Stereo-EEG-based ictal functional connectivity in patients with periventricular nodular heterotopia-related epilepsy.

Nodular heterotopia (NH)-related drug-resistant epilepsy is challenging due to the deep location of the NH and the complexity of the underlying epileptogenic network. Using ictal stereo-electroencephalography (SEEG) and functional connectivity (FC) analyses in 14 patients with NH-related drug-resistant epilepsy, we aimed to determine the leading structure during seizures. For this purpose, we compared node IN and OUT strength between bipolar channels inside the heterotopia and inside gray matter, at the group level and at the individual level. At seizure onset, the channels within NH belonging to the epileptogenic and/or propagation network showed higher node OUT-strength than the channels within the gray matter (p = .03), with higher node OUT-strength than node IN-strength (p = .03). These results are in favor of a "leading" role of NH during seizure onset when involved in the epileptogenic- or propagation-zone network (50% of patients). However, when looking at the individual level, no significant difference between NH and gray matter was found, except for one patient (in two of three seizures). This result confirms the heterogeneity and the complexity of the epileptogenic network organization in NH and the need for SEEG exploration to characterize more precisely patient-specific epileptogenic network organization.

Prognostic significance of MRI contrast enhancement in newly diagnosed glioblastoma, IDH-wildtype according to WHO 2021 classification.

BACKGROUND AND OBJECTIVES: Contrast enhancement in glioblastoma, IDH-wildtype is common but not systematic. In the era of the WHO 2021 Classification of CNS Tumors, the prognostic impact of a contrast enhancement and the pattern of contrast enhancement is not clearly elucidated. METHODS: We performed an observational, retrospective, single-centre cohort study at a tertiary neurosurgical oncology centre (January 2006 - December 2022). We screened adult patients with a newly-diagnosed glioblastoma, IDH-wildtype in order to assess the prognosis role of the contrast enhancement and the pattern of contrast enhancement. RESULTS: We included 1149 glioblastomas, IDH-wildtype: 26 (2.3%) had a no contrast enhancement, 45 (4.0%) had a faint and patchy contrast enhancement, 118 (10.5%) had a nodular contrast enhancement, and 960 (85.5%) had a ring-like contrast enhancement. Overall survival was longer in non-contrast enhanced glioblastomas (26.7 months) than in contrast enhanced glioblastomas (10.9 months) (p < 0.001). In contrast enhanced glioblastomas, a ring-like pattern was associated with shorter overall survival than in faint and patchy and nodular patterns (10.0 months versus 13.0 months, respectively) (p = 0.033). Whatever the presence of a contrast enhancement and the pattern of contrast enhancement, surgical resection was an independent predictor of longer overall survival, while age ≥ 70 years, preoperative KPS score < 70, tumour volume ≥ 30cm3, and postoperative residual contrast enhancement were independent predictors of shorter overall survival. CONCLUSION: A contrast enhancement is present in the majority (97.7%) of glioblastomas, IDH-wildtype and, regardless of the pattern, is associated with a shorter overall survival. The ring-like pattern of contrast enhancement is typical in glioblastomas, IDH-wildtype (85.5%) and remains an independent predictor of shorter overall survival compared to other patterns (faint and patchy and nodular).

Impact of frailty on survival glioblastoma, IDH-wildtype patients.

