[Frontal aslant tract: Anatomy and implications in brain glioma neurosurgery]. / Tracto oblicuo frontal: anatomía e implicancia en neurocirugía de gliomas cerebrales.

The frontal aslant tract (FAT) connects the supplementary motor area (SMA) with the pars opercularis. Its role in language and its implications in glioma surgery remain under discussion. We present an anatomosurgical study of three cases with surgical resolution. Three patients with gliomas in the left frontal lobe were operated on using an awake patient protocol with cortical and subcortical mapping techniques, conducting motor and language evaluations. Tractography was performed using DSI Studio software. All three patients showed intraoperative language inhibition through subcortical stimulation of the FAT. Resection involving the FAT correlated with language deficits in all cases and movement initiation deficits in two cases. All patients recovered from their deficits at six months postoperatively. In conclusion, the tract has been successfully reconstructed, showing both anatomical and functional complexity, supporting the idea of its mapping and preservation in glioma surgery. Future interdisciplinary studies are necessary to determine the transient or permanent nature of the deficits.

El tracto oblicuo frontal (TOF) conecta el área motora suplementaria (AMS) con la pars opercularis. Su rol en el lenguaje y su implicancia en la cirugía de gliomas siguen en discusión. Presentamos un estudio anatomoquirúrgico de tres casos con resolución quirúrgica. Se operaron tres pacientes con gliomas en el lóbulo frontal izquierdo utilizando protocolo de paciente despierto con técnicas de mapeo cortical y subcortical realizando evaluación motora y del lenguaje. Las tractografías fueron realizadas con el software DSI Studio. Los tres pacientes presentaron inhibición intraoperatoria del lenguaje mediante la estimulación subcortical de TOF. La resección en contacto con el TOF se correlacionó con déficits del lenguaje en todos los casos y en dos casos déficits en la iniciación del movimiento. Todos los pacientes recuperaron su déficit a los seis meses postoperatorios. En conclusión, se ha logrado reconstruir al tracto. Éste presenta una complejidad anatómica y funcional, que apoya la idea de su mapeo y preservación en la cirugía de gliomas. Futuros estudios interdisciplinarios son necesarios para determinar el carácter transitorio o permanente de los déficits.

Delimitation of the risk area of the vertebral artery during the paramedian suboccipital approach.

OBJECTIVE: The V3 segment of the vertebral artery (V3-VA) is at risk during diverse approaches to the craniovertebral junction. Our objective is to present a system of anatomic and topographic landmarks to identify the V3-VA during the paramedian suboccipital approach (PMSOA) with the help of minimal or basic tools. MATERIAL AND METHODS: The first was a retrospective analysis of the angiotomography (CTA) of 50 patients over 18-years old, and 9 anatomical dissections. A series of lines were defined between the different bony landmarks. Within this lines the risk area of the vertebral artery (RAsV3-VA) and the risk point of the vertebral artery (RPsV3-VA) were defined. The second stage was a prospective study, where the previously defined measurements were carried out by using neuronavigation in 10 patients (20 sides) operated with the PMSO approach in order to confirm the presence of the V3 segment in the RAsV3-VA and RPsV3-VA. RESULTS: In the first stage, the V3 segment was found in the middle third of the X line in 96,6% of the cases. The distance between the inion and the UCP (percentile 5) was 20 mm and to the LCP (percentile 95) was 40 mm. In the range between the UCP and the LCP, in the middle third of the inion-mastoid line (RAsV3-VA), we found 90% of the V3-VA. The measurements taken during the second stage revealed that the artery was in the middle third of the X line in 97% of the cases. 85% of the patients presented the total of the V3s-VA on the RAsV3-VA and in 85% there was a direct relationship with the V3 segment and the RPV3s-VA. CONCLUSION: We propose an easy-to-implement system to delimit the risk area of the V3-VA during the PMSOA. We believe that these landmarks provide a practical, reliable, costless and useful tool that could decrease the risk of lesion of the V3-VA during this approach without the need of using.

Surgical Anatomy and Technique of Peri-Insular Hemispherotomy in Pediatric Epilepsy.

BACKGROUND AND OBJECTIVES: Hemispherotomy is a highly complex procedure that demands a steep learning curve. An incomplete brain disconnection often results in failure of seizure control. The purpose of this article was to present a step-by-step guide to the surgical anatomy of this procedure. It is composed of a 7-stage approach, enhancing access to and improving visualization of deep structures. METHODS: A retrospective analysis of 39 pediatric patients with refractory epilepsy who underwent this technique was conducted. Engel scores were assessed 1 year postsurgery. Cadaveric dissections were performed to illustrate the procedure. RESULTS: Between 2015 and 2022, 39 patients were surgically treated using the peri-insular technique. The technique involved 7 stages: patient positioning, operative approach, opercular resection, transventricular callosotomy, fronto-orbital disconnection, anterior temporal disconnection, and posterior temporal disconnection. Most of the patients (92.30%) were seizure-free (Engel class I) at 1 year postoperative, 5.13% were nearly seizure-free (Engel II), and 2.56% showed significant improvement (Engel III). Complications occurred in 8% of cases, including 1 infection, 2 cases of aseptic meningitis, and 1 non-shunt-requiring acute hydrocephalus. CONCLUSION: The peri-insular hemispherotomy technique offers excellent seizure control with a low complication rate. Our visual documentation of surgical anatomy, complemented by detailed descriptions of surgical nuances, significantly contributes to a comprehensive understanding of this technique.

