[Vestibular schwannomas: Surgical treatment of 67 cases in 10 years]. / Schwannomas vestibulares: experiencia en el tratamiento quirúrgico de 67 casos en 10 años.

INTRODUCTION: Vestibular Schwannomas (VS) are benign intracranial tumors, for which their current management is a matter of debate, although microsurgical treatment remains the mode of choice in the majority of cases. OBJECTIVE: To describe the surgical outcome of patients operated on for a VS in a Chilean Public Hospital. MATERIAL AND METHOD: A series of 67 patients treated surgically between 2002 and 2012, in the Institute of Neurosurgery Asenjo is presented. RESULTS: Sixty-five cases (97%) corresponded to Koos III and IV tumors, of which 52% were large (3-4 cm) or Giant (>4 cm). Forty-one cases were operated on using a retrosigmoid transmeatalapproach (61%). Total resection was achieved in 97% of the cases and subtotal in the remaining 3%. A mean six months follow-up showed that good facial function (House-Brackmann I or II) was obtained in 32.7% of the patients, and moderate function (House-Brackmann III or IV) in 42.3%. Cardiopulmonary complications were the most frequent (28%), and mortality was 1.5%. CONCLUSIONS: The VS are tumors that can cause significant neurological deficit in advanced stages, despite their benign nature. Surgical treatment is very complex, and must be performed by specialized teams to ensure optimal functional results.

[Treatment of giant acoustic neuromas]. / Tratamiento del neurinoma acústico gigante.

INTRODUCTION AND OBJECTIVES: To analyze the treatment modality and outcome of a series of patients with giant acoustic neuromas, a particular type of tumour characterised by their size (extracanalicular diameter of 4cm or more) and high morbidity and mortality. MATERIALS AND METHODS: This was a retrospective unicentre study of patients with acoustic neuromas treated in a period of 12 years. In our institutional series of 108 acoustic neuromas operated on during that period, we found 13 (12%) cases of giant acoustic neuromas. We reviewed the available data of these cases, including presentation and several clinical, anatomical, and microsurgical aspects. RESULTS: All patients were operated on by the same neurosurgeon and senior author (EU) using the suboccipital retrosigmoid approach and complete microsurgical removal was achieved in 10 cases. In one case, near total removal was deliberately performed, in another case a CSF shunt was placed as the sole treatment measure, and in the remaining case no direct treatment was given. One patient died in the immediate postoperative period. One year after surgery, 4 patients showed facial nerve function of iii or more in the House-Brackman scale. CONCLUSIONS: The 4 most important prognostic characteristics of giant acoustic neuromas are size, adhesion to surrounding structures, consistency and vascularity. Only the first of these is evident in neuroimaging. Giant acoustic neuromas are characterised by high morbidity at presentation as well as after treatment. Nevertheless, the objective of complete microsurgical removal with preservation of cranial nerve function is attainable in some cases through the suboccipital retrosigmoid approach.

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.

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.

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.

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.

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.

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.

Factores radiológicos predictores de grado de resección en pacientes con schwannomas vestibulares / Radiological factors that predict the degree of resection and functional preservation in patients with vestibular schwannomas

Introducción: Existen diversos factores predictores de grado de resección en la cirugía de los schwannomas vestibulares (SV). Nuestro equipo en Tucumán realizó un estudio sistemático perioperatorio con un protocolo específico de resonancia magnética (RM) en estos pacientes. El objetivo del presente estudio fue determinar la utilidad de la RM como predictor de grado de resección de los SV. Materiales y métodos: Se realizó un estudio de serie, de tipo correlacional, descriptivo y retrospectivo de pacientes operados de SV, por nuestro equipo en Tucumán, entre enero 2014 y diciembre 2020 (n:92). Se realizó correlación estadística, entre las características imagenológicas con el grado de resección. Resultados: Un tumor sólido aumenta 39,19 veces la probabilidad de tener una resección completa en comparación con un tumor quístico. Conclusión: La RM permite definir adecuadamente la consistencia tumoral; un tumor sólido se asocia a una mayor probabilidad de resección total(AU)

