Non-navigated 2D intraoperative ultrasound: An unsophisticated surgical tool to achieve high standards of care in glioma surgery.

PURPOSE: In an era characterized by rapid progression in neurosurgical technologies, traditional tools such as the non-navigated two-dimensional intraoperative ultrasound (nn-2D-IOUS) risk being overshadowed. Against this backdrop, this study endeavors to provide a comprehensive assessment of the clinical efficacy and surgical relevance of nn-2D-IOUS, specifically in the context of glioma resections. METHODS: This retrospective study undertaken at a single center evaluated 99 consecutive, non-selected patients diagnosed with both high-grade and low-grade gliomas. The primary objective was to assess the proficiency of nn-2D-IOUS in generating satisfactory image quality, identifying residual tumor tissue, and its influence on the extent of resection. To validate these results, early postoperative MRI data served as the reference standard. RESULTS: The nn-2D-IOUS exhibited a high level of effectiveness, successfully generating good quality images in 79% of the patients evaluated. With a sensitivity rate of 68% and a perfect specificity of 100%, nn-2D-IOUS unequivocally demonstrated its utility in intraoperative residual tumor detection. Notably, when total tumor removal was the surgical objective, a resection exceeding 95% of the initial tumor volume was achieved in 86% of patients. Additionally, patients in whom residual tumor was not detected by nn-2D-IOUS, the mean volume of undetected tumor tissue was remarkably minimal, averaging at 0.29 cm3. CONCLUSION: Our study supports nn-2D-IOUS's invaluable role in glioma surgery. The results highlight the utility of traditional technologies for enhanced surgical outcomes, even when compared to advanced alternatives. This is particularly relevant for resource-constrained settings and emphasizes optimizing existing tools for efficient patient care. NCT05873946 - 24/05/2023 - Retrospectively registered.

Current Evidence, Limitations and Future Challenges of Survival Prediction for Glioblastoma Based on Advanced Noninvasive Methods: A Narrative Review.

Background and Objectives: Survival estimation for patients diagnosed with Glioblastoma (GBM) is an important information to consider in patient management and communication. Despite some known risk factors, survival estimation remains a major challenge. Novel non-invasive technologies such as radiomics and artificial intelligence (AI) have been implemented to increase the accuracy of these predictions. In this article, we reviewed and discussed the most significant available research on survival estimation for GBM through advanced non-invasive methods. Materials and Methods: PubMed database was queried for articles reporting on survival prognosis for GBM through advanced image and data management methods. Articles including in their title or abstract the following terms were initially screened: ((glioma) AND (survival)) AND ((artificial intelligence) OR (radiomics)). Exclusively English full-text articles, reporting on humans, published as of 1 September 2022 were considered. Articles not reporting on overall survival, evaluating the effects of new therapies or including other tumors were excluded. Research with a radiomics-based methodology were evaluated using the radiomics quality score (RQS). Results: 382 articles were identified. After applying the inclusion criteria, 46 articles remained for further analysis. These articles were thoroughly assessed, summarized and discussed. The results of the RQS revealed some of the limitations of current radiomics investigation on this field. Limitations of analyzed studies included data availability, patient selection and heterogeneity of methodologies. Future challenges on this field are increasing data availability, improving the general understanding of how AI handles data and establishing solid correlations between image features and tumor's biology. Conclusions: Radiomics and AI methods of data processing offer a new paradigm of possibilities to tackle the question of survival prognosis in GBM.

Extradural anterior clinoidectomy through endoscopic transorbital approach: laboratory investigation for surgical perspective.

