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Background: Performing transopercular frontal approaches to the insula, widely used in glioma surgeries, necessitates a meticulous understanding of both cortical and subcortical neuroanatomy. This precision is vital for preserving essential structures and accurately interpreting the results of direct electrical stimulation. Nevertheless, acquiring a compelling mental image of the anatomy of this region can be challenging due to several factors, among which stand out its complexity and the fact that white matter fasciculi are imperceptible to the naked eye in the living brain. Aim: In an effort to optimize the study of the anatomy relevant to this topic, we performed a procedure-guided laboratory study using subpial dissection, fiber dissection, vascular coloration, and stereoscopic photography in a "real-life" surgical perspective. Methods: Nine cerebral specimens obtained from body donation were extracted and fixed in formalin. Colored silicone injection and a variant of Klinglers's technique were used to demonstrate vascular and white matter structures, respectively. We dissected and photographed the specimens in a supero-antero-lateral view to reproduce the surgeon's viewpoint. The anatomy related to the development of the surgical corridor and resection cavity was documented using both standard photography and the red-cyan anaglyph technique. Results: The anatomy of frontal transopercular approaches to the insula involved elements of different natures—leptomeningeal, cortical, vascular, and fascicular—combining in the surgical field in a complex disposition. The disposition of these structures was successfully demonstrated through the aforementioned anatomical techniques. Among the main structures in or around the surgical corridor, the orbital, triangular, and opercular portions of the inferior frontal gyrus are critical landmarks in the cortical stage, as well as the leptomeninges of the Sylvian fissure and the M2–M4 branches of the middle cerebral artery in the subpial dissection stage, and the inferior fronto-occipital, uncinate and arcuate fasciculi, and the corona radiata in establishing the deep limits of resection. Conclusions: Procedure-guided study of cerebral hemispheres associating subpial, vascular, and fiber dissection from a surgical standpoint is a powerful tool for the realistic study of the surgical anatomy relevant to frontal transopercular approaches to the insula. [ABSTRACT FROM AUTHOR]

Advances in the techniques for assessing human cerebral white matter have recently contributed to greater attention to structural connectivity. Yet, little is known about the vascularization of most white matter fasciculi and the fascicular composition of the vascular territories. This paper presents an original method to label the arterial supply of macroscopic white matter fasciculi based on a standardized protocol for post-mortem injection of colored material into main cerebral arteries combined with a novel fiber dissection technique. Twelve whole human cerebral hemispheres obtained post-mortem were included. A detailed description of every step, from obtaining the specimen to image acquisition of its dissection, is provided. Injection and dissection were reproducible and manageable without any sophisticated equipment. They successfully showed the arterial supply of the dissected fasciculi. In addition, we discuss the challenges we faced and overcame during the development of the presented method, highlight its originality. Henceforth, this innovative method serves as a tool to provide a precise anatomical description of the vascularization of the main white matter tracts. [ABSTRACT FROM AUTHOR]

Purpose: In the present study, we performed biometric characterization of the temporomandibular joints (TMJs) of clinically normal subjects. Methods: Fifty-one healthy volunteers underwent high-resolution computerized tomography examination of the TMJs in the position of maximal intercuspidation according to a standardized protocol. Frontal and sagittal reconstructions were then performed to obtain measurements and indexes in three planes of space. Results: Correlations are observed with age, gender, amplitude of mouth opening and presence of dental abrasion. The lateral stability index reflects the degree of mobility of the temporo-discal compartment of the joint. The coverage index reflects how much the mandibular condyle is inserted into the articular fossa and may be related to the risk of occurrence and severity of regressive remodeling phenomena. Conclusions: This study supports the interest in examining morphological aspects of the TMJ and performing intra-articular measurements. The biometric examination of the TMJ has important applications in the domain of TMJ pathology. [ABSTRACT FROM AUTHOR]

The anatomy and functional role of the inferior fronto-occipital fascicle (IFOF) remain poorly known. We accurately analyze its course and the anatomical distribution of its frontal terminations. We propose a classification of the IFOF in different subcomponents. Ten hemispheres (5 left, 5 right) were dissected with Klingler's technique. In addition to the IFOF dissection, we performed a 4-T diffusion tensor imaging study on a single healthy subject. We identified two layers of IFOF. The first one is superficial and antero-superiorly directed, terminating in the inferior frontal gyrus. The second is deeper and consists of three portions: posterior, middle and anterior. The posterior component terminates in the middle frontal gyrus (MFG) and dorso-lateral prefrontal cortex. The middle component terminates in the MFG and lateral orbito-frontal cortex. The anterior one is directed to the orbito-frontal cortex and frontal pole. In vivo tractography study confirmed these anatomical findings. We suggest that the distribution of IFOF fibers within the frontal lobe corresponds to a fine functional segmentation. IFOF can be considered as a 'multi-function' bundle, with each anatomical subcomponent subserving different brain processing. The superficial layer and the posterior component of the deep layer, which connects the occipital extrastriate, temporo-basal and inferior frontal cortices, might subserve semantic processing. The middle component of the deep layer could play a role in a multimodal sensory-motor integration. Finally, the anterior component of the deep layer might be involved in emotional and behavioral aspects. [ABSTRACT FROM AUTHOR]

