Guía de práctica clínica sobre el manejo del schwannoma vestibular / Clinical practice guideline on the management of vestibular schwannoma

Introducción: El schwannoma vestibular (SV) es el tumor más frecuente del ángulo pontocerebeloso. La mayor accesibilidad a las pruebas radiológicas ha incrementado su diagnóstico. Teniendo en cuenta las características del tumor, la clínica y la edad del paciente se han propuesto tres estrategias terapéuticas, observación, cirugía o radioterapia. La elección de la más adecuada para cada paciente es un motivo de controversia frecuente. Material y métodos: El presente trabajo incluye una revisión exhaustiva sobre cuestiones relativas al SV que pueden servir de guía clínica en el manejo de pacientes con estas lesiones. La presentación se ha orientado en forma de preguntas que el clínico se hace habitualmente y las respuestas están redactadas y/o revisadas por un panel de expertos nacionales e internacionales consultados por la Comisión de Otología de la SEORL-CCC. Resultados: Se ha elaborado un listado con los 13 bloques temáticos más controvertidos sobre el manejo del SV en forma de 50 preguntas y se han buscado las respuestas a todas ellas mediante una revisión sistemática de la literatura (artículos publicados en PubMed y Cochrane Library entre 1992 y 2023 sobre cada bloque temático). Treinta y tres expertos, liderados por la Comisión de Otología de la SEORL-CCC, han analizado y discutido todas las respuestas. En el Anexo 1 pueden encontrarse 14 preguntas adicionales divididas en cuatro bloques temáticos. Conclusiones: Esta guía de práctica clínica sobre el manejo del SV ofrece respuestas consensuadas a las preguntas más habituales que se plantean sobre este tumor. La ausencia de suficientes estudios prospectivos hace que los niveles de evidencia sobre el tema sean en general medios o bajos. Este hecho incrementa el interés de este tipo de guías de práctica clínica elaboradas por expertos.(AU)

IntroductionVestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy. Material and methods: This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC. Results: A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found. Conclusions: This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.(AU)

Clinical practice guideline on the management of vestibular schwannoma.

INTRODUCTION: Vestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy. MATERIAL AND METHODS: This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC. RESULTS: A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found. CONCLUSIONS: This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.

Utilidad de la monitorización neurofisiológica intraoperatoria como valor pronóstico de la parálisis facial posquirúrgica en schwannomas vestibulares / Utility of the intraoperative neurophysiological monitoring as a prognostic value of postoperative facial paresis in vestibular schwannomas

Antecedentes y objetivo La monitorización neurofisiológica intraoperatoria permite predecir la situación funcional del nervio facial tras la cirugía de schwannoma vestibular. Dada la gran variabilidad de los protocolos neurofisiológicos utilizados para ello, el objetivo del presente estudio es determinar la capacidad pronóstica del protocolo neurofisiológico usado en nuestro servicio. Material y métodos Se realizó un análisis estadístico de los datos de monitorización neurofisiológica recogidos en los pacientes intervenidos entre marzo de 2009 y julio de 2021 en el Servicio de Neurocirugía de Salamanca según su situación funcional, tanto en el período posquirúrgico inmediato como al año de la cirugía. Resultados Se analizó a 51 pacientes de entre 46 y 63 años (mediana: 54). Al estudiar el valor umbral de la intensidad de estimulación del nervio facial y la variación de los potenciales motores evocados córtico-bulbares, se hallaron diferencias significativas (p=0,043 y p=0,011, respectivamente) entre los pacientes con buena y mala situación clínica tras la cirugía. El valor umbral de intensidad más discriminativo fue 0,35mA (sensibilidad: 85%; especificidad: 48%). No se halló relación estadística en el grupo de estudio al año de la cirugía. Conclusiones El protocolo de monitorización intraoperatoria utilizado nos permite predecir la situación clínica de los pacientes en el período posquirúrgico inmediato y mejorar la información al paciente y sus familiares tras la intervención. No podemos, en cambio, utilizar estos parámetros para la predicción de la situación funcional al año de la cirugía ni para la toma de decisiones clínicas al respecto (AU)