BACKGROUND: The endoscopic transorbital approach (eTOA) is a new mini-invasive procedure used to explore different areas of the skull base. Authors propose an extradural anterior clinoidectomy (AC) through this corridor, defining the anatomical landmarks of the anterior clinoid process (ACP) projection onto the posterior orbit wall and the technical feasibility of this approach. We describe the exposure of the opticocarotid region and the surgical freedom and the angles of attack obtained with this novel approach. METHODS: Five cadaver heads underwent an eTOA at the Laboratory of Surgical Neuroanatomy of the University of Barcelona. A step-by-step description of the extradural endoscopic transorbital clinoidectomy was provided. A volumetric analysis of the morphometrics characteristics of the sphenoid wings was evaluated before and after dissection using CT scans. Pterional approach was performed to ascertain ACP removal. RESULTS: In all the specimens, it was possible to resect the ACP endo-orbitally aiming an optimal optic canal (OC) unroofing. The surface of the triangle corresponding to the ACP projection onto the posterior orbit wall was 0.42 ± 0.20 cm2. The drilled area to perform the extradural clinoidectomy via eTOA was 3.11 ± 2.27 cm2, and the volume of bone removal corresponding to the greater sphenoid wing (GSW) and lesser sphenoid wing (LSW) was 2.55 ± 1.41 and 0.26 ± 0.18 cm3 respectively. The area of surgical freedom provided by the eTOA was (3.11 ± 2.27cm2), and the angles of attack were 21.39 ± 9.13° in the horizontal axel and 30.63 ± 18.51° in the vertical. CONCLUSIONS: The described extradural anterior clinoidectomy by eTOA uses specific landmarks to localize the ACP on the posterior orbit wall. Resection of the ACP is a technically feasible approach, achieving the main goals of any clinoidectomy.

Giant Posterior Communicating Artery Aneurysm Presenting as Trigeminal Neuralgia.

BACKGROUND: We report an extremely rare case of trigeminal neuralgia (TN) caused by a giant posterior communicating artery aneurysm. METHODS: We describe the case of a 73-year-old man who suffered disabling TN, which was deeply exacerbated when he laid down. Computed tomography angiography and digital angiography revealed an unruptured giant posterior left communicating artery aneurysm projecting to the posterior fossa and contacting the trigeminal root. RESULTS: The size and projection of the aneurysm seemed responsible for both the neuralgia itself and its peculiar clinical characteristic of exacerbation when the patient laid down. The aneurysm was surgically clipped, then opened and emptied to decompress the trigeminal root. The patient reported an immediate complete remission of the neuralgia. CONCLUSION: The finding of TN secondary to aneurysms is rare but even more in the case of a posterior communicating aneurysm. The clinical clue that should alert physicians about the presence of an aneurysm as the cause of TN is exacerbation of pain by adopting a supine position. Due to the high risk of rupture associated with giant and symptomatic aneurysms, we believe that treatment should be aggressive in this case, not only to solve the symptomatic TN but also to avoid the risk of aneurysm rupture in the future. The treatment selection between surgical clipping or endovascular coiling with or without stenting, depends on patient's clinical condition and the size and shape of the aneurysm.

Microvascular decompression for trigeminal neuralgia secondary to vertebrobasilar dolichoectasia. Case report, literature review, and pooled case analysis.

INTRODUCTION: Vertebrobasilar dolichoectasia is a condition in which there is elongation and dilatation of the vertebral and basilar arteries. Few studies have been reported that focus on cases of trigeminal neuralgia (TN) secondary to vertebrobasilar dolichoectasia (VD) and treated by microvascular decompression (MD). PATIENTS AND METHODS: A case is presented of trigeminal neuralgia caused by vertebral artery compression. An analysis of the microsurgical technique, as well as a systematic review of the literature about this uncommon nerve compression is performed, in order to investigate, by pooled case analysis, if MD is a good option for this type of patient. RESULTS: A total of 7 studies were included for analysis, to which the present case was added, making a total of 56 patents. There were excellent results in 53 cases, and partial recovery in 3, with a mean follow up of 54 months. No major complications were found. DISCUSSION: The good clinical results and absence of postoperative mortality or severe morbidity in our pooled case series lead us to recommend MD as the preferred treatment for TN caused by VD in patients in whom major surgery is not contraindicated.

