Ependimomas de fosa posterior de tipo lateral en la edad pediátrica / Lateral-type posterior fossa ependymomas in pediatric population

Antecedentes y objetivos: Los ependimomas de fosa posterior de tipo lateral son un subtipo clínico e histológico característico, con un pronóstico poco favorable. Su incidencia es baja y su manejo quirúrgico es particularmente complejo. El objetivo del presente trabajo es revisar nuestra serie de ependimomas de fosa posterior de tipo lateral y contrastar nuestros resultados con la literatura disponible. Materiales y métodos: Sobre una muestra de 30 ependimomas intervenidos en neurocirugía pediátrica en los últimos 10 años, se identifican 7 casos de ependimomas de tipo lateral de la fosa posterior. Sobre esta serie de casos se realiza un estudio descriptivo retrospectivo. Resultados: La edad media de nuestros pacientes al diagnóstico fue de 3,75 años. Seis se presentaron con hidrocefalia. El volumen tumoral medio al diagnóstico fue de 61cm3. En 6 casos se llevó a cabo una resección completa y en un caso una resección casi completa. Cinco pacientes precisaron de forma transitoria una traqueostomía y una gastrostomía. La media de seguimiento fue de 58 meses. Durante este tiempo se produjo un caso de recidiva que posteriormente evolucionó a muerte. Cuatro casos de hidrocefalia posquirúrgica precisaron una derivación ventriculoperitoneal de LCR y 2 casos fueron manejados con ventriculostomía endoscópica. En la última revisión en consulta 4 pacientes llevaban una vida normal y 2 mostraban una restricción leve de la actividad de acuerdo con la escala de Lansky. Conclusiones: El objetivo del tratamiento quirúrgico de los ependimomas de tipo lateral de fosa posterior es la resección completa. Los déficits asociados a la disfunción de los pares bajos en nuestra serie fueron muy frecuentes pero transitorios. La progresiva caracterización molecular de estos tumores puede identificar diferentes grupos de riesgo sobre los que dirigir de forma adecuada la intensidad de los tratamientos adyuvantes.(AU)

Background and aims: Lateral-type posterior fossa ependymomas are a well-defined subtype of tumors both clinically and pathologically, with a poor prognosis. Their incidence is low and surgical management is challenging. The objective of the present work is to review our series of lateral-tye posterior fossa ependymomas and compare our results with those of previous series. Materials and methods: Among 30 cases of ependymoma operated in our pediatric department in the last 10 years, we identified seven cases of lateral-type posterior fossa ependymomas. We then performed a retrospective, descriptive study. Results: Mean age of our patients was 3.75 years. Six cases presented with hydrocephalus. Mean tumor volume at diagnosis was 61cc. A complete resection was achieved in six cases and a near-total resection in one patient. Five patients transiently required a gastrostomy and a tracheostomy. Mean follow-up was 58 months. One case progressed along this period and eventually died. Four cases of hydrocephalus required a ventriculoperitoneal CSF shunt and two were managed with a third ventriculostomy. At last follow-up four patients carried a normal life and two displayed a mild restriction according to Lansky's scale. Conclusions: The aim of surgical treatment in lateral-type posterior fossa ependymomas is complete resection. Neurological deficits associated to lower cranial nerve dysfunction are common but transient. Deeper genetic characterization of these tumors may identify risk factors that guide stratification of adjuvant therapies.(AU)

El papel de la RMN en el diagnóstico de la patología audiovestibular / The role of MRI in the diagnosis of audio-vestibular pathology

