (p = 0.0353). Gender and differences in the expression of the proliferation marker MIB1 had no influence on preoperative hearing. In the multivariate nominal logistic regression older age (OR 27.60 (CI 9.17-87.18), p < 0.0001), larger preoperative tumor volume (OR 20.20 (CI 3.43-128.58), p = 0.0011) and widening of the internal acoustic canal (OR 7.86 (CI 1.77-35.46), p = 0.0079) remained independent factors associated with non-serviceable hearing. Widening of the internal acoustic canal is an independent factor for non-serviceable preoperative hearing in vestibular schwannoma patients together with older age and larger preoperative tumor volume.

Single-Center Experience in Microsurgical Resection of Acoustic Neurinomas and the Benefit of Microscope-Based Augmented Reality.

Background and Objectives: Microsurgical resection with intraoperative neuromonitoring is the gold standard for acoustic neurinomas (ANs) which are classified as T3 or T4 tumors according to the Hannover Classification. Microscope-based augmented reality (AR) can be beneficial in cerebellopontine angle and lateral skull base surgery, since these are small areas packed with anatomical structures and the use of this technology enables automatic 3D building of a model without the need for a surgeon to mentally perform this task of transferring 2D images seen on the microscope into imaginary 3D images, which then reduces the possibility of error and provides better orientation in the operative field. Materials and Methods: All patients who underwent surgery for resection of ANs in our department were included in this study. Clinical outcomes in terms of postoperative neurological deficits and complications were evaluated, as well as neuroradiological outcomes for tumor remnants and recurrence. Results: A total of 43 consecutive patients (25 female, median age 60.5 ± 16 years) who underwent resection of ANs via retrosigmoid osteoclastic craniotomy with the use of intraoperative neuromonitoring (22 right-sided, 14 giant tumors, 10 cystic, 7 with hydrocephalus) by a single surgeon were included in this study, with a median follow up of 41.2 ± 32.2 months. A total of 18 patients underwent subtotal resection, 1 patient partial resection and 24 patients gross total resection. A total of 27 patients underwent resection in sitting position and the rest in semi-sitting position. Out of 37 patients who had no facial nerve deficit prior to surgery, 19 patients were intact following surgery, 7 patients had House Brackmann (HB) Grade II paresis, 3 patients HB III, 7 patients HB IV and 1 patient HB V. Wound healing deficit with cerebrospinal fluid (CSF) leak occurred in 8 patients (18.6%). Operative time was 317.3 ± 99 min. One patient which had recurrence and one further patient with partial resection underwent radiotherapy following surgery. A total of 16 patients (37.2%) underwent resection using fiducial-based navigation and microscope-based AR, all in sitting position. Segmented objects of interest in AR were the sigmoid and transverse sinus, tumor outline, cranial nerves (CN) VII, VIII and V, petrous vein, cochlea and semicircular canals and brain stem. Operative time and clinical outcome did not differ between the AR and the non-AR group. However, use of AR improved orientation in the operative field for craniotomy planning and microsurgical resection by identification of important neurovascular structures. Conclusions: The single-center experience of resection of ANs showed a high rate of gross total (GTR) and subtotal resection (STR) with low recurrence. Use of AR improves intraoperative orientation and facilitates craniotomy planning and AN resection through early improved identification of important anatomical relations to structures of the inner auditory canal, venous sinuses, petrous vein, brain stem and the course of cranial nerves.

Tumors of the nervous system and hearing loss: Beyond vestibular schwannomas.

