Presentación simultánea de quiste epidermoide del ángulo pontocerebeloso y colesteatoma infiltrante del oído medio. Reporte de caso y revisión de literatura / Simultaneous presentation of an epidermoid cyst of the cerebellopontine angle and infiltrating cholesteatoma of the middle ear. Case report and literature review

Introducción: los quistes epidermoides son el tercer tumor más común del ángulo pontocerebeloso (APC). Es infrecuente detectar simultáneamente un colesteatoma infiltrativo del oído medio (OM). Caso clínico: paciente de 51 años acude a urgencias por cefalea hemicraneal intensa, pulsátil secundaria a hidrocefalia aguda, requirió ventriculostomía. En la resonancia magnética nuclear (RMN) cerebral contrastada se reporta una masa en el APC sugestivo de quiste epidermoide y simultáneamente un colesteatoma infiltrativo del OM. La paciente fue intervenida primero con resección de colesteatoma del OM; en un segundo tiempo resección del quiste epidermoide del APC por vía translaberíntica. El posoperatorio la evolución clínica fue satisfactoria. Discusión: los quistes epidermoides del APC son histopatológicamente idénticos al colesteatoma del OM y pueden ser secundarios a estos. Conclusión: se debe individualizar el manejo sin descartar la posibilidad de tener las dos enfermedades de manera simultánea.

Introduction: cysts are the third most common tumor of the cerebellopontine angle (CPA). It is rare to simultaneously detect an infiltrative cholesteatoma of the middle ear (OM). Clinical case: a 51-year-old patient attended the emergency department due to intense throbbing hemicranial headache secondary to acute hydrocephalus, requiring ventriculostomy. Contrast-enhanced cerebral magnetic resonance imaging (MRI) reported a mass in the APC suggestive of an epidermoid cyst and simultaneously an infiltrative cholesteatoma of the OM. The patient underwent first surgery with resection of the OM cholesteatoma; in a second stage, resection of the epidermoid cyst of the APC through a translabyrinthine approach. The postoperative clinical evolution was satisfactory. Discussion: APC epidermoid cysts are histopathologically identical to OM cholesteatoma and may be secondary to them. Conclusion: management must be individualized without ruling out the possibility of having both diseases simultaneously.

"Releyendo a"Sawamura Y, Abe H. Hypoglossal­facial nerve side-to-end anastomosis for preservation of hypoglossal function: results of delayed treatment with a new technique / "Rereading a..." Sawamura Y, Abe H. Hypoglossal­facial nerve side-to-end anastomosis for preservation of hypoglossal function: results of delayed treatment with a new technique

El artículo publicado por Sawamura Y. y Abe H. hace más de dos décadas representó una técnica revolucionaria para las cirugías contemporáneas de reanimación facial con axones del nervio hipogloso.1 Estos procedimientos se realizan cuando no es posible neurotizar al nervio facial con un cabo proximal del propio nervio. Esta situación se observa luego de la exéresis de tumores del ángulo pontocerebeloso, en la que se daña al VII par en su trayecto cisternal. La dificultad de realizar la neo anastomosis del hipogloso con el facial en su porción extracranal reside en la distancia anatómica en la que se encuentran

A minimally invasive endoscope assisted retrosigmoid approach for removal of arachnoid cysts in the internal auditory canal: a step by step description / Abordagem retrosigmoide minimamente invasiva assistida por endoscopia para remoção de cistos aracnóides no conduto auditivo interno: descrição passo a passo

Abstract Introduction: Arachnoid cyst in the internal auditory canal is a quite rare pathology but due to its compressive action on the nerves in this district should be surgically removed. Several surgical techniques have been proposed but no surgeons have used the minimally assisted endoscope retrosigmoid approach for its removal. Objective: To investigate the feasibility of using a minimally invasive endoscope assisted retro-sigmoid approach for surgical removal of arachnoid cysts in the internal auditory canal. Methods: Minimally invasive endoscope assisted retrosigmoid approach allows to access to the internal auditory canal through a minimally invasive retrosigmoid approach that combines the use of a microscope and an endoscope. It is performed in six steps: soft tissue step, bone step, dura step, cerebellopontine angle step (performed using an endoscope and a microscope), microscope-endoscope assisted arachnoid cysts removal and closure. We tested minimally invasive endoscope assisted retrosigmoid approach for removal of arachnoid cysts in the internal auditory canal on two human cadaveric heads (specimens) of subjects affected from audio-vestibular disorders and with arachnoid cysts in the internal auditory canal confirmed by magnetic resonance imaging. Results: The mass was completely and successfully removed from the two specimens with no damage to the nerves and/or vessels in the surgical area. Conclusion: The results of our study are encouraging and support the feasibility of using minimally invasive endoscope assisted retrosigmoid approach for removal of arachnoid cysts in the internal auditory canal. While further clinical in-vivo studies are needed to confirm the accuracy and safety of using the minimally invasive endoscope assisted retrosigmoid approach for this specific surgery, our group has successfully used the minimally invasive endoscope assisted retrosigmoid approach in the treatment of microvascular compressive syndrome, schwannoma removal and vestibular nerve resection.