Introducción y objetivo: El schwanoma vestibular es un tumor benigno, de lento crecimiento que aparece en la vaina de mielina que rodea al nervio vestibular. Estos tumores representan el 6% de todos los tumores intracraneales y el 85% de los tumores del ángulo pontocerebeloso. El síntoma de aparición más frecuente es la hipoacusia unilateral, seguida del acúfeno unilateral, inestabilidad, vértigo, cefalea e incluso, en determinados casos, parestesias faciales o parálisis facial. Todo ello depende del tamaño del tumor y su localización. Actualmente, el diagnóstico de estos tumores se realiza mediante la realización de una historia clínica completa, pruebas complementarias audiológicas y vestibulares y, como prueba de imagen, una RMN. Según el American College of Radiology (ACR) la RMN de base de cráneo y conductos auditivos internos es la prueba de elección para el diagnóstico del schwanoma vestibular. Ésta puede ser con y sin contraste (generalmente Gadolinio) y permite detectar tumores de muy pequeño tamaño. Nuestro objetivo con este trabajo es aportar evidencia científica que permita al profesional seguir un protocolo diagnóstico de los schwanomas vestibulares y, consecuentemente, optimizar los recursos hospitalarios. Método: De una muestra total de 685 se revisaron todas las historias clínicas de los pacientes a los que se les había solicitado una RMN por síntomas audiovestibulares (hipoacusia, acúfeno, vértigo, parálisis facial y otros). Se llevó a cabo un estudio descriptivo y observacional en el cual se mostraban los síntomas que había padecido cada paciente, el motivo de petición de la prueba de imagen, el diagnóstico final y el tipo de resonancia magnética empleada. Con toda esta información se creó una base de datos y se analizaron los resultados estadísticamente. Resultados: ... (AU)

Introduction and objective: Vestibular schwannoma is a benign, slow-growing tumor that appears in the myelin sheath surrounding the vestibular nerve. These tumors represent 6% of all intracranial tumors and 85% of tumors in the cerebellopontine angle. The most common initial symptom is unilateral hearing loss, followed by unilateral tinnitus, instability, vertigo, headache, and, in certain cases, facial paresthesia or facial paralysis. All of these symptoms depend on the size and location of the tumor. Currently, the diagnosis of these tumors is made through a complete medical history, complementary audiological and vestibular tests, and, as an imaging test, an MRI. According to the American College of Radiology (ACR), the MRI of the skull base and internal auditory canals is the gold standard for diagnosing vestibular schwannoma. This can be performed with and without contrast (usually Gadolinium) and allows the detection of very small tumors. Our objective with this article is to provide scientific evidence that enables professionals to diagnose vestibular schwannomas and optimize hospital resources. Method: From a total sample of 685 patients, all medical records of them who had been requested an MRI for audiovestibular symptoms (hearing loss, tinnitus, vertigo, facial paralysis, and others) were reviewed. A descriptive and observational study was carried out, showing the symptoms experienced by each patient, the reason for requesting the imaging test, the final diagnosis, and the type of MRI used. With all this information, a database was created, and the results were analyzed statistically. Results: ... (AU)

Posición semisentada en cirugía del ángulo pontocerebeloso: análisis de sus complicaciones y cómo evitarlas / Semisitting position for cerebello-pontine angle surgery: Analysis of complications and how to avoid it

Objetivo: Analizar las complicaciones asociadas a la posición semisentada en pacientes intervenidos de patología del ángulo pontocerebeloso (APC).MétodosEstudio retrospectivo, se analizaron los pacientes operados de patología tumoral del APC por un abordaje retrosigmoideo en posición semisentada. Se analizó la incidencia, gravedad, momento de aparición, forma de resolución, duración y repercusiones del embolismo aéreo venoso (EAV), neumoencéfalo, hipotensión postural y otras complicaciones. Se analizó el tiempo de estancia en unidad de críticos (TUCRI), tiempo de estancia hospitalaria (TEH) y puntuación en escala de Rankin a los seis meses.ResultadosSe intervinieron 50 pacientes, once (22%) presentaron EAV (8 ± 4,5 minutos duración media): cinco (10%) durante la resección tumoral, cuatro (8%) durante la apertura dural. Diez (20%) se resolvieron tapando el lecho quirúrgico, aspirando burbujas y aplicando compresión de yugulares, uno (2%) requirió cambio de posición. Uno (2%) tuvo repercusión hemodinámica intraoperatoria. La única variable asociada con desarrollar EAV fue una anatomía patológica de meningioma OR = 4,58, p = 0,001. El TUCRI fue superior en pacientes con EAV (5,5 ± 1,06 vs. 1,9 ± 0,20 días, p = 0,01). No hubo diferencias en la escala Rankin. Todos presentaron neumoencéfalo posquirúrgico con buen nivel de consciencia, salvo uno (2%) que requirió de evacuación. Siete pacientes (14%) presentaron una hipotensión arterial, tres (6%) tras la colocación y uno (2%) tras un EAV, todos revertieron con vasoactivos. No se registraron otras complicaciones asociadas a la posición ni mortalidad en esta serie. (AU)