Experience in awake glioma surgery in a South American center. Correlation between intraoperative evaluation, extent of resection and functional outcomes.

Introduction: Gliomas are the second most frequent primary brain tumors. Surgical resection remains a crucial part of treatment, as well as maximum preservation of neurological function. For this reason awake surgery has an important role.The objectives of this article are to present our experience with awake surgery for gliomas in a South American center and to analyze how intraoperative functional findings may influence the extent of resection and neurological outcomes. Materials and methods: Retrospective single center study of a cohort of adult patients undergoing awake surgery for brain glioma, by the same neurosurgeon, between 2012 and 2022 in the city of Buenos Aires, Argentina. Results: A total of 71 patients were included (mean age 34 years, 62% males). Seventy seven percent of tumors were low grade, with average extent of resection reaching 94% of preoperative volumetric assessment. At six months follow up, 81.7% of patients presented no motor or language deficit.Further analysis showed that having a positive mapping did not have a negative impact in the extent of resection, but was associated with short term postoperative motor and language deficits, among other variables, with later improvement. Conclusion: Awake surgery for gliomas is a safe procedure, with the proper training. In this study it was observed that guiding the resection by negative mapping did not worsen the results and that positive subcortical mapping correlated with short term postoperative neurological deficits with posterior improvement within six months in most cases.

¿Cuál es la presión de drenaje óptima en hidrocefalias tumorales obstructivas? Análisis de factores subyacentes al sobredrenado valvular, revisión de casos y desarrollo de protocolo quirúrgico / What is the optimal drainage pressure in obstructive tumors hydrocephalus? Analysis of factors underlying valve overdrainage, case review and development of surgical protocol

Introducción: La hidrocefalia es una complicación frecuente dentro de la patología tumoral del SNC. La colocación de válvulas de derivación ventrículo-peritoneal (VDVP) en estos casos es, al día de la fecha, la práctica estándar para tratar esta patología y prevenir las complicaciones y comorbilidades que esta conlleva. Al momento, no existe un protocolo ni una presión valvular inicial establecida para estos pacientes, en los cuales hemos observado una tendencia al sobredrenado de líquido cefalorraquídeo (LCR). El objetivo de este trabajo es analizar nuestra experiencia en el tratamiento de hidrocefalias obstructivas secundarias a patología tumoral, determinar factores relacionados al advenimiento de sobredrenado, el manejo terapéutico del mismo y subsiguientemente protocolizar de manera sencilla y económica la colocación de este tipo de prótesis así como identificar una presión terapéutica que reduzca el riesgo de sobredrenado. Materiales y métodos: Estudio monocéntrico, analítico, retrospectivo de una cohorte de pacientes operados en nuestra institución por hidrocefalia obstructiva secundaria a patología tumoral entre los años 2013-2022.Se analizaron historias clínicas, imágenes y protocolos quirúrgicos. Se identificaron aquellos pacientes que desarrollaron sobredrenado. Subsiguientemente se analizaron mediante un modelo estadístico explicativo multivariado aquellas variables demográficas, clínicas y terapéuticas implicadas en el mismo.En una segunda etapa se propone un protocolo rápido, sencillo y económico a fin de determinar la presión óptima dentro de cada caso en particular. Resultados: Dentro de los 56 pacientes incluidos, 32 pacientes (57%) presentaron sobredrenado; 10 pacientes (18%) presentaron higromas en imágenes postoperatorias, y de estos, 3 pacientes (5.4%) requirieron intervenciones quirúrgicas. El 94% de los sobredrenados ocurrieron a presiones menores o igual a 160 mmH20. Así mismo, 8 de los 11 pacientes con VDVP de presión fija media (100-110 mmH20) no regulable presentaron sobredrenado.En un 27% de los pacientes debió aumentarse la presión valvular como consecuencia de hallazgos clínicos o radiológicos de sobredrenado. Conclusión: Las hidrocefalias secundarias a patología tumoral presentan un comportamiento distinto al de las normotensivas. La tasa de sobredrenado en estos pacientes es superior y por consiguiente debe ser tenida en cuenta como una posible complicación relevante. Dada la heterogeneidad de tumores, cada paciente presenta presiones de LCR distintas y por ende debe individualizarse el tratamiento. Proponemos el uso del protocolo de medición intraquirúrgica de presión a fin de colocar la VDVP a la presión óptima para cada paciente, y evitar de esta manera el sobredrenado de LCR