Resumo Introdução: O cisto aracnóide no conduto auditivo interno é uma doença bastante rara, mas, devido à sua ação compressiva sobre os nervos deste local, ele deve ser removido cirurgicamente. Várias técnicas cirúrgicas foram propostas, mas ninguém utilizou a abordagem retrosigmoide minimamente invasiva assistida por endoscopia para a sua remoção. Objetivo: Investigar a viabilidade do uso da abordagem retrosigmoide minimamente invasiva assistida por endoscopia para remoção cirúrgica de cistos aracnóides no conduto auditivo interno. Método: A abordagem retrosigmoide minimamente invasiva assistida por endoscopia permite o acesso ao conduto auditivo interno através de uma abordagem retrosigmóide minimamente invasiva que combina o uso de um microscópio e um endoscópio. É realizada em seis etapas: do tecido mole, óssea, dura-máter, do ângulo pontocerebelar (realizado com um endoscópio e um microscópio), remoção e fechamento assistidos por endoscópio-microscópico. Testamos a abordagem retrosigmoide minimamente invasiva assistida por endoscopia para remoção de cistos aracnóides no conduto auditivo interno em duas cabeças de cadáveres humanos (espécimes) de indivíduos afetados por distúrbios auditivos-vestibulares e com cistos aracnóides no conduto auditivo interno confirmado por imagem de ressonância magnética. Resultados: A lesão foi removida completamente e com sucesso nos dois espécimes sem dano aos nervos e/ou vasos na área cirúrgica. Conclusão: Os resultados do nosso estudo são encorajadores e apoiam a viabilidade do uso da abordagem retrosigmoide minimamente invasiva assistida por endoscopia para remoção de cistos aracnóides no conduto auditivo interno. Embora mais estudos clínicos in vivo sejam necessários para confirmar a precisão e a segurança do uso da abordagem retrosigmoide minimamente invasiva assistida por endoscopia para essa cirurgia específica, nosso grupo utilizou com sucesso a abordagem retrosigmoide minimamente invasiva assistida por endoscopia no tratamento da síndrome compressiva microvascular, remoção de schwannoma e ressecção do nervo vestibular.

Melanocitoma meníngeo del ángulo pontocerebeloso: claves imagenológicas para su abordaje / Cerebellopontine meningeal melanocytoma: keys for imaging diagnostic approach

Resumen: Las lesiones del ángulo pontocerebeloso (APC) representan el 6 al 10% de las neoplasias intracraneales, siendo los schwannomas vestibulares y meningiomas los más comunes. Sin embargo, hasta el 15% pueden ser otras lesiones, entre ellas las derivadas a partir de restos de células melanocíticas presentes en las leptomeninges. El diagnóstico diferencial de las patologías tumorales del APC es extenso, siempre teniendo en cuenta las lesiones más comunes. Sin embargo, cuando las características radiológicas no son las esperadas, el enfoque debe orientarse hacia las lesiones inusuales, poniendo en contexto las diferentes estirpes celulares que pueden dar origen a las neoplasias en esta localización, como las neoplasias melanocíticas. Se presenta el caso de un masculino de 74 años con síndrome cerebeloso de tórpida evolución, al cual se le realiza RM de cerebro contrastada, identificando una lesión de base dural en el APC izquierdo, con hiperintensidad de señal en T1 e hipointensidad en T2, atípico para las lesiones más comunes en esta región, que sugiere su contenido melanocítico.