Objective: To analyze the primary complications related to semisitting position in patients undergoing cerebelo-pontine angle surgery.MethodsRetrospective data analysis from patients undergoing elective tumoral cerebelo-pontine angle surgery in a semisitting position. The incidence, severity, occurrence moment, treatment, duration, and outcomes of venous air embolism (VAE), pneumocephalus, postural hypotension, and other complications were recorded. Neurointensive care unit (NICU), length of stay (LOS), hospital LOS, and modified Rankin scale scores were calculated six months after surgery.ResultsFifty patients were operated on. Eleven (22%) presented VAE (mean duration 8 ± 4.5 min): five (10%) during tumor resection, and four (8%) during dural opening. Ten (20%) were resolved by covering the surgical bed, air bubbles aspiration, jugular compression, and one (2%) tilted to a steep Trendelenburg position. One (2%) had intraoperative hemodynamic instability. The only variable associated with VAE was meningioma at histopathology OR = 4.58, P = 0.001. NICU was higher in patients with VAE (5.5 ± 1.06 vs. 1.9 ± 0.20 days, P = 0.01). There were no differences in the Rankin scale. All patients presented postoperative pneumocephalus with a good level of consciousness, except one (2%) who required evacuation. Seven patients (14%) showed postural hypotension, three (6%) after positioning, and one (2%) after developing a VAE; all were reversed with usual vasoactive drugs. No other position-related complications or mortality were registered in this series. (AU)

Lateral-type posterior fossa ependymomas in pediatric population.

BACKGROUND: Lateral-type posterior fossa ependymomas are a well-defined subtype of tumours both clinically and pathologically, with a poor prognosis. Their incidence is low and surgical management is challenging. The objective of the present work is to review our series of lateral-tye posterior fossa ependymomas and compare our results with those of previous series. METHODS: Among 30 cases of ependymoma operated in our paediatric department in the last ten years, we identified seven cases of lateral-type posterior fossa ependymomas. We then performed a retrospective, descriptive study. RESULTS: Mean age of our patients was 3.75 years. 6 cases presented with hydrocephalus. Mean tumour volume at diagnosis was 61 cc. A complete resection was achieved in six cases and a near-total resection in one patient. 5 patients transiently required a gastrostomy and a tracheostomy. Mean follow-up was 58 months. One case progressed along this period and eventually died. 4 cases of hydrocephalus required a ventriculoperitoneal CSF shunt and two were managed with a third ventriculostomy. At last follow-up 4 patients carried a normal life and two displayed a mild restriction according to Lansky´s scale. CONCLUSIONS: The aim of surgical treatment in lateral-type posterior fossa ependymomas is complete resection. Neurological deficits associated to lower cranial nerve dysfunction are common but transient. Deeper genetic characterization of these tumours may identify risk factors that guide stratification of adjuvant therapies.

Semisitting position for cerebello-pontine angle surgery: Analysis of complications and how to avoid it.