Background and objective Intraoperative neurophysiological monitoring allows us to predict the functional status of the facial nerve after vestibular schwannoma surgery. Due to the great variability of the neurophysiological protocols used for it, the goal of this study is to determine the prognostic ability of our neurophysiological protocol. Material and methods We have performed a statistical analysis of the neurophysiological monitoring data collected from patients operated between March 2009 and July 2021 at the Neurosurgery Service of Salamanca according to their functional status, both in the immediate post-surgical period and one year after surgery. Results A number of 51 patients between 46 and 63 years old (median: 54) were analyzed. We have found significant differences studying the threshold value of the stimulation intensity of the facial nerve and the variation of the Cortico-bulbar Evoked Motor Potentials (P=0.043 and P=0.011, respectively) between the patients with good and bad clinical situation after surgery. The most discriminating intensity threshold value was 0.35mA (Sensitivity: 85%; Specificity: 48%). No statistical relationship was found in the study group one year after surgery. Conclusions Our intraoperative monitoring protocol allows us to predict the clinical situation of patients in the immediate postoperative period and improve information for the patient and her relatives after surgery. We cannot, however, use these parameters to predict the functional situation one year after surgery and make clinical decisions in this regard (AU)

Identification of Follow-Up Markers for Rehabilitation Management in Patients with Vestibular Schwannoma.

This study delves into the absence of prognostic or predictive markers to guide rehabilitation in patients afflicted with vestibular schwannomas. The objective is to analyze the reweighting of subjective and instrumental indicators following surgery, at 7 days and 1 month postoperatively. This retrospective cohort encompasses 32 patients who underwent unilateral vestibular schwannoma surgery at the Marseille University Hospital between 2014 and 2019. Variations in 54 indicators and their adherence to available norms are calculated. After 1 month, one-third of patients do not regain the norm for all indicators. However, the rates of variation unveil specific responses linked to a preoperative error signal, stemming from years of tumor adaptation. This adaptation is reflected in a postoperative visual or proprioceptive preference for certain patients. Further studies are needed to clarify error signals according to lesion types. The approach based on variations in normative indicators appears relevant for post-surgical monitoring and physiotherapy.

[Utility of the intraoperative neurophysiological monitoring as a prognostic value of postoperative facial paresis in vestibular schwannomas]. / Utilidad de la monitorización neurofisiológica intraoperatoria como valor pronóstico de la parálisis facial posquirúrgica en schwannomas vestibulares.

BACKGROUND AND OBJECTIVE: Intraoperative neurophysiological monitoring allows us to predict the functional status of the facial nerve after vestibular schwannoma surgery. Due to the great variability of the neurophysiological protocols used for it, the goal of this study is to determine the prognostic ability of our neurophysiological protocol. MATERIAL AND METHODS: We have performed a statistical analysis of the neurophysiological monitoring data collected from patients operated between March 2009 and July 2021 at the Neurosurgery Service of Salamanca according to their functional status, both in the immediate post-surgical period and one year after surgery. RESULTS: A number of 51 patients between 46 and 63 years old (median: 54) were analyzed. We have found significant differences studying the threshold value of the stimulation intensity of the facial nerve and the variation of the Cortico-bulbar Evoked Motor Potentials (P=0.043 and P=0.011, respectively) between the patients with good and bad clinical situation after surgery. The most discriminating intensity threshold value was 0.35mA (Sensitivity: 85%; Specificity: 48%). No statistical relationship was found in the study group one year after surgery. CONCLUSIONS: Our intraoperative monitoring protocol allows us to predict the clinical situation of patients in the immediate postoperative period and improve information for the patient and her relatives after surgery. We cannot, however, use these parameters to predict the functional situation one year after surgery and make clinical decisions in this regard.

