IRE1 endoribonuclease signaling promotes myeloid cell infiltration in glioblastoma.

BACKGROUND: Intrinsic or environmental stresses trigger the accumulation of improperly folded proteins in the endoplasmic reticulum (ER), leading to ER stress. To cope with this, cells have evolved an adaptive mechanism named the unfolded protein response (UPR) which is hijacked by tumor cells to develop malignant features. Glioblastoma (GB), the most aggressive and lethal primary brain tumor, relies on UPR to sustain growth. We recently showed that IRE1 alpha (referred to IRE1 hereafter), 1 of the UPR transducers, promotes GB invasion, angiogenesis, and infiltration by macrophage. Hence, high tumor IRE1 activity in tumor cells predicts a worse outcome. Herein, we characterized the IRE1-dependent signaling that shapes the immune microenvironment toward monocytes/macrophages and neutrophils. METHODS: We used human and mouse cellular models in which IRE1 was genetically or pharmacologically invalidated and which were tested in vivo. Publicly available datasets from GB patients were also analyzed to confirm our findings. RESULTS: We showed that IRE1 signaling, through both the transcription factor XBP1s and the regulated IRE1-dependent decay controls the expression of the ubiquitin-conjugating E2 enzyme UBE2D3. In turn, UBE2D3 activates the NFκB pathway, resulting in chemokine production and myeloid infiltration in tumors. CONCLUSIONS: Our work identifies a novel IRE1/UBE2D3 proinflammatory axis that plays an instrumental role in GB immune regulation.

Clipping Versus Coiling for Ruptured MCA Aneurysms Associated with Intracerebral Hematoma Requiring Surgical Evacuation.

BACKGROUND: Ruptured middle cerebral artery aneurysm (MCAa) can lead to intracerebral hematoma, and surgical evacuation can be performed in these cases. MCAa can be treated by clipping or before by endovascular therapy (EVT). Our objective was to compare the impact on the functional outcome of MCAa in patients with intracerebral hematoma requiring evacuation. METHODS: This is a multicenter, retrospective, cohort study with nine French neurosurgical units from January 1, 2013, to December 31, 2020. All participants were adult patients who required evacuation of an intracerebral hematoma. We looked for risk factors for poor outcomes by comparing the baseline characteristics and treatments performed by using the 6-month modified Rankin scale score. Poor outcomes were defined by an modified Rankin scale score of 3-6. RESULTS: A total of 162 patients were included. A total of 129 (79.6%) patients were treated by microsurgery, and 33 (20.4%) patients were treated by EVT. In multivariate analysis, factors associated with poor outcomes included hematoma volume, realization of a decompressive craniectomy, occurrence of procedure-related symptomatic cerebral ischemia, occurrence of delayed cerebral ischemia, and EVT. In the propensity score matching analysis (n = 33 per group), poor outcomes were observed in 30% of the patients in the clipping group versus 76% in the EVT group (P < 0.001). These differences may have been related to a longer delay between hospital admission and hematoma evacuation in the EVT group. CONCLUSIONS: In the specific subgroup of ruptured MCAa with intracerebral hematoma that requires surgical evacuation, clipping with concomitant hematoma evacuation could provide better functional outcomes than EVT followed by surgical evacuation.

Natural history of spinal cord metastasis from brain glioblastomas.

BACKGROUND AND OBJECTIVES: Spinal cord metastasis arising from an intracranial glioblastoma is a rare and late event during the natural course of the disease. These pathological entities remain poorly characterized. This study aimed to identify and investigate the timeline, clinical and imaging findings, and prognostic factors of spinal cord metastasis from a glioblastoma. METHODS: Consecutive histopathological cases of spinal cord metastasis from glioblastomas in adults entered in the French nationwide database between January 2004 and 2016 were screened. RESULTS: Overall, 14 adult patients with a brain glioblastoma (median age 55.2 years) and harboring a spinal cord metastasis were included. The median overall survival as 16.0 months (range, 9.8-22.2). The median spinal cord Metastasis Free Survival (time interval between the glioblastoma diagnosis and the spinal cord metastasis diagnosis) was 13.6 months (range, 0.0-27.9). The occurrence of a spinal cord metastasis diagnosis greatly impacted neurological status: 57.2% of patients were not ambulatory, which contributed to dramatically decreased Karnofsky Performance Status (KPS) scores (12/14, 85.7% with a KPS score ≤ 70). The median overall survival following spinal cord metastasis was 3.3 months (range, 1.3-5.3). Patients with a cerebral ventricle effraction during the initial brain surgery had a shorter spinal cord Metastasis Free Survival (6.6 vs 18.3 months, p = 0.023). Out of the 14 patients, eleven (78.6%) had a brain IDH-wildtype glioblastoma. CONCLUSIONS: Spinal cord metastasis from a brain IDH-wildtype glioblastoma has a poor prognosis. Spinal MRI can be proposed during the follow-up of glioblastoma patients especially those who have benefited from cerebral surgical resection with opening of the cerebral ventricles.