Background: Hydrocephalus is a common complication in CNS tumors pathology. The placement of ventriculoperitoneal shunt in these cases is, to date, the standard practice to treat this pathology and prevent the complications and comorbidities that it entails. At present, there is no protocol or initial valve pressure established for these patients, in whom we have observed a tendency toward overdrainage of cerebrospinal fluid (CSF).The objective of this work is to analyze our experience in the treatment of obstructive hydrocephalus secondary to tumor pathology, determine factors related to the occurrence of overdrainage, its therapeutic management and subsequently protocolize in a simple and economical way the placement of this type of prosthesis as well as identify a therapeutic pressure that reduces the risk of overdrainage. Methods: Monocentric, analytical, retrospective study of a cohort of patients operated on at our institution for obstructive hydrocephalus secondary to tumors, between the years 2013-2022.Medical records, images and surgical protocols were analyzed. Those patients who developed overdrainage were identified. Subsequently, the demographic, clinical and therapeutic variables involved in it were analyzed using a multivariate explanatory statistical model.In a second stage, a quick, simple, and economical protocol is proposed to determine the optimal pressure within each case. Results: Among the 56 patients included, 32 patients (57%) presented overdrainage; 10 patients (18%) presented hygromas on postoperative images, and of these, 3 patients (5.4%) required surgical interventions. 94% of overdrains occurred at pressures less than or equal to 160 mmH20. Likewise, 8 of the 11 patients with non-adjustable medium fixed pressure shunt (100-110 mmH20) presented overdrainage.In 27% of patients, valve pressure had to be increased because of clinical or radiological findings of overdrainage. Conclusion: Hydrocephalus secondary to tumors presents a different behavior than normotensive ones. The rate of overdrainage in these patients is higher and therefore must be considered as a possible relevant complication. Given the heterogeneity of tumors, each patient has different CSF pressures and therefore treatment must be individualized. We propose the use of the intrasurgical pressure measurement protocol to place the shunt at the optimal pressure for each patient, and thus avoid CSF overdrainage

Hemisferotomía peri-insular y Hemisferectomía funcional pediátrica para el tratamiento de la epilepsia severa refractaria al tratamiento médico: comparación de dos técnicas / Peri-insular Hemispherotomy and Pediatric Functional Hemispherectomy for the Treatment of Severe Epilepsy Refractory to Medical Treatment: Comparison of Two Techniques

Introducción. Desde que se describió por primera vez en la década de 1970, la hemisferectomía funcional ha sido una herramienta esencial en el tratamiento de la epilepsia refractaria al tratamiento médico secundaria a una enfermedad hemisférica unilateral difusa. Objetivos. Presentar nuestra experiencia con la técnica de hemisferectomía funcional (HF) y de hemisferotomía peri-insular modificada (HPI); describir además la técnica quirúrgica peri-insular, revisar los resultados después de la cirugía, y discutir las diferencias entre las técnicas en cuanto a complicaciones y resultados postoperatorios. Material y Métodos. Se realizo un estudio retrospectivo de 23 pacientes con epilepsia refractaria que fueron sometidos a hemisferectomía cerebral. Se realizó un análisis de las características clínicas, las imágenes, las técnicas quirúrgicas y los resultados postoperatorios. Analizamos tambien la técnica quirúrgica de la HPI modificada. Resultados. Entre 2000 y 2020, 23 pacientes pediátricos con convulsiones refractarias se sometieron a hemisferotomía (12 HF, 11 HPI modificada). El 91,3% de los pacientes estaban libres de crisis a los 6 meses, el 87% al año y el 78,3% en el último seguimiento. Ninguno de los 23 pacientes presentó Engel IV como resultado final. Se encontró que la HF presentó una duración quirúrgica estadísticamente más larga que la HPI (5 ± 1,5 frente a 3,83 ± 0,5 horas; p = <0,001). Como resultados generales, la esfera cognitiva mejoró en dos tercios de los pacientes (66,9%) y además demostramos una mejoría de la actividad motora en la mayoría de los pacientes, independientemente de la patología y la técnica quirúrgica. Conclusión. Cuando los pacientes se seleccionan adecuadamente, la hemisferectomía es un tratamiento eficaz para la epilepsia pediátrica resultante la marcada disfunción de un solo hemisferio cerebral, no sólo brindando al paciente una alta probabilidad de ausencia de convulsiones, sino también proporcionando una mejora en las habilidades motoras y cognitivas. En nuestro caso particular y en base al presente estudio, la HPI modificada resulta ser una técnica altamente efectiva. No solo tiene un tiempo quirúrgico más corto sino también una tasa de complicaciones muy baja