PURPOSE: Frailty increases the risk of mortality among patients. We studied the prognostic significance of frailty using the modified 5-item frailty index (5-mFI) in patients harboring a newly diagnosed supratentorial glioblastoma, IDH-wildtype. METHODS: We retrospectively reviewed records of patients surgical treated at a single neurosurgical institution at the standard radiochemotherapy era (January 2006 - December 2021). Inclusion criteria were: age ≥ 18, newly diagnosed glioblastoma, IDH-wildtype, supratentorial location, available data to assess the 5-mFI index. RESULTS: A total of 694 adult patients were included. The median overall survival was longer in the non-frail subgroup (5-mFI < 2, n = 538 patients; 14.3 months, 95%CI 12.5-16.0) than in the frail subgroup (5-mFI ≥ 2, n = 156 patients; 4.7 months, 95%CI 4.0-6.5 months; p < 0.001). 5-mFI ≥ 2 (adjusted Hazard Ratio (aHR) 1.31; 95%CI 1.07-1.61; p = 0.009) was an independent predictor of a shorter overall survival while age ≤ 60 years (aHR 0.78; 95%CI 0.66-0.93; p = 0.007), KPS score ≥ 70 (aHR 0.71; 95%CI 0.58-0.87; p = 0.001), unilateral location (aHR 0.67; 95%CI 0.52-0.87; p = 0.002), total removal (aHR 0.54; 95%CI 0.44-0.64; p < 0.0001), and standard radiochemotherapy protocol (aHR 0.32; 95%CI 0.26-0.38; p < 0.0001) were independent predictors of a longer overall survival. Frailty remained an independent predictor of overall survival within the subgroup of patients undergoing a first-line oncological treatment after surgery (n = 549) and within the subgroup of patients who benefited from a total removal plus adjuvant standard radiochemotherapy (n = 209). CONCLUSION: In newly diagnosed supratentorial glioblastoma, IDH-wildtype patients treated at the standard combined radiochemotherapy era, frailty, defined using a 5-mFI score ≥ 2 was an independent predictor of overall survival.

Radiographic growth rate as a predictor of aggressiveness of diffuse gliomas without 1p19q codeletion.

OBJECTIVE: The 2021 WHO classification of CNS tumors has refined the definition of adult-type diffuse gliomas without 1p19q codeletion. Nevertheless, the aggressiveness of gliomas is based exclusively on histomolecular criteria performed on a limited sample of the tumor. The authors aimed to assess whether the spontaneous radiographic tumor growth rate is associated with tumor aggressiveness and allows preoperative identification of malignancy grade of adult-type diffuse gliomas without 1p19q codeletion. METHODS: The authors retrospectively reviewed the records of adult patients harboring a newly diagnosed supratentorial diffuse glioma without 1p19q codeletion, with available preoperative MRI follow-up between January 2008 and April 2022. The spontaneous radiographic tumor growth rate was quantified by tumor volume segmentation and regression of the evolution of the mean tumor diameter over time and was compared with clinical, imaging, histomolecular, and survival data. RESULTS: Ninety-six patients were included. The spontaneous radiographic tumor growth rates (mean 17.8 ± 38.8 mm/year, range 0-243.5 mm/year) significantly varied according to IDH1/2 mutation (p < 0.001), grade of malignancy (p < 0.001), and presence of microvascular proliferation (p < 0.001). The spontaneous radiographic tumor growth rate allowed preoperative identification of high-grade cases: 100% of grade 3 and 4 IDH-mutant diffuse astrocytomas had a spontaneous radiographic tumor growth rate ≥ 8.0 mm/year, and 100% of IDH-wild-type glioblastomas had a spontaneous radiographic tumor growth rate ≥ 42.0 mm/year. A spontaneous radiographic growth rate ≥ 8.0 mm/year was an independent predictor of shorter progression-free (p = 0.014) and overall (p = 0.007) survival. A mitotic count threshold ≥ 4 mitoses was the optimal threshold for identifying aggressive IDH-mutant astrocytomas based on spontaneous radiographic tumor growth. CONCLUSIONS: The spontaneous radiographic tumor growth rates could be used as an additional tool to preoperatively screen tumor aggressiveness of adult-type diffuse gliomas without 1p19q codeletion.

Safety and efficacy of frameless stereotactic robot-assisted intraparenchymal brain lesion biopsies versus image-guided biopsies: a bicentric comparative study.

