Zanello et al. examine the life and achievements of Jean Bancaud who, together with Jean Talairach, pioneered stereoelectroencephalography (SEEG). Although initially met with scepticism, the methodology they developed in the late 1950s remains the cornerstone of preoperative assessment in refractory epilepsy today.

Custom-made porous hydroxyapatite cranioplasty is widely used for reconstruction of cranial defects after decompressive craniectomy and in other clinical settings, such as postoperative surgical site infection or perioperative brain oedema, but its long-term complications remain poorly characterized. Understanding the durability of custom-made porous hydroxyapatite cranioplasty will help refine surgical decision-making and postoperative follow-up. Retrospective analysis of 234 consecutive custom-made porous hydroxyapatite cranioplasty procedures performed in 217 patients at a single tertiary neurosurgical center between 2008 and 2025. Surgery-related complications including epidural hematoma, infection, implant fracture, and cranioplasty removal were assessed with Kaplan–Meier survival analysis at one, two, five, 10, and 15 years. Mean follow-up was 7.3 years (range, 0.2–16.8). Cranioplasty removal for any reason occurred in 15.8

Background and objectives Skull-involving meningiomas remain ill-defined, resulting in heterogeneous classifications and terminology. Existing schemes mainly describe bone-dura relationships and often overlook the relative burden of the intracranial soft-tissue component. This study aimed to develop and apply a deterministic, atlas-normalized, MRI-based radiological framework for the standardized description of imaging-defined osteomeningiomas and to explore associations between compartmental tumor distribution, radiological phenotype, and clinical presentation. Methods We retrospectively reviewed adults with skull-involving meningiomas at our tertiary neurosurgical center between 2000 and 2024. Tumors were segmented on contrast-enhanced T1-weighted MRI, normalized to MNI152 space, and classified using a deterministic voxel-based radiological framework across osseous, juxta-osseous/dural, and intradural compartments. Tumors were classified as primary osteomeningioma (POM; isolated osseous compartment involvement) or secondary osteomeningioma (SOM; osseous plus adjacent juxta-osseous/dural compartment involvement), with subtypes SOM-I (no intradural extension), SOM-IIA (all three compartments involved, with an osseous component equal to or greater than the intradural component), and SOM-IIB (all three compartments involved, with an intradural component greater than the osseous component). These imaging-defined categories were intended as radiological descriptors of compartmental tumor distribution rather than distinctions between microscopic osseous invasion, reactive hyperostosis, or osseous metaplasia. All analyses were performed at the tumor level, with a predefined sensitivity analysis restricted to one index tumor per patient. Exploratory multivariable logistic regression models were fitted for brain edema, epileptic seizure, raised intracranial pressure, and exophthalmos. Results A total of 168 tumors from 149 patients were analyzed. Distribution was POM in 6 cases (3.6%), SOM-I in 37 cases (22.0%), SOM-IIA in 57 cases (33.9%), and SOM-IIB in 68 cases (40.5%). Convexity predominated in POM but was less common in other subtypes. SOM-IIB had the largest intracranial soft tissue component (29.9 ± 30.2 cm3) and the highest rate of brain edema, whereas SOM-IIA had the largest osseous component (24.8 ± 25.9 cm3). Epileptic seizures and signs of raised intracranial pressure were most frequent in SOM-IIB, exophthalmos in SOM-I, and subcutaneous mass in POM. In exploratory adjusted analyses, SOM-IIB remained associated with brain edema, epileptic seizure, and raised intracranial pressure, whereas SOM-I remained associated with exophthalmos. Conclusions This voxel-based, atlas-normalized MRI framework provides a radiological standardization for the description of skull-involving meningiomas. Rather than establishing histological proof of bone or dural invasion, it standardizes compartmental tumor burden across osseous, juxta-osseous/dural, and intradural spaces. In exploratory analyses, the proposed imaging-defined subtypes were associated with distinct clinicoradiological presentation patterns, which warrant further pathological, multimodal, and external validation.

Thierry de Martel was a pioneer of French neurosurgery and a decorated World War I veteran. During World War II, he organized and modernized neurosurgical care for French soldiers at the American and Laennec Hospitals in Paris. As the German army advanced in June 1940, de Martel, aged 64, sought to join a last-ditch resistance effort. Disillusioned by France's military defeat and political collapse and burdened by the death of his only son in World War I, he took his own life on June 14, 1940, the day German troops entered Paris. This article reconstructs the final weeks of de Martel's life through archival materials, medical records, and eyewitness accounts, offering a unique historical perspective on the ethical, emotional, and professional dilemmas faced by physicians during wartime. De Martel's final act was both a protest and a legacy-a message of surgical precision, patriotic despair, and moral clarity. His story resonates today as a testament to the enduring tension between duty to life and devotion to country.