Background. Since it was first described in the 1970s, functional hemispherotomy has been an essential tool in treating disabling, medically refractory epilepsy resulting from diffuse unilateral hemispheric disease. Objectives. To report our experience with 23 patients who underwent hemispherotomy, both using the functional hemispherotomy (FH) as well as a modified peri-insular hemispherotomy (PIH) technique; to present the surgical technique, review outcomes following disconnection surgery and discuss the differences between the techniques when it comes to complications and postoperative results. Methods. A retrospective study of 23 patients with refractory seizures who underwent cerebral hemispherectomy. A thorough analysis of the clinical, imaging, surgical features and postoperative results was performed. We also review the surgical technique for the modified PIH technique. Results. Between 2000 and 2020, 23 pediatric patients with refractory seizures underwent hemispherotomy (12 FHs, 11 modified PIHs). 91.3% of patients were seizure free at 6 months, 87% at 1 year, and 78.3% at last follow-up. None of the 23 patients presented Engel IV outcome. FH was found to have statistically longer surgical duration (5 ± 1.5 vs 3.83 ± 0.5 hours; p = <0.001). Neurocognition was improved in two thirds of the patients (66.9%). Our study also shows improvement of motor activity in most of the patients, regardless of the pathology and surgical technique. Conclusion. When patients are wisely selected, the hemispherotomy procedure should be considered as a most attractive and curative treatment for children with refractory seizures, not only giving the patient a high chance of seizure freedom but also providing an improvement in motor and cognitive skills. In our case and based on the present study, the modified PIH proves to be a highly effective technique. It not only has a shorter surgical time but also a very low complication rate

Intradural extramedullary tumors. Retrospective cohort study assessing prognostic factors for functional outcome in adult patients.

OBJECTIVE: The purpose of this study is to analyze a series of patients with intradural extramedullary tumors (IDEM) and assess factors that may modify or determine the final long term outcome and management. MATERIALS AND METHODS: Single Center, retrospective study of a series of surgical patients with IDEM lesions from our Institution operated between 2010 and 2021. Patients with less than 6 months of follow up were excluded. Several preoperative demographics, clinical, imaging and surgical features, as well as histopathology, recurrence and adjuvancy were assessed. Patients' final clinical outcome was categorized using the McCormick scale. RESULTS: A total of 203 patients with a mean follow-up of 30.50 months (range 6-130) were included. 57.64% of the analyzed population was female and the mean age was 50.51 years. The most frequent location of the tumors was dorsal (34.98%) followed by the lumbar region (32.02%). Total resection was achieved in 84.24% of cases, and the most frequent histopathology was Schwannoma (36.45%), followed by Meningioma (30.05%). Pain was the most usual initial symptom (63.05%). In our analysis, functional outcome after surgery was associated with statistical significance with preoperative McCormick grade, tumor type, EOR and postoperative complications such as hematoma and sphincter involvement. CONCLUSION: The management of these lesions depends on many factors. It is worthy of mention that clinical presentation, EOR, histopathology and postoperative complications have shown significant prognostic value for the final outcome. Early treatment with the intention of achieving GTR when possible, using carefully tailored approaches, should be considered before the onset of significant symptoms.

[Endoscopic vs. microscopic techniques for the treatment of trigeminal neuralgia. Our experience at an Argentine care center]. / Descompresión microvascular endoscópica versus microscópica en neuralgia trigeminal en un Centro argentino.

INTRODUCTION: Trigeminal neuralgia is a highly invalidating pathology, whose natural course has been modified thanks to decompressive microvascular surgery. The intervention can be carried out either with a microscope or via an endoscopic technique. Our goal was to compare these two techniques for the treatment of this complex pathology. METHODS: Retrospective, analytical study of a cohort of patients treated by a single surgeon at our institution, in the period between 2015 and 2021. RESULTS: We identified 31 patients and divided them into two groups: 15 (49%) treated using the microscopic technique (group M), and 16 (51%) exclusively via an endoscopic one (group E). Differences were observed between the means of the size of the craniectomy in group M (3.7 cm) compared to group E (2.5 cm); The mean length of hospital stay for patients in group E was shorter (4.46 days compared to that of patients in group M, whose hospital stay averaged 2.43 days). There were no differences between the two groups regarding the length of the procedure. In both groups, the predominant compression was due to the superior cerebellar artery (SCA). Pain outcomes were equivalent, with every patient in both groups having an improved postoperative Barrow Neurological Institute Pain Intensity Score (BNI). DISCUSSION: Endoscopic microvascular decompression is an attractive option for the resolution of neurovascular conflict as it provides functional results similar to the microscope technique, without requiring an extensive craniectomy and associated to shorter in-hospital stay, which is beneficial for both the patient and the institution.

