Standardization of Strategies to Perform a Parafascicular Tubular Approach for the Resection of Brain Tumors in Eloquent Areas.

OBJECTIVE: The aim of this work is to define a methodological strategy for the minimally invasive tubular retractor (MITR) parafascicular transulcal approach (PTA) for the management of brain tumors sited in eloquent areas. METHODS: An observational prospective study was designed to evaluate the benefits of PTA associated with MITRs, tractography and intraoperative cortical stimulation. They study was conducted from June 2018 to June 2021. Information regarding white matter tracts was processed, preventing a potential damage during the approach and/or resection. All patients older than 18 years who had a single brain tumor lesion were included in the study. Patients with a preoperative Karnofsky Performance Scale (KPS) score greater than 70% and a Glasgow Coma Scale (GCS) score > 14 points were included. RESULTS: 72 patients were included in the study, the mean age was 49.6, the most affected gender was male, 12.5% presented aphasia, 11.1% presented paraphasia, 41.6% had motor deficit, 9.7% had an affection in the optic pathway, the most frequently affected region was the frontal lobe (26.3%), the most frequent lesions were high-grade gliomas (34.7%) and the measurement of the incisions was on average 5.58 cm. Of the patients, 94.4% underwent a total macroscopic resection and 90.2% did not present new postoperative neurological deficits. In all cases, a PTA was used. CONCLUSION: Tubular minimally invasive approaches (MIAs) allow one to perform maximal safe resection of brain tumors in eloquent areas, through small surgical corridors. Future comparative studies between traditional and minimally invasive techniques are required to further investigate the potential of these surgical nuances.

Anatomic variations of the floor of the third ventricle: Surgical implications for endoscopic third ventriculostomy.

Background: Endoscopic third ventriculostomy (ETV) is currently used as a treatment for different types of hydrocephalus. However, the anatomical endoscopic variants of the third ventricle floor (3VF), as well as their surgical implications, have been underrated. The anatomic variations of the 3VF can influence the technique and the success rate of the ETV. The purpose of this article is to describe the anatomical variations of 3VF, assess their incidence, and discuss the implications for ETV. Methods: Intraoperative videos of 216 patients who underwent ETV between January 2012 and February 2020 at Hospital Infantil Universitario de San José, Bogotá, Colombia were reviewed. One hundred and eighty patients who met the criteria to demonstrate the type of 3VF were selected. Results: 3VF types were classified as follows: (1) Thinned, (2) thickened, (3) partially erased, (4) globular or herniated, and (5) narrowed. Conclusion: Knowledge of anatomical variations of the 3VF is paramount for ETV and it influences the success rate of the procedure.

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.

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.

Microvascular Decompression for a Patient with a Glossopharyngeal Neuralgia: A Technical Note.

The glossopharyngeal neuralgia (GPN) constitutes approximately 0.2-1.3% of all facial pain syndromes. The GPN is a syndrome of neuropathic pain characterized by paroxysmal pain episodes localized in the posterior tongue, tonsil, throat, or external ear canal. The first-line treatment is pharmacological. Patients who are refractory to medical therapy can be treated surgically with microvascular decompression (MVD) or sectioning the IX nerve and the upper rootlets of the X nerve. We aim to describe the technical nuances of MVD of the IX cranial nerve with a targeted inferior mini-craniotomy in a patient with a neurovascular compression.

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.