Background:Maximal safe awake resection is the standard for diffuse gliomas, as it optimizes extent of resection while preserving functional integrity. Progressive loss of accuracy during neurocognitive testing may preclude completion of a maximal function-based resection. We assessed the prevalence, feasibility, safety, and efficacy of a 2-step awake craniotomy approach and identified predictors for requiring a second awake procedure to achieve maximal function-based resection. Methods:We conducted a retrospective single-center cohort study of 449 consecutive supratentorial diffuse glioma awake craniotomies (2009-2024). Clinical, neurocognitive, imaging, oncological, and intraoperative data were collected. Results:Among 449 awake craniotomies, 12 (2.8%) required a second awake procedure. The first surgeries were interrupted due to increasing spontaneous errors during intraoperative tests, fatigue, loss of participation, or pain-induced high blood pressure. The interval between procedures ranged from 1.0 to 7.5 months. Compared with all other awake surgeries, the second procedure showed no increase in intraoperative adverse events. Compared to the first awake procedure, the second awake procedure achieved a median additional resection rate of 32.3% (mean 38.6 ± 24.4%; range 8%-83.2%) across all patients. The proportion of complete resections increased from 0/12 to 6/12. Independent predictors of a 2-step awake craniotomy were preoperative attention impairment (P = .021), left-hemispheric location (P = .017), and insular involvement (P = .016). Conclusion:Two-step awake craniotomy is a rare but effective and safe strategy when the initial awake procedure must be prematurely stopped. Patients with attention deficits, left-sided lesions, or insular tumor involvement are more likely to require a 2-step awake craniotomy.

A large MRI voxel-based atlas mapped intracranial meningioma distributions, linking location to symptoms, management, and malignancy grade, and provided a standardized spatial reference to anticipate presentation and guide clinical decision-making.

Background:Meningiomas are the most common primary brain tumours in adults. Concerns have emerged about a possible link between progestogen use and intracranial meningioma; we assessed this association. Methods:In this systematic review and meta-analysis, we searched PubMed/MEDLINE, Embase, Cochrane Library, EPI-PHARE database (from inception up to November 01, 2025), pharmacovigilance reports, and backward snowballing. Eligible publications were English or French epidemiological studies, reporting associations between progestogens and intracranial meningiomas. We excluded non-original reports, abstracts-only, and studies without eligible progestogen exposure or meningioma outcomes. We extracted summary data from published reports. Risk of bias was assessed with the Newcastle-Ottawa Scale, and certainty of evidence with GRADE. The primary outcome was intracranial meningioma. Secondary outcomes were malignancy, location, and regression. Random-effects models were used, and heterogeneity was assessed with I2; a narrative synthesis was also performed. Findings:Of 542 records screened, 78 studies were included in the review, and 14 high-quality observational studies in meta-analysis; all 14 were NOS high quality, although residual confounding and potential outcome misclassification cannot be excluded. Cyproterone acetate (CPA) was associated with increased meningioma risk (5 studies; 1047 exposed; pooled-OR 12.36 (95% CI: 7.47-20.45); I2: 73.8%; GRADE: moderate). Depot medroxyprogesterone acetate was also associated (6 studies; 842 exposed; pooled-OR 2.68 (95% CI: 1.72-4.19); I2: 92.7%; GRADE: low). Chlormadinone acetate (CMA), nomegestrol acetate (NOMAC), promegestone, medrogestone, and desogestrel showed signals of increased risk (CMA 3 studies, 164-683 exposed; NOMAC 3, 171-969; promegestone 1, 83; medrogestone 1, 42; desogestrel 2, 115-287). We did not pool these estimates due to sparse, heterogeneous evidence. No signal was found for norgestrel, levonorgestrel, progesterone, dydrogesterone, or spironolactone; evidence for dienogest and hydroxyprogesterone was insufficient. Regression after withdrawal was reported for CPA and NOMAC. Tumours were predominantly anterior/middle skull base, and malignant meningiomas were more frequent with CPA, CMA, and NOMAC. Interpretation:The certainty of evidence was limited by the observational design, residual confounding, heterogeneity, and imprecision for some exposures. Use of specific progestogens, particularly high dose macroprogestogens may be associated with an increased risk of intracranial meningioma. Transparent patient information and careful clinical and, where appropriate, imaging follow-up are essential. Funding:None.