OBJECTIVE: To analyze the primary complications related to semisitting position in patients undergoing cerebelo-pontine angle surgery. METHODS: Retrospective data analysis from patients undergoing elective tumoral cerebelo-pontine angle surgery in a semisitting position. The incidence, severity, occurrence moment, treatment, duration, and outcomes of venous air embolism (VAE), pneumocephalus, postural hypotension, and other complications were recorded. Neurointensive care unit (NICU), length of stay (LOS), hospital LOS, and modified Rankin scale scores were calculated six months after surgery. RESULTS: Fifty patients were operated on. Eleven (22%) presented VAE (mean duration 8±4.5min): five (10%) during tumor resection, and four (8%) during dural opening. Ten (20%) were resolved by covering the surgical bed, air bubbles aspiration, jugular compression, and one (2%) tilted to a steep Trendelenburg position. One (2%) had intraoperative hemodynamic instability. The only variable associated with VAE was meningioma at histopathology OR=4.58, p=0.001. NICU was higher in patients with VAE (5.5±1.06 vs. 1.9±0.20 days, p=0.01). There were no differences in the Rankin scale. All patients presented postoperative pneumocephalus with a good level of consciousness, except one (2%) who required evacuation. Seven patients (14%) showed postural hypotension, three (6%) after positioning, and one (2%) after developing a VAE; all were reversed with usual vasoactive drugs. No other position-related complications or mortality were registered in this series. CONCLUSIONS: The semisitting position is a safe option with the knowledge, prevention, detection, and early solution of all the possible complications. The development of VAE rarely implies hemodynamic instability or greater disability after surgery. Postoperative pneumocephalus is very common and rarely requires evacuation. Excellent cooperation between anesthesia, nursing, neurophysiology, and neurosurgery teams is essential to manage complications.

Meningiomas de ángulo pontocerebeloso: tratamiento con radiocirugía mediante LINAC / Cerebellopontine angle meningiomas: LINAC stereotactic radiosurgery treatment

Objetivos Evaluar el resultado del tratamiento con radiocirugía estereotáctica (RC) mediante acelerador lineal (LINAC) en meningiomas de ángulo pontocerebeloso (APC). Métodos Analizamos 80 pacientes diagnosticados de meningiomas de APC entre los años 2001-2014, tratados mediante RC. El 81,9% (n=68) fueron mujeres, con una media de edad de 59,1años (32-79). La RC se aplicó como tratamiento primario en el 83,7% (n=67), y en el 16,3% (n=13) como adyuvante a la cirugía. El tratamiento con RC se lleva a cabo en un acelerador lineal (Varian600, 6MeV) con micromultiláminas M3 (BrainLab) y marco estereotáxico. El volumen tumoral medio fue de 3,14cm3 (0,34-10,36cm3) y la dosis de cobertura media fue de 14Gy (12-16Gy). Se realiza un análisis descriptivo retrospectivo, un análisis de supervivencia método Kaplan-Meier y se contrasta la relación entre las variables del estudio mediante análisis univariados. Resultados Tras un periodo de seguimiento medio de 86,9meses (12-184), la tasa de control tumoral fue del 92,8% (n=77). Se comprobó una reducción global del volumen tumoral al final del estudio del 32,8%, con un volumen medio final de 2,11cm3 (0-10,35cm3). La tasa de supervivencia libre de progresión fue del 98% al año, del 95% a los 5años y del 83,3% a los 10 y 12años. El mayor volumen tumoral previo al tratamiento (p=0,047) se relacionó con la progresión. Se produjo la mejoría clínica en el 26,5% (n=21) de los casos y el deterioro en el 16,2% (n=13); el empeoramiento se relaciona con la dosis de radiación que recibe el troncoencéfalo (p=0,02). Respecto a las complicaciones, el 8,7% (n=7) sufrieron deterioro de la audición, el 5% (n=4) radionecrosis y el 3,7% (n=3) neuropatía del Vpar craneal. La dosis máxima alcanzada (p=0,037) y el tamaño tumoral inicial (p=0,033) se relacionan con la progresión de la hipoacusia, y el desarrollo de radionecrosis, con la dosis máxima alcanzada (p=0,037) (AU)

