A history of Colombian neurosurgery: events, persons, and outcomes that have shaped the specialty in the country.

The history of Colombian neurosurgery is a collective legacy of neurosurgeon-scientists, scholars, teachers, innovators, and researchers. Anchored in the country's foundational values of self-determination and adaptability, these pioneers emerged from the Spanish colonial medical tradition and forged surgical alliances abroad. From the time of Colombian independence until the end of World War I, exchanges with the French medical tradition produced an emphasis on anatomical and systematic approaches to the emerging field of neurosurgery. The onset of American neurosurgical expertise in the 1930s led to a new period of exchange, wherein technological innovations were added to the Colombian neurosurgical repertoire. This diversity of influences culminated in the 1950s with the establishment of Colombia's first in-country neurosurgery residency program. A select group of avant-garde neurosurgeons from this period expanded the domestic opportunities for patients and practitioners alike. Today, the system counts 10 recognized neurosurgery residency programs and over 500 neurosurgeons within Colombia. Although the successes of specific individuals and innovations were considered, the primary purpose of this historical survey was to glean relevant lessons from the past that can inform present challenges, inspire new opportunities, and identify professional and societal goals for the future of neurosurgical practice and specialization.

Resección Tubular Microquirúrgica de un Subependimoma Extenso del Ventrículo Lateral Izquierdo: Video Operatorio en 2D / Microsurgical Tubular Resection of an Extensive Subependymoma of the Left Lateral Ventricle: Operative Video in 2D

Introducción: Los subependimomas intracraneales son raros, representan el 0.2-0.7% de todos los tumores del sistema nervioso central1,2 y se originan en los ventrículos laterales en el 30-40% de los casos.3 Los síntomas usualmente se asocian a hipertensión endocraneana secundaria a hidrocefalia obstructiva.4 La resección completa del tumor es curativa en esta patología.5 El abordaje trans-surcal es seguro para lesiones ventriculares profundas y el uso de los retractores tubulares minimizan la retracción del parénquima cerebral evitando la compresión directa con valvas. Esto permite disminuir la presión del tejido cerebral que puede ocluir los vasos y producir isquemia local generando una lesión neurológica permanente. Descripción del caso: Se presenta el caso de una paciente de 66 años, diestra, con cefalea crónica que aumenta en frecuencia en el último mes. La resonancia cerebral contrastada muestra un tumor extenso en el ventrículo lateral izquierdo con signos de hidrocefalia obstructiva. Intervención: Se coloca la paciente en posición supina. Se hace una incisión bicoronal y se hace un abordaje trans-surcal F1/F2 izquierdo. Se coloca un retractor tubular guiado con el puntero de neuronavegación, introduciéndolo directamente en el parénquima cerebral y fijándolo al soporte de Leyla. Se colocó un catéter de ventriculostomía contralateral y se retira a las 48 horas sin complicaciones asociadas. La resonancia contrastada postoperatoria demuestra una resección completa del tumor. El análisis de patología reveló un subependimoma grado I de la clasificación de la Organización Mundial de la Salud. La paciente presentó transitoriamente apatía y pérdida del control del esfínter urinario que resolvieron completamente a las 3 semanas después de la cirugía. Se firmó un consentimiento firmado para la publicación de la información utilizada en este trabajo. Conclusión: La resección completa microscópica de un subependimoma extenso del ventrículo lateral izquierdo es factible a través de un abordaje tubular transulcal.

Introduction: Intracranial subependymomas are rare, representing only 0.2-0.7% of all central nervous system tumors1,2 and arise in the lateral ventricles in 30-40% of the cases.3 Symptoms depend on tumor location and usually arise when the cerebrospinal fluid (CSF) is blocked, generating a consequent intracranial hypertension.4 Microsurgical gross-total resection is possible and curative for these tumors.5 The transcortical/trans-sulcal approach is a safe approach for the access of deep-seated intraventricular lesions. The use of tubular retractor systems minimizes retraction injury when passing through the cortex and deep white matter tracts. This allows a decrease in the pressure on brain tissue that can occlude the brain vessels and produce local ischemia and a consequent permanent neurological injury. Case description: This is a case of a 66-year-old woman who presented chronic headaches that increased in frequency in the last month. Enhanced-brain MRI demonstrated a large left ventricular lesion with signs of obstructive hydrocephalus. Procedure: Patient was positioned supine. A bicoronal incision was used to perform a left frontal craniotomy. An F1/F2 transcortical/trans-sulcal approach was used. A guided tubular retractor is placed with the neuronavigation pointer, inserting it directly into the brain parenchyma and fixing it to the Leyla support. Postoperative postcontrast MRI demonstrated a complete resection of the tumor. Histopathological analysis revealed a subependymoma (World Health Organization Grade I). The patient presented transient apathy and loss of urinary sphincter control that completely resolved 3 weeks after surgery. Written informed consent was obtained for publication of information used for this work. Conclusions: A complete microsurgical resection of a large left ventricular subependymoma is feasible through a trans-sulcal tubular approach.