Hearing loss is a common side effect of many tumor treatments. However, hearing loss can also occur as a direct result of certain tumors of the nervous system, the most common of which are the vestibular schwannomas (VS). These tumors arise from Schwann cells of the vestibulocochlear nerve and their main cause is the loss of function of NF2, with 95 % of cases being sporadic and 5 % being part of the rare neurofibromatosis type 2 (NF2)-related Schwannomatosis. Genetic variations in NF2 do not fully explain the clinical heterogeneity of VS, and interactions between Schwann cells and their microenvironment appear to be critical for tumor development. Preclinical in vitro and in vivo models of VS are needed to develop prognostic biomarkers and targeted therapies. In addition to VS, other tumors can affect hearing. Meningiomas and other masses in the cerebellopontine angle can compress the vestibulocochlear nerve due to their anatomic proximity. Gliomas can disrupt several neurological functions, including hearing; in fact, glioblastoma multiforme, the most aggressive subtype, may exhibit early symptoms of auditory alterations. Besides, treatments for high-grade tumors, including chemotherapy or radiotherapy, as well as incomplete resections, can induce long-term auditory dysfunction. Because hearing loss can have an irreversible and dramatic impact on quality of life, it should be considered in the clinical management plan of patients with tumors, and monitored throughout the course of the disease.

Retrosigmoid versus middle fossa approach for hearing and facial nerve preservation in vestibular schwannoma surgery: A systematic review and comparative meta-analysis.

BACKGROUND: Vestibular schwannomas (VS) are benign tumors arising from vestibular nerve's Schwann cells. Surgical resection via retrosigmoid (RS) or middle fossa (MF) is standard, but the optimal approach remains debated. This meta-analysis evaluated RS and MF approaches for VS management, emphasizing hearing preservation and Cranial nerve seven (CN VII) outcomes stratified by tumor size. METHODS: Systematic searches across PubMed, Cochrane, Web of Science, and Embase identified relevant studies. Hearing and CN VII outcomes were gauged using the American Academy of Otolaryngology-Head and Neck Surgery, Gardner Robertson, and House-Brackmann scores. RESULTS: Among 7228 patients, 56 % underwent RS and 44 % MF. For intracanalicular tumors, MF recorded 38 % hearing loss, compared to RS's 54 %. In small tumors (<1.5 cm), MF showed 41 % hearing loss, contrasting RS's lower 15 %. Medium-sized tumors (1.5 cm-2.9 cm) revealed 68 % hearing loss in MF and 55 % in RS. Large tumors (>3cm) were only reported in RS with a hearing loss rate of 62 %. CONCLUSION: Conclusively, while MF may be preferable for intracanalicular tumors, RS demonstrated superior hearing preservation for small to medium-sized tumors. This research underlines the significance of stratified outcomes by tumor size, guiding surgical decisions and enhancing patient outcomes.

High-throughput RNA sequencing identifies the miRNA expression profile, target genes, and molecular pathways contributing to growth of sporadic vestibular schwannomas.

PURPOSE: To assess the differences in the miRNA expression profile between small (stage I Koos classification) and large solid vestibular schwannoma (VS) tumors, using the RNA-seq technique. METHODS: Twenty tumor samples (10 small and 10 large tumors) were collected from patients operated for VS in a Tertiary Academic Center. Tumor miRNA expression was analyzed using high-throughput RNA sequencing (RNA-seq) technique, with NovaSeq 6000 Illumina system. Bioinformatics analysis was done using statistical software R. Gene enrichment and functional analysis was performed using miRTargetLink 2.0 and DIANA miRpath 3.0 online tools. RESULTS: We identified 9 differentially expressed miRNAs in large VS samples: miR-7, miR-142 (-3p and -5p), miR-155, miR-342, miR-1269, miR-4664, and miR-6503 were upregulated, whereas miR-204 was significantly down-regulated in comparison to small VS samples. Gene enrichment analysis showed that the most enriched target genes were SCD, TMEM43, LMNB2, JARID2, and CCND1. The most enriched functional pathways were associated with lipid metabolism, along with signaling pathways such as Hippo and FOXO signaling pathway. CONCLUSION: We identified a set of 9 miRNAs that are significantly deregulated in large VS in comparison to small, intracanalicular tumors. The functional enrichment analysis of these miRNAs suggests novel mechanisms, such as that lipid metabolism, as well as Hippo and FOxO signaling pathways that may play an important role in VS growth regulation.