Abstract: Cerebellopontine angle tumors (CPA) represent approximately 6 to 10% of intracranial tumors. Vestibular Schwannomas and meningiomas are the most common, however up to 15% can be of other origin, including from melanocytes derived from the neural crest. The differential diagnosis of CPA pathologies is extensive, always taking into account the most common ones. However, if the radiological characteristics are not the expected, the approach should be directed towards unusual lesions, putting into context the different cell lines that can give rise to the neoplasm at this location, such as melanotic neoplasms. We present a case of a 74-year-old male, who presented with a cerebellar syndrome. Due to an atypical clinical evolution, a contrast enhanced head MRI was performed, revealing a dural based tumor on the left CPA, which was hyperintense on T1 and hypointense on T2 weighted sequences, which is not expected from the common lesions at this region and suggested it's melanotic content.

Fibrous Meningioma with Ring Enhancement in Cerebellopontine Angle Region:Report of One Case / 中国医学科学院学报

Fibrous meningioma is a common subtype of meningioma. Contrast-enhanced scan typically shows evident homogeneous enhancement,while ring enhancement has not been described. In this article,we report a case of fibrous meningioma with ring enhancement in cerebellopontine angle region.

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.

Isolated Trigeminal Neuralgia Presented Due to Cerebellopontine Angle Epidermoid Cyst

Trigeminal neuralgia (TN) is a paroxysmal shock like pain restricted to the innervations of the areas of one or more trigeminal branches. The pathogenesis of TN is uncertain and typically is idiopathic, but it may be due to a structural lesion. Various etiologies such as vascular anomaly, tumor, infectious agents, and multiple sclerosis have been implicated as possible causes. Here we report two young patients diagnosed with trigeminal neuralgia secondary to epidermoid cyst at the cerebellopontine angle.

Signos de alarma en neuralgia del trigémino / Alarm signs in trigeminal neuralgia

La neuralgia del trigémino es característica en personas mayores de 50 años, comprometiendo principalmente el territorio V2 y V3 de dicho nervio de manera unilateral y la carbamezepina es el fármaco con mayor efectividad, pero no siempre responden. La presentación atípica y los signos de alarma ponen en consideración el estudio con resonancia magnética cerebral, pues obliga a descartar una causa secundaria, siendo necesario el análisis de neuroimágenes. Debido a esto, presentamos un caso de quiste epidermoide con neuralgia secundaria, que se presenta con signos de alarma y se deben considerar los estudios complementarios.

Classic trigeminal neuralgia (TN) is most common after 50 years of age, predominantly unilateral within the distribution of the V2 and V3 branches of the trigeminal nerve. Carbamazepine is the most effective medication, although not all patients respond to it. In consideration physicians should arrange a brain magnetic resonance imaging study when facing TN patients with atypical presentation and alarm signs, as secondary causes must be ruled out. We present a case of epidermoid cyst with secondary TN which presented with "red flag" signs. Image studies were therefore mandatory.

Una propuesta de clasificación del complejo arteria cerebelosa anteroinferior ­ arteria subarcuata basada en el desarrollo embriológico / A proposed classification of the anteroinferior cerebellar artery - subarcuate artery complex based on embryological development

Introducción: El recorrido del "loop subarcuato" de la arteria cerebelosa anteroinferior (ACAI) presenta múltiples variaciones que condicionan además su principal eferencia, la arteria subarcuata (ASA). El espectro de variaciones de este complejo ha sido referido en la literatura de forma inconexa y desorganizada. Material y Métodos: Se propuso una clasificación sistematizada de las variantes del complejo ACAI-ASA, basada en la interacción del hueso petroso y la ACAI en el periodo embrionario. La misma fue aplicada en una serie de pacientes estudiados mediante secuencia CISS (constructive interference in steady state) de resonancia magnética para categorizar las relaciones presentes en el ángulo pontocerebeloso (APC). Resultados: Se evaluaron 84 pacientes, incluyendo 161 APC. Todos los grados propuestos fueron identificados en la serie evaluada. Las proporciones encontradas en la gradación propuesta se mantuvieron en el rango de las publicaciones aisladas. Conclusión: La clasificación propuesta para el complejo ACAI-ASA permitió distinguir y objetivar consistentemente el espectro de variaciones.