Delayed [ 18 F]-FDG PET Imaging Increases Diagnostic Performance and Reproducibility to Differentiate Recurrence of Brain Metastases From Radionecrosis.

PURPOSE: Differentiating brain metastasis recurrence from radiation necrosis can be challenging during MRI follow-up after stereotactic radiotherapy. [ 18 F]-FDG is the most available PET tracer, but standard images performed 30 to 60 minutes postinjection provide insufficient accuracy. We compared the diagnostic performance and interobserver agreement of [ 18 F]-FDG PET with delayed images (4-5 hours postinjection) with the ones provided by standard and dual-time-point imaging. METHODS: Consecutive patients referred for brain [ 18 F]-FDG PET after inconclusive MRI were retrospectively included between 2015 and 2020 in 3 centers. Two independent nuclear medicine physicians interpreted standard (visually), delayed (visually), and dual-time-point (semiquantitatively) images, respectively. Adjudication was applied in case of discrepancy. The final diagnosis was confirmed histologically or after 6 months of MRI follow-up. Areas under the receiver operating characteristic curves were pairwise compared. RESULTS: Forty-eight lesions from 46 patients were analyzed. Primary tumors were mostly located in the lungs (57%) and breast (23%). The median delay between radiotherapy and PET was 15.7 months. The final diagnosis was tumor recurrence in 24 of 48 lesions (50%), with histological confirmation in 19 of 48 lesions (40%). Delayed images provided a larger area under the receiver operating characteristic curve (0.88; 95% confidence interval [CI], 0.75-0.95) than both standard (0.69; 95% CI, 0.54-0.81; P = 0.0014) and dual-time-point imaging (0.77; 95% CI, 0.63-0.88; P = 0.045), respectively. Interobserver agreement was almost perfect with delayed images ( κ = 0.83), whereas it was moderate with both standard ( κ = 0.48) and dual-time-point images ( κ = 0.61). CONCLUSIONS: [ 18 F]-FDG PET with delayed images is an accurate and reliable alternative to differentiate metastasis recurrence from radiation necrosis in case of inconclusive MRI after brain stereotactic radiotherapy.

Impact of point-spread function reconstruction on dynamic and static 18F-DOPA PET/CT quantitative parameters in glioma.

BACKGROUND: Quantification of dynamic and static parameters extracted from 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (18F-DOPA, FDOPA) positron emission tomography (PET)/computed tomography (CT) plays a critical role for glioma assessment. The objective of the present study was to investigate the impact of point-spread function (PSF) reconstruction on these quantitative parameters. METHODS: Fourteen patients with untreated gliomas and investigated with FDOPA PET/CT were analyzed. The distribution of the 14 cases was as follows: 6 astrocytomas-isocitrate dehydrogenase-mutant; 2 oligodendrogliomas/1p19q-codeleted-isocitrate dehydrogenase-mutant; and 6 isocitrate dehydrogenase-wild-type glioblastomas. A 0-20-min dynamic images (8×15, 2×30, 2×60, and 3×300 s post-injection) and a 0-20-min static image were reconstructed with and without PSF. Tumoral volumes-of-interest were generated on all of the PET series and the background volumes-of-interest were generated on the 0-20-min static image with and without PSF. Static parameters (SUVmax and SUVmean) of the tumoral and the background volumes-of-interest and kinetic parameters (K1 and k2) of the tumoral volumes-of-interest extracted from using full kinetic analysis were provided. PSF and non-PSF quantitative parameters values were compared. RESULTS: Thirty-three tumor volumes-of-interest and 14 background volumes-of-interest were analyzed. PSF images provided higher tumor SUVmax than non-PSF images for 23/33 VOIs [median SUVmax =3.0 (range, 1.4-10.2) with PSF vs. 2.7 (range, 1.4-9.1) without PSF; P<0.001] and higher tumor SUVmean for 13/33 volumes-of-interest [median SUVmean =2.0 (range, 0.8-7.6) with PSF vs. 2.0 (range, 0.8-7.4) without PSF; P=0.002]. K1 and k2 were significantly lower with PSF than without PSF [respectively median K1 =0.077 mL/ccm/min (range, 0.043-0.445 mL/ccm/min) with PSF vs. 0.101 mL/ccm/min (range, 0.055-0.578 mL/ccm/min) without PSF; P<0.001 and median k2 =0.070 min-1 (range, 0.025-0.146 min-1) with PSF vs. 0.081 min-1 (range, 0.027-0.180 min-1) without PSF; P<0.001]. Background SUVmax and SUVmean were statistically unaffected [respectively median SUVmax =1.7 (range, 1.3-2.0) with PSF vs. 1.7 (range, 1.3-1.9) without PSF; P=0.346 and median SUVmean =1.5 (range, 1.0-1.8) with PSF vs. 1.5 (range, 1.0-1.7) without PSF; P=0.371]. CONCLUSIONS: The present study confirms that PSF significantly increases tumor activity concentrations measured on PET images. PSF algorithms for quantitative PET/CT analysis should be used with caution, especially for quantification of kinetic parameters.