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)

Hipoacusia sensorineural asimétrica en el diagnóstico de schwannoma vestibular / Asymmetric sensorineural hearing loss in the diagnosis of vestibular schwannoma

Introducción: se ha descrito que los pacientes con hipoacusia asimétrica cursan en un 2% con lesiones retrococleares. La conducta de escrutinio se ha basado en la audiometría. Existen varias definiciones de asimetría audiométrica descritas en la literatura, pero sin llegar a un consenso. Aunque la prueba de oro para el diagnóstico de schwannoma vestibular es la resonancia magnética con gadolíneo, la sospecha clínica se hace en base a la asimetría audiométrica. Objetivo: hacemos una revisión de los trabajos publicados al respecto en la literatu-ra y comentamos nuestra experiencia. Reflexión: queremos enfatizar en la importancia de estudiar a los pacientes con hipoacusia asimétrica con el fin de descartar patología retrococlear. Conclusión: a pesar de que no existe un consenso claro en la definición de hi-poacusia asimétrica, la sospecha clínica de un schwannoma vestibular se basa en la audiometría

Background: It is described that 2% of patients with asymmetric hearing loss have retrocochlear lesions. The scrutiny behavior has been based on audiometry. There are several definitions of audiometric asymmetry described in the literature, but without reaching a consensus. Although the gold standard for the diagnosis of vestibular schwannoma is gadolinium magnetic resonance imaging, the clinical sus-picion is based on audiometric asymmetry. Objective: we review the results published in this regard in the literature and com-ment on our own experience. Reflection: we want to emphasize the importance of studying asymmetric hearing loss patients in order to rule out retrocochlear etiology. Conclusions: although there is no clear consensus on the definition of asym-metric hearing loss, the clinical suspicion of a vestibular schwannoma is based on the audiometry.

Intralabyrinthine neurinoma: Management, exeresis and auditory restoration with cochlear implant.

BACKGROUND AND OBJECTIVE: Vestibular schwannoma is a benign tumour that originates in the eighth cranial nerve. It is termed intralabyrinthine schwannoma (ILS) when it develops in the inner ear, this being a rare origin. We present our experience in the management of three patients with ILS. MATERIALS AND METHODS: The results of tumour excision and cochlear implantation were evaluated in three patients with ILS: two intracochlear schwannomas (ICS) and one intravestibular schwannoma (IVS). RESULTS: Prior to surgery, all patients presented progressive sensorineural hearing loss and tinnitus. Complete tumour resection and cochlear implantation was possible in all patients, with favourable hearing rehabilitation. CONCLUSIONS: The therapeutic approach will depend on tumour size, growth rate, degree of hearing loss and presence of vestibular symptoms. Cochlear implantation (CI) in patients with ILS is possible when the cochlear nerve is present and functional. CI in patients, whether or not preceded by tumour excision, is an option with good hearing results in selected patients.

Neurinoma intralaberíntico: manejo, exéresis y restauración auditiva con implante coclear / Intralabyrinthine neurinoma: Management, exeresis and auditory restoration with cochlear implant

Introducción y objetivo: El schwannoma vestibular es un tumor benigno que se origina en el octavo par craneal. Se denomina schwannoma intralaberíntico (SIL) cuando se origina en el oído interno, siendo este origen poco frecuente. Presentamos nuestra experiencia en el manejo de 3 pacientes con SIL.Material y métodosLos resultados de la exéresis tumoral e implantación coclear fueron evaluados en 3 pacientes con SIL: 2 casos de schwannoma intracoclear y un caso de schwannoma intravestibular.ResultadosPrevio a la cirugía, todos los pacientes presentaban hipoacusia neurosensorial progresiva y acúfeno ipsilateral. La resección tumoral completa y la colocación de un implante coclear fue posible en todos los casos, con una rehabilitación auditiva favorable.ConclusionesLa actitud terapéutica dependerá del tamaño del tumor, el crecimiento, el grado de pérdida auditiva y los síntomas vestibulares. La implantación coclear en pacientes con SIL es posible cuando el nervio coclear está presente y es funcionante. El IC en el SIL, ya sea con exéresis previa o no del tumor, es una opción con buenos resultados auditivos en pacientes seleccionados. (AU)