Objectives To evaluate the efficacy of treatment with linear accelerator-based stereotactic radiosurgery (LINAC) in cerebellopontine angle meningiomas. Methods We analyzed 80 patients diagnosed with cerebellopontine angle meningiomas between 2001 and 2014, treated with stereotactic radiosurgery (SRS), of whom 81.9% (n=68) were women, with an average age of 59.1years (32-79). SRS was applied as primary treatment in 83.7% (n=67) and in 16.3% (n=13) as an adjuvant treatment to surgery. SRS treatment was provided using LINAC (Varian600, 6MeV) with M3 micromultilamines (brainLab) and stereotactic frame. The average tumor volume was 3.12cm3 (0.34-10.36cm3) and the coverage dose was 14Gy (12-16Gy). We performed a retrospective descriptive analysis and survival analysis was performed with the Kaplan-Meier method and multivariate analysis to determine those factors predictive of tumor progression or clinical improvement. Results After an average follow-up period of 86.9months (12-184), the tumor control rate was 92.8% (n=77). At the end of the study, there was an overall reduction in tumor volume of 32.8%, with an average final volume of 2.11cm3 (0-10.35cm3). The progression-free survival rate at 5, 10 and 12years was 98%, 95% and 83.3% respectively. The higher tumor volume (P=.047) was associated with progression. There was clinical improvement in 26.5% (n=21) of cases and clinical worsening in 16.2% (n=13). Worsening is related to the radiation dose received by the brainstem (P=.02). Complications were 8.7% (7 cases) of hearing loss, 5% (4 cases) of brain radionecrosis, and 3.7% (3 cases) of cranial nerveV neuropathy. Hearing loss was related to initial tumor size (P=.033) and maximum dose (P=.037). The occurrence of radionecrosis with the maximum dose (P=.037). Conclusions Treatment of cerebellopontine angle meningiomas with single-dose SRS using LINAC is effective in the long term. Better tumor control rates were obtained in patients with small lesions (AU)

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.

Cerebellopontine angle meningiomas: LINAC stereotactic radiosurgery treatment.

OBJECTIVES: To evaluate the efficacy of treatment with linear accelerator-based stereotactic radiosurgery (LINAC) in cerebellopontine angle meningiomas. METHODS: We analyzed 80 patients diagnosed with cerebellopontine angle meningiomas between 2001 and 2014, treated with stereotactic radiosurgery (SRS), of whom 81.9% (n=68) were women, with an average age of 59.1 years (32-79). SRS was applied as primary treatment in 83.7% (n=67) and in 16.3% (n=13) as an adjuvant treatment to surgery. SRS treatment was provided using LINAC (Varian 600, 6MeV) with M3 micromultilamines (brainLab) and stereotactic frame. The average tumor volume was 3.12cm3 (0.34-10.36cm3) and the coverage dose was 14Gy (12-16Gy). We performed a retrospective descriptive analysis and survival analysis was performed with the Kaplan-Meier method and multivariate analysis to determine those factors predictive of tumor progression or clinical improvement. RESULTS: After an average follow-up period of 86.9 months (12-184), the tumor control rate was 92.8% (n=77). At the end of the study, there was an overall reduction in tumor volume of 32.8%, with an average final volume of 2.11cm3 (0-10.35cm3). The progression-free survival rate at 5, 10 and 12 years was 98%, 95% and 83.3% respectively. The higher tumor volume (p=0.047) was associated with progression. There was clinical improvement in 26.5% (n=21) of cases and clinical worsening in 16.2% (n=13). Worsening is related to the radiation dose received by the brainstem (p=0.02). Complications were 8.7% (7 cases) of hearing loss, 5% (4 cases) of brain radionecrosis, and 3.7% (3 cases) of cranial nerve V neuropathy. Hearing loss was related to initial tumor size (p=0.033) and maximum dose (p=0.037). The occurrence of radionecrosis with the maximum dose (p=0.037). CONCLUSIONS: Treatment of cerebellopontine angle meningiomas with single-dose SRS using LINAC is effective in the long term. Better tumor control rates were obtained in patients with small lesions.

Vascular loop in the cerebellopontine angle: Clinical-radiological correlation.