Antony Chipault (1866-1920) was the first French surgeon to devote his entire professional career to the nervous system. A brilliant scholar, polyglot, and accomplished illustrator, he authored monumental textbooks, including the two-volume Chirurgie opératoire du système nerveux (Operative Surgery of the Nervous System, 1894-1895) and the three-volume collaborative treatise L'État actuel de la chirurgie nerveuse (Current State of Neurological Surgery, 1902), which united contributors from 34 countries. His writings-richly illustrated with his own drawings-emphasized cadaveric validation, meticulous anatomic correlation, statistical analysis, and an international perspective uncommon for his time. Between 1896 and 1902, Chipault published an annual review initially entitled Travaux de neurologie chirurgicale (Surgical Neurology Works), which is recognized as the first recurring periodical dedicated to neurosurgery. Clinically, Chipault was among the first in France to perform craniotomies and spinal procedures and among the earliest worldwide to use radiography to localize intracranial foreign bodies. Yet, despite his vision, he failed to convince many contemporaries of the promise of neurological surgery. Forced into early retirement by illness at the age of 39, he died in obscurity in 1920. This historical vignette revisits his life and work, highlighting Chipault's legacy as a visionary who anticipated neurosurgery as a distinct specialty in France decades before its formal recognition.

The optimal oncological management of adult patients with IDH-mutant CNS WHO grade 3 diffuse gliomas remains debated, particularly given the potential neurotoxic effects of adjuvant therapies on cognition and health-related quality-of-life. We conducted a retrospective single-center cohort study including 87 consecutive patients with IDH-mutant CNS WHO grade 3 glioma who underwent awake craniotomy. Patients were stratified into a surgery only group (n = 23) or an adjuvant oncological group (radiotherapy with or without chemotherapy; n = 64). Neurocognitive outcomes, seizure control, and return-to-work rates were assessed. Voxel-wise lesion-symptom mapping was performed to identify associations between radiation dose distribution and postoperative neurocognitive performance. Patients who did not receive postoperative adjuvant therapy showed better language (100 Grade 3 glioma patients without adjuvant radiochemotherapy showed better neurocognitive and return-to-work outcomes, with no loss of seizure control. Voxel-wise mapping linked cognitive decline to irradiation of specific white matter pathways. Standard adjuvant radiochemotherapy in IDH-mutant grade 3 gliomas may impact neurocognitive outcomes, creating an onco-functional paradox in which functional connectivity meticulously preserved during awake surgery is subsequently compromised by postoperative adjuvant radiochemotherapy. Using voxel-wise lesion-symptom mapping, we show that postoperative impairments in language, executive and social function, attention, and memory correspond to radiation exposure of distinct white matter pathways. Patients who did not receive adjuvant radiochemotherapy demonstrated better neurocognitive performance and faster return-to-work rates. These findings support a more individualized postoperative strategy in patients, aiming to preserve health-related quality-of-life while maintaining safe oncological management. This study provides a practical framework for tailoring adjuvant treatment decisions in modern neuro-oncology.

The impact of Carmustine wafer implantation on epileptic seizure control in adult patients with newly diagnosed supratentorial glioblastoma, IDH-wildtype, remains unclear. We assessed whether Carmustine wafer implantation influences postoperative seizure control. We conducted an observational, retrospective, single-centre cohort study at a tertiary neurosurgical oncology center between January 2006 and December 2024. We included adults treated with surgical resection for a newly diagnosed supratentorial glioblastoma, IDH-wildtype with or without Carmustine wafer implantation in the early postoperative period and during the first six months of adjuvant oncological treatment. 676 patients who benefited from a first-line surgical resection with (n = 257) or without (n = 419) Carmustine wafer implantation were included. Epilepsy at diagnosis was present in 244 patients (36.1

Although stereotactic frame-based techniques remain widely used for deep brain stimulation (DBS) implantation, robot-assisted procedures have demonstrated improved accuracy, enhanced precision, and reduced operative time. Our team has over two decades of experience in robot-assisted surgery and intraoperative imaging. We detail our current surgical workflow for DBS implantation, combining the Neuromate robot (Renishaw), the NeuroLocate frameless registration module, and intraoperative cone-beam CT imaging using the O-Arm system (Medtronic). This approach provides a safe, efficient, and reproducible alternative to traditional methods, supporting its broader adoption in modern functional neurosurgery.

