Unveiling the neuroplastic capacity of the bilingual brain: insights from healthy and pathological individuals.

Research on the neural imprint of dual-language experience, crucial for understanding how the brain processes dominant and non-dominant languages, remains inconclusive. Conflicting evidence suggests either similarity or distinction in neural processing, with implications for bilingual patients with brain tumors. Preserving dual-language functions after surgery requires considering pre-diagnosis neuroplastic changes.

A novel cognitive neurosurgery approach for supramaximal resection of non-dominant precuneal gliomas: a case report.

Despite mounting evidence pointing to the contrary, classical neurosurgery presumes many cerebral regions are non-eloquent, and therefore, their excision is possible and safe. This is the case of the precuneus and posterior cingulate, two interacting hubs engaged during various cognitive functions, including reflective self-awareness; visuospatial and sensorimotor processing; and processing social cues. This inseparable duo ensures the cortico-subcortical connectivity that underlies these processes.

"Neural dynamics supporting longitudinal plasticity of action naming across languages: MEG evidence from bilingual brain tumor patients".

Previous evidence suggests that distinct ventral and dorsal streams respectively underpin the semantic processing of object and action knowledge. Recently, we found that brain tumor patients with dorsal gliomas in frontoparietal hubs show a selective longitudinal compensation (post-vs. pre-surgery) during the retrieval of lexico-semantic information about actions (but not objects), indexed by power increases in beta rhythms (13-28 Hz).

What Can Glioma Patients Teach Us about Language (Re)Organization in the Bilingual Brain: Evidence from fMRI and MEG.

Recent evidence suggests that the presence of brain tumors (e.g., low-grade gliomas) triggers language reorganization.

Oscillatory and structural signatures of language plasticity in brain tumor patients: A longitudinal study.

Recent evidence suggests that damage to the language network triggers its functional reorganization. Yet, the spectro-temporal fingerprints of this plastic rearrangement and its relation to anatomical changes is less well understood. Here, we combined magnetoencephalographic recordings with a proxy measure of white matter to investigate oscillatory activity supporting language plasticity and its relation to structural reshaping.

A Practical Approach to Imaging of the Supplementary Motor Area and Its Subcortical Connections.

Purpose Of Review: First, an anatomical and functional review of these cortical areas and subcortical connections with T-fMRI and tractography techniques; second, to demonstrate the value of this approach in neurosurgical planning in a series of patients with tumors close to the SMA.

Recent Findings: Implications in language and cognitive networks with a clear hemispheric lateralization of these SMA/pre-SMA. The recommendation of the use of the advanced neuroimaging studies for surgical planning and preservation of these areas.

MULTIMAP: Multilingual picture naming test for mapping eloquent areas during awake surgeries.

Picture naming tasks are currently the gold standard for identifying and preserving language-related areas during awake brain surgery. With multilingual populations increasing worldwide, patients frequently need to be tested in more than one language. There is still no reliable testing instrument, as the available batteries have been developed for specific languages.

Spatiotemporal dynamics of postoperative functional plasticity in patients with brain tumors in language areas.

Postoperative functional neuroimaging provides a unique opportunity to investigate the neural mechanisms that facilitate language network reorganization. Previous studies in patients with low grade gliomas (LGGs) in language areas suggest that postoperative recovery is likely due to functional neuroplasticity in peritumoral and contra-tumoral healthy regions, but have attributed varying degrees of importance to specific regions. In this study, we used Magnetoencephalography (MEG) to investigate functional connectivity changes in peritumoral and contra-tumoral regions after brain tumor resection.

Surgical resection of cavernous angioma located within eloquent brain areas: International survey of the practical management among 19 specialized centers.

Purpose: The practical management of cavernous angioma located within eloquent brain area before, during and after surgical resection is poorly documented. We assessed the practical pre-operative, intra-operative, and post-operative management of cavernous angioma located within eloquent brain area.

Method: An online survey composed of 61 items was sent to 26 centers to establish a multicenter international retrospective cohort of adult patients who underwent a surgical resection as the first-line treatment of a supratentorial cavernous angioma located within or close to eloquent brain area.

Predictors of Epileptic Seizures and Ability to Work in Supratentorial Cavernous Angioma Located Within Eloquent Brain Areas.

Background: The postoperative outcomes and the predictors of seizure control are poorly studied for supratentorial cavernous angiomas (CA) within or close to the eloquent brain area.

Objective: To assess the predictors of preoperative seizure control, postoperative seizure control, and postoperative ability to work, and the safety of the surgery.

Methods: Multicenter international retrospective cohort analysis of adult patients benefitting from a functional-based surgical resection with intraoperative functional brain mapping for a supratentorial CA within or close to eloquent brain areas.

Survey on current practice within the European Low-Grade Glioma Network: where do we stand and what is the next step?

Diffuse low-grade glioma form a rare entity affecting young people. Despite advances in surgery, chemotherapy, and radiation therapy, diffuse low-grade glioma are still incurable. According to current guidelines, maximum safe resection, when feasible, is the first line of treatment.

Brain tumors in eloquent areas: A European multicenter survey of intraoperative mapping techniques, intraoperative seizures occurrence, and antiepileptic drug prophylaxis.