PURPOSE: User-friendly robotic assistance and image-guided tools have been developed in the past decades for intraparenchymal brain lesion biopsy. These two methods are gradually becoming well accepted and are performed at the discretion of the neurosurgical teams. However, only a few data comparing their effectiveness and safety are available. METHODS: Population-based parallel cohorts were followed from two French university hospitals with different surgical methods and defined geographical catchment regions (September 2019 to September 2022). In center A, frameless robot-assisted stereotactic intraparenchymal brain lesion biopsies were performed, while image-guided intraparenchymal brain lesion biopsies were performed in center B. Pre-and postoperative clinical, radiological, and histomolecular features were retrospectively collected and compared. RESULTS: Two hundred fifty patients were included: 131 frameless robot-assisted stereotactic intraparenchymal brain lesion biopsies in center A and 119 image-guided biopsies in center B. The clinical, radiological, and histomolecular features were comparable between the two groups. The diagnostic yield (96.2% and 95.8% respectively; p = 1.000) and the overall postoperative complications rates (13% and 14%, respectively; p = 0.880) did not differ between the two groups. The mean duration of the surgical procedure was longer in the robot-assisted group (61.9 ± 25.3 min, range 23-150) than in the image-guided group (47.4 ± 11.8 min, range 25-81, p < 0.001). In the subgroup of patients with anticoagulant and/or antiplatelet therapy administered preoperatively, the intracerebral hemorrhage > 10 mm on postoperative CT scan was higher in the image-guided group (36.8%) than in the robot-assisted group (5%, p < 0.001). CONCLUSION: In our bicentric comparative study, robot-assisted stereotactic and image-guided biopsies have two main differences (shorter time but more frequent postoperative hematoma for image-guided biopsies); however, both techniques are demonstrated to be safe and efficient.

Clinico-Radio-Histo-Molecular and Neurocognitive Characteristics of Diffuse Gliomas in Adolescent and Young Adults: A Comprehensive Review.

BACKGROUND: Diffuse gliomas are the most frequent neoplasms in adolescent and young adults (AYAs), especially high-grade gliomas, which have the highest mortality rate. Recent histo-molecular advances are in favour of specialized therapeutic management of AYA patients, which we have analysed in this comprehensive review of the literature. SUMMARY: A literature search was conducted to identify all studies concerning diffuse gliomas and AYAs (15-39 years). We assessed epidemiology, clinical and imaging findings, histo-molecular characteristics, neurosurgical and neuro-oncological management, prognosis, and health-related quality of life. KEY MESSAGES: Diffuse gliomas remain the most frequent brain tumours in the AYA population. Symptoms mainly depend on the tumour location, which varies due to histo-molecular profiles. Specific imaging patterns of histo-molecular subtypes of diffuse gliomas are identified; however, no specific pattern related to the age group has been identified. The literature review favours optimizing the extent of surgical resection for diffuse gliomas, whichever the grade, and suggests a dedicated management for these patients. It seems more relevant to consider the treatment according to the histo-molecular profile of the diffuse glioma rather than the age group. Clinical trials will allow AYA patients to benefit from innovative therapies that could improve their outcome. This literature review suggests the need for a close and long-term psychological follow-up for AYA patients with brain tumour during the transitional care, during adulthood, as well as for their family members. Collaborative efforts are needed between paediatric and adult neurosurgical and neuro-oncological teams, to move forward in the therapeutic management of AYA patients harbouring diffuse gliomas.

Carmustine wafer implantation for supratentorial glioblastomas, IDH-wildtype in "extreme" neurosurgical conditions.