Tratamiento multimodal en los schwanomas vestibulares grandes / Multimodal Treatment for Large Vestibular Schwannomas

Introducción: Los schwanomas vestibulares son lesiones clasificadas como grado I por la Organización Mundial de la Salud. Las opciones conductuales incluyen la observación, la radiocirugía o la resección microquirúrgica endoscópica. Objetivo: Describir el rol del tratamiento multimodal en los schwanomas vestibulares. Métodos: Se realizó una búsqueda sistemática de literatura médica para la identificación e inclusión de artículos en las siguientes bases de datos: PubMed/Medline, SciELO y Google Scholar, además de los servidores de preprints BioRvix y MedRvix. Se usaron los siguientes descriptores: vestibular schwanoma OR acoustic neuroma AND nerve centered approach OR combined approach AND partial resection OR subtotal resection OR near total resection. Se excluyeron editoriales, cartas al editor, libros, revisiones, metaanálisis y aquellos artículos con método deficiente de más de 20 años de publicación o sin mención al tema de interés. Fueron incluidos 16 artículos. Desarrollo: Los artículos incluyeron un total de 699 pacientes, de los cuales solo 228 (32,6 porciento) recibieron radioterapia en el período posoperatorio. El período de seguimiento promedió 49,6 meses. La preservación de la función facial se logró en el 88,3 porciento de los casos y el control tumoral en el 80,7 porciento. El estado de la preservación auditiva solo fue informado en el 50 porciento de los estudios. El uso de la radioterapia adyuvante mostró gran variabilidad. Conclusiones: El tratamiento multimodal para los schwanomas vestibulares grandes -compuesto por la resección subtotal, vaciamiento intratumoral, seguido de radiocirugía- se ha convertido en una opción plausible. Se necesita la publicación de mayor cantidad de reportes para ofrecer recomendaciones y estratificar la conducta(AU)

Introduction: Vestibular schwannomas are lesions classified as grade I by the World Health Organization. Behavioral options include observation, radiosurgery or endoscopic microsurgical resection. Objective: To describe the role of multimodal treatment for vestibular schwannomas. Methods: A systematic search of medical literature, for the identification and inclusion of articles, was carried out in the databases PubMed/Medline, SciELO and Google Scholar, as well as in the preprint servers BioRvix and MedRvix. The following descriptors were used: vestibular schwannoma OR acoustic neuroma AND nerve centered approach OR combined approach AND partial resection OR subtotal resection OR near total resection. Editorials, letters to the editor, books, reviews and metaanalyses were excluded, as well as articles with deficient method of more than 20 years of publication or not mentioning the topic of interest. Sixteen articles were included. Development: The articles included a total of 699 patients, of which only 228 (32.6 ) received radiotherapy in the postoperative period. The average follow-up period was 49.6 months. Preservation of facial function was achieved in 88.3 percent of cases; and tumor control, in 80.7 percent. Hearing preservation status was reported in only 50 percent of the studies. The usage of adjuvant radiotherapy showed great variability. Conclusions: Multimodal treatment for large vestibular schwannomas -composed of subtotal resection and intratumoral draining, followed by radiosurgery- has become a plausible option. The publication of a greater amount of reports is necessary to provide recommendations and stratify the behavior(AU)

Hearing loss in vestibular schwannoma

Introducción y objetivo: La hipoacusia es uno de los síntomas más frecuentes en el debut de un schwannoma vestibular (SV). El objetivo de este estudio es analizar la pérdida auditiva en pacientes con SV y determinar en qué medida se relaciona con el tamaño tumoral. Método: Se lleva a cabo un estudio retrospectivo observacional en 291 pacientes diagnosticados de SV entre 1995 y 2017 en el servicio de Otorrinolaringología y Cirugía Cervicofacial del Hospital Clínico Universitario de Salamanca analizándose diferentes datos pre y postoperatorios de los pacientes así como hallazgos radiológicos y quirúrgicos.Resultados: El síntoma más frecuente de consulta es la hipoacusia unilateral progresiva (31.6%). La asociación entre el tamaño del SV y la hipoacusia no es estadísticamente significativa (p=0.099).Conclusiones: La pérdida auditiva producida por un SV no es patrimonio de ningún estadio, aunque las pérdidas severas y profundas son más indicativas de neurinomas grados III-IV, y ante una pérdida auditiva leve o audición normal tendremos con más probabilidad un neurinoma grado I-II. (AU)