Background: There are various predictors of degree of resection surgery for vestibular schwannomas (SV). Our team in Tucumán carried out a systematic perioperative study with a specific magnetic resonance imaging (MRI) protocol in these patients. The objective of the present study was to determine the usefulness of MRI as a predictor of the degree of resection of VS. Methods: A serial, correlational, descriptive, and retrospective study of patients operated on for SV was carried out by our team in Tucumán, between January 2014 and December 2020 (n: 92). Statistical correlation was made between the imaging characteristics with the degree of resection. Results: A solid tumor increases 39.19 times the probability of having a complete resection compared to a cystic tumor. Conclusion: MRI allows to adequately define tumor consistency; a solid tumor is associated with a higher probability of total resection(AU)

Pilocytic Astrocytoma of the Cerebellopontine Angle with cerebrospinal fluid Spread in an Adult: A Case Report / Astrocitoma pilocítico no ângulo pontocerebelar com disseminação liquórica em paciente adulto: Relato de caso

Introduction Pilocytic astrocytoma of the cerebellopontine angle (CPA) is uncommon, and its spread to the cerebrospinal fluid (CSF) at the time of diagnosis has not been reported in the literature. Case Presentation We report the case of a 33-year-old man with multifocal pilocytic astrocytoma diagnosed by magnetic resonance imaging (MRI) and confirmed by histopathological examination, and present the radiological and histopathological findings. Conclusion In the case herein reported, we observed spread of the pilocytic astrocytoma of the CPA to the CSF at the initial diagnosis, and early detection by MRI is very important regarding the treatment modality and prognosis.

Introdução O astrocitoma pilocítico no ângulo pontocerebelar (APC) é incomum, e sua disseminação liquórica no momento do diagnóstico não foi relatada na literatura. Apresentação do Caso Relatamos o caso de um homem de 33 anos com astrocitoma pilocítico multifocal diagnosticado por ressonância magnética (RM) e confirmado por exame histopatológico, e apresentamos os achados radiológicos e histopatológicos. Conclusão No caso relatado, observou-se disseminação liquórica de astrocitoma pilocítico no APC no diagnóstico inicial, e a detecção precoce por RM é muito importante para a modalidade de tratamento e o prognóstico.

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.

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.

Surgical treatment of vestibular schwannoma. Review of 420 cases. / Tratamiento quirúrgico del schwannoma vestibular. Revisión de 420 casos.

INTRODUCTION AND OBJECTIVES: Vestibular schwannoma is the most frequent cerebellopontine angle tumor. The aim of our study is to reflect our experience in the surgical treatment of this tumor MATERIAL AND METHODS: Retrospective study of 420 vestibular schwannomas operated in our hospital between 1994-2014. We include tumor size, preoperative hearing, surgical approaches, definitive facial and hearing functional results, and complications due to surgery. RESULTS: A total of 417 patients with 420 tumors were analyzed, 209 female (50.1%) and 208 male (49.9%). Mean age at diagnosis was 49.8±13.2 years. The majority of the tumors were resected through a translabyrinthine approach (80.2%). Total tumor removal was achieved in 411 tumors (98.3%), and anatomic preservation of facial nerve in 404 (96.2%). Definitive facial nerve outcome was House-Brackmann grade I and II in 69.9%, and was significantly better in tumors under 20mm. Surgical complications included cerebrospinal fluid leakage in 3 patients (0.7%) and retroauricular subcutaneous collection in 16 (3.8%), 5 cases of meningitis (1.2%), 4 patients with intracraneal bleeding (0.9%), and death in 3 patients (0.7%). CONCLUSIONS: Surgery is the treatment of choice for vestibular schwannoma in the majority of patients. In our experience, the complication rate is very low and tumor size is the main factor influencing postoperative facial nerve function.

Our experience with facial nerve monitoring in vestibular schwannoma surgery under partial neuromuscular blockade.

INTRODUCTION AND OBJECTIVES: Facial nerve monitoring is fundamental in the preservation of the facial nerve in vestibular schwannoma surgery. Our objective was to analyse the usefulness of facial nerve monitoring under partial neuromuscular blockade. METHODS: This was a retrospective analysis of 69 patients operated in a tertiary hospital. RESULTS: We monitored 100% of the cases. In 75% of the cases, we could measure an electromyographic response after tumour resection. In 17 cases, there was an absence of electromyographic response. Fifteen of them had an anatomic lesion with loss of continuity of the facial nerve and, in 2 cases, there was a lesion with preservation of the nerve. Preoperative facial palsy (29% 7%; P=.0349), large tumour size (88 vs. 38%; P=.0276), and a non-functional audition (88 vs. 51%; P=.0276) were significantly related with an absence of electromyographic response. CONCLUSIONS: Facial nerve monitoring under neuromuscular blockade is possible and safe in patients without previous facial palsy. If the patient had an electromyographic response after tumour excision, they developed better facial function in the postoperative period and after a year of follow up.