We assessed the feasibility of Carmustine wafer implantation in "extreme" conditions (i.e. patients > 80 years and Karnofsky Performance Status score < 50) and of implantation ≥ 12 Carmustine wafers in adult patients harbouring a newly diagnosed supratentorial glioblastoma, IDH-wildtype. We performed an observational, retrospective single-centre cohort study at a tertiary surgical neuro-oncological centre between January 2006 and December 2021. Four hundred eighty patients who benefited from a surgical resection at first-line treatment were included. We showed that Carmustine wafer implantation in patients > 80 years, in patients with a Karnofsky performance status score < 50, and that implantation ≥ 12 Carmustine wafers (1) did not increase overall postoperative complication rates, (2) did not affect the completion of standard radiochemotherapy protocol, (3) did not worsen the postoperative Karnofsky Performance Status scores, and (4) did not significantly affect the time to oncological treatment. We showed that the implantation of ≥ 12 Carmustine wafers improved progression-free survival (31.0 versus 10.0 months, p = 0.025) and overall survival (39.0 versus 16.5 months, p = 0.041) without increasing postoperative complication rates. Carmustine wafer implantation during the surgical resection of a newly diagnosed supratentorial glioblastoma, IDH-wildtype is safe and efficient in patients > 80 years and in patients with preoperative Karnofsky Performance Status score < 50. The number of Carmustine wafers should be adapted (up to 16 in our experience) to the resection cavity to improve survival without increasing postoperative overall complication rates.

Predictors of postoperative epidural hematomas after custom-made porous hydroxyapatite cranioplasty: a single-center experience of 194 consecutive cases.

Cranioplasty is important for improving cosmesis and functional recovery after decompressive craniectomy. We assessed the incidence and predictors of post-cranioplasty epidural hematomas requiring surgical evacuation. A single-institution, retrospective study enrolled 194 consecutive patients who underwent a cranioplasty using custom-made hydroxyapatite between February 2008 and April 2022. Variables associated with postoperative epidural hematoma requiring surgical evacuation at the p < 0.1 level in unadjusted analysis were entered into multivariable analyses. Nine patients (4.6%) experienced postoperative epidural hematomas requiring evacuation, with time interval between craniectomy and cranioplasty <6 months (adjusted odds ratio (aOR), 20.75, p = 0.047), cranioplasty-to-bone shift > half of the bone thickness (aOR, 17.53, p = 0.008), >10 mm difference between pre-cranioplasty and post-cranioplasty midline brain shift contralateral to the cranioplasty (aOR, 17.26, p < 0.001), and non-resorbable duraplasty (aOR, 17.43, p = 0.011) identified as independent predictors. Seventeen patients (8.8%) experienced post-cranioplasty hydrocephalus requiring shunt placement. Twenty-six patients (13.4%) experienced postoperative infection. Sixteen patients (8.2%) had postoperative epileptic seizures. The identification of independent predictors of post-cranioplasty epidural hematomas requiring surgical evacuation will help identify at-risk patients, guide prophylactic care, and reduce morbidity of this common and important procedure.

Robot-assisted endoscopic third ventriculostomy under intraoperative CT imaging guidance.

BACKGROUND: The robot-assisted neurosurgical procedures have recently benefited of the evolution of intraoperative imaging, including mobile CT unit available in the operating room. This facilitated use paved the way to perform more neurosurgical procedures under robotic assistance. Endoscopic third ventriculocisternostomy requires both a safe transcortical trajectory and a smooth manipulation. METHOD: We describe our technique of robot-assisted endoscopic third ventriculocisternostomy combining robotic assistance and intraoperative CT imaging. CONCLUSION: Robot-assisted endoscopic third ventriculocisternostomy using modern intraoperative neuroimaging can be easily implemented and prevented erroneous trajectory and abrupt endoscopic movements, reducing surgically induced brain damages.

Latest Views on the Mechanisms of Action of Surgically Implanted Cervical Vagal Nerve Stimulation in Epilepsy.