The most common reason for consultation in patients suffering from Vestibular Schwannoma (VS) is progressive hearing loss. The main objective of this study is analyzing the hearing loss in patients with VS and determining the extent to which the tumor grade and the hearing loss are related. Methods: An observational retrospective study was conducted with a sample of 291 patients diag-nosed with VS between 1995 and 2017 in the Department of Otorhinolaryngology and Head and Neck Surgery of the Tertiary Care Primary Center of Salamanca. We analyzed preoperative and postoperative data from patients with VS as well as radiological and surgical findings. Results: The most common reason for consultation at diagnosis was progressive unilateral hearing loss (31.6%). The relationship between the size of the VS and hearing loss in the patients who reported progressive unilateral hearing loss as a reason for consultation was not statistically significant (p=0.099). Conclusion: The most common reason for consultation in VS is progressive unilateral hearing loss. The hearing loss caused by VS does not have a statistically significant association with any tumor grade, although severe and profound hearing loss is more commonly associated with grade III-IV neurinomas, whereas mild hearing loss or normal hearing are more likely in grade I-II tumors. (AU)

Applicability of contemporary quality indicators in vestibular surgery-do they accurately measure tumor inherent postoperative complications of vestibular schwannomas?

BACKGROUND: Due to rising costs in health care delivery, reimbursement decisions have progressively been based on quality measures. Such quality indicators have been developed for neurosurgical procedures, collectively. We aimed to evaluate their applicability in patients that underwent surgery for vestibular schwannoma and to identify potential new disease-specific quality indicators. METHODS: One hundred and three patients operated due to vestibular schwannoma were subject to analysis. The primary outcomes of interest were 30-day and 90-day reoperation, readmission, mortality, nosocomial infection and surgical site infection (SSI) rates, postoperative cerebral spinal fluid (CSF) leak, facial, and hearing function. The secondary aim was the identification of prognostic factors for the mentioned primary outcomes. RESULTS: Thirty-day (90-days) outcomes in terms of reoperation were 10.7% (14.6%), readmission 9.7% (13.6%), mortality 1% (1%), nosocomial infection 5.8%, and SSI 1% (1%). A 30- versus 90-day outcome in terms of CSF leak were 6.8% vs. 10.7%, new facial nerve palsy 16.5% vs. 6.1%. Hearing impairment from serviceable to non-serviceable hearing was 6.8% at both 30- and 90-day outcome. The degree of tumor extension has a significant impact on reoperation (p < 0.001), infection (p = 0.015), postoperative hemorrhage (p < 0.001), and postoperative hearing loss (p = 0.026). CONCLUSIONS: Our data demonstrate the importance of entity-specific quality measurements being applied even after 30 days. We identified the occurrence of a CSF leak within 90 days postoperatively, new persistent facial nerve palsy still present 90 days postoperatively, and persisting postoperative hearing impairment to non-serviceable hearing as potential new quality measurement variables for patients undergoing surgery for vestibular schwannoma.

Suppression head impulse testing is recommended for vestibular testing of patients with untreated unilateral vestibular schwannoma.