Integration of Raman spectra with transcriptome data in glioblastoma multiforme defines tumour subtypes and predicts patient outcome.

Raman spectroscopy is an imaging technique that has been applied to assess molecular compositions of living cells to characterize cell types and states. However, owing to the diverse molecular species in cells and challenges of assigning peaks to specific molecules, it has not been clear how to interpret cellular Raman spectra. Here, we provide firm evidence that cellular Raman spectra (RS) and transcriptomic profiles of glioblastoma can be computationally connected and thus interpreted. We find that the dimensions of high-dimensional RS and transcriptomes can be reduced and connected linearly through a shared low-dimensional subspace. Accordingly, we were able to predict global gene expression profiles by applying the calculated transformation matrix to Raman spectra and vice versa. From these analyses, we extract a minimal gene expression signature associated with specific RS profiles and predictive of disease outcome.

Combining 18F-DOPA PET and MRI with perfusion-weighted imaging improves delineation of high-grade subregions in enhancing and non-enhancing gliomas prior treatment: a biopsy-controlled study.

PURPOSE: We aimed to compare spatial extent of high-grade subregions detected with combined [18F]-dihydroxyphenylalanine (18F-DOPA) PET and MRI to the one provided by advanced multimodal MRI alone including Contrast-enhanced (CE) and Perfusion weighted imaging (PWI). Then, we compared the accuracy between imaging modalities, in a per biopsy analysis. METHODS: Participants with suspected diffuse glioma were prospectively included between June 2018 and September 2019. Volumes of high-grade subregions were delineated respectively on 18F-DOPA PET and MRI (CE and PWI). Up to three per-surgical neuronavigation-guided biopsies were performed per patient. RESULTS: Thirty-eight biopsy samples from sixteen participants were analyzed. Six participants (38%) had grade IV IDH wild-type glioblastoma, six (38%) had grade III IDH-mutated astrocytoma and four (24%) had grade II IDH-mutated gliomas. Three patients had intratumoral heterogeneity with coexisting high- and low-grade tumor subregions. High-grade volumes determined with combined 18F-DOPA PET/MRI (median of 1.7 [interquartile range (IQR) 0.0, 19.1] mL) were larger than with multimodal MRI alone (median 1.3 [IQR 0.0, 12.8] mL) with low overlap (median Dice's coefficient 0.24 [IQR 0.08, 0.59]). Delineation volumes were substantially increased in five (31%) patients. In a per biopsy analysis, combined 18F-DOPA PET/MRI detected high-grade subregions with an accuracy of 58% compared to 42% (p = 0.03) with CE MRI alone and 50% (p = 0.25) using multimodal MRI (CE + PWI). CONCLUSIONS: The addition of 18F-DOPA PET to multimodal MRI (CE and PWI) enlarged the delineation volumes and enhanced overall accuracy for detection of high-grade subregions. Thus, combining 18F-DOPA with advanced MRI may improve treatment planning in newly diagnosed gliomas.

Additive Value of Dynamic FDOPA PET/CT for Glioma Grading.