BACKGROUND: Vagus nerve stimulation (VNS) is approved as an adjunctive treatment for drug-resistant epilepsy. Although there is a substantial amount of literature aiming at unraveling the mechanisms of action of VNS in epilepsy, it is still unclear how the cascade of events triggered by VNS leads to its antiepileptic effect. OBJECTIVE: In this review, we integrated available peer-reviewed data on the effects of VNS in clinical and experimental research to identify those that are putatively responsible for its therapeutic effect. The topic of transcutaneous VNS will not be covered owing to the current lack of data supporting the differences and commonalities of its mechanisms of action in relation to invasive VNS. SUMMARY OF THE MAIN FINDINGS: There is compelling evidence that the effect is obtained through the stimulation of large-diameter afferent myelinated fibers that project to the solitary tract nucleus, then to the parabrachial nucleus, which in turn alters the activity of the limbic system, thalamus, and cortex. VNS-induced catecholamine release from the locus coeruleus in the brainstem plays a pivotal role. Functional imaging studies tend to point toward a common vagal network that comes into play, made up of the amygdalo-hippocampal regions, left thalamus, and insular cortex. CONCLUSIONS: Even though some crucial pieces are missing, neurochemical, molecular, cellular, and electrophysiological changes occur within the vagal afferent network at three main levels (the brainstem, the limbic system [amygdala and hippocampus], and the cortex). At this final level, VNS notably alters functional connectivity, which is known to be abnormally high within the epileptic zone and was shown to be significantly decreased by VNS in responders. The effect of crucial VNS parameters such as frequency or current amplitude on functional connectivity metrics is of utmost importance and requires further investigation.

Accuracy and safety of 101 consecutives neurosurgical procedures for newly diagnosed central nervous system lymphomas: a single-institution experience.

INTRODUCTION: Brain surgery is required to ascertain the diagnosis of central nervous system lymphoma. We assessed the diagnostic yield and safety of the surgical procedures, the predictors of postoperative morbidity, and of overall survival. METHODS: Observational single-institution retrospective cohort study (1992-2020) of 101 consecutive adult patients who underwent stereotactic biopsy, open biopsy, or resection for a newly diagnosed central nervous system lymphoma. RESULTS: The diagnostic yield was 100% despite preoperative steroid administration in 48/101 cases (47.5%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.006) was an independent predictor of a new postoperative focal neurological deficit (7/101 cases, 6.9%). A previous history of hematological malignancy (p = 0.049), age 65 years or more (p = 0.031), and new postoperative neurological deficit (p < 0.001) were independent predictors of a Karnofsky Performance Status score decrease 20 points or more postoperatively (13/101 cases, 12.9%). A previous history of hematological malignancy (p = 0.034), and preoperative Karnofsky Performance Status score less than 70 (p = 0.024) were independent predictors of postoperative hemorrhage (13/101 cases, 12.9%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.019), and a previous history of hematological malignancy (p = 0.014) were independent predictors of death during hospital stay (8/101 cases, 7.9%). In the 82 immunocompetent patients harboring a primary central nervous system lymphoma, age 65 years or more (p = 0.044), and time to hematological treatment more than 21 days (p = 0.008), were independent predictors of a shorter overall survival. A dedicated hematological treatment (p < 0.001) was an independent predictor of a longer overall survival. CONCLUSION: Brain biopsy is feasible with low morbidity for central nervous system lymphomas. Postoperatively, patients should be promptly referred for hematological treatment initiation.

Discriminating surgical bed cysts from bacterial brain abscesses after Carmustine wafer implantation in newly diagnosed IDH-wildtype glioblastomas.

Carmustine wafers can be implanted in the surgical bed of high-grade gliomas, which can induce surgical bed cyst formation, leading to clinically relevant mass effect. An observational retrospective monocentric study was conducted including 122 consecutive adult patients with a newly diagnosed supratentorial glioblastoma who underwent a surgical resection with Carmustine wafer implantation as first line treatment (2005-2018). Twenty-two patients (18.0%) developed a postoperative contrast-enhancing cyst within the surgical bed: 16 surgical bed cysts and six bacterial abscesses. All patients with a surgical bed cyst were managed conservatively, all resolved on imaging follow-up, and no patient stopped the radiochemotherapy. Independent risk factors of formation of a postoperative surgical bed cyst were age ≥ 60 years (p = 0.019), number of Carmustine wafers implanted ≥ 8 (p = 0.040), and partial resection (p = 0.025). Compared to surgical bed cysts, the occurrence of a postoperative bacterial abscess requiring surgical management was associated more frequently with a shorter time to diagnosis from surgery (p = 0.009), new neurological deficit (p < 0.001), fever (p < 0.001), residual air in the cyst (p = 0.018), a cyst diameter greater than that of the initial tumor (p = 0.027), and increased mass effect and brain edema compared to early postoperative MRI (p = 0.024). Contrast enhancement (p = 0.473) and diffusion signal abnormalities (p = 0.471) did not differ between postoperative bacterial abscesses and surgical bed cysts. Clinical and imaging findings help discriminate between surgical bed cysts and bacterial abscesses following Carmustine wafer implantation. Surgical bed cysts can be managed conservatively. Individual risk factors will help tailor their steroid therapy and imaging follow-up.