Neuroanatomía funcional de la escala de coma de Glasgow / Functional neuroanatomy of the Glasgow coma scale

Introducción: La escala de coma de Glasgow (ECG) es una escala mundialmente reconocida para la clasificación de pacientes con trauma craneoencefálico de acuerdo a su compromiso neurológico. Esta escala evalúa la apertura ocular, la respuesta verbal y la respuesta motora. La neuroanatomía funcional representa un compromiso secuencial para el descenso en el puntaje de cada uno de estos ítems. El objetivo de esta revisión es describir la anatomía del sistema reticular activador ascendente (SRAA), la anatomía funcional del lenguaje, la anatomía del tallo cerebral y de las vías motoras que representan cada ítem evaluado por la ECG. Materiales y métodos: Se hizo una revisión narrativa bibliográfica de las principales vías para cada ítem de la ECG. Resultados: Las principales vías en relación con la apertura ocular se concentran en las vías del SRAA, las vías de la respuesta verbal incluyen las vías del lenguaje y las vías que provienen del putamen y del cerebelo que regulan la emisión del lenguaje, mientras que las vías que regulan la respuesta motora principalmente se relacionan con la vía piramidal, el sistema rubro-espinal y vestíbulo-espinal. Conclusiones: El descenso del puntaje en los tres ítems que evalúa la ECG se relacionan con vías específicas que predominan en los ganglios basales y en el tallo cerebral.

Introduction: The Glasgow Coma Scale (GCS) is a globally recognized scale for the classification of patients with traumatic brain injury according to their neurological impairment. This scale evaluates the ocular opening, the verbal response and the motor response. Functional neuroanatomy represents a sequential decrease in the score of each of these items. The objective of this review is to describe the anatomy of the ascending reticular activating system (ARAS), the functional anatomy of the language, and the anatomy of the brainstem and the motor pathways that represent each item evaluated by the GCS. Materials and methods: A narrative literature review of the main routes for each item of the scale was performed. Results: The main pathways in relation to the ocular opening are concentrated in the ARAS, the verbal response pathways include the language pathways and the connections that come from the putamen and the cerebellum that regulate the production of the language, while the pathways that regulate the motor response mainly relate to the pyramidal tract, the rubro-spinal and vestibulo-spinal systems. Conclusions: The decline of the score in the three items that evaluates the GCS is related to specific pathways that predominate in the basal ganglia and in the brainstem.

Identification of Preoperative Language Tracts for Intrinsic Frontotemporal Diseases: A Pilot Reconstruction Algorithm in a Middle-Income Country.

OBJECTIVE: Diffusion tensor imaging (DTI) tractography provides useful information that can be used to optimize surgical planning and help avoid injury during subcortical dissection of eloquent tracts. The objective is to provide a safe, timely, and affordable algorithm for preoperative DTI language reconstruction for intrinsic frontotemporal diseases. METHODS: We reviewed a prospectively acquired database of preoperative DTI reconstruction for resection of left frontotemporal lesions over 3 years at Hospital de San José and Hospital Infantil Universitario San José, Fundación Universitaria de Ciencias de la Salud, Bogota, Colombia. Preoperative and postoperative clinical and radiographic features were determined from retrospective chart review. A comprehensive review of the structural and functional anatomy of the language tracts was performed. Separate reconstruction of both ventral (semantic) and dorsal (phonologic) stream pathways is described: arcuate fasciculus, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, and inferior longitudinal fasciculus. RESULTS: Between January 2015 and January 2018, 44 tumor cases were found to be resected with preoperative fiber tracking planning and neuronavigation-guided surgery. Ten patients (7 women, 3 men) aged 28-65 years underwent resection of an intrinsic frontotemporal lesion with preoperative DTI tractography reconstruction of language tracts. Eight cases (80%) were high-grade gliomas and 2 (20%) were cavernous malformations. In 5 cases (50%), the lesion was in the frontal lobe and in 5 (50%), it was in the temporal lobe. The extent of resection was classified as gross total resection (100%), subtotal resection (>90%), or partial resection (<90%). Gross total resection was achieved in 5 cases (50%), subtotal resection was achieved in 4 cases (40%), and partial resection in the remaining case (10%). Compromised tracts included superior longitudinal fasciculus in 7 (70%), inferior longitudinal fasciculus in 4 (40%), the arcuate fasciculus in 3 (30%), and uncinate fasciculus in 1 (10%). Language function was unchanged or improved in 90% of patients. New-onset postoperative language decline occurred in 1 patient, who recovered transient phonemic paraphasias 1 month after resection. The mean follow-up time was 7 months (range, 4-12 months). Residual tumors were treated with radiation and/or with chemotherapy as indicated in an outpatient setting. CONCLUSIONS: We present a safe and efficacious preoperative DTI language reconstruction algorithm that could be used as a feasible treatment strategy in a challenging subset of tumors in low- to middle-income countries.