BACKGROUND: The brainstem, situated in the posterior fossa, connects the brain to the spinal cord. Owing to its location, the nerves of the brainstem are closely related with vascular structures. OBJECTIVES: To correlate the finding of vascular loops in the cerebellopontine angle on imaging with symptoms indicative of vestibulocochlear involvement. MATERIALS AND METHODS: This retrospective descriptive study included all patients evaluated between 2011 and 2017 with findings suggestive of vascular loops in the cerebellopontine angle for whom the clinical history and imaging studies were available. RESULTS: A total of 102 patients (63 women and 39 men) had vestibulocochlear involvement. The most common clinical indication was dizziness (41.18%). A unilateral vascular loop was found in 43 patients (right: 21.57%, left: 20.59%) and bilateral loops were found in 59 (57.84%) patients. The most common type of vascular loop was type II (right: 69.14%; left: 58.75%). The most common origin of vascular loops was the anterior inferior cerebellar artery (right: 66.67%, left: 65.00%). No associations were observed between vascular loops and sensorineural hearing, nystagmus, or vertigo. There was an association with tinnitus. CONCLUSIONS AND SIGNIFICANCE: The presence of vascular loops is not associated with most auditory symptoms. Nevertheless, all findings on imaging studies must be reported. The interpretation of the findings of imaging studies must be correlated with the clinical symptoms after other more common causes that can explain the symptoms have been ruled out.

Correlación clínico-radiológica del asa vascular del ángulo pontocerebeloso / Vascular loop in the cerebellopontine angle: clinical-radiological correlation

Antecedentes: El tronco encefálico, situado en la fosa posterior, conecta el cerebro con la médula espinal. Debido a su ubicación, sus componentes nerviosos guardan una estrecha relación con estructuras vasculares. Objetivos: Describir una relación clínico-radiológica del asa vascular del ángulo pontocerebeloso en pacientes con síntomas indicativos de afectación vestibulococlear mediante evaluación por neuroimagen. Materiales y métodos: Se realizó un estudio retrospectivo y descriptivo. Se incluyeron todos los pacientes evaluados entre 2011 y 2017 con indicios de asa vascular del ángulo pontocerebeloso e historial clínico y estudios de diagnóstico por imagen disponibles. Resultados: 102 pacientes (63 mujeres y 39 hombres) presentaban afectación vestibulococlear. La indicación clínica más frecuente fue mareos (41,18%). Se halló asa vascular unilateral en 43 pacientes (derecho: 21,57%, izquierdo: 20,59%) y bilateral en 59 pacientes (57,84%). El tipo de asa vascular más frecuente fue el tipo II (derecho: 69,14%; izquierdo: 58,75%). El origen más frecuente fue la arteria cerebelosa anteroinferior (ACAI) (derecha: 66,67%, izquierda: 65,00%). No se observó ninguna asociación entre asas vasculares y pérdida de audición neurosensitiva, nistagmo o vértigo. Se halló una asociación con acúfenos. Conclusiones y significación: La presencia de asas vasculares no se asocia a la mayoría de los síntomas auditivos. No obstante, deben notificarse todos los hallazgos de los estudios por imagen. La interpretación de los hallazgos de los estudios por imagen debe correlacionarse con los síntomas clínicos después de excluir otras causas más frecuentes que puedan explicar la sintomatología.(AU)

Background: The brainstem, situated in the posterior fossa, connects the brain to the spinal cord. Owing to its location, the nerves of the brainstem are closely related with vascular structures. Objectives: To correlate the finding of vascular loops in the cerebellopontine angle on imaging with symptoms indicative of vestibulocochlear involvement. Materials and methods: This retrospective descriptive study included all patients evaluated between 2011 and 2017 with findings suggestive of vascular loops in the cerebellopontine angle for whom the clinical history and imaging studies were available. Results: A total of 102 patients (63 women and 39 men) had vestibulocochlear involvement. The most common clinical indication was dizziness (41.18%). A unilateral vascular loop was found in 43 patients (right: 21.57%, left: 20.59%) and bilateral loops were found in 59 (57.84%) patients. The most common type of vascular loop was type II (right: 69.14%; left: 58.75%). The most common origin of vascular loops was the anterior inferior cerebellar artery (right: 66.67%, left: 65.00%). No associations were observed between vascular loops and sensorineural hearing, nystagmus, or vertigo. There was an association with tinnitus. Conclusions and significance: The presence of vascular loops is not associated with most auditory symptoms. Nevertheless, all findings on imaging studies must be reported. The interpretation of the findings of imaging studies must be correlated with the clinical symptoms after other more common causes that can explain the symptoms have been ruled out.(AU)