Purpose: The aim of this study was to assess the value of the FDOPA PET kinetic parameters extracted using full kinetic analysis for tumor grading with neuronavigation-guided biopsies as reference in patients with newly-diagnosed gliomas. Methods: Fourteen patients with untreated gliomas were investigated. Twenty minutes of dynamic positron-emission tomography (PET) imaging and a 20-min static image 10 min after injection were reconstructed from a 40-min list-mode acquisition immediately after FDOPA injection. Tumors volume-of-interest (VOI) were generated based on the MRI-guided brain biopsies. Static parameters (TBRmax and TBRmean) and kinetic parameters [K1 and k2 using full kinetic analysis with the reversible single-tissue compartment model with blood volume parameter and the time-to-peak (TTP)] were extracted. Performances of each parameter for differentiating low-grade gliomas (LGG) from high-grade gliomas (HGG) were evaluated by receiver-operating characteristic analyses (area under the curve; AUC). Results: Thirty-two tumoral VOI were analyzed. K1, k2, and TTP were significantly higher for HGG than for LGG (median K1-value = 0.124 vs. 0.074 ml/ccm/min, p = 0.025, median k2-value = 0.093 vs. 0.063 min-1, p = 0.025, and median TTP-value = 10.0 vs. 15.0 min, p = 0.025). No significant difference was observed for the static parameters. The AUC for the kinetic parameters was higher than the AUC for the static parameters (respectively, AUCK1 = 0.787, AUCk2 = 0.785, AUCTTP = 0.775, AUCTBRmax = 0.551, AUCTBRmean = 0.575), significantly compared to TBRmax (respectively, p = 0.001 for K1, p = 0.031 for k2, and p = 0.029 for TTP). Conclusion: The present study suggests an additive value of FDOPA PET/CT kinetic parameters for newly-diagnosed gliomas grading.

Ventriculitis: A Severe Complication of Central Nervous System Infections.

BACKGROUND: Ventriculitis, a dreaded complication of brain abscess, meningitis, and various neurosurgical procedures, has attracted limited attention in the medical literature. METHODS: This is a retrospective, single-center study. We screened the medical files of all patients who had a brain imaging report that included the word "ventriculitis" during years 2005-2019. Only patients with clinical, microbiological, and imaging features of ventriculitis were included. Data were collected through a standardized questionnaire. RESULTS: Ninety-eight patients fulfilled inclusion criteria: 42 women and 56 men, and the median age was 60 years (interquartile range, 48-68). The primary mechanism for ventriculitis was classified as follows: brain abscess (n = 29, 29.6%), meningitis (n = 27, 27.6%), intraventricular catheter-related (n = 17, 17.3%), post-neurosurgery (n = 13, 13.3%), and hematogenous (n = 12, 12.2%). The main neuroimaging features were intraventricular pus (n = 81, 82.7%), ependymal enhancement (n = 70, 71.4%), and intraventricular loculations (n = 15, 15.3%). The main pathogens were streptococci (n = 44, 44.9%), Gram-negative bacilli (n = 27, 27.6%), and staphylococci (n = 15, 15.3%). In-hospital and 1-year mortality rates were 30.6% (n = 30) and 38.8% (n = 38), respectively. Neurological sequelae were reported in 34 of 55 (61.8%) survivors, including cognitive impairment (n = 11), gait disturbances (n = 9), paresis (n = 7), behavior disorder (n = 6), and epilepsy (n = 5). On multivariate analysis, age >65 years, Glasgow Coma Scale score <13 at initial presentation, status epilepticus, hydrocephalus, and positive cerebrospinal fluid culture were associated with 1-year mortality. We built a scoring system to stratify patients with ventriculitis into low risk (12.5%), intermediate risk (36.5%), and high risk (71.4%) of death. CONCLUSIONS: Ventriculitis is a severe complication of brain abscess, meningitis, or neurosurgery, with an in-hospital mortality rate of 30% and neurological sequelae in 60% of survivors.

Reflux of Endoplasmic Reticulum proteins to the cytosol inactivates tumor suppressors.

In the past decades, many studies reported the presence of endoplasmic reticulum (ER)-resident proteins in the cytosol. However, the mechanisms by which these proteins relocate and whether they exert cytosolic functions remain unknown. We find that a subset of ER luminal proteins accumulates in the cytosol of glioblastoma cells isolated from mouse and human tumors. In cultured cells, ER protein reflux to the cytosol occurs upon ER proteostasis perturbation. Using the ER luminal protein anterior gradient 2 (AGR2) as a proof of concept, we tested whether the refluxed proteins gain new functions in the cytosol. We find that refluxed, cytosolic AGR2 binds and inhibits the tumor suppressor p53. These data suggest that ER reflux constitutes an ER surveillance mechanism to relieve the ER from its contents upon stress, providing a selective advantage to tumor cells through gain-of-cytosolic functions-a phenomenon we name ER to Cytosol Signaling (ERCYS).