Awake surgery with intraoperative brain mapping is highly recommended for patients with diffuse low-grade gliomas in language areas, to maximise the extent of resection while preserving the integrity of functional networks and thus quality of life. The picture-naming test 'DO.80' is the gold standard for language assessment before, during, and after surgery. Cognitive functioning is correlated with quality of life, itself linked with return to work. Our objective was to evaluate the significance of measuring naming speed, and its correlation with the return to professional activities. Two complementary studies are reported. In the first retrospective study, eleven patients were examined post-operatively. Five patients were selected because they were not able to resume their professional activities ('no return group 1'). They were compared with a control group of six patients who are working normally after surgery ('return group 1'). The eleven patients performed a global language and neuropsychological assessment, with a post-operative median follow-up of 35 months. In a subsequent prospective study, twelve patients were examined pre-operatively and post-operatively. Six patients who were not able to return to work ('no return group 2') were compared with a control group of six patients who were working normally after the surgery ('return group 2'). The twelve patients performed a pre and post-operative language assessment, with a median follow-up of 9 months. Our results show, for the first time, that naming speed is significantly correlated with a major criterion of quality of life: the return to professional activities. There were no differences between the two groups regarding other measures of cognition. Assessing naming times, and not only naming accuracy, is essential in the management of low-grade glioma patients, before, during, and after surgery, to preserve their quality of life by resuming their previous professional activity. Our results have fundamental implications concerning the comprehension of language processing and its relationship with cognitive functioning. [ABSTRACT FROM AUTHOR]

Diffuse WHO grade II (GIIG) may be unresectable when involving critical structures. To assess the feasibility and functional tolerance (cognition and quality of life) of an original therapeutic strategy combining neoadjuvant chemotherapy followed by surgical resection for initially inoperable GIIG. Ten patients underwent Temozolomide for unresectable GIIG, as initial treatment or at recurrence after previous partial resection, due to invasion of eloquent areas or bi-hemispheric diffusion preventing a total/subtotal removal. Functional outcome after both treatments was assessed, with evaluation of seven cognitive domains. Chemotherapy induced tumor shrinkage (median volume decrease 38.9%) in ipsilateral functional areas in six patients and in the contralateral hemisphere in four. Only four patients had a 1p19q codeletion. The tumor shrinkage made possible the resection (mean extent of resection 93.3%, 9 total or subtotal removals) of initially inoperable tumors. Postoperatively, three patients had no deficits, while verbal episodic memory and executive functions were slightly impaired in seven patients. However, global quality of life was roughly preserved on the EORTC QLQ C30 + BN 20 (median score: 66.7%). Role functioning score was relatively reduced (median score: 66.7%) whereas KPS was preserved (median score: 90, range 80-100). Seven patients became seizure-free while three improved. This combined treatment is feasible, efficient (surgery made possible by neoadjuvant chemotherapy) and well-tolerated (preservation of quality of life, no serious cognitive disturbances). Cognitive deficits seem mostly related to tumor location. Because KPS is not reliable enough, a detailed neuropsychological assessment should be systematically performed in GIIG. [ABSTRACT FROM AUTHOR]

Recent diffusion tensor imaging (DTI) tractography studies indicate that the supramarginal gyrus (SMG) represents a relay between frontal and temporal language sites. Some authors postulate that pathways connecting SMG to the posterior temporal lobe, i.e., the posterior part of the superior longitudinal fascicle (SLF) subserve semantic aspects of language. However, DTI provides only anatomic but not functional data. Therefore, it is impossible to conclude. Interestingly, intra-operative electrical mapping of cortical and subcortical language structures during tumor surgery is recognized as a reliable technique in functional neuroanatomy research. We mapped the underlying white matter of the SMG, especially the SLF, in 11 patients who underwent awake surgery for a glioma involving the left inferior parietal lobule. Using direct electrostimulation, we investigated the exact role of the SLF in language. Our findings indicate that the white matter under the inferior parietal lobule is highly involved in the dorsal phonological system. First, the SMG, connected to the ventral premotor cortex by horizontal fibers of the SLF, subserves articulatory processing, as demonstrated by dysarthria elicited by stimulation. Second, long arcuate fibers, found deeper in the white matter, subserve phonological processing, as supported by phonemic paraphasia induced by electrostimulation. Third, the most important result is that no semantic disturbances were elicited by stimulating the SLF, including its posterior part. Furthermore, no semantic disorders occurred postoperatively. Subcortical brain mapping by direct electrical stimulation does not provide arguments for a possible role of the left SLF in language semantic processing. [ABSTRACT FROM AUTHOR]

Introduction: Chronically shunted patients are believed to be unable to have a shunt-free life. Nevertheless, sometimes shunt removal is possible after an endoscopic third ventriculostomy, even after long periods of cerebral spinal fluid diversion. Results and discussion: We perform a literature review that leads to a discussion of this subject in the light of the current medical knowledge. [ABSTRACT FROM AUTHOR]

Glioblastoma Multiforme (GBM) invasiveness renders complete surgical resection impossible and highly invasive Glioblastoma Initiating Cells (GICs) are responsible for tumour recurrence. Their dissemination occurs along pre-existing fibrillary brain structures comprising the aligned myelinated fibres of the corpus callosum (CC) and the laminin (LN)-rich basal lamina of blood vessels. The extracellular matrix (ECM) of these environments regulates GIC migration, but the underlying mechanisms remain largely unknown. In order to recapitulate the composition and the topographic properties of the cerebral ECM in the migration of GICs, we have set up a new aligned polyacrylonitrile (PAN)-derived nanofiber (NF) scaffold. This system is suitable for drug screening as well as discrimination of the migration potential of different glioblastoma stem cells. Functionalisation with LN increases the spatial anisotropy of migration and modulates its mode from collective to single cell migration. Mechanistically, equally similar to what has been observed for mesenchymal migration of GBM in vivo, is the upregulation of galectin-3 and integrin-β1 in Gli4 cells migrating on our NF scaffold. Downregulation of Calpain-2 in GICs migrating in vivo along the CC and in vitro on LN-coated NF underlines a difference in the turnover of focal adhesion (FA) molecules between single-cell and collective types of migration. [ABSTRACT FROM AUTHOR]