Intraoperative mapping and monitoring techniques for eloquent area tumors are routinely used world wide. Very few data are available regarding mapping and monitoring methods and preferences, intraoperative seizures occurrence and perioperative antiepileptic drug management. A questionnaire was sent to 20 European centers with experience in intraoperative mapping or neurophysiological monitoring for the treatment of eloquent area tumors.

Double dissociation between visual recognition and picture naming: a study of the visual language connectivity using tractography and brain stimulation.

Background: Study of the corticosubcortical functional anatomy of reading and picture naming.

Objective: To study the role of the left basal occipitotemporal area and its white matter pathways.

Methods: Three patients underwent awake surgery for lesions in the left basal posterotemporal region with intraoperative electrostimulations.

Impact of intraoperative stimulation brain mapping on glioma surgery outcome: a meta-analysis.

Purpose: Surgery for infiltrative gliomas aims to balance tumor removal with preservation of functional integrity. The usefulness of intraoperative stimulation mapping (ISM) has not been addressed in randomized trials. This study addresses glioma surgery outcome on the basis of a meta-analysis of observational studies.

New insights into the anatomic dissection of the temporal stem with special emphasis on the inferior fronto-occipital fasciculus: implications in surgical approach to left mesiotemporal and temporoinsular structures.

Objective: To analyze the 3-dimensional relationships of the inferior fronto-occipital fasciculus (IFOF) within the temporal stem using anatomic dissection and to study the surgical application.

Methods: Ten postmortem human hemispheres (5 right, 5 left) were dissected using the Klingler fiber dissection technique. The 3-dimensional relationships of the IFOF with different landmarks of the temporal stem, insula, and temporal lobe were analyzed and measured.

Surgical management of World Health Organization Grade II gliomas in eloquent areas: the necessity of preserving a margin around functional structures.

Object: Recent surgical studies have demonstrated that the extent of resection is significantly correlated with median survival in WHO Grade II gliomas. Consequently, thanks to advances in intraoperative functional mapping, the authors questioned whether it is actually necessary to leave a "security" margin around eloquent structures.

Methods: The authors first reviewed the classic literature, especially that based on epilepsy surgery and functional neuroimaging techniques, which led them to propose the rule of a security margin.

Parasagittal transinsular electrodes for stereo-EEG in temporal and insular lobe epilepsies.

Objective: Direct invasive EEG recordings of the insula - due to its particular anatomical position, deeply seated between both opercula - can only be performed with intracerebral electrodes. To date, the technique most commonly used for insular stereoelectroencephalography (SEEG) is the orthogonal-transopercular electrode approach with the Talairach methodology. We propose another technique utilizing MRI with transinsular parasagittal electrodes and a posterior entry point.

Discrepancies between preoperative stereoencephalography language stimulation mapping and intraoperative awake mapping during resection of focal cortical dysplasia in eloquent areas.

Background/aims: To compare the reliability of preoperative stereoencephalography (SEEG) and intraoperative electrostimulation regarding functional mapping, and to select the indication for surgery for focal cortical dysplasia (FCD) in language areas.

Methods: The authors present the case of a 21-year-old, right-handed female, suffering from chronic pharmacologically resistant epilepsy since the age of 8. MRI showed a subcortical hypersignal on FLAIR and T(2) sequences at the posterior end of the left superior temporal sulcus compatible with an FCD.

Long-term brain plasticity allowing a multistage surgical approach to World Health Organization Grade II gliomas in eloquent areas.

Although the goal of surgery for World Health Organization Grade II gliomas is maximal extent of resection, complete tumor removal is not always possible when the glioma involves eloquent areas. The authors propose a multistage surgical approach to highly crucial areas that are classically considered inoperable, enabling optimization of the extent of resection while avoiding permanent cognitive deficits due to induced functional reshaping in the interim between the 2 consecutive operations. To demonstrate such plasticity, the authors used a combination of sequential functional MR imaging and intraoperative electrical stimulation mapping before and during surgeries spaced by several years in 2 patients who each underwent 2 separate resections of Grade II gliomas located in the left dominant premotor area.

Long-term follow-up of Huntington disease treated by bilateral deep brain stimulation of the internal globus pallidus.

Deep brain stimulation is now accepted as a safe and efficient treatment for movement disorders including selected types of dystonia and dyskinesia. Very little, however, is known about its effect on other movement disorders, particularly for "choreic" movements. Huntington disease is a fatal autosomal-dominant neurodegenerative disorder characterized by movement disorders, progressive cognitive impairment, and psychiatric symptoms.

Brain tumors and epilepsy.

When treating patients harboring a brain tumor, it is mandatory to integrate the dogmas of epilepsy into a neuro-oncological viewpoint. The frequency of seizures differs widely between low- and high-grade tumors because of different mechanisms of epileptogenesis. The modern theories of pathological neural networks, especially in low-grade gliomas, can provide the key for an in-depth understanding of the principles of connectionism that underline both seizures, cognitive impairment and plasticity.

Antero-ventral internal pallidum stimulation improves behavioral disorders in Lesch-Nyhan disease.

The Lesch-Nyhan syndrome is an X-linked recessive disorder caused by a deficiency in hypoxanthine-guanine phosphoribosyl transferase, a purine salvage enzyme. Affected individuals exhibit a characteristic neurobehavioral disorder with delayed acquisition of motor skills, dystonia, severe self-mutilations, and aggressive behavior. Deep brain stimulation has been previously proposed for controlling isolated involuntary movements and psychiatric disorders.