Histology of a cerebral hemorrhage: AVM as a seat of a metastatic choriocarcinoma.

INTRODUCTION: There are published cases of cerebral hemorrhage secondary to vascular alterations caused by choriocarcinoma metastases. However, it is extremely rare to find this type of bleeding secondary to an association of such a metastasis with a brain arteriovenous malformation (AVM). CLINICAL CASE: We present the case of a 19-year-old male who came to the Emergency Department complaining of intense headache of abrupt onset. His physical examination revealed a striking increase in size of the right testicle of tumoral origin. Chest X-ray evidenced metastasis to the lungs and a brain CT showed a frontal hemorrhage of probably metastatic origin. The latter eventually progressed to cause the death of the patient. Pathology of the brain hematoma disclosed a choriocarcinoma within the brain AVM nidus. CONCLUSIONS: The case presented is an extremely rare confluence of choriocarcinoma brain metastasis within an AVM. The hemorrhagic onset could have been secondary to bleeding from either of the two histological components of the subjacent mixed pathological lesion.

Chiasmal haemorrhage secondary to glioma with unusual MRI appearance.

OBJECTIVE: To report a unique case of haemorrhagic presentation of a chiasmal and optic tract glioma (OPG) appearing as an extra-axial lesion on MRI scans. CASE REPORT: A 30-year-old female with a preoperative radiological diagnosis of dermoid cyst was operated. No lesion was found in the chiasmal or carotid cisterns within the operative field. The right posterolateral corner of the chiasma and the beginning of the right optic tract appeared swollen. The area was incised and a haemorrhagic fluid poured through the opening. Several samples were taken and the pathological diagnosis was of pilocytic glioma. CONCLUSIONS: We present a unique case of chiasmal bleeding into the optic pathway secondary to an optic glioma which radiologically mimicked an intracisternal cyst. In similar cases, rapid clinical evolution of the symptoms may be vital for the differential diagnosis. Surgery is warranted to prevent permanent damage to the visual pathway.

Integrating Endovascular Techniques into Established Open Neurosurgery Practice: A Temporal Analysis of Treatment Evolution in a Dual-Trained Neurosurgical Unit.

OBJETIVE: In Europe, units with Dual-trained Neurovascular Surgeons (DTNS) skilled in both open neurosurgery (ON) and endovascular neurosurgery (EN) are scarce. For instance, in Spain, our unit is unique within the public health system, where all neurovascular procedures are carried out by DTNS. Our study aims to evaluate the evolution in treating ruptured intracranial aneurysms (rICAs) and assess the impact of this evolution on clinical outcomes. METHODS: A retrospective cohort study was performed on rICAs treated in our unit from October 2012 to June 2023. We reviewed clinical and radiological data to analyze the evolution of ON and EN over time, as well as their impact on patient outcomes. Univariate, multivariate, and mixed-effects models were utilized to discern temporal changes. RESULTS: The modified Fisher Scale (mFS) and the modified World Federation of Neurological Surgeons scale (mWFNS) showed strong correlation with the outcome at 6 months outcomes, both with p < 0.00001. However, the surgical intervention method, ON versus EN, did not significantly affect outcomes (p > 0.85). In adjusted multivariate logistic regression, mFS (-1.579, p: 0.011) and mWFNS (-0.872, p < 0.001) maintained their significance. rICAs location was significant when comparing ON to EN p = 0.0001. A significant temporal trend favored the selection of EN p = 0.0058). Mixed-effects time series modeling indicated that while patient characteristics and rICA specifics did not predict treatment choice, the year of treatment was significantly correlated (0.161, p = 0.002). Logistic regression with interaction terms for time and treatment type did not produce significant results. CONCLUSION: Our findings suggest that despite an increased adoption of EN techniques, there has been no change in patient outcomes. Even with the rise of EN, our unit continues to perform ON for a higher proportion of rICAs than most national hospitals. We propose that a "dual approach" offers advantages in a patient individualized treatment decision protocol in the European context.