Introduction: The pathway of the anterior inferior cerebellar artery's (AICA) "subarcuate loop" can vary extensively. This variability also affects its main branch, the subarcuate artery (SAA). The spectrum of variations observed with this combination of vessels is inadequately described in the literature. Methods and Materials: A systematized classification system for AICA-SAA complex variants was proposed, based upon interactions between the petrosal bone and the AICA in embryos. This classification scheme then was applied to a series of patients assessed by magnetic resonance CISS (constructive interference in steady state) sequences, to categorize the cerebellopontine angle (CPA) relationships. Results: Eighty-four patients were evaluated, encompassing 161 CPA. All the proposed grades were identified in the evaluated series. The proportions found with the proposed gradation system were within the range of previous publications. Conclusions: The AICA-SAA complex classification system that we proposed allowed for consistently distinguishing and objectifying the spectrum of variations seen in the subarcuate loop.

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).

Primary Glioblastoma of the Cerebellopontine Angle: Case Report and Review of the Literature

Glioblastoma multiforme (GBM) is located most frequently in the cerebral hemispheres. Glioblastoma presenting as an extraaxial mass of cerebellopontine angle (CPA) is very rare in adults. We report a rare case of GBM arising in the CPA. The patient was a 71-year-old female, who complained of progressive gait disturbance and poor memory. Initial magnetic resonance imaging (MRI) revealed a 1.4×1.3 cm mass in the left CPA, with broad base to the petrous bone, showing homogenous enhancement. Follow-up MRI showed a rapid increase in size of mass (2.7×2.2 cm) with a necrotic portion. A stereotactic biopsy was done under the guidance of navigation system, and the histopathologic diagnosis was GBM, World Heath Organization grade IV. Further surgical resection was not performed considering her general condition, and the patient underwent concurrent chemotherapy with radiation therapy. Although rare, the possibility of glioblastoma should be included in the differential diagnosis of atypical CPA tumor.

Extra-Axial Cerebello-Pontine Angle Medulloblastoma

Medulloblastoma is the most common central nervous system tumor in children. Extraaxial medulloblastomas, especially tumors with no connection to the brain stem or cerebellum are extremely rare. We report a case of a 3-year-old patient, who presented with a history of subacute headache and vomiting. After performing a head computed tomography scan, a mass was detected in the left cerebello-pontine angle, along with concomitant hydrocephalus. The treatment was total resection of the tumor. Despite the fact that extra-axial medulloblastomas are extremely rare, this differential diagnosis should be included in the management of pediatric patients who present with posterior fossa tumors.

Meduloblastoma é o tumor do sistema nervoso central mais comum em crianças. Meduloblastomas extra-axiais, especialmente tumores sem conexão com o tronco encefálico ou cerebelo, são extremamente raros. Relatamos o caso de uma paciente de 3 anos de idade, que apresentou um histórico de cefaleia subaguda e vômitos. Por meio de um exame de tomografia computadorizada, foi identificada uma massa no ângulo ponto-cerebelar esquerdo, acompanhada de hidrocefalia. O tratamento foi resseção total do tumor. Apesar de meduloblastomas extra-axiais serem extremamente raros, este diagnóstico diferencial deve ser incluído no manejo de pacientes pediátricos que apresentem tumores da fossa posterior.

Hemangiopericytoma of the Cerebellopontine Angle: A Wolf in Sheep's Clothing

Primary meningeal hemangiopericytoma (HPC) is a rare, aggressive dura based tumor that remarkably mimics a meningioma clinically and radiologically. Its occurrence within the cerebellopontine angle (CPA) is exceptional, and establishing the exact diagnosis is of the utmost importance since total resection remains the cornerstone of treatment. A 42-year-old man presented with a three-month history of progressively worsening vertigo and difficulty in walking. On admission, his neurological examination revealed a right peripheral facial palsy, right abducens palsy and left hemiparesis, suggesting the diagnosis of Millard-Gubler syndrome. Computed tomography and magnetic resonance imaging demonstrated a homogeneously enhancing dura based lesion of the right CPA causing major brain stem compression. There was no widening of the ipsilateral internal auditory canal. A standard retrosigmoid craniotomy was performed to access the right CPA. Exposure of the lesion revealed a well-encapsulated, gray, fibrous lesion, which appeared to originate from the tentorium. Gross total resection was achieved and confirmed radiologically. The microscopic features and the immunohistochemical profile confirmed the diagnosis of a HPC, and adjuvant radiation therapy was administered. Ten years later, the patient presented with a severe neurological deficit due to a local recurrence, but at that time refused any second intervention. He died three months later. HPC can locate within the CPA and present as a Millard-Gubler syndrome. The diagnosis should be kept in mind in case of a CPA dura based tumor. Radical surgery plus radiation therapy can maximize the recurrence-free survival and close follow-up remains mandatory to spot recurrences early.