Introducción: La descompresión microvascular (DMV) en la neuralgia trigeminal es una técnica quirúrgica cuyo objetivo es revertir la compresión a la que se ve sometido un nervio por una estructura vascular. El objetivo de este estudio fue realizar una comparación directa entre la descompresión microvascular endoscópica (DMV-E) y la misma a través del uso del microscopio (DMV-M) en el tratamiento de la neuralgia del trigémino. Métodos: Se realizó un estudio de cohorte retrospectivo de pacientes operados de neuralgia de trigémino, por un mismo cirujano, entre 2015 y 2021 en nuestra institución, tanto por técnica microquirúrgica como endoscópica. Resultados: Se obtuvieron un total de 31 pacientes divididos en dos grupos: Grupo M correspondiente a 15 (49%) pacientes abordados con técnica microscópica y Grupo E, con 16 (51%) pacientes intervenidos con técnica endoscópica. Se identificaron diferencias en el tamaño de la craniectomía, más pequeña en el grupo E (2.50 cm vs 3.70 cm grupo M); y en el tiempo de internación, de 2.43 días en el grupo E vs. 4.46 días en el grupo M. El tiempo de cirugía fue similar para ambas técnicas quirúrgicas La principal compresión fue dada por la arteria cerebelosa superior (ACS) en ambos grupos. Todos los pacientes presentaron mejoría del Barrow Neurological Institute Pain Intensity Score (BNI) en el postoperatorio en ambos grupos. Discusión: La DMV-E constituye una alternativa quirúrgica interesante a la ya conocida DMV-M para el tratamiento de la neuralgia trigeminal, por requerir menores dimensiones en la incisión cutánea y tamaño de la craniectomía, acortando el tiempo de internación, lo cual no solo implica un beneficio para el paciente, sino que también representa menor costo de internación.

Descompresión microvascular endoscópica versus microscópica en neuralgia trigeminal en un centro Argentino / Endoscopic vs. microscopic techniques for the treatment of trigeminal neuralgia. Our experience at an Argentine care center

Resumen Introducción: La descompresión microvascular (DMV) en la neuralgia trigeminal es una técnica quirúrgica cuyo objetivo es revertir la compresión a la que se ve someti do un nervio por una estructura vascular. El objetivo de este estudio fue realizar una comparación directa entre la descompresión microvascular endoscópica (DMV-E) y la misma a través del uso del microscopio (DMV-M) en el tratamiento de la neuralgia del trigémino. Métodos: Se realizó un estudio de cohorte retrospec tivo de pacientes operados de neuralgia de trigémino, por un mismo cirujano, entre 2015 y 2021 en nuestra institución, tanto por técnica microquirúrgica como endoscópica. Resultados: Se obtuvieron un total de 31 pacientes divididos en dos grupos: Grupo M correspondiente a 15 (49%) pacientes abordados con técnica microscópica y Grupo E, con 16 (51%) pacientes intervenidos con técnica endoscópica. Se identificaron diferencias en el tamaño de la cra niectomía, más pequeña en el grupo E (2.50 cm vs 3.70 cm grupo M); y en el tiempo de internación, de 2.43 días en el grupo E vs. 4.46 días en el grupo M. El tiempo de cirugía fue similar para ambas técnicas quirúrgicas La principal compresión fue dada por la arteria ce rebelosa superior (ACS) en ambos grupos. Todos los pacientes presentaron mejoría del Barrow Neurological Institute Pain Intensity Score (BNI) en el postoperatorio en ambos grupos. Discusión: La DMV-E constituye una alternativa qui rúrgica interesante a la ya conocida DMV-M para el tratamiento de la neuralgia trigeminal, por requerir menores dimensiones en la incisión cutánea y tamaño de la craniectomía, acortando el tiempo de internación, lo cual no solo implica un beneficio para el paciente, sino que también representa menor costo de internación.

Abstract Introduction: Trigeminal neuralgia is a highly invali dating pathology, whose natural course has been modi fied thanks to decompressive microvascular surgery. The intervention can be carried out either with a microscope or via an endoscopic technique. Our goal was to compare these two techniques for the treatment of this complex pathology. Methods: Retrospective, analytical study of a cohort of patients treated by a single surgeon at our institution, in the period between 2015 and 2021. Results: We identified 31 patients and divided them into two groups: 15 (49%) treated using the microscopic technique (group M), and 16 (51%) exclusively via an endoscopic one (group E). Differences were observed between the means of the size of the craniectomy in group M (3.7 cm) compared to group E (2.5 cm); The mean length of hospital stay for patients in group E was shorter (4.46 days compared to that of patients in group M, whose hospital stay averaged 2.43 days). There were no differences between the two groups regarding the length of the procedure. In both groups, the predomi nant compression was due to the superior cerebellar artery (SCA). Pain outcomes were equivalent, with every patient in both groups having an improved postoperative Barrow Neurological Institute Pain Intensity Score (BNI). Discussion: Endoscopic microvascular decompression is an attractive option for the resolution of neurovas cular conflict as it provides functional results similar to the microscope technique, without requiring an exten sive craniectomy and associated to shorter in-hospital stay, which is beneficial for both the patient and the institution.