Posterior cervical triangle approach for carotid endarterectomy: Technical note and results.

INTRODUCTION: Carotid endarterectomy (CEA) is usually performed using the anterior cervical triangle as a surgical corridor but, when needed, the retromandibular space makes dissection of higher structures difficult in some cases. The posterior cervical triangle (PCT) can be useful in these demanding cases. METHODS: We retrospectively reviewed cases from July 2013 to November 2019 in which PCT was used as an approach for CEA. The surgical technique used was explained, and the complications and evolution of the patients were analysed. RESULTS: We found 7 CEAs performed through this approach, of which 2 presented transient trapezius paresis. There were no cases of severe complications in this series. CONCLUSION: The PCT approach for performing CEA represents a useful and easy technique that avoids the need for mandibular mobilisation or osteotomies for lesions located in anatomically high carotid bifurcations.

The Río Hortega University Hospital Glioblastoma dataset: A comprehensive collection of preoperative, early postoperative and recurrence MRI scans (RHUH-GBM).

Glioblastoma, a highly aggressive primary brain tumor, is associated with poor patient outcomes. Although magnetic resonance imaging (MRI) plays a critical role in diagnosing, characterizing, and forecasting glioblastoma progression, public MRI repositories present significant drawbacks, including insufficient postoperative and follow-up studies as well as expert tumor segmentations. To address these issues, we present the "Río Hortega University Hospital Glioblastoma Dataset (RHUH-GBM)," a collection of multiparametric MRI images, volumetric assessments, molecular data, and survival details for glioblastoma patients who underwent total or near-total enhancing tumor resection. The dataset features expert-corrected segmentations of tumor subregions, offering valuable ground truth data for developing algorithms for postoperative and follow-up MRI scans.

Mortality Prediction of Patients with Subarachnoid Hemorrhage Using a Deep Learning Model Based on an Initial Brain CT Scan.

BACKGROUND: Subarachnoid hemorrhage (SAH) entails high morbidity and mortality rates. Convolutional neural networks (CNN) are capable of generating highly accurate predictions from imaging data. Our objective was to predict mortality in SAH patients by processing initial CT scans using a CNN-based algorithm. METHODS: We conducted a retrospective multicentric study of a consecutive cohort of patients with SAH. Demographic, clinical and radiological variables were analyzed. Preprocessed baseline CT scan images were used as the input for training using the AUCMEDI framework. Our model's architecture leveraged a DenseNet121 structure, employing transfer learning principles. The output variable was mortality in the first three months. RESULTS: Images from 219 patients were processed; 175 for training and validation and 44 for the model's evaluation. Of the patients, 52% (115/219) were female and the median age was 58 (SD = 13.06) years. In total, 18.5% (39/219) had idiopathic SAH. The mortality rate was 28.5% (63/219). The model showed good accuracy at predicting mortality in SAH patients when exclusively using the images of the initial CT scan (accuracy = 74%, F1 = 75% and AUC = 82%). CONCLUSION: Modern image processing techniques based on AI and CNN make it possible to predict mortality in SAH patients with high accuracy using CT scan images as the only input. These models might be optimized by including more data and patients, resulting in better training, development and performance on tasks that are beyond the skills of conventional clinical knowledge.

Predicting Regions of Local Recurrence in Glioblastomas Using Voxel-Based Radiomic Features of Multiparametric Postoperative MRI.