Local intracerebral inhibition of IRE1 by MKC8866 sensitizes glioblastoma to irradiation/chemotherapy in vivo.

Glioblastoma multiforme (GBM) is the most severe primary brain cancer. Despite an aggressive treatment comprising surgical resection and radio/chemotherapy, patient's survival post diagnosis remains short. A limitation for success in finding novel improved therapeutic options for such dismal disease partly lies in the lack of a relevant animal model that accurately recapitulates patient disease and standard of care. In the present study, we have developed an immunocompetent GBM model that includes tumor surgery and a radio/chemotherapy regimen resembling the Stupp protocol and we have used this model to test the impact of the pharmacological inhibition of the endoplasmic reticulum (ER) stress sensor IRE1, on treatment efficacy.

Optimization of time frame binning for FDOPA uptake quantification in glioma.

INTRODUCTION: 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (FDOPA) uptake quantification in glioma assessment can be distorted using a non-optimal time frame binning of time-activity curves (TAC). Under-sampling or over-sampling dynamic PET images induces significant variations on kinetic parameters quantification. We aimed to optimize temporal time frame binning for dynamic FDOPA PET imaging. METHODS: Fourteen patients with 33 tumoral TAC with biopsy-proven gliomas were analysed. The mean SUVmax tumor-to-brain ratio (TBRmax) were compared at 20 min and 35 min post-injection (p.i). Five different time frame samplings within 20 min were compared: 11x10sec-6x15sec-5x20sec-3x300sec; 8x15sec- 2x30sec- 2x60sec- 3x300sec; 6x20sec- 8x60sec- 2x300sec; 10x30sec- 3x300sec and 4x45sec- 3x90sec- 5x150sec. The reversible single-tissue compartment model with blood volume parameter (VB) was selected using the Akaike information criterion. K1 values extracted from 1024 noisy simulated TAC using Monte Carlo method from the 5 different time samplings were compared to a target K1 value as the objective, which is the average of the K1 values extracted from the 33 lesions using an imaging-derived input function for each patient. RESULTS: The mean TBRmax was significantly higher at 20 min p.i. than at 35 min p.i (respectively 1.4 +/- 0.8 and 1.2 +/- 0.6; p <0.001). The target K1 value was 0.161 mL/ccm/min. The 8x15sec- 2x30sec- 2x60sec- 3x300sec time sampling was the optimal time frame binning. K1 values extracted using this optimal time frame binning were significantly different with K1 values extracted from the other time frame samplings, except with K1 values obtained using the 11x10sec- 6x15sec -5x20sec-3x300sec time frame binning. CONCLUSIONS: This optimal sampling schedule design (8x15sec- 2x30sec- 2x60sec- 3x300sec) could be used to minimize bias in quantification of FDOPA uptake in glioma using kinetic analysis.

Fluorescein-guided surgery for spinal dural arteriovenous fistulas: A short series.

The gold standard treatment of spinal dural arteriovenous fistulas (SDAVF) is surgical exclusion. The main surgical challenge is to localize the origin of the shunting vein and to ensure its complete exclusion. In that context, intra operative angiography technologies have been developed, such as fluorescein video angiography (FVA). The objective of this preliminary study was to assess the utility of FVA in SDAVF surgery through a short surgical series. We retrospectively studied the cases of six patients who had a FVA for a SDAVF. FVA was performed after dural opening and visualization of the suspected shunting vein. In 5 cases, FVA was performed after ligation to ensure the complete exclusion. In 2 cases, FVA was performed before the ligation to confirm the localization of the shunt. In 1 case, FVA was performed before and after ligation. FVA was judged useful in all cases to localize the origin of the shunting vein. FVA permitted to ensure the complete exclusion after ligation. No anaphylactic events were noticed. Our preliminary study suggests that fluorescein video angiography is feasible and helpful for SDAVF surgery.

Spinal Dural Arteriovenous Fistulas: Clinical Outcome After Surgery Versus Embolization: A Retrospective Study.