Postoperative Third Nerve Palsy after Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenoma: Elucidating its Mechanism.

Third nerve palsy is a rare complication of transsphenoidal surgery and has been merely mentioned in different studies, but there is not any rigorous analysis focusing on this particular complication. The purpose of this study is to analyze this complication after transsphenoidal surgery for a pituitary adenoma to better understand its pathophysiology and outcome. The authors retrospectively analyzed 3 cases of third nerve palsy selected from the 377 patients operated via a transsphenoidal route between 2012 and 2021 at FLENI, a private tertiary neurology and neurosurgical medical center located in Buenos Aires, Argentina. The three patients who presented this complication were operated on via an endoscopic approach. It was observed that an extension into the cavernous sinus (Knosp grade 4) and to the oculomotor cistern was present in the three patients. The deficit was apparent immediately after surgery in two patients. For these two patients, the supposed mechanism of ophthalmoplegia was an intraoperative nerve lesion. The other patient became symptomatic in the 48 h following the surgery. The mechanism implied in this case was intracavernous hemorrhagic suffusion. The latter patient completely recovered the third nerve deficit in the 3 months that followed, while the other two recovered after 6 months postoperative. Oculomotor nerve palsy after transsphenoidal surgery is a very rare complication and appears to be transient in most cases. The invasion of both the cavernous sinus and the oculomotor cistern seems to be a major factor in its physiopathology and should be preoperatively analyzed on magnetic resonance imaging (MRI); recognizing such extension should play an important role in the surgeon's operative considerations.

Resultados a largo plazo del tratamiento quirúrgico de las fístulas arteriovenosas durales espinales en un centro Argentino / Surgical treatment of spinal dural arteriovenous fistulas: Management and long-term results in a series of patients operated in an Argentinian center

Resumen Introducción: La fístula dural arteriovenosa espinal (FDAVE) es una enfermedad vascular frecuentemente subdiagnosticada. El tratamiento puede ser microqui rúrgico o endovascular. Métodos: Estudio retrospectivo de una serie de pa cientes con FDAVE tratados por microcirugía entre los años 2010 y 2021. Fueron evaluados parámetros como edad, sexo, cuadro clínico pre y postoperatorio medido con las escalas de Aminoff-Logue y Rankin modificada (mRs). Los estudios diagnósticos se utilizaron para de terminar nivel lesional y resultados quirúrgicos. Resultados: Se incluyeron doce pacientes (10 hombres y 2 mujeres) con un promedio de edad de 60 años. El tiempo de evolución del cuadro clínico al diagnóstico fue menor a 12 meses salvo un caso de 32 meses. Las FDAVE fueron localizadas, 8 a nivel dorsal, 3 a nivel lumbar y una a nivel sacro. La arteria de Adamkiewicz se identificó en 5 casos en L1, 2 en D12, 2 en D10, 2 en D9 y un caso en D7. De los 12 pacientes operados, 3 fueron embolizados previamente; dos permanecieron estables en su evolución y 10 mejoraron uno o más puntos del mRs. No hubo complicaciones en el postoperatorio. Todos mostraron mejoría del edema medular en reso nancia magnética y la angiografía digital, luego de los 6 meses, fue negativa. El seguimiento promedio fue de 40 meses con un rango de 6 a 122 meses y ningún paciente presentó recidiva de la FDAVE. Conclusión: El tratamiento quirúrgico de las FDAVE es un método muy eficaz, de baja morbilidad y menor tasa de recurrencia comparado con el tratamiento en dovascular.

Abstract Introduction: Spinal dural arteriovenous fistula (SDA VF) is a rare vascular disease, of unknown etiology, fre quently underdiagnosed. Treatment can be microsurgical or endovascular. Methods: Retrospective and monocentric analysis of 12 SDAVF patients treated by microsurgery between 2010 and 2021. Parameters including age, sex, pre and postoperative clinical condition were analyzed according to modified Aminoff-Logue and Rankin scales. Diagnos tic studies such as magnetic resonance imaging (MRI), magnetic resonance angiogram (MRA) and spinal digital subtraction angiography (DSA), were evaluated for lesion level, as were surgical results. Results: Twelve patients (10 men and 2 women), average age: 60 years, were operated. The interval from symptom onset to diagnosis was <12 months in all cases except one (32 months). SDAVF locations were thoracic in 8 cases, between T6 and T12, 3 at lumbar spine (L1- L2) and at S1 in one case, with no difference regarding side. The Adamkiewicz artery was identified in 5 cases at L1, 2 at D12, 2 at D10, 2 at D9 and 1 at D7 (7 left-sided and 5 right-sided). Three of the 12 patients operated had undergone prior embolization. Postoperative neu rological outcomes showed: 2 patients remained stable and 10 improved one or more points on the mRs; no postoperative complications were observed. Follow-up MRI images improved in all cases and spinal DSA was negative at 6 months. Average follow-up was 40 months (range 6 to 122) and no patient presented recurrence. Conclusion: Microsurgical treatment of SDAVF proved to be efficient, with low morbidity and lower recurrence rates compared to endovascular results.