The globally accepted surgical strategy in glioblastomas is removing the enhancing tumor. However, the peritumoral region harbors infiltration areas responsible for future tumor recurrence. This study aimed to evaluate a predictive model that identifies areas of future recurrence using a voxel-based radiomics analysis of magnetic resonance imaging (MRI) data. This multi-institutional study included a retrospective analysis of patients diagnosed with glioblastoma who underwent surgery with complete resection of the enhancing tumor. Fifty-five patients met the selection criteria. The study sample was split into training (N = 40) and testing (N = 15) datasets. Follow-up MRI was used for ground truth definition, and postoperative structural multiparametric MRI was used to extract voxel-based radiomic features. Deformable coregistration was used to register the MRI sequences for each patient, followed by segmentation of the peritumoral region in the postoperative scan and the enhancing tumor in the follow-up scan. Peritumoral voxels overlapping with enhancing tumor voxels were labeled as recurrence, while non-overlapping voxels were labeled as nonrecurrence. Voxel-based radiomic features were extracted from the peritumoral region. Four machine learning-based classifiers were trained for recurrence prediction. A region-based evaluation approach was used for model evaluation. The Categorical Boosting (CatBoost) classifier obtained the best performance on the testing dataset with an average area under the curve (AUC) of 0.81 ± 0.09 and an accuracy of 0.84 ± 0.06, using region-based evaluation. There was a clear visual correspondence between predicted and actual recurrence regions. We have developed a method that accurately predicts the region of future tumor recurrence in MRI scans of glioblastoma patients. This could enable the adaptation of surgical and radiotherapy treatment to these areas to potentially prolong the survival of these patients.

Contralateral approach for middle cerebral artery aneurysms with long M1 segment: report of 2 cases.

INTRODUCTION: Contralateral clipping of middle cerebral artery (MCA) aneurysms is not practiced widely and has been reported only in case series. Some of the neurosurgeons proposing this approach have even postulated that a short M1 segment is a basic requirement for performing it. CASES: We present our experience using a contralateral approach with 2 patients who had 3 MCA aneurysms located more than 2.5cm from the carotid bifurcation. All 3 aneurysms were completely occluded, as demonstrated on postoperative CT angiography, and the patients' neurological evolution was uneventful. DISCUSSION: The contralateral approach can be regarded as a safe and effective technique for MCA aneurysm clipping. One contraindication frequently stated is the length of the MCA M1 segment; however, our experience proves that long distances can be reached if an adequate Sylvian fissure dissection is performed. We consider that the use of a contralateral approach requires fine technical skills and should be the choice only under judicious case-to-case planning, always bearing the preferences and experience of the neurosurgeon in mind.

Treatment of unruptured middle cerebral artery aneurysms: Systematic review in an attempt to perform a network meta-analysis.

Objective: Open surgical clipping has been generally considered the best treatment option for unruptured middle cerebral artery aneurysms (uMCAAs). However, this type of aneurysm is being treated endovascularly with the appearance of new devices. We have carried out a systematic review of randomized and quasi-experimental studies to conduct a network meta-analysis (NMA) to assess the safety and efficacy of the different treatment methods currently used in uMCAAs. Methods: The literature was searched by using PubMed and Google Scholar databases. Eligibility criteria were randomized or quasi-experimental studies including at least five cases per arm and reporting duration of follow-up and number of lost cases. The end points were: angiographic success, final neurological outcome, and the need for retreatments. Results: We could only analyze four quasi-experimental studies with 398 uMCAAs. All of them compared clipping vs. coiling. Clipping showed better results than coiling in all analyzed end points. We could not conduct the proposed NMA because of the absence of randomized or quasi-experimental studies. Instead, a systematic review is further discussed. Conclusions: There is an urgent need for comparative studies on the treatment of uMCAAs.

Brain dural arteriovenous fistulas in the COVID-19 Era: A warning and rationale for association.