Keyhole endoscópico retrosigmoideo en tumores del ángulo pontocerebeloso. Resultados de una serie / Endoscopic retrosigmoid keyhole approach in cerebellopontine angle tumors. A surgical cohort

Introducción y objetivos Evaluar la seguridad y eficacia del abordaje tipo keyhole endoscópico retrosigmoideo en pacientes con tumores del ángulo pontocerebeloso. Material y método Se expone una serie clínica retrospectiva y unicéntrica de pacientes con tumores del ángulo pontocerebeloso tratados en un periodo de cuatro años, empleando craneotomía retrosigmoidea tipo keyhole con visualización completamente endoscópica. Se analizaron variables preoperatorias, transoperatorias y postoperatorias.Resultados Se estudiaron 40 pacientes con edad promedio de 49,4 años y proporción masculino/femenino de 0,4:1. De ellos, 31 presentaron schwanomas vestibulares (77,5%), cinco meningiomas (12,5%), dos colesteatomas (5,0%) y dos metástasis (5,0%). Predominaron los schwanomas vestibulares tipo Hannover IIIb, IVa y IVb. La resección fue total o casi total en el 92,5% de los pacientes. Se conservó la audición en el 62,5% de los pacientes y el 80% presentó función aceptable del nervio facial a los seis meses. La estadía hospitalaria promedio fue de 7,5 días. Se observó un elevado porcentaje de resección total o casi total y de recuperación funcional. La frecuencia de complicaciones fue baja. Conclusiones El abordaje tipo keyhole endoscópico retrosigmoideo constituyó un procedimiento seguro y eficaz en los pacientes con tumores del ángulo pontocerebeloso seleccionados (AU)

Introduction and objectives To determine the safety and efficacy of endoscopic keyhole surgery in patients with cerebellopontine angle tumors. Materials and methods This was a retrospective study of patients with cerebellopontine angled tumors treated by fully endoscopic retrosigmoid keyhole approach in a tertiary center during a period of four years. Preoperative, transoperative and postoperative variables were analyzed. Results A number of 40 patients were included. The age average was 49.4 years and male/female proportion was 0.4-1. We found 31 vestibular schwannomas (77.5%), five meningiomas (12,5%), two cholesteatomas (5,0%) and two metastases (5.0%). Vestibular schwannomas Hannover type IIIb, IVa and IVb predominated. The surgical resection was total or near-total 92.5% of patients. Hearing preservation rate was 62.5% and acceptable facial function nerve function rate was 80% after six months. Hospital stay was 7.5 days. The total or near total resection and functionally preservation rate was high. Complications were unusual. Conclusions Endoscopic retrosigmoid keyhole approach represented a safe and efficient procedure in selected patients with cerebellopontine angle tumors (AU)

Endoscopic retrosigmoid keyhole approach in cerebellopontine angle tumors. A surgical cohort.

INTRODUCTION AND OBJECTIVES: To determine the safety and efficacy of endoscopic keyhole surgery in patients with cerebellopontine angle tumours. MATERIALS AND METHODS: This was a retrospective study of patients with cerebellopontine angled tumours treated by fully endoscopic retrosigmoid keyhole approach in a tertiary centre during a period of four years. Preoperative, transoperative and postoperative variables were analysed. RESULTS: A number of 40 patients were included. The age average was 49.4 years and male/female proportion was 0.4-1. We found 31 vestibular schwannomas (77.5%), five meningiomas (12.5%), two cholesteatomas (5.0%) and two metastases (5.0%). Vestibular schwannomas Hannover type IIIb, IVa and IVb predominated. The surgical resection was total or near-total 92.5% of patients. Hearing preservation rate was 62.5% and acceptable facial function nerve function rate was 80% after six months. Hospital stay was 7.5 days. The total or near total resection and functionally preservation rate was high. Complications were unusual. CONCLUSIONS: Endoscopic retrosigmoid keyhole approach represented a safe and efficient procedure in selected patients with cerebellopontine angle tumours.

