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• At low voltage, FCC5h/FCC6h-Mz stimulation evoked larger Cb-MEPs than C3/C4-Cz. • At low voltage, FCC5h/FCC6h-Mz stimulation induced less peripheral responses by direct activation of facial nerve than C5/C6-Cz. • FCC5h/FCC6h-Mz stimulation is safe and increases the accuracy and the specificity of Cb-MEPs with respect to facial nerve outcome. 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. 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. 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. FCC5h/FCC6h-Mz stimulation showed the best performances for monitoring the facial nerve functioning, maintaining excellent diagnostic measures even at low stimulus voltages. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• RS excels in small-medium VS hearing. • MF for intracanalicular, RS for larger. • Meta-analysis favors RS for VS. 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. 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. 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 (>3 cm) were only reported in RS with a hearing loss rate of 62 %. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• Vestibular schwannomas originate from Schwann cells of the vestibulocochlear nerve. • Variations in NF2 gene do not fully explain the clinical heterogeneity of vestibular schwannomas. • Schwann cells and tumor microenvironment interactions emerge as critical for its development. • Preclinical models are needed to develop prognostic biomarkers and targeted therapies. • Gliomas and other neural tumors can cause hearing loss by disrupting the auditory pathway. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Los tumores cerebrales son infrecuentes durante el embarazo. Los neurinomas del acústico pueden ser sintomáticos por primera vez durante la gestación y representan el 6-8% de las neoplasias intracraneales. El objetivo de esta comunicación es presentar el caso de una primigesta adolescente que presentó sintomatología neurológica de afectación del VIII par y de fosa posterior, característica de la neurofibromatosis tipo 2.Brain tumors are infrequent during pregnancy. Neurinomas of auditive nerve can get to be symptomatic during gestation, representing 6-8% of the intracranial neoplasias. The objective is to report a case of a pregnant adolescent who present a neurological symptoms of VIII pair affectation and posterior cranial fossa, characteristic of the neurofibromatosis type 2.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To review the natural course of tumor size and hearing during conservative management of 151 patients with unilateral vestibular schwannoma (VS), and to evaluate the same parameters for the part of the group (n = 84) who were treated by LINAC stereotactic radiosurgery (SRS).Methods: In prospectively collected data, patients underwent MRI and complete audiovestibular tests at inclusion, during the conservative management period and after SRS. Hearing was graded according to the Gardner-Robertson (GR) scale and tumor size according to Koos. Statistics were performed using Kaplan-Meier survival analysis and multivariate analyses including linear and logistic regression. Specific insight was given to patients with serviceable hearing.Results: During the conservative management period (mean follow-up time: 24 months, range: 6-96), the annual risk of GR class degradation was 6% for GRI and 15% for GR II patients. Hearing loss as an initial symptom was highly predictive of further hearing loss (p = 0.003). Tumor growth reached 25%. For SRS patients, functional hearing preservation was 51% at 1 year and 36% at 3 years. Tumor control was 94 and 91%, respectively.Conclusion: In VS patients, hearing loss at the time of diagnosis is a predictor of poorer hearing outcome. LINAC SRS is efficient for tumor control. Patients who preserved their pretreatment hearing presented less hearing loss per year after SRS than before treatment, suggesting a protective effect of SRS when cochlear function can be preserved. [ABSTRACT FROM AUTHOR]

We present our experience with 83 patients with acoustic neurinomas (January 1988 to November 1996); 81 patients underwent surgery and 2 patients with intracanalicular neurinomas received conservative therapy due to their advanced age (1 case) and patient's option (1 case). The surgical approach was retrosigmoid/ trasmeatal and the goal was total removal in one procedure with preservation of facial and cochlear nerves. Radical removal of lesion was attempted in 79 cases and it was possible in 77 patients. Subtotal tumor resection was planned in 2 cases. Facial nerve function (grades 1 to III, House and Brackman) was preseved in 90% and hearing in 58% of those with preoperative hearing. Three patients died due to postoperative complications. Early diagnosis of acoustic neurinomas is the most important factor in the prognosis and is one of the most important conquest of neurophysiology and modern neuroimaging. The management of these patients still present many controversial points. This article presents the diagnostic procedures used for acoustic neurinomas, the advantages and disadvantages of the different surgical approaches and the alternative management of these lesions.Apresentamos nossa experiência no tratamento de 83 pacientes com neurinomas do acústico (Janeiro-1988 a Novembro-1996). Cirurgia foi realizada em 81 pacientes e tratamento conservador (idade avançada e escolha do paciente) em 2 casos de neurinomas intracanalicures. O objetivo da cirurgia foi ressecção radical com preservação dos nervos facial e coclear. Em 77 de 79 pacientes foi obtida remoção total. Em 2 casos foi proposta ressecção sub-total devido às más condições clínicas (1 paciente) e por tratar-se de neurofibromatose tipo 2 com lesão dos nervos facial e coclear do outro lado (1 paciente). Preservação do nervo facial (grau I a III, House e Brackman) foi possível em 90% dos casos com função facial pre-operatória normal. Dos 12 pacientes que apresentavam audição no pré-operatório, 7 mantiveram a audição. Ocorreram 3 óbitos no pós-operatório imediato. As vantagens e desvantagens dos acessos cirúrgicos mais utilizados na cirurgia do neurinoma do acústico são demonstradas. O fator mais importante no prognóstico desses pacientes é o diagnóstico precoce, possível com o desenvolvimento de novos métodos neurofisiológicos e neurorradiológicos. O tratamento no entanto pode apresentar algumas controvérsias, variando desde o simples acompanhamento clínico à remoção cirúrgica ou o uso de radiocirurgia.