OBJECTIVES: Brain dural arteriovenous fistulas(bDAVFs) are anomalous connections between dural arteries and cerebral veins or sinuses. Cerebral venous thrombosis(CVT) often precedes or coincides with bDAVFs and is considered a risk factor for these vascular malformations. Recently, vaccine-induced thrombotic thrombocytopenia causing CVTs has been associated with COVID-19 vaccines. Concurrently with the start of massive vaccination in our region, we have observed a fivefold increase in the average incidence of bDAVFs. Our objective is to raise awareness of the potential involvement of COVID-19 vaccines in the pathogenesis of bDAVF. METHODS: A retrospective review of demographic, clinical, radiological, COVID-19 infection and vaccination data of patients diagnosed with bDAVFs between 2011 and 2021 was conducted. Patients were divided into two cohorts according to their belonging to pre- or post-COVID-19 vaccination times. Cohorts were compared for bDAVFs incidences and demographic and clinical features. RESULTS: Twenty-one bDAVFs were diagnosed between 2011 and 2021, 7 of which in 2021. The mean age was 57.7 years, and 62 % were males. All cases except one were treated; of them, 85 % exclusively managed with surgery. All treated cases were successfully occluded. The incidence in 2021 was significantly higher than that in the prevaccination period (1.72 vs 0.35/100,000/year;p = 0.036; 95 %Confidence Interval=0.09-2.66). Cohorts were not different in age, sex, hemorrhagic presentation, dural sinus thrombosis or presence of prothrombotic or cardiovascular risk factors. CONCLUSION: The significant increase in the incidence of bDAVF following general vaccination policies against COVID-19 observed in our region suggests a potential correlation between these two facts. Our findings need confirmation from larger cohorts and further pathogenic research.

Advantages and Limitations of Intraoperative Ultrasound Strain Elastography Applied in Brain Tumor Surgery: A Single-Center Experience.

BACKGROUND: Strain elastography is an intraoperative ultrasound (ioUS) modality currently under development with various potential applications in neurosurgery. OBJECTIVE: To describe the main technical aspects, usefulness, and limitations of ioUS strain elastography applied in a large case series of brain tumors. METHODS: We retrospectively analyzed patients who underwent craniotomy for a brain tumor between March 2018 and March 2021. Cases with an ioUS strain elastography study were included. The elastograms were processed semiquantitatively, and the mean tissue elasticity (MTE) values were calculated from the histogram of intensities. An analysis was performed to correlate the histopathological groups and the tumor and peritumoral MTE values using the Kruskal-Wallis test and a decision tree classifier. Furthermore, elastogram quality was assessed to discuss possible artifacts and weaknesses of the ultrasound technique. RESULTS: One hundred two patients with the following histopathological diagnoses were analyzed: 43 high-grade gliomas, 11 low-grade gliomas, 28 meningiomas, and 20 metastases. The tumor MTE values were significantly different between the histopathological groups (P < .001). The decision tree classifier showed an area under the curve of 0.73 and a classification accuracy of 72%. The main technical limitations found in our series were the presence of artifacts after dural opening, the variability of the frequency and amplitude of the mechanical pulsations, and the challenge in evaluating deep lesions. CONCLUSION: Tumor stiffness revealed by ioUS strain elastography has a plausible histopathological correlation. Thus, this fast and versatile technique has enormous potential to be exploited in the coming years.

Relationship between the overall survival in glioblastomas and the radiomic features of intraoperative ultrasound: a feasibility study.

PURPOSE: Predicting the survival of patients diagnosed with glioblastoma (GBM) is essential to guide surgical strategy and subsequent adjuvant therapies. Intraoperative ultrasound (IOUS) can contain biological information that could be correlated with overall survival (OS). We propose a simple extraction method and radiomic feature analysis based on IOUS imaging to estimate OS in GBM patients. METHODS: A retrospective study of surgically treated glioblastomas between March 2018 and November 2019 was performed. Patients with IOUS B-mode and strain elastography were included. After preprocessing, segmentation and extraction of radiomic features were performed with LIFEx software. An evaluation of semantic segmentation was carried out using the Dice similarity coefficient (DSC). Using univariate correlations, radiomic features associated with OS were selected. Subsequently, survival analysis was conducted using Cox univariate regression and Kaplan-Meier curves. RESULTS: Sixteen patients were available for analysis. The DSC revealed excellent agreement for the segmentation of the tumour region. Of the 52 radiomic features, two texture features from B-mode (conventional mean and the grey-level zone length matrix/short-zone low grey-level emphasis [GLZLM_SZLGE]) and one texture feature from strain elastography (grey-level zone length matrix/long-zone high grey-level emphasis [GLZLM_LZHGE]) were significantly associated with OS. After establishing a cut-off point of the statistically significant radiomic features, we allocated patients in high- and low-risk groups. Kaplan-Meier curves revealed significant differences in OS. CONCLUSION: IOUS-based quantitative texture analysis in glioblastomas is feasible. Radiomic tumour region characteristics in B-mode and elastography appear to be significantly associated with OS.