Neurosurgical developments of Thierry de Martel (1875-1940), French neurosurgery pioneer, during World Wars I and II.

Following France's entry into World War I on August 3, 1914, Thierry de Martel (1875-1940), the French neurosurgery pioneer, served on the front line and was wounded on October 3, 1914. He was then assigned as a surgeon in temporary hospitals in Paris, where he published his first observations of cranioencephalic war wounds. In 1915, de Martel met Harvey Cushing at the American Hospital in Neuilly, where de Martel was appointed chief surgeon in 1916. In 1917, he published with the French neurologist Charles Chatelin a book (Blessures du crâne et du cerveau. Clinique et traitement) with the aim to optimize the practice of wartime brain surgery. This book, which included the results of more than 5000 soldiers with head injuries, was considered the most important ever written on war neurology at that time and was translated into English in 1918 (Wounds of the Skull and Brain; Their Clinical Forms and Medical and Surgical Treatment). In this book, de Martel detailed the fundamentals of skull injuries, classified the various craniocerebral lesions, recommended exploratory craniectomy for cranioencephalic injuries, recommended the removal of metal projectiles from the brain using a magnetic nail, and advocated for the prevention of infectious complications. Between the World Wars, de Martel undertook several developments for neurosurgery in France alongside neurologists Joseph Babinski and Clovis Vincent. Following France's entry into World War II on September 3, 1939, de Martel took over as head of the services of the American Hospital of Paris in Neuilly. He updated his work on war surgery with the new cases he personally treated. Together with Vincent, de Martel presented his new approach in "Le traitement des blessures du crâne pendant les opérations militaires" ("The treatment of skull injuries during military operations") on January 30, 1940, and published his own surgical results in April 1940 in "Plan d'un travail sur le traitement des plaies cranio-cérébrales de guerre" ("Work Plan on the Treatment of Cranio-Cerebral Wounds of War"), intended for battlefield surgeons. On June 14, 1940, the day German troops entered Paris, de Martel injected himself with a lethal dose of phenobarbital. Thierry de Martel played a central role in establishing modern neurosurgery in France. His patriotism led him to improve the management of wartime cranioencephalic injuries using his own experience acquired during World Wars I and II.

MRI-based and robot-assisted stereotactic biopsy with intraoperative CT imaging.

BACKGROUND: As a pioneer center in the field of stereotaxy, Sainte-Anne school has always advocated the use of intraoperative imaging for stereotactic procedures to optimize both safety and accuracy. With the advent of intraoperative mobile CT unit, the robot-assisted stereotactic biopsy procedure has been recently updated. METHOD: Herein, we aim at describing our new surgical procedure that combines robotic assistance (NeuroMate, Renishaw) and intraoperative cone beam CT imaging (O-Arm, Medtronic). CONCLUSION: Intraoperative imaging with the O-Arm was efficiently incorporated into the workflow. This new equipment leads to optimizing operative time and an easier realization of intraoperative imaging.

Evolution of the neurosurgical management of progestin-associated meningiomas: a 23-year single-center experience.