Copyright of Arquivos de Neuro-Psiquiatria is the property of Thieme Medical Publishing Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE: Tinnitus in one of the most common complaints of patients with acoustic neurinoma, which could lead to early diagnosis. Because postoperative tinnitus can have a profound effect on patients' quality of life, candidates for surgery should be thoroughly informed about the possible effect of the operation on their tinnitus status. Questionnaires were the only source of information for tinnitus evaluation in previous studies, most of which were retrospective. MATERIALS and METHODS: Twelve patients with unilateral tinnitus and hearing loss and definite diagnosis of acoustic neurinoma were operated via translabyrithine tumour resection. One week before and 3 months after complete translabyrinthine removal of tumour, tinnitus evaluation test was performed and pitch match of tinnitus and loudness match of tinnitus were measured. Then patients were asked to complete two Persian validated questionnaires,Tinnitus Handicap Inventory-Persian and Tinnitus Questionnaire-Persian. RESULTS: Psychoacoustic and psychometric aspects were improved in three patients, did not change in one patient, and worsened in one patient. In three patients, tinnitus disappeared and in four patients without preoperative tinnitus, it did not occur. CONCLUSION: Partial improvement in postoperative tinnitus was seen but prediction about tinnitus after surgery is not possible yet. Nonetheless, postoperative tinnitus is not bothersome and does not affect patients'lives. [ABSTRACT FROM AUTHOR]

Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Introduction: For postoperative CSF-fistula prevention a better understanding of its origins and risk factors is necessary. To identify the role of the tumor growth for the risk to develop CSF-fistula we performed a retrospective analysis. Methods: 519 patients between the years 2000 and 2007 had a retrosigmoidal surgical removal of vestibular schwannoma in a standardized procedure. 22 CSF-fistula-patients were chosen for evaluation. 78 patients were randomly selected as control group in four equally sized cohorts: male/female with small/large tumors. Preoperative CT-scans were analyzed regarding IAC-length, diameter of the IAC porus (IAP), tumor size and pneumatization of the posterior wall (PW) of the IAC. Results: The mean length of the IAC was 1.2cm, SD 0.17. There was a significant difference between the diameter of the IAP in cases of small tumors and those of large tumors. Patients with small tumors also showed a larger fraction with visible pneumatization of the PW (34.88%) in the CT-scan than patients with large tumors (24.07%). There is a positive correlation between tumor grade and diameter of the IAP. At the same time there is an inverse correlation between tumor grade and pneumatization of the PW. Conclusions: Widening of the IAC by tumor growth may leads to obliteration of air cells in the PW and therefore can be protective concerning CSF-fistula. At the same time patients with small tumors and a visible pneumatization in the PW must be expected to have a higher risk of CSF-fistula. [Copyright &y& Elsevier]

Purpose: To evaluate tumor control and side effects associated with radiosurgery (RS) and stereotactic fractionated radiotherapy (SFR) for vestibular schwannomas (VSs) in a group of patients treated at the same institution. Methods and Materials: Between May 1997 and June 2007, 115 consecutive cases of VS were treated in our department. The SFR group (47 patients), including larger tumors (maximum diameter >1.5 cm), received a total dose of 54 Gy at 1.8 Gy per fraction. The RS group (68 patients, maximum diameter <1.5 cm) received a total dose of 12 Gy at the 100% isodose. Evaluation included serial imaging tests (magnetic resonance imaging) and neurologic and functional hearing examinations. Results: The tumor control rate was 97.9% in the SFR group for a mean follow-up time of 32.1 months and 98.5% in the RS group for a mean follow-up time of 30.1 months. Hearing function was preserved after RS in 85% of the patients and after SFR in 79%. Facial and trigeminal nerve function remained mostly unaffected after SFR. After RS, new trigeminal neuropathy occurred in 9 of 68 patients (13%). Conclusions: A high tumor control rate and low number of side effects are registered after SFR and RS of VS. These results confirm that considering tumor diameter, both RS and SFR are good treatment modalities for VS. [ABSTRACT FROM AUTHOR]

