Background: The arcuate fasciculus (AF) is a critical white matter (WM) tract that connects key cortical language-processing regions, including the so-called Broca’s and Wernicke’s areas. The aim of the present study was to quantitatively assess its radiological–anatomical–morphometric modifications according to different brain tumor histotypes. Methods: A retrospective multicentric Italian study was conducted. AF reconstructions were calculated for both hemispheres for each patient diagnosed with glioblastoma (GBM), low-grade glioma (LGG), brain metastasis, and meningioma using Elements Fibertracking 2.0 software (Brainlab AG, Munich, Germany). A 3D object of each fascicle was evaluated for its volume, average fractional anisotropy (FA), and length. The cerebral healthy hemisphere was compared to the pathological contralateral in different tumor histotypes. Results: In total, 1294 patients were evaluated. A total of 156 met the inclusion criteria. We found a significant difference between healthy hemisphere and the contralateral for AF mean length and volume (p = 0.01 and p < 0.001, respectively). Considering separately the different tumor histotypes, the GBM subgroup (98, 63%) confirmed the results for mean FA and volume (p-value < 0.001); LGG patients (26, 17%) showed no significant difference between healthy and pathological hemisphere for AF mean length, mean FA, and volume (p-value 0.5, p-value 0.3, p-value <0.1, respectively). In patients affected by brain metastasis (18, 12%), Student’s t-test showed a significant difference for FA (p-value 0.003). No differences were found in patients affected by meningiomas (14, 9%) (14). Conclusions: Thorough knowledge of the microscopic anatomy and function of the arcuate fasciculus, as well as the pattern of growth of the different brain tumor histotypes, along with a careful preoperative neuroradiological assessment are mandatory to plan a tailored surgical strategy and perform a safe and effective surgical technique. The AF could be displaced and infiltrated/destructed by the solid component and peritumoral edema, respectively, of GBM. LGG shows a prevalent infiltrative pattern. Metastases account for AF dislocation due to peritumoral edema. Meningiomas do not affect WM anatomy.

A comprehensive understanding of white matter anatomy is essential for neurosurgical education and surgical planning. Traditional educational tools, including cadaveric dissection, 2-dimensional atlases, and histological preparations, while valuable, have inherent limitations in representing the spatial complexity of white matter architecture. Although microsurgical dissection remains the gold standard, no study to date has specifically evaluated the use of 3-dimensional (3D)-printed simulators focused on white matter tract anatomy as a preparatory learning tool. The study involved 17 residents in different years of the neurosurgery residency at Università Cattolica del Sacro Cuore through a structured training program including theoretical sessions, practical dissections using the simulator, and pretraining and post-training assessments. Quantitative improvements were analyzed by comparing knowledge and clinical reasoning scores before and after training. The simulator was perceived as highly realistic and educationally valuable: 81% of participants rated its anatomical accuracy as high or very high. Residents demonstrated significant improvements in clinical reasoning (P = 0.002) and overall test performance (P = 0.005) after training. Specific gains included improved identification of critical white matter tracts at risk during common surgical approaches, enhanced selection of safer trajectories, and better anticipation of intraoperative mapping strategies. The simulator was consistently described as user-friendly and effective in integrating 3D spatial anatomy into surgical decision-making. This study highlights the utility of 3D-printed simulators in neurosurgical training, offering an accessible platform for learning white matter anatomy. While not a replacement for cadaveric dissections, these simulators provide a complementary tool for early-stage education, bridging the gap between theoretical knowledge and practical application.

BACKGROUND: Sympathetic hyperactivation is a rare but potentially severe form of autonomic dysregulation. It is typically associated with traumatic brain injury or acute intracranial pathology. Its occurrence following endoscopic third ventriculostomy (ETV) is exceptionally uncommon, and reports in adult patients are lacking. Understanding this complication is important because of the close anatomical relationship between the third ventricular floor and hypothalamic autonomic centers. OBSERVATIONS: A 57-year-old patient with long-standing overt ventriculomegaly in adults underwent an uncomplicated ETV. Immediately on emergence from anesthesia, the patient developed abrupt autonomic instability, including severe tachycardia, hypertension, tachypnea, tremors, diaphoresis, and hyperthermia, despite a normal neurological examination. This complication required deep sedation with high-dose propofol, followed by dexmedetomidine infusion. Complete resolution occurred within 48 hours, with no further autonomic disturbances. LESSONS: This case shows that acute sympathetic hyperactivation may occur after ETV, likely due to transient disturbance of hypothalamic or periventricular autonomic pathways or rapid changes in CSF dynamics. Although rare, this entity should be considered among the causes of postoperative hemodynamic instability after third ventricular procedures. Early recognition and targeted supportive management are essential to avoid potentially life-threatening cardiovascular and metabolic consequences. https://thejns.org/doi/10.3171/CASE25935

"Letter to the Editor. Mapping and monitoring: considerations on optimizing neurophysiological monitoring parameters" published on 06 Dec 2024 by American Association of Neurological Surgeons.