PURPOSE: The improving knowledge of interactions between meningiomas and progestin refines the management of this specific condition. We assessed the changes over time of the management of progestin-associated meningiomas. METHODS: We retrospectively studied consecutive adult patients who had at least one meningioma in the context of progestin intake (October 1995-October 2018) in a tertiary adult Neurosurgical Center. RESULTS: 71 adult women with 125 progestin-associated meningiomas were included. The number of progestin-associated meningioma patients increased over time (0.5/year before 2008, 22.0/year after 2017). Progestin treatment was an approved indication in 27.0%. A mean of 1.7 ± 1.2 meningiomas were discovered per patient (median 1, range 1-6). Surgery was performed on 36 (28.8%) meningiomas and the histopathologic grading was WHO grade 1 in 61.1% and grade 2 in 38.9%. The conservative management of meningiomas increased over time (33.3% before 2008, 64.3% after 2017) and progestin treatment withdrawal increased over time (16.7% before 2008, 95.2% after 2017). Treatment withdrawal varied depending on the progestin derivative used (88.9% with cyproterone acetate, 84.6% with chlormadinone acetate, 28.6% with nomegestrol acetate, 66.7% with progestin derivative combination). The main reason for therapeutic management of meningiomas was the presence of clinical signs. Among the 54 meningiomas managed conservatively for which the progestin had been discontinued, MRI follow-up demonstrated a regression in 29.6%, a stability in 68.5%, and an ongoing growth in 1.9% of cases. CONCLUSIONS: Conservative management, including progestin treatment discontinuation, has grown over time with promising results in terms of efficacy and safety.

Automated neurosurgical stereotactic planning for intraoperative use: a comprehensive review of the literature and perspectives.

The creation of intracranial stereotactic trajectories, from entry point to target point, is still mostly done manually by the neurosurgeon. The development of automated stereotactic planning tools has been described in the literature. This systematic review aims to assess the effectiveness of stereotactic planning procedure automation and develop tools for patients undergoing neurosurgical stereotactic procedures. PubMed/MEDLINE, EMBASE, Google Scholar, CINAHL, PsycINFO, and Cochrane Register of Controlled Trials databases were searched from inception to September 1, 2019, at the exception of Google Scholar (from 1 January 2010 to September 1, 2019) in French and English. Eligible studies included all studies proposing automated stereotactic planning. A total of 1543 studies were screened. Forty-two studies were included in the systematic review, including 18 (42.9%) conference papers. The surgical procedures planned automatically were mainly deep brain stimulation (n = 14, 33.3%), stereoelectroencephalography (n = 12, 28.6%), and not specified (n = 10, 23.8%). The most frequently used surgical constraints to plan the trajectory were blood vessels (n = 32, 76.2%), cerebral sulci (n = 27, 64.3%), and cerebral ventricles (n = 23, 54.8%). The distance from blood vessels ranged from 1.96 to 4.78 mm for manual trajectories and from 2.47 to 7.0 mm for automated trajectories. At least one neurosurgeon was involved in 36 studies (85.7%). The automated stereotactic trajectory was preferred in 75.4% of the studied cases (range 30-92.9). Only 3 (7.1%) studies were multicentric. No study reported prospective use of the planning software. Stereotactic planning automation is a promising tool to provide valuable stereotactic trajectories for clinical applications.

Is function-based resection using intraoperative awake brain mapping feasible and safe for solitary brain metastases within eloquent areas?