Non surgical treatment of vestibular schwannoma.

INTRODUCTION AND OBJECTIVES: To evaluate the results of local control and complications in the treatment of vestibular schwannoma treated with radiation. METHODS: A retrospective study of 194 patients diagnosed with vestibular schwannoma, treated consecutively with radiation (either stereotactic radiosurgery or fractionated radiotherapy) from 1997 to 2012. We analyze the local control of tumors, as well as secondary complications to treatment with radiation. RESULTS: A total of 132 (68%) tumors 68% are grade I-II tumors of the Koos classification, 40 (19%) are grade III, and 22 (13%) are grade IV. The tumors associated with neurofibromatosis (NF2), are 3.6% (6 tumors in 4 patients). The tumor control for the overall serie is 97% at 5 years, with a median follow-up of 80.4 months. For large tumors the local control is 91% at 5 years. Free survival of chronic complications is 89% at 5 years. Additionally, 50 tumors were subjected to regular follow-up with MRI without treatment, and 28 (58%) did not experienced tumor growth. CONCLUSIONS: Radiation and follow up with MRI, are an alternative to surgery in the treatment of vestibular schwannoma, with a low level of complications inside of multidisciplinary approach.

Conservative management of vestibular schwannoma.

INTRODUCTION: Vestibular schwannoma (VS) is a benign, slow-growing tumour originating in the 8th cranial nerve. The treatment includes microsurgery, stereotactic radiotherapy and conservative management of tumours with periodic radiological tests. METHODS: This was a retrospective study of patients with VS following conservative management in a tertiary hospital between 1993 and 2013. A total of 73 patients were enrolled in our protocol. The mean age at diagnosis was 59.7 years. The average size was 11.9mm (4-27mm); 58.9% of the tumours were intracanalicular and 41.1%, extracanalicular. The mean follow-up period was 35.75 months. RESULTS: In 87.7% of patients there was no evidence of tumour growth. A total of 9 tumours (12.3%) increased in size. The average growth rate was 0.62mm/year. The percentage of extracanalicular tumours that grew (20%) was higher than that of intracanalicular tumours (7%). Seven patients (9.5%) experienced significant changes in their symptoms and 6 of these (8.2%) experienced a loss of useful hearing. Six patients (8.2%) left follow-up and underwent surgery. CONCLUSIONS: Periodic monitoring of vestibular schwannomas with magnetic resonance imaging represents an option for management, because most small tumours experience little or no growth over time.

[Clinical and radiological evolution of a group of untreated acoustic neuromas]. / Evolución clínica y radiológica de un grupo de neurinomas del acústico no tratados.

INTRODUCTION: The acoustic neuroma is a benign tumour that originates in the vestibular branch of the eighth cranial nerve. The main treatment is surgery, but many authors suggest that with elderly patients or in small neuromas we can opt for watchful waiting. METHODS: This was a retrospective study from 2007 to 2013 that included 27 patients diagnosed of acoustic neuroma that had not been treated due to the size of the tumour, age and comorbidities, or by patient choice. We evaluated overall condition, hearing thresholds, degree of canal paresis and central disorders. RESULTS: After 6 years of follow up, clinical manifestations of 18 patients remained unchanged, 5 patients underwent hearing loss and developed tinnitus, 2 cases had more intense tinnitus and 2 cases had dizziness. The radiological controls by magnetic resonance imaging showed that the initial maximum diameters (5-16mm) increased by 1.7mm on average, with annual growth rates below 0.5mm. CONCLUSION: In selected cases, such as for small neuromas and in elderly patients, the conservative option of close monitoring with magnetic resonance imaging is an important alternative given that, in our cases, clinical features and radiological image did not suffer major changes. If there were any such changes, therapeutic options could be proposed.

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.

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)