PURPOSE: Suppression head impulse testing (SHIMP) is a new vestibular method capable of quantifying vestibular function. The aim of this study was to evaluate the feasibility of this test in patients with existing or newly diagnosed vestibular schwannoma (VS) patients by comparing the results with the traditionally used video head impulse test (vHIT or HIMP). METHODS: Fifty-five patients with unilateral VS underwent a wide battery of audiological and vestibular tests. HIMP results were evaluated using newly introduced objective guidelines based on the trace evaluation of pathological saccades. The sensitivity and specificity of HIMP and SHIMP were evaluated and compared. A new SHIMP parameter is presented; the anticompensatory saccade amplitude ratio (ASAR). RESULTS: We found a marked increase in specificity in HIMP testing using the objective guidelines. SHIMP testing revealed a gain threshold of 0.7 to be optimal in terms of achieving high specificity and sensitivity in relation to HIMP testing. Significant correlations were found between a low ASAR and a high degree of vestibular pathology. CONCLUSION: The SHIMP test is a viable addition to the standard HIMP test in patients with VS, especially with the addition of the ASAR, which could prove useful in monitoring the residual vestibular function. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: N/A.

Long-term prognosis of preserved useful hearing after surgery in patients with vestibular schwannoma: a study of 91 cases.

BACKGROUND: In patients with a vestibular schwannoma, some studies have reported that useful hearing preserved initially after surgery deteriorates gradually in the long term. Studies with more patients are needed to clarify the maintenance rate of postoperative hearing function and to identify prognostic of hearing function. METHOD: Ninety-one patients (mean age, 39.5 years; mean tumor size, 18.9 mm) with preserved useful hearing immediately after surgery were retrospectively analyzed. The useful hearing was defined as the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) classes A and B. Hearing tests, including auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE), were evaluated preoperatively, immediately after surgery, and at outpatient follow-up. RESULTS: At the final follow-up (mean, 63.0 months), the useful hearing was maintained in 79 patients (87%), and the hearing class remained unchanged during the follow-up period in 40 patients (44%). Significant predictors of useful hearing maintenance were AAO-HNS class A immediately after surgery, improvement of ABR, and the absence of postoperative DPOAE deterioration. Postoperative DPOAE deterioration correlated with hearing class deterioration. CONCLUSIONS: Despite hearing being preserved in vestibular schwannoma patients immediately after surgery, Thirteen percent lost their useful hearing during the long follow-up period, and hearing class worsened in 55% of the patients. This study, which analyzed one of the largest series of vestibular schwannoma patients, demonstrated that retrocochlear condition is a key factor for useful hearing maintenance. In patients with vestibular schwannoma who have preserved hearing function, regular postoperative monitoring of hearing function is as important as regular MRI.

Tumor miRNA expression profile is related to vestibular schwannoma growth rate.

OBJECTIVE: Our objective was to investigate if the tumor microRNA (miRNA) expression profile was related to tumor growth rate. Growth-related miRNAs might be potential targets for future therapeutic intervention. MATERIAL AND METHODS: Tumor tissue was sampled during surgery of patients with a sporadic vestibular schwannoma. Tumor growth rate was determined by tumor measurement on the two latest pre-operative MRI scans. Tumor miRNA expression was analyzed using the Affymetrix Gene Chip® protocol, and CEL files were generated using GeneChip® Command Console® Software and normalized using Partek Genomics Suite 6.5. The CEL files were analyzed using the statistical software program R. Principal component analysis, affected gene ontology analysis, and analysis of miRNA expression fold changes were used for analysis of potential relations between miRNA expression profile and tumor growth rate. RESULTS AND CONCLUSION: Tumor miRNA expression is related to the growth rate of sporadic vestibular schwannomas. Rapid tumor growth is associated with deregulation of several miRNAs, including upregulation of miR-29abc, miR-19, miR-340-5p, miR-21, and miR-221 and downregulation of miR-744 and let-7b. Gene ontologies affected by the deregulated miRNAs included neuron development and differentiation, gene silencing, and negative regulation of various biological processes, including cellular and intracellular signaling and metabolism.