Introduction and objective: Vestibular schwannoma is a benign tumour that originates in the eighth cranial nerve. It is termed intralabyrinthine schwannoma (ILS) when it develops in the inner ear, this being a rare origin. We present our experience in the management of three patients with ILS.Material and methodsThe results of tumour excision and cochlear implantation were evaluated in three patients with ILS: two intracochlear schwannomas (ICS) and one intravestibular schwannoma (IVS).ResultsPrior to surgery, all patients presented progressive sensorineural hearing loss and tinnitus. Complete tumour resection and cochlear implantation was possible in all patients, with favourable hearing rehabilitation.ConclusionsThe therapeutic approach will depend on tumour size, growth rate, degree of hearing loss and presence of vestibular symptoms. Cochlear implantation (CI) in patients with ILS is possible when the cochlear nerve is present and functional. CI in patients, whether or not preceded by tumour excision, is an option with good hearing results in selected patients. (AU)

Primera Radiocirugía de schwannoma vestibular en el sistema público uruguayo, Hospital Regional de Tacuarembó. Centro Oncológico del Norte

Resumen: Los schwannomas vestibulares son tumores benignos de lento crecimiento. Aproximadamente el 90% son de presentación unilateral, el 10% restante, son bilaterales y se encuentran asociados al síndrome de Neurofibromatosis tipo 2. Las opciones de tratamiento son observación, cirugía o radiocirugía. La radiocirugía es un tratamiento seguro, con altas tasas de control local y baja morbilidad en schwannomas vestibulares menores a 3 cm de diámetro mayor. Reportamos la primera radiocirugía realizada en el sistema público uruguayo para este tipo de patologías.

Abstract: Vestibular schwannomas are slow-growing benign tumors. Approximately 90% are unilateral, the remaining 10% are bilateral and are associated with Neurofibromatosis type 2 syndrome. Treatment options are observation, surgery or radiosurgery. Radiosurgery is a safe treatment, with high local control rates and low morbidity in vestibular schwannomas smaller than 3 cm in major diameter. We report the first radiosurgery performed in the Uruguayan public system for this type of pathology.

Resumo: Os schwannomas vestibulares são tumores benignos de crescimento lento. Aproximadamente 90% são unilaterais, os restantes 10% são bilaterais e estão associados à síndrome de neurofibromatose tipo 2. As opções de tratamento são observação, cirurgia ou radiocirurgia. A radiocirurgia é um tratamento seguro, com altas taxas de controle local e baixa morbilidade em schwannomas vestibulares com menos de 3 cm de diâmetro maior. Relatamos a primeira radiocirurgia realizada no sistema público uruguaio pra este tipo de patologia.

Neurofibromatosis tipos 1 y 2 / Neurofibromatosis type 1 and 2

La neurofibromatosis (NF) comprende un grupo de enfermedades genéticas de herencia autosómica dominante, que se clasifican de la siguiente manera: neurofibromatosis tipo 1 (NF1), neurofibromatosis tipo 2 (NF2) y schwannomatosis (también conocida como neurofibromatosis tipo 3). Esta última es una enfermedad muy infrecuente, con una prevalencia aproximada de 1/126 000 personas, por lo que solo profundizaremos las dos primeras. La NF1, también conocida como la enfermedad de Von Recklinghausen, es la más frecuente de las tres y afecta principalmente la piel y el sistema nervioso periférico. Se caracteriza por la presencia de máculas "café con leche", pecas axilares o inguinales, nódulos de Lisch (hamartomas en el iris) y neurofibromas (tumores de la vaina de nervios periféricos). Otras manifestaciones menos frecuentes, aunque de mayor gravedad, incluyen gliomas del nervio óptico, meningiomas, neurofibromas malignos, escoliosis y displasia de la tibia. Su diagnóstico se suele realizar al nacimiento o durante los primeros años de vida, y se estima que un 50% de quienes la padecen presenta dificultades cognitivas. No hay datos concluyentes sobre la mortalidad en los pacientes con NF1, aunque se sabe que la expectativa de vida es menor que en la población general. La NF2 tiene una prevalencia considerablemente menor que la NF1 y su inicio es más tardío, afectando principalmente a adultos jóvenes. La presentación clínica típica se caracteriza por acúfenos, hipoacusia y ataxia en contexto de la presencia de schwannomas vestibulares bilaterales. Otros hallazgos menos frecuentes incluyen schwannomas de nervios periféricos, meningiomas, ependimomas o astrocitomas. La esperanza de vida es de unos 36 años, con una supervivencia media desde el momento del diagnóstico de 15 años. (AU)