OBJECTIVE: Spinal dural arteriovenous fistulas (SDAVFs) are rare vascular spinal malformations. According to the reported data, surgery seems to result in better occlusion rates than endovascular treatment. However, the post-treatment evolution of neurological symptoms stratified by the treatment remains unknown. The main objective of the present study was to compare the clinical outcomes for patients according to the treatment method. METHODS: The data from 63 patients with SDAVFs from 2000 to 2017 at 4 academic neurosurgical departments were retrospectively analyzed. Preoperative and postoperative examination neurological status was assessed using the Aminoff-Logue scale (ALS), which evaluates gait and micturition disturbances. Initial occlusion, late recurrence, and complications of the 2 techniques were also reviewed. RESULTS: Patients who had undergone surgery and embolization improved clinically on the ALS (P = 0.0009), and no significant differences were found between the 2 techniques. Subgroup analysis using the ALS showed that patients who had undergone surgery and embolization without late recurrence improved (P < 0.0001 and P = 0.0334, respectively) and that patients who had undergone surgery or embolization with late recurrence did not improve. The initial occlusion rate was in favor of surgery, with 91.3% versus 70% for endovascular treatment (P = 0.050). The late recurrence rate was higher for embolization (21.4% vs. 9.1% for surgery; P = 0.28). CONCLUSIONS: Surgery can be proposed as first-line treatment of SDAVFs after multidisciplinary discussion between neurosurgeons and neuroradiologists. The development of late recurrence negatively affects the neurological outcome of patients.

Should the clinic matter to nonphysician scientists?

Translational medicine has been nurtured by the creation of M.D.-Ph.D. programs, a system that now needs to reinvent itself. Now, clinically oriented training programs targeting nonphysician scientists have opened new avenues to improve transdisciplinary approaches in health sciences.

Comparison of neurogenic lower urinary tract dysfunctions in open versus closed spinal dysraphism: A prospective cross-sectional study of 318 patients.

AIMS: To compare the neurogenic lower urinary tract dysfunction (NLUTD) in patients with closed spinal dysraphism (CSD) versus patients with open spinal dysraphism (OSD) as well as their management patterns. METHODS: A prospective cross-sectional study was conducted between September 2007 and December 2015 including all spina bifida patients seen at the multidisciplinary French national referral center for spina bifida. NLUTD and its management were compared between the OSD and CSD groups. RESULTS: Three hundred and eighteen patients were included for analysis: 100 with a CSD (31.5%) and 218 with an OSD (68.6%). The prevalence of urinary incontinence did not differ significantly between the two groups (43% vs 52.8%; P = 0.11), the mean Qualiveen score was also similar (2.7 vs 2.5, P = 0.22). The voiding mechanism was clean intermittent catheterization, spontaneous voiding, suprapubic tube, and ileal conduit in 55% versus 44%; 29.8% versus 47%; 2.8% versus 3% and 11.9% versus 6% of OSD and CSD patients, respectively (P = 0.02). There were comparable prevalences of detrusor overactivity (36.5% vs 38.8%; P = 0.68) and impaired bladder compliance (34.9% vs 31.7%; P = 0.56) in both groups. Augmentation cystoplasty was more common in patients with OSD (32.1% vs 11%; P < 0.0001). CONCLUSIONS: In this prospective cohort, NLUTD were more common in OSD with a higher rate of patients requiring a surgical treatment and a lower rate of patients with preserved spontaneous voiding. However, when present, NLUTD was as severe and troublesome in patients with closed versus open spinal dysraphism.

Modern Management of Meningiomas Compressing the Optic Nerve: A Systematic Review.

OBJECTIVE: Meningiomas that compress the optic nerve (ON) can lead to different visual outcomes depending on the segment of ON affected (intraorbital, canalicular, and intracranial). In this study, we performed a comprehensive comparison of the management options (surgery, radiation, or observation alone) for meningiomas compressing the ON, categorized by location and relation to the ON. METHODS: MEDLINE, EMBASE, Web of Science, and the Cochrane Database of Systematic reviews databases were searched according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Data were extracted from the articles regarding anatomic location, initial visual impairment, surgical procedure, visual outcome, morbidity and mortality, gross total removal, and requirement for postoperative radiotherapy. RESULTS: Of the 47 articles eligible for full-text reading, 9 surgical studies met our inclusion criteria. Data from 317 patient cases were extracted. In patients in whom the intracranial segment of the ON was impaired in isolation, 49% experienced visual improvement after surgery. When the meningioma affected the canalicular segment or intraorbital segment, visual improvement after surgery was 31% and 11%, respectively. Of patients who underwent surgery for the intraorbital segment of the ON, 56% experienced a decline in visual outcome. CONCLUSIONS: When a neurosurgeon deals with a meningioma compressing the ON, opening the optic canal is suggested if invasion is suspected on the preoperative imaging. Extra caution should be used when operating on meningiomas with ON sheath adhesion, given the higher evidence of postoperative visual worsening.