High-grade glioma, IDH- and H3-wildtype in young adults is a rare and poorly known entity. We compared newly diagnosed cases in young adults (18–39 years) to those in adult patients (> 39 years). We performed an observational, retrospective, single-centre cohort study at a tertiary neurosurgical oncology centre between January 2006 and December 2023. We included 1.139 adult patients with a newly diagnosed high-grade glioma, IDH- and H3-wildtype. Young adults: (1) represent a small proportion of patients with high-grade glioma (n = 33, 2.9

BACKGROUND:Brain diffuse gliomas are highly epileptic and infiltrative tumors. Glioma surgery consists of the resection of the tumor core and the maximum of the peritumoral zone, infiltrated by tumor cells, guided by the intraoperative assessment of brain functionality and connectivity. However, its electrophysiological characteristics are poorly characterized. METHODS:We studied the characteristics of electrocorticographic (ECoG) signals, in the context of glioma surgery in awake conditions on 29 patients, using EEG activity sampled on the tumor itself versus on its borders and in healthy areas. We assessed the features of frequency bands and aperiodic components (offset and slope) of ECoG power spectra during awake glioma surgery, according to cortical tumoral versus peritumoral and healthy status. RESULTS:We found that tumor contacts present a decrease in activity for all the frequency bands except for delta activity, which was increased. Second, the peritumoral cortex was characterized by an increase in relative beta activity and slopes between 20 and 40 Hz. Low cortical tumor cell infiltration was directly correlated with a reduction in the production of physiological brain rhythms. Finally, an automatic classifier based on neural networks allowed the classification of the electrodes based on their power spectrum characteristics. CONCLUSIONS:This intraoperative study shows that ECoG during glioma surgery in awake condition may characterize the peritumoral cortices, key for pathophysiology and therapy, and deepens our knowledge of the effects of tumor cell infiltration on nervous tissue activity. Its assessment during the surgical procedure should better delineation of the cortical areas to be removed.

Purpose.Glioblastomas, IDH- and H3-wildtype in young adults is a rare and poorly known entity. We compared newly diagnosed glioblastomas, IDH- and H3-wildtype in young adults (18–39 years) to those in adult patients (> 39 years).Methods.We performed an observational, retrospective, single-centre cohort study at a tertiary neurosurgical oncology centre between January 2006 and December 2022.Results.We included 1.139 adult patients with a newly diagnosed glioblastoma, IDH- and H3-wildtype. Young adults: 1) represent a small proportion of patients with glioblastoma, IDH- and H3-wildtype (n = 33, 2.9%); 2) have a high rate of unclassified cases according to WHO criteria and epigenetics (n = 10, 30.3%); 3) have a longer progression-free survival (p = 0.003) and overall survival (p = 0.001) and; 4) do not have higher surgically-related adverse event rates (p = 0.198). Concerning young adults, surgical resection was associated with improved progression-free and overall survival (p < 0.001 and p < 0.001, respectively). The DNA-methylation class significantly impacts the overall survival (p = 0.028), however, the MGMT methylation status is not significantly associated with either progression-free or overall survival (p = 0.320 and p = 0.639, respectively).Conclusion.Glioblastomas, IDH- and H3-wildtype is a rare histo-molecular subtype in young adults with a better prognosis than older adults. In young adults, DNA-methylation subtypes are different from their adult counterpart and had a significant impact on survival unlike MGMT status. Given the rarity of glioblastoma IDH- and H3-wildtype in young adults, a dedicated management in specialized neurosurgical oncology centres is preferred. Further histo-molecular and epigenetic analyses are required to understand the differences in prognosis compared to adult patients.