Abstract: The vestibulo-ocular reflex (VOR) was studied to examine the utility of off-vertical axis rotation (OVAR) in the diagnosis of acoustic neurinoma. Subjects were sinusoidally rotated with eyes open in complete darkness at frequencies of 0.4 and 0.8Hz with a maximum angular velocity of 60°/s at either earth-vertical axis rotation (EVAR) or OVAR. Thirteen patients with acoustic neurinomas were investigated. Results showed that VOR gain during OVAR at 0.8Hz and in a 30° nose-up position in patients with internal auditory canal tumors was significantly less than the gain measured during EVAR. The VOR gain measured from all patients (including those with tumors extending to the cerebellopontine angle) was not significantly different when the patients were subjected to EVAR and OVAR. These observations were possibly due to superior vestibular nerve dysfunction. We concluded that certain stimulating parameters—patient''s nose tilted up 30°; sinusoidal OVAR at 0.8Hz and 60°/s maximum angular head velocity—were useful for evaluating vestibular function in patients suffering from an acoustic neurinoma located within the internal auditory canal. [Copyright &y& Elsevier]

Gross intratumoral haemorrhage is rare in vestibular schwannomas. The authors describe the clinical features of this entity in 6 patients, the histopathologic findings in 5 of them, and discuss possible factors predisposing to haemorrhage in these tumors. Detailed radiological and histopathological evaluation identified two factors which may be associated with higher likelihood of haemorrhage, namely preoperative radiation therapy and vascular abnormalities. Tumor size may not be a major risk factor for haemorrhage. Good outcomes can be achieved with microsurgical management. The histological features presented here differ clearly from findings in previously published case reports. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Our protocol to manage the intralabyrinthine schwannoma (ILS). Methods: Retrospective chart review of 7 consecutive patients managed for ILS. Results: Five patients underwent surgical removal of the lesions and none experienced significant complications or recurrent disease. One patient refused surgical treatment and was closely followed by serial MRI scans with no signs of tumor growth. One patient is presently managed conservatively due to a good hearing. Conclusions: Diagnosis of ILS is based on high resolution MRI scans and should be included in the differential diagnosis of patients investigated for cochleovestibular symptoms. Treatment modality of ILS is controversial and depends patients’ age, severity of vertigo and hearing loss. In the authors’ experience surgery is indicated in all cases with invalidating vertigo and in the young patients with severe hearing loss. Conservative strategy is advised in older patients and in cases with preserved good hearing and no invalidating vertigo. These patients must be followed up using high resolution MRI because of the risk of tumor growth into the internal auditory canal. While tumors with exclusive involvement of the inner ear may be removed by means of a completely extradural approach, tumor growth with involvement of the internal auditory canal dictates the necessity of opening the dura exposing the patients to the potential risks associated with the procedure. [Copyright &y& Elsevier]

Conclusions. The precise risk factors for neurological complications after acoustic neurinoma radiosurgery were identified on long-term follow-up. Type 2 neurofibromatosis was found to be a risk factor for hearing loss and peripheral tumor dose was a risk factor for seventh and fifth cranial nerve injuries. These risk factors corresponded to those reported at other institutions. At the present time, controversy exists regarding history of prior surgical resection and tumor size as risk factors for cranial nerve complications. Objectives. To identify more precisely the risk factors for neurological complications after stereotactic radiosurgery (SRS) based on long-term follow-up. Patients and methods. Between June 1990 and September 1998, 138 patients with acoustic neurinomas had SRS at Tokyo University Hospital. Of these, the 125 patients who were followed up for at least 6 months were entered into the present study. The patients' ages ranged from 13 to 77 years (median 53 years). The average tumor diameter ranged from 6.7 to 25.4 mm (mean 13.9 mm). The maximum tumor doses ranged from 20 to 40 Gy (mean 29.8 Gy), and the peripheral doses ranged from 12 to 25 Gy (mean 15.4 Gy). One to 12 isocenters were used (median 4). The follow-up period ranged from 6 to 191 months (median 60 months). The potential risk factors for neurological complications were analyzed using two univariate actuarial analyses. The neurological complications studied included hearing loss, facial palsy, and trigeminal nerve dysfunction. The variables analyzed were age, gender, prior operation, neurofibromatosis type 2 (NF2), tumor diameter, maximum tumor dose, peripheral tumor irradiation dose, and the number of isocenters. Variables with significant p values (<0.05) on both actuarial analyses were considered risk factors. Results. NF2 was significantly correlated with both total hearing loss and pure tone threshold (PTA) elevation; a history of prior surgical resection, tumor size, and the peripheral tumor dose were significantly correlated with facial palsy; and the peripheral tumor dose was significantly correlated with trigeminal neuropathy. [ABSTRACT FROM AUTHOR]