Recovery of consciousness after a brainstem cavernous malformation hemorrhage: A descriptive study of preserved reticular activating system with tractography.

The aim of this study is to describe the imaging features, the relevant anatomy, and the fractional anisotropy (FA) values in diffusion tensor tractography (DTT) of the ascending reticular activating system (ARAS) fiber tracts in 2 patients who recovered from initial altered consciousness after presenting with a brainstem cavernous malformation (BSCM) hemorrhage. A DTT was performed in 2 patients with impaired consciousness after a brainstem cavernous malformation hemorrhage. A 1.5 T scanner was used to obtain the axial tensors. Post-processing was performed and the mean FA values were recorded. The FA maps were used to seed the following regions of interest: the ventromedial midbrain, the anterior thalamus bilaterally, and the hypothalamus bilaterally. The first case presented with posterior displacement of the dorsal raphè fiber tracts, with preservation of all the ascending reticular activating fiber tracts and spontaneous recovery of consciousness after 20 days. The second case presented with no destruction but also had posterior displacement of the inferior dorsal raphè fiber tracts, with recovery of consciousness 1 month after resection surgery. Described in this study are affected fibers of the ARAS, as well as the FA value abnormalities in 2 patients, with recovery of a transient disorder of consciousness after a BSCM hemorrhage.

Reconstruction of the Ascending Reticular Activating System with Diffusion Tensor Tractography in Patients with a Disorder of Consciousness after Traumatic Brain Injury.

This work describes the reconstruction of the ascending reticular activating system (ARAS) with diffusion tensor tractography in three patients with altered consciousness after traumatic brain injury. A diffusion tensor tractography was performed in three patients with impaired consciousness after a severe traumatic brain injury. A 1.5 T scanner was used to obtain the tensor sequences; axial tensors were acquired. Post-processing was performed, and the mean fractional anisotropy (FA) values were recorded. The FA maps were used to do a manual tracing of the following regions of interest (ROIs): the ventromedial midbrain, the anterior thalamus, and the hypothalamus. Case 1 presented destruction of the right dorsal and ventral tegmental tracts as well as destruction of the right middle forebrain bundle, case 2 had destruction of the right dorsal tegmental tract, and case 3 had destruction of the bilateral ventral and dorsal tegmental tracts, as well as destruction of the right middle forebrain bundle. The affected fibers of the ascending reticular activating system with diffuse axonal injury and the FA values abnormalities in the ascending reticular activating system in three patients with a disorder of consciousness (DOC) after traumatic brain injury are described.

Embriología del sistema ventricular cerebral / Cerebral ventricular system embryology

El Sistema Ventricular Cerebral se desarrolla de forma paralela al resto del Sistema Nervioso Central, facilitando la circulación del Líquido Cefalorraquídeo, desde su separación del líquido amniótico a nivel embrionario. Este desarrollo es necesario para entender correctamente la anatomía ventricular y facilitar el abordaje para patologías intraventriculares. El objetivo de esta revisión es reconocer los puntos más importantes en la embriología ventricular para facilitar el aprendizaje de la anatomía quirúrgica ventricular.

The cerebral ventricular system is developed in parallel with the rest of the central nervous system, facilitating the circulation of cerebrospinal fluid, from the amniotic fluid separation in the embryonic phases. This development is necessary to correctly understand the ventricular anatomy and facilitate approach to intraventricular pathologies. The objective of this review is to recognize the most important points in the ventricular embryology and in the intraventricular endoscopic vision to facilitate learning of the ventricular surgical anatomy.