Validation of Presurgical Simulation of White Matter Damage Using Diffusion Tensor Imaging.

BACKGROUND: The understanding of white matter (WM) was revolutionized by the emergence of tractography based on diffusion tensor imaging (DTI). Currently, DTI simulations are implemented in preoperative planning to optimize surgical approaches. The reliability of these simulations has been questioned and investigated seeking for correlation between neurological performance and anomalies in DTI parameters. However, the ability of preoperative WM simulations to predict a surgical injury has not been thoroughly evaluated. Our objective was to assess the reliability of preoperatively simulated WM injuries for conventional neurosurgical procedures. METHODS: WM surgical damage was preoperatively simulated by creating a 3-dimensional volume representing the endoscope or the surgical trajectory. This volume was used as an additional region of interest in the fascicle reconstruction to be subtracted from the original fascicle. Simulated, injured fascicles were compared in terms of the number of fibers and volume to those created from postoperative DTI studies. Reliability was assimilated into the correlation between the simulation and the postoperative reconstruction; evaluated using the intraclass correlation coefficient or Lin's Concordance correlation coefficient (CCC), and represented on Bland-Altman plots. RESULTS: The preoperative and postoperative DTI studies of 30 patients undergoing various neurosurgical approaches were processed. The correlation between simulated injuries and postoperative studies was high in terms of fibers (Concordance correlation coefficient = Rho.C = 0.989 [95% confidence interval = 0.979-0.995]) and volume (intraclass correlation coefficient = 0.95 [95% CI = 0.89-0.97]). Bland-Altman plots demonstrated that the great majority of cases fell within the mean ± 2 Standard deviations. CONCLUSIONS: Presurgical simulation of WM fascicles based on DTI is consistent with postoperative DTI studies. These findings require further validation by neurophysiological and clinical correlation.

Acute changes in diffusion tensor-derived metrics and its correlation with the motor outcome in gliomas adjacent to the corticospinal tract.

BACKGROUND: This study involves analysis of the relationship between variables obtained using diffusion tensor imaging (DTI) and motor outcome in gliomas adjacent to the corticospinal tract (CST). METHODS: Histologically confirmed glioma patients who were to undergo surgery between January 2018 and December 2019 were prospectively enrolled. All patients had a preoperative magnetic resonance imaging (MRI) study that included DTI, a tumor 2 cm or less from the CST, and postsurgical control within 48 h. Patients with MRI that was performed at other center, tumors with primary and premotor cortex invasion, postsurgical complications directly affecting motor outcome and tumor progression <6 months were excluded in the study. In pre- and post-surgical MRI, we measured the following DTI-derived metrics: fractional anisotropy (FA), mean diffusivity, axial diffusivity, and radial diffusivity of the entire CST and peritumoral CST regions and in the contralateral hemisphere. The motor outcome was assessed at 1, 3, and 6 months using the Medical Research Council scale. RESULTS: Eleven patients were analyzed, and six corresponded to high-grade gliomas and five to low-grade gliomas. Four patients had previous motor impairment and seven patients had postsurgical motor deficits (four transient and three permanent). An FA ratio of 0.8 between peritumoral CST regions and the contralateral hemisphere was found to be the cutoff, and lower values were obtained in patients with permanent motor deficits. CONCLUSION: Quantitative analysis of DTI that was performed in the immediate postsurgery period can provide valuable information about the motor prognosis after surgery for gliomas near the CST.