Resección microquirúrgica de schwannoma vestibular grado IVa con preservación de la función facial / Microsurgical resection of vestibular schwannoma grade IVa with preservation of facial function

Introducción: La cirugía de los schwannoma vestibulares constituye un desafío para los neurocirujanos. Debido a que se trata de un tumor benigno la resección completa de la lesión implica la curación del paciente. Sin embargo, este objetivo no siempre es fácil de lograr preservando la función de los nervios facial y acústico, especialmente en tumores de gran tamaño. Objetivos: Presentar detalles técnicos de la cirugía de resección de un schwannoma vestibular de gran tamaño (IVa) en el que se pudo preservar la función facial. Materiales y métodos: Se presenta el caso de una paciente femenina de 36 años que consultó por hipoacusia izquierda. En la RM preoperatoria se evidenciaba una lesión ocupante de espacio del ángulo pontocerebeloso izquierdo compatible con schwannoma vestibular con compresión del tronco encefálico y sin efecto de masa sobre el IV ventrículo (grado IVa). Mediante un abordaje suboccipital retromastoideo en posición de decúbito lateral se realizó la resección de la lesión en forma completa asistida por monitoreo del nervio facial. En todo momento se pudo preservar el plano aracnoideo que separaba el tumor de los nervios adyacentes. Resultados: Se logró una resección macroscópicamente completa con preservación de la función del nervio facial. La paciente permaneció internada por 96 hs en el postoperatorio sin complicaciones derivadas del procedimiento. Conclusión: La preservación del plano aracnoideo es un detalle técnico de mucha importancia para disminuir las posibilidades de lesión de los nervios facial y auditivo en la cirugía de resección de los schwannoma vestibulares.

Introduction: The surgery of vestibular schwannomas is a challenge for neurosurgeons.Because it is a benign tumor, complete resection of the lesion involves healing the patient. However, this objective is not always easy to achieve, preserving the function of both the facial and acoustic nerves, especially when dealing with large tumors. Objective: The objective of the video is to present some technical details of a large vestibular schwannoma (IVa) surgery in which the facial function could be preserved. Materials and methods: We present the case of a 36-year-old female patient who consulted for left hearing loss. The preoperative MRI showed a space- occupying lesion of the left pontocerebellar angle, which was compatible with vestibular schwannoma, with compression of the brainstem but with no mass effect on the IV ventricle (grade IVa). By means of a retromastoid suboccipital approach in the lateral prone position, the lesion was completely resected assisted by neurophysiological monitoring of the facial nerve. At all times, the arachnoid plane separating the tumor from the adjacent nerves was preserved. Results: A macroscopically complete resection was achieved preserving the facial nerve function. The patient stayed hospitalized for 96 hours during the postoperative period without any complication from the procedure. Conclusion: Preserving the arachnoid plane is a very important technical detail to reduce the possibilities of injury of the facial and auditory nerves in the vestibular schwannoma resection surgery.

De Novo Vestibular Schwannoma: A Report of Three Cases.

The reported growth rate of vestibular schwannoma varied widely in the literature. However, emergence of vestibular schwannoma remains unsolved. We presented three patients who had undergone previous magnetic resonance imaging (MRI) confirming the absence of tumor and were diagnosed with a unilateral vestibular schwannoma with a diameter of 18-30 mm, 6-9 years after the initial MRI. One patient had solid tumor and experienced stereotactic radiosurgery. Following stereotactic radiosurgery, continuous tumor growth led to hydrocephalus and trigeminal dysfunction, resolved by surgical removal. Other two patients had the tumor with cystic component and experienced surgical removal as first treatment. All tumors were pathologically diagnosed as schwannomas without evidence of high potential of proliferation. This is the first report of three patients with de novo vestibular schwannoma, showing tumor emergence and rapid growth in a short period. Considering a de novo aspect, the "wait and scan" policy may not be appropriate for the subset of VS such as de novo VS.

Quality of life in the management of small vestibular schwannomas: Observation, radiotherapy and microsurgery.