OBJECTIVE:Magnetic resonance imaging-based, robot-assisted stereotactic brain biopsy is increasingly used worldwide. However, large series reporting nonyield biopsy rates of robot-assisted biopsies are lacking in the literature. The aim of this study was to report a 21-year-long experience on MRI-based, robot-assisted stereotactic biopsy for brain lesions. METHODS:The records from a single-center, retrospective, and consecutive collection of all adult patients undergoing MRI-based, robot-assisted stereotactic biopsy for a brain lesion in a tertiary neurosurgical center from December 2002 to January 2024 were reviewed. RESULTS:A total of 911 patients (377 females, mean age at surgery 61.1 ± 16.7 years) were included. Of these patients, 15 (1.6%) had a nonyield biopsy. The nonyield biopsy rate remained stable over the 21-year-long study period (p = 0.224). The nonyield biopsy rate was significantly higher for neurological diseases (4/19, 21.5%) than infectious diseases (1/20, 5.0%) and tumors (10/872, 1.1%) (p < 0.001). There were significantly more nonyield biopsies for deep-seated lesions (8/261, 3.1%) than for superficial lesions (6/612, 1.0%) (p = 0.025) and non-contrast-enhanced lesions (6/99, 6.1%) than in contrast-enhanced lesions (9/797, 1.1%) (p < 0.001). Patients in the nonyield biopsy group had significantly smaller lesions on both contrast-enhanced 3D T1-weighted sequences (1.9 ± 2.2 vs 27.1 ± 29.5 cm3, p = 0.046) and FLAIR sequences (14.0 ± 17.0 vs 80.7 ± 73.3 cm3, p < 0.001). Preoperative corticosteroid administration (407/911, 44.7%; with the bias that corticosteroids were avoided in patients with suspected lymphoma), number of biopsy samples (mean 4.9 ± 2.4), neurosurgeon experience, and WHO classification versions were not associated with a higher risk of nonyield biopsy (p = 0.274, p = 0.053, p = 0.968, and p = 0.366, respectively). CONCLUSIONS:MRI-based, robot-assisted stereotactic biopsy led to a low rate of nonyield biopsy. Neurological disease, non-contrast-enhanced lesions, and deep-seated lesions were more at risk of nonyield biopsy.

OBJECTIVE:Although awake craniotomy can guide functional brain mapping and resection, its feasibility and safety have been poorly studied in large series of patients with drug-resistant focal epilepsy surgery. METHODS:We conducted an observational, retrospective, single-center cohort study of 588 consecutive awake craniotomies (2010-2024). Patients with drug-resistant focal epilepsy were compared to controls, with a focus on subgroup analysis of patients with low-grade, developmental, epilepsy-associated brain tumor and an associated nontumoral epileptogenic brain lesion group (46/558 patients, 8.2%), patients with ≥2 years of uncontrolled epileptic seizures (32/558 patients, 5.6%), and patients on ≥2 antiseizure medications (77/588 patients, 13.1%). Feasibility outcomes included time to awakening, intraoperative cooperation, and procedure abortion. Safety outcomes included surgery-related risks and intraoperative and early postoperative epileptic seizures. RESULTS:Compared to controls, patients with medically drug-resistant focal epilepsy (1) did not present higher rates of late awakening (6.5%-14.3% vs. 8.7%-9.8%, p = .450, p = .972, p = .143) or of insufficient intraoperative cooperation (0%-9.1% vs. 5.0%-6.1%, p = .019, p = .345, p = .173), (2) did not require abortion of the awake procedure because of epilepsy (0% vs. 0%, p = 1.0), (3) did not present a higher rate of intraoperative epileptic seizures (4.3%-9.1% vs. 2.7%-5.0%, p = .226, p = .529), (4) presented a higher rate of intraoperative epileptic seizures when presenting a ≥2-year history of uncontrolled epileptic seizures (12.9% vs. 2.3%, p < .001), and (5) did not exhibit a higher rate of early postoperative epileptic seizures (13.0%-19.3% vs. 9.8%-10.6%, p = .613, p = .143, p = .078). In multivariable analysis, drug-resistant focal epilepsy was not independently associated with time to awakening, intraoperative cooperation, procedure abortion, or occurrence of intraoperative or early postoperative epileptic seizures. SIGNIFICANCE:Awake craniotomy appears feasible and safe in patients with medically drug-resistant focal epilepsy, with similar and low rates of adverse events, including intraoperative epileptic seizures.