[Surgical treatment of spinal dural arteriovenous fistulas: Management and long-term results in a series of patients operated in an Argentinian Center]. / Resultados a largo plazo del tratamiento quirúrgico de las fístulas arteriovenosas durales espinales en un Centro argentino.

INTRODUCTION: Spinal dural arteriovenous fistula (SDAVF) is a rare vascular disease, of unknown etiology, frequently underdiagnosed. Treatment can be microsurgical or endovascular. METHODS: Retrospective and monocentric analysis of 12 SDAVF patients treated by microsurgery between 2010 and 2021. Parameters including age, sex, pre and postoperative clinical condition were analyzed according to modified Aminoff-Logue and Rankin scales. Diagnostic studies such as magnetic resonance imaging (MRI), magnetic resonance angiogram (MRA) and spinal digital subtraction angiography (DSA), were evaluated for lesion level, as were surgical results. RESULTS: Twelve patients (10 men and 2 women), average age: 60 years, were operated. The interval from symptom onset to diagnosis was < 12 months in all cases except one (32 months). SDAVF locations were thoracic in 8 cases, between T6 and T12, 3 at lumbar spine (L1-L2) and at S1 in one case, with no difference regarding side. The Adamkiewicz artery was identified in 5 cases at L1, 2 at D12, 2 at D10, 2 at D9 and 1 at D7 (7 left-sided and 5 right-sided). Three of the 12 patients operated had undergone prior embolization. Postoperative neurological outcomes showed: 2 patients remained stable and 10 improved one or more points on the mRs; no postoperative complications were observed. Follow-up MRI images improved in all cases and spinal DSA was negative at 6 months. Average follow-up was 40 months (range 6 to 122) and no patient presented recurrence. CONCLUSION: Microsurgical treatment of SDAVF proved to be efficient, with low morbidity and lower recurrence rates compared to endovascular results.

Introducción: La fístula dural arteriovenosa espinal (FDAVE) es una enfermedad vascular frecuentemente subdiagnosticada. El tratamiento puede ser microquirúrgico o endovascular. Métodos: Estudio retrospectivo de una serie de pacientes con FDAVE tratados por microcirugía entre los años 2010 y 2021. Fueron evaluados parámetros como edad, sexo, cuadro clínico pre y postoperatorio medido con las escalas de Aminoff-Logue y Rankin modificada (mRs). Los estudios diagnósticos se utilizaron para determinar nivel lesional y resultados quirúrgicos. Resultados: Se incluyeron doce pacientes (10 hombres y 2 mujeres) con un promedio de edad de 60 años. El tiempo de evolución del cuadro clínico al diagnóstico fue menor a 12 meses salvo un caso de 32 meses. Las FDAVE fueron localizadas, 8 a nivel dorsal, 3 a nivel lumbar y una a nivel sacro. La arteria de Adamkiewicz se identificó en 5 casos en L1, 2 en D12, 2 en D10, 2 en D9 y un caso en D7. De los 12 pacientes operados, 3 fueron embolizados previamente; dos permanecieron estables en su evolución y 10 mejoraron uno o más puntos del mRs. No hubo complicaciones en el postoperatorio. Todos mostraron mejoría del edema medular en resonancia magnética y la angiografía digital, luego de los 6 meses, fue negativa. El seguimiento promedio fue de 40 meses con un rango de 6 a 122 meses y ningún paciente presentó recidiva de la FDAVE. Conclusión: El tratamiento quirúrgico de las FDAVE es un método muy eficaz, de baja morbilidad y menor tasa de recurrencia comparado con el tratamiento endovascular.

Frontal Aslant Tract and Its Role in Language: A Journey Through Tractographies and Dissections.

BACKGROUND: The frontal aslant tract (FAT) is a bilateral tract located within each frontal lobe. It connects the supplementary motor area in the superior frontal gyrus with the pars opercularis in the inferior frontal gyrus. There is a new and broader conceptualization of this tract called the extended FAT (eFAT). The eFAT tract role is believed to be related to several brain functions, including verbal fluency as one of its main domains. METHODS: Tractographies were performed by using DSI Studio software on a template of 1065 healthy human brains. The tract was observed in a three-dimensional plane. The Laterality Index was calculated based on the length, volume, and diameter of fibers. A t test was performed to verify the statistical significance of global asymmetry. The results were compared with cadaveric dissections performed according to the Klingler technique. An illustrative case enlightens the neurosurgical application of this anatomic knowledge. RESULTS: The eFAT communicates the superior frontal gyrus with the Broca area (within the left hemisphere) or its contralateral homotopic area within the nondominant hemisphere. We measured the commisural fibers, traced cingulate, striatal, and insular connections and showed the existence of new frontal projections as part of the main structure. The tract did not show a significant asymmetry between the hemispheres. CONCLUSIONS: The tract was successfully reconstructed, focusing on its morphology and anatomic characteristics.