Hemangiopericytoma of the Cerebellopontine Angle: A Wolf in Sheep's Clothing

Primary meningeal hemangiopericytoma (HPC) is a rare, aggressive dura based tumor that remarkably mimics a meningioma clinically and radiologically. Its occurrence within the cerebellopontine angle (CPA) is exceptional, and establishing the exact diagnosis is of the utmost importance since total resection remains the cornerstone of treatment. A 42-year-old man presented with a three-month history of progressively worsening vertigo and difficulty in walking. On admission, his neurological examination revealed a right peripheral facial palsy, right abducens palsy and left hemiparesis, suggesting the diagnosis of Millard-Gubler syndrome. Computed tomography and magnetic resonance imaging demonstrated a homogeneously enhancing dura based lesion of the right CPA causing major brain stem compression. There was no widening of the ipsilateral internal auditory canal. A standard retrosigmoid craniotomy was performed to access the right CPA. Exposure of the lesion revealed a well-encapsulated, gray, fibrous lesion, which appeared to originate from the tentorium. Gross total resection was achieved and confirmed radiologically. The microscopic features and the immunohistochemical profile confirmed the diagnosis of a HPC, and adjuvant radiation therapy was administered. Ten years later, the patient presented with a severe neurological deficit due to a local recurrence, but at that time refused any second intervention. He died three months later. HPC can locate within the CPA and present as a Millard-Gubler syndrome. The diagnosis should be kept in mind in case of a CPA dura based tumor. Radical surgery plus radiation therapy can maximize the recurrence-free survival and close follow-up remains mandatory to spot recurrences early.

Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor

BACKGROUND AND PURPOSE: Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor. METHODS: Twenty-eight patients (21 women; age=64+/-12 years, mean+/-SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification. RESULTS: Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction. CONCLUSIONS: Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors.

Right Cerebellopontine Angle Tumor Localized by Blink Reflex Abnormality

No abstract available.

Right Cerebellopontine Angle Tumor Localized by Blink Reflex Abnormality

No abstract available.

Microneurosurgery for the trigeminal neuralgia and hemifacial spasm and glosspharyngeal neuralgia with endoscopic / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#Discussing the use of endoscopy in the operation of microvascular decompression of cranial nerves to treat trigeminal neuralgia (TN), hemifacial spasm (HFS), glosspharyngeal neuralgia (GN) and some tumors of the cerebellopontine angle (CPA).@*METHOD@#Since 2006, 973 cases (including 420 cases of TN, 487 cases of HFS, 66 cases of GN) had received the operation of nervous decompression by approach of postauricular suboccipital to the CPA. All cases who used the endoscopy and the material was described in detail.@*RESULT@#In 420 TN patients, 390 (92.9%) were found responsible blood vessels. Two (0.5%) were found no responsible blood vessels but arachnoid adhesion, 28 were found CPA tumor secondary trigeminal neuralgia. In 487 HFS patients, 486 were found responsible blood vessels. Between the vascular and trigeminal nerve, teflon was used to decompress and isolate the facial nerve. In 66 GN, the glossopharyngeal nerve were cut and vagus nerve were decompressed. The short-term cure rate was 100%. Cerebrospinal fluid rhinorrhea occurred in 3 cases, 1 case of cerebellar infarction, 2 patients of cerebellar hemorrhage, 2 cases of pneumatosis. All complications were cured at last. There were no deaths. All cases were followed-up for 1 to 5 years. Four cases of TN and 4 cases of HFS recurrent, and none of GN recurrence.@*CONCLUSION@#The microneurosurgery of nervous decompression endoscopy technology for the treatment of TN, HFS, GN and some tumors of the CPA is an ideally functional and etiotropic operation. It is helpful to detect the responsible blood vessel and to protect the brain tissue and nerve function with endoscope, which can improve the success rate of the operation and avoid the complications. This technology has clinical application value.