Neurofibromatosis (NF) includes a group of genetic diseases with an autosomal-dominant inheritance pattern, and they are classified as follows: Neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2) and Schwannomatosis (also known as neurofibromatosis type 3). This last one is a very rare disease, with an approximate prevalence of 1/126000, so we will only deepen in the first two. NF1, also known as von Recklinghausen disease, is the most frequent, and mainly affects the skin and peripheral nervous system. Its typical manifestations are the presence of café-au-lait macules, axillary or inguinal freckles, Lisch nodules (hamartomas in the iris) and neurofibromas (peripheral nerve sheath tumors). Less frequent manifestations, although more serious, include optic nerve gliomas, meningiomas, malignant neurofibromas, scoliosis and tibial dysplasia. The diagnosis is usually made at birth or during the first years of life, and approximately 50% of patients present cognitive difficulties. There is no conclusive data on mortality in patients with NF1, although it is known that life expectancy is lower than in general population. NF2 has a considerably lower prevalence than NF1, and its onset is later in life, mainly affecting young adults. Its typical clinical presentation is characterized by tinnitus, hearing loss and ataxia in the context in the presence of bilateral vestibular schwannomas. Less frequent findings include peripheral nerve schwannomas, meningiomas, ependymomas or astrocytomas. Life expectancy is about 36 years old, with a median survival from the moment of diagnosis of 15 years. (AU)

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.

LINAC radiosurgery treatment for vestibular schwannoma.

OBJECTIVE: The aims of our study were to evaluate tumour response in a series of patients with vestibular schwannoma (VS) treated with linear accelerator stereotactic radiosurgery (LINAC-RS), to describe the complications and to analyze the variables associated with the response to treatment. MATERIAL AND METHODS: This retrospective descriptive study included 64 patients treated from 2010 to 2016 with a minimum follow-up of one year, excluding patients with neurofibromatosis. Clinical-radiological parameters were evaluated. The treatment was performed using LINAC-RS. The prescribed dose was 12Gy at 90% isodose. RESULTS: The mean age at treatment was 53 years, 56% were women. Ninety-eight percent of the patients had hearing loss, 71% with grade III according to the Gardner-Robertson Classification. The mean volume at treatment was 2.92cc and the mean follow-up, 40.95 months. The overall therapeutic success was 90%, reaching 100% at 12 and 24 months, and 86% after 36 months of follow-up. The radiological result was significantly related to the initial tumour volume (p<0.037). In 20 patients there was evidence of transient tumour growth compatible with pseudoprogression. Acute complications were present in 37.5%, and transitory complications in 50%. Chronic complications were found in 20%, with 84% being permanent. The rate of acute complications was lower in patients with regression (p<0.016). Chronic complications were more frequent in the 41-60 year old age group (p<0.040). CONCLUSIONS: In our study, the overall tumour control was in accordance with other published series. The radiological result significantly related to the tumour volume at the commencement of treatment. The rate of acute complications was lower in patients with regression.

Contralateral sensorineural hearing loss after vestibular schwannoma surgery.