A four-channel device may enhance the sensitivity of electromyography (EMG). Determination of stimulation thresholds (STs) below 0.05 mA improves facial prognostic information after vestibular schwannoma (VS) surgery. To compare intraoperative observations with electromyographic data for predicting the immediate facial function outcome after VS surgery. A total of 111 VS patients operated on and intraoperatively monitored using four-channel facial EMG between October 2002 and September 2003 were included in this multicentre, prospective study. Mascular activity detection was performed in the frontal, orbicularis oculi, orbicularis oris and platysma muscles. Intraoperative observations were made concerning adhesion and nerve stretch, and facial function was graded (House–Brackmann classification) at postoperative Days 1 and 8. Facial function at postoperative Days 1 and 8 was related to the intraoperative nerve STs at the brainstem and in the adhesion zone (range 0.01–3 mA for a response > 100 µV). At postoperative Day 8, good facial function (Grades 1 or 2) was observed in 93% of cases for STs in the adhesion zone of 0.01–0.04 mA, 85% for STs of 0.05–0.3 mA and 79% for STs > 0.3 mA. These STs were related to the degree of tumor adhesion and not to the nerve stretch. The maximal EMG response was detected in the frontal or platysma muscles in 26% of cases, and in the orbicularis oris and orbicularis oculi muscles in 74%. [ABSTRACT FROM AUTHOR]

Objective --In the past, various attempts were made to perform a quantitative analysis of nystagmographic findings but their diagnostic value was limited. Therefore, the authors present a multivariate analysis of nystagmus findings with the aim of increasing the precision of diagnostic differentiation in cases of vestibular dysfunction. Material and Methods --A group of 387 patients and 40 healthy volunteers were examined over a 14-month period using electronystagmography after stimulation by bithermal, bilateral irrigation of the labyrinth. Amplitude, slow-phase velocity, frequency and directional preponderance were evaluated. Results --No defined normal values for caloric nystagmus parameters could be obtained. However, by using the Mann-Whitney U-test and logistic regression analysis a differentiation between pathological and healthy findings as well as between central and peripheral vestibular disorders and even between distinct vestibular disease entities is possible. Using these methods, the nystagmus amplitude was found to be the strongest discriminating parameter. Therefore, sole assessment of nystagmographic findings by selective calculation of the nystagmus slow-phase velocity falls short of the potential offered by electronystagmographic registration. Conclusion --For daily clinical routine, counting nystagmus beats leads to the same diagnostic precision as the analysis of slow-phase velocities. In contrast, multivariate analysis of several nystagmus parameters can distinguish between distinct diseases with fairly high precision. This stepwise analysis of nystagmographic data could create the basis for an expert-system tool in the near future. [ABSTRACT FROM AUTHOR]

The authors report two surgical cases with acoustic neurinoma in which haemorrhagic infarction occurred via a compromise in cerebral deep venous outflow. In both cases, surgery was performed via the posterior petrosal approach, and the neurinomas were completely removed. In the first case, the haemorrhagic infarction was considered to have resulted from transection of the tentorial sinus, the presence of which had not been predictable by preoperative angiography. In the second case, the haemorrhagic infarction was caused by a coagulation of the petrosal vein, which was firmly adherent to a tumour. With the posterior petrosal approach, meticulous care is necessary to preserve the deep anastomotic veins into and around the cerebellar tentorium. Thereby, catastrophic morbidity related to compromised deep cerebral venous outflow can be avoided. [ABSTRACT FROM AUTHOR]