Posterior Fossa Calcifying Pseudoneoplasm of the Neuraxis (CAPNON): Presentation of Three Surgical Cases.

BACKGROUND: Calcifying pseudoneoplasm of the neuraxis (CAPNON) is an extremely rare entity with fewer than 150 cases reported in the literature and mostly with a supratentorial or spinal location. Posterior fossa CAPNON has been reported scarcely, and association with perilesional edema is a topic not yet approached which might play a significant role in treatment decision and clinical progression. Our objective is to report, to our knowledge, the first series of 3 posterior fossa CAPNON surgically treated in a single institution and assess features that help provide a systematic approach to diagnosis and timely treatment. METHODS: This was a monocentric, retrospective study of surgical patients diagnosed with a posterior fossa CAPNON in the last 5 years. A thorough bibliographic research was conducted. RESULTS: Three patients were included. Locations involved IV ventricle, right cerebellopontine angle with extension to foramen magnum, and cerebellar vermis. Two of them presented with symptoms linked to acute hydrocephalus, and the other one presented with progressive cranial nerve palsy and brainstem compression signs. The 3 of them showed radiological signs of perilesional edema on their preoperative magnetic resonance imaging. Gross total resection was accomplished in one case, with near and subtotal resections in the others. There were no complications. The outcome was favorable in all cases. CONCLUSIONS: It is essential to contemplate this infrequent diagnosis in cases of calcified lesions involving the posterior fossa. When symptoms manifest, surgery should be considered. Perilesional edema could be associated with symptomatic progression and hence a sign suggesting the need for surgical treatment.

Surgical Treatment of IV Ventricle Calcifying Pseudoneoplasm of the Neuraxis (CAPNON) Operative Nuances.

Calcifying pseudoneoplasm of the neuroaxis (CAPNON) is a rare, slow growing, and generally benign fibro osseous mass that can emerge throughout the entire central nervous system (CNS). When diagnosed, prompt surgical treatment can determine a good neurological outcome and possibly curative resolution. The objective of the present work is to present a step by step technical report with its video. We present a 37 year old female presented with occipital headache and cervical pain associated with dysphagia, nausea, and gait disturbances. Computed tomography (CT) scan showed a focal calcified lesion on the floor of the IV ventricle projecting toward the vermis with associated supratentorial hydrocephalus and transependymal edema. The telovelar approach was chosen for the procedure. The outcome was favorable, with no complications. Postoperative CT was performed, which revealed no residual lesion. A step by step report of a IV ventricle CAPNON that manifested with hydrocephalus is described.

Global Rostral Midbrain Syndrome (GRMS) and Corpus callosum infarction in the context of shunt overdrainage.

We report 3 cases of Global rostral midbrain syndrome (GRMS) and Corpus Callosum (CC) infarction, in the context of hydrocephalus followed by shunt dysfunction and slit ventricles. Prior shunt implantation had been indicated for adult-onset hydrocephalus secondary to aqueductal stenosis of varying causes. All three patients had been stable for months before developing repeated shunt dysfunctions, ultimately progressing to parkinsonism, Parinaud syndrome, akinetic mutism, pyramidal signs, cognitive impairment, CC infarction and slit ventricles, in the context of CSF overdrainage. Parkinsonism-related symptoms responded to dopa in all cases, but Parinaud syndrome and cognitive impairment persisted. Although GRMS has been described in the context of a transtentorial pressure gradient after shunt blockage, in these three cases with similar clinical presentation, reverse transtentorial pressure gradient and slit ventricles due to shunt overdrainage was the likely cause. The authors discuss the role of CC infarction and provide a detailed analysis after gathering previously described data, to unify information under a recognizable clinical entity and better understand the underlying pathophysiology, treatment options and outcome.

"Este caso me desorientó... " / "This case disoriented me..."

Paciente masculino de 66 años que se presentó al servi-cio de guardia y urgencias por cuadro clínico caracteriza-do por mareos de 3 meses de evolución e inestabilidad de la marcha de 24 hs de evolución. Como único signo positi-vo al examen físico se constató dismetría de miembros su-periores. Se decidió estudiar con TC de cerebro en donde se identificó, en topografía pineal y tercer ventrículo, una voluminosa lesión ocupante de espacio, sólida, de aproxi-madamente 27 x 21 mm de densidad heterogénea, con pro-bable relación a restos hemáticos en distintos estadios evo-lutivos asociada a calcificaciones periféricas