INTRODUCTION: Contralateral sensorineural hearing loss (CSNHL) after vestibular schwannoma (VS) is a severe complication, especially in those cases in which hearing preservation in the operated side was not possible. There are several theories that attempt to explain this issue, but there is no established guideline of treatment. MATERIAL AND METHODS: We report 4 patients treated in our institution who developed a severe CSNHL after surgery. RESULTS: Of the 185 cases of VS treated with surgery, 4 patients (2.2%) developed a CSNHL after VS surgery. After medical treatment, partial recovery of hearing occurred in one patient the other 3 patients presented a well-established severe SNHL. CONCLUSIONS: Established treatment guidelines do not exist, but the use of high doses of corticosteroids has been recommended and cochlear implant in cases with no recovery and complete hearing loss may be useful.

Local Tumor Control and Clinical Symptoms After Gamma Knife Radiosurgery for Residual and Recurrent Vestibular Schwannomas.

BACKGROUND: The use of Gamma Knife radiosurgery (GKRS) for recurrent or residual vestibular schwannoma (VS) after microsurgery (MS) has been investigated in several retrospective studies. The purpose of this study was to identify potential risk factors for both neurologic deterioration and tumor progression after GKRS for previously operated VSs in a prospective setting. METHODS: Patients who underwent GKRS for previously operated and histopathologically confirmed VS between 1998 and 2015 were prospectively followed-up. Risk factors for therapy side effects and predictors for tumor control were investigated in uni- and multivariate analyses. RESULTS: A total of 160 individuals with a median age of 55 years were included. Median tumor volume prior to GKRS was 1.40 cm3 (range, 0.06-35.80 cm3). After a median follow-up of 36 months, hearing and facial nerve function were serviceable (modified Gardner-Robertson and House-Brackmann grades I and II) in 7 (5%) and 82 (55%) patients, respectively. Deterioration to a nonserviceable facial nerve function after GKRS was found in 3% (3/89) and tended to increase with rising tumor volume (odds ratio, 1.65 per cm3; 95% confidence interval, 1.00-2.71; P = 0.051). Median tumor volume prior to GKRS was higher in patients with radiologic (P = 0.020) or clinical tumor progression (P < 0.001). Critical tumor volume prior to GKRS to predict clinical and radiologic tumor progression was 1.30 cm3 (P < 0.001) and 3.30 cm3 (P = 0.019), respectively. However, in multivariate analyses, none of the analyzed variables were found to independently predict tumor progression. CONCLUSIONS: Intended submaximal resection followed by GKRS is a viable treatment for VS. Because tumor remnant size after MS is an important predictor for recurrence after adjuvant GKRS, both brainstem and cerebellar decompression and maximal safely achievable resection should remain major goals of microsurgery.

Fresado de la fosa subarcuata para liberar la arteria cerebelosa anteroinferior en una cirugía de un schwannoma vestibular / Reaming the subarcuate fossa to release the anteroinferior cerebellar artery in surgery for a vestibular schwannoma

Introducción: El abordaje suboccipital retrosigmoideo es la vía principal para la resección de los schwannomas vestibulares (SV). La relación vascular más constante de los nervios del conducto auditivo interno es la arteria cerebelosa anteroinferior (ACAI); pudiendo su recorrido presentarse como un serio obstáculo para la resección completa de la lesión. Descripción del caso: Paciente varón de 38 años, con diagnóstico presuntivo de SV por resonancia magnética (Grado T3B). Se realiza cirugía por vía retrosigmoidea. Se observa a la ACAI totalmente recubierta por tejido dural y óseo, cuya liberación fue posible mediante fresado en la fosa subarcuata. Se logra una exéresis completa del tumor. El paciente evolucionó durante el estado posoperatorio sin déficit neurológico agregado. Discusión: La ACAI ha sido descripta fijada a la duramadre y/o incrustada en el hueso de la fosa subarcuata en escasas publicaciones, impidiendo la resección completa de un SV, especialmente de la porción intracanalicular. Sin embargo, su liberación supone riesgo adicional de lesión vascular. Conclusión: La lesión de la ACAI puede ser causal de alta morbilidad, por lo que el neurocirujano debe estar preparado para reconocer y resolver este tipo de situaciones.