Abstract Objective Vagus nerve stimulation (VNS) is an established therapy for drug‐resistant epilepsy (DRE) and is indicated for implantation on the left vagus nerve‐only. In rare cases right‐sided VNS may be the only option. With only seven published cases in the literature, data on safety and effectiveness of right‐sided VNS is very limited. Methods An anonymous 38‐item questionnaire was sent to expert surgeons implanting VNS for DRE. The questions covered demographics and clinical characteristics, the reason for right‐sided implantation and both neurological and surgical outcomes of right‐sided VNS. Results The survey captured 38 cases of right‐sided VNS (18 females, mean age at surgery of 28.0 ± 16.3 years). Right‐sided VNS was performed because of VNS lead deficiency (n = 20), anatomical constraints (n = 8), infection of a left‐sided VNS site (n = 9), and presence of a left ventricular shunt (n = 1). Thirty‐two patients (84%) had a preoperative cardiac assessment. Three patients presented postoperative cardiac side‐effects. Right‐sided VNS was stopped at last follow‐up in three patients: due to deep infection (n = 1), due to dyspnea (n = 1), and due to sleep apnea syndrome (n = 1). Twenty‐one patients (55%) were responders to right‐sided VNS and the mean reduction of seizure frequency under right‐sided VNS was 56.2 ± 18.8%. Focusing on seizure frequency reduction between right‐sided VNS and left‐sided VNS: 20 patients experienced similar effectiveness, 1 experienced lesser effectiveness, and 2 patients experienced greater effectiveness with right‐sided VNS. Interpretation This multicenter case series significantly augments the available literature on right‐sided VNS. This suggests comparable effectiveness to left‐sided VNS but potentially lower tolerability. Further studies are warranted to better evaluate safety and efficacy of right‐sided VNS.

Applying large language models (LLM) in specialized medical disciplines presents unique challenges requiring precision, reliability, and domain-specific relevance. We evaluated a specialized LLM-driven system against neurosurgeons in vagus nerve stimulation (VNS) for drug-resistant epilepsy knowledge assessment—a complex neuromodulation therapy requiring transdisciplinary expertise in neural anatomy, epileptic disorders, and device technology. Thirty-six European neurosurgeons who completed a 2-day VNS masterclass were assessed using a multiple-choice questionnaire comprising 14 items with 67 binary propositions. We deployed open-source models—LLaMa 2 70B and MXBAI embedding model—using Neura, an AI infrastructure enabling transparent grounding through advanced retrieval augmented generation. The knowledge base consisted of 125 VNS-related publications curated by multidisciplinary faculty. Scoring ranged from -1 to + 1 per question. Performance was analyzed using Wilcoxon signed-rank tests, confusion matrices, and metrics including accuracy, precision, recall, and specificity. The AI achieved a score of 0.75, exceeding the highest individual clinician score (0.68; median: 0.50), with statistical significance (p < 0.001). AI performed better in questions involving anatomical and technical information, while clinicians excelled in scenarios requiring practical judgment. Confusion matrices revealed higher true correct and true incorrect rates for AI, demonstrating perfect precision and specificity scores with no hallucinations detected. Specialized LLM performance in this VNS knowledge assessment, coupled with its verifiability, points to promising applications across neurosurgical subspecialties for clinical decision support and education. The complementary strengths observed suggest that valuable implementations will emerge from synergistic approaches combining human experiential knowledge with AI's information processing capabilities across the broader field of neurosurgery.

BACKGROUND:Correlating the human connectome with clinical responses elicited during intraoperative brain mapping helps understanding of the intrinsic organization of the human brain. Methods for locating eloquent sites on neuroimaging are not standardized. In the present study, we standardized a methodology for locating subcortical eloquent sites identified during intraoperative mapping for awake brain tumor resection on a reference brain template. METHODS:Subcortical eloquent sites were tagged by co-registration of intraoperative photographs with early postoperative MRI ( < 48 h). Neuroimaging data were normalized into MNI152 space. To assess whether the location of subcortical eloquent sites on the MNI template was concordant with the expected brain connectivity, we compared each subcortical eloquent site with the Human Connectome Project 1065 probabilistic tractography atlas. RESULTS:We analyze 290 subcortical eloquent sites identified during 69/90 awake surgeries. 2/290 (0.7%) subcortical eloquent sites identified intraoperatively do not intersect with a fiber tract according to the reference atlas. Among the other 288 that successfully intersect with, at least, one white matter tract, 255/288 (88.5%) have a clinical response elicited intraoperatively that is congruent with the intersected white matter tract. In the remaining 33/288 (11.5%) functional incongruent and the 2/290 (0.7%) anatomical incongruent subcortical sites, the minimal mean distance between the eloquent site and a congruent with matter tract is 3.6 ± 4.4 mm (range 1.0-23.9, median 3.6, interquartile range 2.5-5.4). CONCLUSIONS:We propose a standardized methodology to locate with accuracy on a reference brain template subcortical eloquent sites identified intraoperatively during functional brain mapping using direct electrical stimulations under awake condition.