Summary The authors report on their series of 40 patients with 41 acoustic neurinomas (ACNs), including one patient with bilateral acoustic neurinomas suffering from neurofibromatosis type 2 (NF II) who were treated with the gamma knife unit at their institution between August 1992 and October 1995. Of these 41 tumours, 21 ACNs had been operated on before (1 to 4 times), 20 ACNs were exclusively treated by gamma knife radiosurgery (GKRS). The maximal axial tumour diameter ranged from 6 to 33 mm (median: 25 mm), the maximal transverse tumour diameter ranged from 7 mm to 36 mm (median: 16 mm). The dose distributed to the tumour margin was 10 to 17 Gy (median: 12 Gy) by enclosing the tumour with the 40% to 95% isodose line (median: 50% isodose line) and using 1 to 12 isocenters (median: 5 isocenters). Central loss of contrast enhancement was observed in 78% of the patients within six to 12 months after radiosurgery. Thirty-two patients were observed over a minimum follow up period of at least 36 months, 9 patients were lost to follow up as they died of unrelated causes or refused further check-ups. Within the follow up period of up to seven years, magnetic resonance imaging (MRI) control scans revealed the tumour diameter stable or decreased in 29 cases and increased in three tumours. Of 14 patients with useful hearing before treatment, 9 patients were examined in addition to pure tone audiogramm by measurement of brainstem auditory evoked potentials (BAEPs) one to four years after radiosurgery. None of these patients showed a postoperative loss of the cochlea function. According to slight alterations of the cochlea function (cochlea summating action potential), pure tone audiometry of those patients revealed only slight changes of the hearing level (HL) within a maximum range of ±15 Decibel (dB). The hearing threshold improved in two, was stable in four and deteriorated in three patients, respectively. We observed postradiosurgical aggravation of a pre-existing facial weakness in two out of 13 patients, a new occurrence of facial palsy was seen in two cases (four years after treatment), one of them was previously operated on and both suffered from cystic degeneration with mass effect. Tinnitus improved in six out of 13 patients, deteriorated in two and never appeared as a new permanent sequela. Trigeminal hypaesthesia did also not appear as a new permanent symptom, improved in three out of 9, and deteriorated in one out of 9 patients. Vertigo increased in six out of 23, was stable in 8 and decreased in nine out of 23 patients each. GKRS proves to be a safe and highly satisfactory therapeutical option or addition to open surgery, especially for radiologically verified regrowing residual ACNs, but also as primary treatment in selected patients. A high rate of tumour control can be achieved with an acceptable rate of neurological deficits. [ABSTRACT FROM AUTHOR]

Summary Though infrequent, acoustic neurinomas have been described during pregnancy and represent a therapeutic challenge for excision without producing any problem for the mother and the foetus. First Author experienced two cases of acoustic neurinomas presenting during pregnancy. One patient presented in the terminal stages of the third trimester of pregnancy and underwent caesarean section, followed by retromastoid craniectomy and excision of the tumour. Operative management of the pregnancy and tumour in the same sitting has not been reported in the literature. Second patient who presented during 2nd trimester of pregnancy, was operated on for the tumour and had a successful continuance of pregnancy. Details of the management are discussed and the relevant literature reviewed. In addition to causing aggravation of symptoms, the larger size and increased vascularity of these tumours during pregnancy, makes them more vulnerable to acute bleeding, which in turn may initiate new or exacerbate pre-existing symptoms, as noted in one of the cases presented in this report. [ABSTRACT FROM AUTHOR]

Background. Even though vestibular schwannomas rarely present during pregnancy, symptoms may appear or worsen particularly in this period. The clinical picture may include tinnitus, hearing abnormalities, and in large tumors, brain-stem and cerebellar compression with involvement of additional cranial nerves. Large vestibular schwannomas (also known as Acoustic Neurinomas) present a great challenge in peripartum management of both the mother and the fetus. Material and method. We present a case of a 24-year old woman, with headache, papilledema, ataxia, and multiple cranial nerve weakness, diagnosed in the 35th week of pregnancy. MRI demonstrated a huge vestibular schwannoma compressing the brainstem and causing obstructive hydrocephalus. Result. In the presence of high intra-cranial pressure a ventriculo-peritoneal shunt was first inserted, enabling delay of tumor surgery until after delivery. A successful elective cesarean section followed at 37 weeks, and radical tumor surgery was performed a week later. Maternal and fetal outcome were excellent. Discussion. The options, sequence and timing of the neurosurgical and obstetrical interventions are discussed. Other reports of large vestibular schwannomas that presented during pregnancy are reviewed. Advances in neurosurgery, neuroradiology, neuroanesthesiology and obstetrics are highlighted, and their impact on outcome is discussed in comparison to the poor results reported in the past. Emphasis is made on the importance of early diagnosis, that necessitates high-index of suspicion by the obstetrician, in any pregnant woman presenting abnormal neurological signs. Conclusion. We conclude that with a cooperative team approach, maternal and fetal prognosis can today be excellent, even in cases of large vestibular schwannomas diagnosed in the late stage of pregnancy. [ABSTRACT FROM AUTHOR]