OBJECTIVE: The aim of this study was to compare quality of life (QOL) in small unilateral vestibular schwannoma (VS) patients managed by microsurgery, radiotherapy or observation. STUDY DESIGN: A retrospective chart review. METHODS: The study included a total of 142 patients with VS stage 1 or 2 according to the Koos classification and treated between January 2004 and December 2015. Microsurgery, radiotherapy and observation groups comprised 43, 46 and 53 patients, respectively. All patients completed four QOL (questionnaires: Short-Form Health Survey 36, Hearing Handicap Inventory, Tinnitus Handicap Inventory and Dizziness Handicap Inventory Short-Form). Clinical symptoms and QOL were compared among groups. RESULTS: The average time interval between management and filling in the questionnaires was 66 months. There was no difference in QOL between the three groups on any of the four questionnaires. The most debilitating symptom was vertigo for all three groups. Tinnitus was a pejorative factor in the surgery group. Hearing level was deteriorated after microsurgery but there was no significant difference between the radiotherapy group and the middle fossa approach. CONCLUSION: Patients with small VS stage 1 and 2 had similar QOL, irrespective of management by observation, radiotherapy or microsurgery. The overall predictor for long-term reduced QOL was vertigo. Vestibular rehabilitation could improve QOL in symptomatic patients.

The outermost "dura-like membrane" of vestibular schwannoma.

BACKGROUND: The membranous structure of vestibular schwannoma is an important factor in its surgical treatment. Herein, we report intraoperative and microscopic findings relating to an outermost dura-like membrane in cases of vestibular schwannoma and the importance of these findings. METHODS: Intraoperative findings of 16 cases of vestibular schwannoma treated with an initial surgery were studied with an aim to determine if the cases had a dura-like membrane. Then we studied microscopic findings of the dura-like membrane using hematoxylin and eosin, Masson trichrome, and immunohistochemical staining in 2 cases. RESULTS: The dura-like membrane was observed in 8 out of 16 cases. The average tumor size of the cases that had a dura-like membrane was 30 ± 8.1 mm, and Koos grading 4 was in 7 out of 8 cases, and one was grade 3. In cases without a dura-like membrane, these values were significantly smaller, with an average tumor size of 12.8 ± 5.2 mm, and Koos grading 4 was only in 1 of 8 cases, grade 3 was in 2 cases, and other 5 cases were grade 2. The outermost dura-like membrane enveloped the vestibular schwannoma around the internal acoustic meatus and was continuous with the dura mater. Reactive angiogenesis was observed in the dura mater. Microscopic findings proved its continuity with the dura mater. In one case, the facial nerve was damaged before it was identified during subcapsular dissection. In that case, the dura-like membrane negatively affected our ability to identify the facial nerve. CONCLUSIONS: A dura-like membrane sometimes envelops vestibular schwannoma around the internal acoustic meatus. Recognition of this membranous structure is important for the surgical preservation of facial and acoustic nerves.

Management of CSF leakage after microsurgery for vestibular schwannoma via the middle cranial fossa approach.

Microsurgery is one of the primary current standard options for the treatment of vestibular schwannoma (VS). Especially the middle cranial fossa (MCF) approach is a safe and efficacious technique for the preservation of hearing and facial nerve function in small VS. Postoperative complications are rare, although a leakage of cerebrospinal fluid (CSF) is common. The aim of this study was to analyze postoperative CSF leaks and to describe strategies for postoperative treatment. Between October 2005 and May 2012, 148 patients suffering from VS and selected for microsurgery via the MCF approach were treated in our department. Postoperative CSF leakage occurred in 19 patients. We found a leakage via the Eustachian tube into the nasopharynx in 18 patients and one case of incisional leakage. In 13 cases leaking stopped within 5 days by conservative management including bed rest and intravenous (i.v) antibiotics. Five patients needed lumbar drainage (LD) and only two patients had to undergo revision surgery to seal and pack the mastoid. Analyzed risk factors were age, gender, tumor size and pneumatization of the mastoid. Only the latter showed a significant influence on CSF leakage. We could demonstrate that a stepwise strategy is needed for successful treatment of CSF leaks.

Cochlear implantation for hearing rehabilitation in single-sided deafness after translabyrinthine vestibular schwannoma surgery.