Introduction: A retrosigmoid suboccipital approach is the route most commonly utilized to resect vestibular schwannomas (VS). However, the anterior inferior cerebellar artery (AICA) usually runs adjacent to internal auditory canal nerves, and its course may severely impede total tumor resection. Case report: A 38-year-old male patient presented with presumed grade T3B VS, diagnosed by magnetic resonance imaging (MRI). Surgery was performed using a retrosigmoid approach, during which the AICA was identified to be completely covered by dural and bone tissue. Further drilling in the subarcuate fossa was necessary to release the AICI, allowing for total gross resection of the VS. No neurological deficits were observed post-operatively. Discussion: On rare occasion, the AICA has been described fixed to the dura and/or embedded within subarcuate fossal bone, thereby preventing removal of the intra-canalicular portion of the VS and, hence, total resection. However, AICA release adds the risk of vascular injury. Conclusion: Injury to the AICA may cause high morbidity in patients with a vestibular schwannoma. Neurosurgeons must be able to recognize and deal with certain anatomical configurations that place patients at particularly-high risk.

Intratumoral Bleeding in a Vestibular Schwannoma

Vestibular schwannomas (VSs) account for 70% of all tumors of the cerebellopontine angle (CPA). Their clinical presentation is often insidious, with progressive hearing loss and involvement of other cranial nerves. Spontaneous hemorrhage in those tumors is very unusual, and generally presents with acute clinical features such as nausea, vomiting, headache and altered consciousness, usually with marked dysfunction of the cranial nerve involved, and with new deficits of neighboring cranial nerves. Asymptomatic patients are extremely rare. We present a case report of an incidental VS with asymptomatic bleeding, which evolved to death after surgery.

Schwannomas vestibulares (SVs) são responsáveis por cerca de 70% de todos os tumores do ângulo pontocerebelar. Sua apresentação costuma ser insidiosa, com perda auditiva progressiva e envolvimento de outros nervos cranianos. Hemorragia espontânea nesses tumores é incomum, e geralmente apresenta-se agudamente, com náusea, vômitos, cefaleia e alterações de consciência, normalmente com disfunção importante dos nervos cranianos envolvidos e com novos déficits dos nervos próximos. Pacientes assintomáticos são extremamente raros. Apresentamos um relato de caso de um SV incidental com sangramento assintomático que evoluiu para o óbito após cirurgia.

Schwannoma gigante del ángulo pontocerebeloso / Giant Schwannoma of the cerebellopontine angle

Los Schwannomas del acústico son tumores benignos de crecimiento lento de la división superior del nervio vestibular, con una incidencia de 1,9 por cada 100.000 habitantes. En la actualidad, la tecnología de la neuroimagen en conjunto con la exploración audiológica clínica e instrumentada permiten el diagnóstico en estadios tempranos e incluso como hallazgo clínico, por tal motivo solo el 6 % a nivel mundial se cataloga como tumor grande al momento del diagnóstico. Se presenta el caso de una mujer de 16 años con cefalea, mareo, vómito, hipoacusia, parálisis facial y diadococinesia, por lo que se realizaron estudios de neuroimagen en los que se evidenció masa ocupativa a nivel ángulo pontocerebeloso; por las dimensiones se cataloga según la clasificación de Koss como estadio IV. Se confirmó diagnóstico mediante estudio histopatológico.

Acoustic schwannomas are benign tumors of slow growth in the top division of the vestibular nerve, with an incidence of 1.9 per 100,000 inhabitants. Currently, imaging technology together with the clinical examination audiological and implemented allow diagnosis at an early stage and even as a clinical finding, on that ground only 6 % worldwide are categorized as large tumor at diagnosis. For a woman of 16 with headache, dizziness , vomiting , hearing loss, facial paralysis and diadochokinesia occurs, so neuroimaging studies in which a space- occupying mass level cerebellopontine angle were made evident ; by the dimensions it is classified as classified as stage IV Koss . Diagnosis was confirmed by histopathology.