To assess feasibility and safety of function-based resection under awake conditions for solitary brain metastasis patients. Retrospective, observational, single-institution case-control study (2014-2019). Inclusion criteria are adult patients, solitary brain metastasis, supratentorial location within eloquent areas, and function-based awake resection. Case matching (1:1) criteria between metastasis group and control group (high-grade gliomas) are sex, tumor location, tumor volume, preoperative Karnofsky Performance Status score, age, and educational level. Twenty patients were included. Intraoperatively, all patients were cooperative; no obstacles precluded the procedure from being performed. A positive functional mapping was achieved at both cortical and subcortical levels, allowing for a function-based resection in all patients. The case-matched analysis showed that intraoperative and postoperative events were similar, except for a shorter duration of the surgery (p<0.001) and of the awake phase (p<0.001) in the metastasis group. A total resection was performed in 18 cases (90%, including 10 supramarginal resections), and a partial resection was performed in two cases (10%). At three months postoperative months, none of the patients had worsening of their neurological condition or uncontrolled seizures, three patients had an improvement in their seizure control, and seven patients had a Karnofsky Performance Status score increase ≥10 points. Function-based resection under awake conditions preserving the brain connectivity is feasible and safe in the specific population of solitary brain metastasis patients and allows for high resection rates within eloquent brain areas while preserving the overall and neurological condition of the patients. Awake craniotomy should be considered to optimize outcomes in brain metastases in eloquent areas.

VNS implantation in a NF1 patient: massive nerve hypertrophy discovered intra-operatively preventing successful electrode placement. Case report.

For the vast majority of surgeons, no specific investigation is necessary before vagal nerve stimulation (VNS) implantation. We report our intraoperative unexpected finding of a massively enlarged vagus nerve in a patient with neurofibromatosis type 1 (NF1). The nerve hypertrophy prevented wrapping the coils of the helical electrode. The patient had no signs of vagus nerve dysfunction preoperatively (no hoarseness or dysphonia). This exceptional mishap is undoubtedly related to NF1-associated peripheral nerve sheath tumors. Even though it is not advisable to routinely perform any imaging prior to VNS, in such specific context, preoperative imaging work-up, especially cervical ultrasound, might be judicious to rule out any asymptomatic enlarged left vagus nerve.

MRI Atlas of IDH Wild-Type Supratentorial Glioblastoma: Probabilistic Maps of Phenotype, Management, and Outcomes.

Background Tumor location is a main prognostic parameter in patients with glioblastoma. Probabilistic MRI-based brain atlases specifying the probability of tumor location associated with important demographic, clinical, histomolecular, and management data are lacking for isocitrate dehydrogenase (IDH) wild-type glioblastomas. Purpose To correlate glioblastoma location with clinical phenotype, surgical management, and outcomes by using a probabilistic analysis in a three-dimensional (3D) MRI-based atlas. Materials and Methods This retrospective study included all adults surgically treated for newly diagnosed IDH wild-type supratentorial glioblastoma in a tertiary adult surgical neuro-oncology center (2006-2016). Semiautomated tumor segmentation and spatial normalization procedures to build a 3D MRI-based atlas were validated. The authors performed probabilistic analyses by using voxel-based lesion symptom mapping technology. The Liebermeister test was used for binary data, and the generalized linear model was used for continuous data. Results A total of 392 patients (mean age, 61 years ± 13; 233 men) were evaluated. The authors identified the preferential location of glioblastomas according to subventricular zone, age, sex, clinical presentation, revised Radiation Therapy Oncology Group-Recursive Partitioning Analysis class, Karnofsky performance status, O6-methylguanine DNA methyltransferase promoter methylation status, surgical management, and survival. The superficial location distant from the eloquent area was more likely associated with a preserved functional status at diagnosis (348 of 392 patients [89%], P < .05), a large surgical resection (173 of 392 patients [44%], P < .05), and prolonged overall survival (163 of 334 patients [49%], P < .05). In contrast, deep location and location within eloquent brain areas were more likely associated with an impaired functional status at diagnosis (44 of 392 patients [11%], P < .05), a neurologic deficit (282 of 392 patients [72%], P < .05), treatment with biopsy only (183 of 392 patients [47%], P < .05), and shortened overall survival (171 of 334 patients [51%], P < .05). Conclusion The authors identified the preferential location of isocitrate dehydrogenase wild-type glioblastomas according to parameters of interest and provided an image-based integration of multimodal information impacting survival results. This suggests the role of glioblastoma location as a surrogate and multimodal parameter integrating several known prognostic factors. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Huang in this issue.