The aim of the study was to investigate the option of cochlear implantation (CI) in resultant single-sided deafness associated with unilateral translabyrinthine resection of sporadic vestibular schwannoma (VS). This is a retrospective study performed at Tertiary Care Academic Centre. Following extensive counselling regarding the potential for delayed CI, translabyrinthine VS resection was performed and an intracochlear placeholder was inserted to allow later CI in 11 patients who showed intraoperative microscopic confirmation of preserved cochlear nerve anatomy. Follow-up magnetic resonance imaging (MRI) and promontory testing were performed 1 year after surgery to confirm the absence of VS recurrence and viable cochlea. Confirmed CI candidates underwent a second procedure where the placeholder was removed and the CI inserted (4/11). Preimplant unaided and CI-aided evaluations at 12 and 24 months were performed for subjective and objective hearing outcomes. Tinnitus suppression was also measured for implant on and off effects. Available audiological data for three patients demonstrated significant hearing benefits for 'speech from deaf/implanted side, noise from the normal-hearing side' in all three patients and localisation ability improved for 2/3 patients. Subjective findings presented similar results. For the two patients with preimplant tinnitus, complete suppression occurred during active CI. CI is beneficial for hearing rehabilitation and tinnitus reduction in SSD patients with remaining viable cochlear nerve after translabyrinthine VS surgery. Counselling on the risks of intracochlear placeholder insertion and the inherent limitations for ongoing MRI investigations of VS recurrence is essential.

The first calcified acoustic neurinoma identified in China: a case report and literature review.

Here we reported the first case of left cerebellopontine angle acoustic neurinoma with calcification in our department. The patient was 65 year-old, suffering from progressive loss of hearing in the left ear for about 30 years and headache with unsteady gait for approximately 6 months. Head CT & MRI scan identified an intracranial lesion located on left cerebellopontine angle. Left suboccipital retrosigmoid approach was applied to perform the operation after patient consent. The tumor was completely resected without complication and the patient recovered well. Histological findings revealed Spindle-shaped tumor cells tightly compacted to form the Antoni A region, while loosely arranged to form the Antoni B region. Hyaline degeneration and calcification formation were observed across the majority of the tumor.

The extracisternal approach in vestibular schwannoma surgery and facial nerve preservation / A abordagem extracisternal na cirurgia de schwannoma vestibular e preservação do nervo facial

The classical surgical technique for the resection of vestibular schwannomas (VS) has emphasized the microsurgical anatomy of cranial nerves. We believe that the focus on preservation of the arachnoid membrane may serve as a safe guide for tumor removal. Method The extracisternal approach is described in detail. We reviewed charts from 120 patients treated with this technique between 2006 and 2012. Surgical results were evaluated based on the extension of resection, tumor relapse, and facial nerve function. Results Overall gross total resection was achieved in 81% of the patients. The overall postoperative facial nerve function House-Brackmann grades I-II at one year was 93%. There was no recurrence in 4.2 years mean follow up. Conclusion The extracisternal technique differs from other surgical descriptions on the treatment of VS by not requiring the identification of the facial nerve, as long as we preserve the arachnoid envelope in the total circumference of the tumor. .

A técnica cirúrgica clássica para ressecção de schwannomas vestibulares enfatiza a anatomia microcirúrgica dos nervos cranianos. Acreditamos que o foco na preservação da membrana aracnóide pode servir como parâmetro seguro para a remoção do tumor. Método A abordagem extracisternal é descrita em detalhe. Analisamos o prontuário de 120 pacientes tratados com esta técnica entre 2006 e 2012. Os resultados cirúrgicos foram baseados em extensão de ressecção, recorrência tumoral e função do nervo facial. Resultados Ressecção total foi obtida em 81% dos pacientes. O resultado global da função do nervo facial (House-Brackmann graus I-II) após um ano da cirurgia foi de 93%. Não houve recidiva em um seguimento médio de 4,2 anos. Conclusão A técnica extracisternal difere de outras descrições cirúrgicas no tratamento de schwannoma vestibular pois não requer a identificação do nervo facial, contanto que o plano de aracnóide seja preservado em toda circunferência do tumor. .