Concomitant Occurrence of Vestibular Schwannoma and Epidermoid Cyst in Neurofibromatosis: Case description and Review of the Literature

We report a case of a 16-year-old female patient harboring neurofibromatosis type 2 who presented with bilateral hearing impairment, which was on the left side, as well as facial paresis (House-Brackmann grade III) and ataxic gait. A magnetic resonance imaging (MRI) exam evidenced bilateral lesions in the cerebellopontine angles (CPAs) with extension into the internal acoustic meatus, and an additional lesion in the right CPA with radiological characteristics of an epidermoid cyst. The patient was submitted to microsurgical resection, confirming a collision of a vestibular schwannoma and an epidermoid cyst in the right CPA. In the present case report, we describe the first case reported in the literature with preoperative diagnostic work-up, intraoperative findings, postoperative course of the patient, as well as a detailed literature review of these specific coinciding pathologies, denoting the importance of further genomic studies regarding multiple central nervous system (CNS) lesions.

Relatamos o caso de uma paciente de 16 anos de idade com neurofibromatose tipo II com deficiência auditiva bilateral, pior no ouvido esquerdo, assim como paresia facial (HouseBrackmann grau III) e ataxia. Estudo de ressonância magnética comprovou lesão bilateral nos ângulos cerebelopontinos (ACPs) com extensão ao meato acústico interno, e uma lesão adicional no ACP direito com características radiológicas de um cisto epidermoide. A paciente foi submetida a ressecção microcirúrgica, confirmando a colisão de um schwannoma vestibular com um cisto epidermoide no ACP direito. No presente estudo, descrevemos o primeiro caso relatado na literatura com trabalho diagnóstico pré-operatório, resultados intraoperatórios, evolução da paciente no pós-operatório, assim como revisão detalhada da literatura específica sobre essas patologias, demonstrando a importância de mais estudos genômicos sobre as múltiplas lesões do sistema nervoso central (SNC).

Trapped Fourth Ventricle in Recurrent Acoustic Schwannoma - A Rarity

Fourth ventricular dilatation is usually seen along with tri-ventriculomegaly in patients with communicating hydrocephalus. Isolated fourth ventricular dilatation is uncommon, especially as a sequelae following infective or post hemorrhagic communicating hydrocephalus. Communicating hydrocephalus is reported in vestibular schwannoma with an incidence of 3.7 to 23.5%, but 4th ventricular dilatation following its treatment has not been reported in the literature. We report a novel case of isolated fourth ventricular obstruction following surgery for recurrent vestibular schwannoma and ventriculoperitoneal shunt placement for communicating hydrocephalus. Management strategies range from endoscopic procedures to ventricular shunt placement. We describe the surgical technique for the placement of a fourth ventricular shunt with the use of a Y connector.

Em pacientes com hidrocefalia comunicante, a dilatação do quarto ventrículo é normalmente vista acompanhada de triventriculomegalia. A dilatação do quarto ventrículo isolado é incomum, especialmente como uma sequela subsequente à hidrocefalia comunicante infecciosa ou hemorrágica. Hidrocefalia comunicante é relatada em schwannoma vestibular com incidência de 3,7 a 23,5%, mas a dilatação do quarto ventrículo subsequente ao tratamento não foi encontrada na literatura. Relatamos caso de obstrução do quarto ventrículo isolado subsequente a cirurgia para schwannoma vestibular recorrente e shunt ventriculoperitoneal para hidrocefalia comunicante. As estratégias de manejo variam de procedimentos endoscópicos a shunt ventricular. Descrevemos técnica cirúrgica para alocação de shunt do quarto ventrículo com o uso de conector Y.