Endoscopic retrosigmoid keyhole approach in cerebellopontine angle tumors. A surgical cohort. / Keyhole endoscópico retrosigmoideo en tumores del ángulo pontocerebeloso. Resultados de una serie.

INTRODUCTION AND OBJECTIVES: To determine the safety and efficacy of endoscopic keyhole surgery in patients with cerebellopontine angle tumors. MATERIALS AND METHODS: This was a retrospective study of patients with cerebellopontine angled tumors treated by fully endoscopic retrosigmoid keyhole approach in a tertiary center during a period of four years. Preoperative, transoperative and postoperative variables were analyzed. RESULTS: A number of 40 patients were included. The age average was 49.4 years and male/female proportion was 0.4-1. We found 31 vestibular schwannomas (77.5%), five meningiomas (12,5%), two cholesteatomas (5,0%) and two metastases (5.0%). Vestibular schwannomas Hannover type IIIb, IVa and IVb predominated. The surgical resection was total or near-total 92.5% of patients. Hearing preservation rate was 62.5% and acceptable facial function nerve function rate was 80% after six months. Hospital stay was 7.5 days. The total or near total resection and functionally preservation rate was high. Complications were unusual. CONCLUSIONS: Endoscopic retrosigmoid keyhole approach represented a safe and efficient procedure in selected patients with cerebellopontine angle tumors.

Vascular loop in the cerebellopontine angle: clinical-radiological correlation. / Correlación clínico-radiológica del asa vascular del ángulo pontocerebeloso.

BACKGROUND: The brainstem, situated in the posterior fossa, connects the brain to the spinal cord. Owing to its location, the nerves of the brainstem are closely related with vascular structures. OBJECTIVES: To correlate the finding of vascular loops in the cerebellopontine angle on imaging with symptoms indicative of vestibulocochlear involvement. MATERIALS AND METHODS: This retrospective descriptive study included all patients evaluated between 2011 and 2017 with findings suggestive of vascular loops in the cerebellopontine angle for whom the clinical history and imaging studies were available. RESULTS: A total of 102 patients (63 women and 39 men) had vestibulocochlear involvement. The most common clinical indication was dizziness (41.18%). A unilateral vascular loop was found in 43 patients (right: 21.57%, left: 20.59%) and bilateral loops were found in 59 (57.84%) patients. The most common type of vascular loop was type II (right: 69.14%; left: 58.75%). The most common origin of vascular loops was the anterior inferior cerebellar artery (right: 66.67%, left: 65.00%). No associations were observed between vascular loops and sensorineural hearing, nystagmus, or vertigo. There was an association with tinnitus. CONCLUSIONS AND SIGNIFICANCE: The presence of vascular loops is not associated with most auditory symptoms. Nevertheless, all findings on imaging studies must be reported. The interpretation of the findings of imaging studies must be correlated with the clinical symptoms after other more common causes that can explain the symptoms have been ruled out.

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.

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.

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.

[Trigeminal neuralgia secondary to petrous endostosis]. / Neuralgia del trigémino secundaria a endostosis del hueso temporal.

Arterial neurovascular compression is hypothesised to be the main cause of primary trigeminal neuralgia. Although it is the most common cause, other pathologies, such as tumours in the cerebellopontine angle, can cause trigeminal pain. We report a case of a 44-year-old female patient with right trigeminal neuralgia without satisfactory response to medical treatment. Cerebral MRI showed no structural injuries. During microvascular decompression of the trigeminal nerve, endostosis of the internal aspect of the petrous bone was found to compress the trigeminal nerve. The pain disappeared completely in the early postsurgical period, after the complete drilling of the endostosis and microvascular decompression. The patient remains asymptomatic one year later. Endostosis of the petrous bone is a rare cause of trigeminal neuralgia. A proper review of preoperative studies would enable the definitive surgical approach to be optimised.