Undergoing Brain Tumor Resection Research Articles

Open access segmentations of intraoperative brain tumor ultrasound images.

Registration and segmentation of magnetic resonance (MR) and ultrasound (US) images could play an essential role in surgical planning and resectioning brain tumors. However, validating these techniques is challenging due to the scarcity of publicly accessible sources with high-quality ground truth information. To this end, we propose a unique set of segmentations (RESECT-SEG) of cerebral structures from the previously published RESECT dataset to encourage a more rigorous development and assessment of image-processing techniques forneurosurgery. The RESECT database consists of MR and intraoperative US (iUS) images of 23 patients who underwent brain tumor resection surgeries. The proposed RESECT-SEG dataset contains segmentations of tumor tissues, sulci, falx cerebri, and resection cavity of the RESECT iUS images. Two highly experienced neurosurgeons validated the quality of the segmentations. Segmentations are provided in 3D NIFTI format in the OSF open-science platform: https://osf.io/jv8bk. The proposed RESECT-SEG dataset includes segmentations of real-world clinical US brain images that could be used to develop and evaluate segmentation and registration methods. Eventually, this dataset could further improve the quality of image guidance inneurosurgery.

Incidence and Risk Factors of Delirium Following Brain Tumor Resection: A Retrospective National Inpatient Sample Database Study

The aim of this study was to evaluate the occurrence and factors predisposing to delirium following brain tumor resection. Data from patients who underwent brain tumor resection surgery from 2016 to 2019 were extracted from the National Inpatient Sample database and retrospectively analyzed. The difference between the 2 groups was compared by Wilcoxon rank test or χ2 test was used. Univariate and multivariate logistic regression analyses were used to identify the risk factors of delirium after brain tumor resection. From 2016 to 2019, 28,340 patients who underwent brain tumor resection were identified in the National Inpatient Sample database, with the incidence of delirium being 4.79% (1357/28,340). It was found that increased incidence of delirium was significantly associated with age over 75years and males (all P<0.001). Besides, patients with delirium were more likely to have multiple comorbidities and to receive elective surgery (all P<0.001). The results of logistic regression analysis showed that self-pay (odds ratio [OR]=0.51; confidence interval [CI]=0.31-0.83; P=0.007), elective admission (OR=0.53; CI=0.47-0.60; P<0.001), obesity (OR=0.77; CI=0.66-0.92; P=0.003), females (OR=0.79; CI=0.71-0.88; P<0.001), and private insurance (OR=0.80; CI=0.67-0.95; P=0.012) were associated with lower occurrence of delirium. Besides, delirium was related to extra total hospital charges (P<0.001), increased length of stay (P<0.001), higher inpatient mortality (P=0.001), and perioperative complications (including heart failure, acute renal failure, urinary tract infection, urinary retention, septicemia, pneumonia, blood transfusion, and cerebral edema) (P<0.001). Many factors were associated with the occurrence of delirium after brain tumor resection. Therefore, clinicians should identify high-risk patients prone to delirium in a timely manner and take effective management measures to reduce adverse outcomes.

Physical Health-Related Quality of Life and Postsurgical Outcomes in Brain Tumor Resection Patients.

Background Patient-reported outcome measures (PROMs) have gained traction in assessing patients' health around surgery. Among these, the 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29) is a widely accepted tool for evaluating overall health, yet its applicability in cranial neurosurgery remains uncertain. Objective This study aimed to evaluate the predictive value of preoperative PROMIS-29 scores for postoperative outcomes in patients undergoing brain tumor resection. Materials and Methods We identified adult patients undergoing brain tumor resection at a single neurosurgical center between January 2018 and December 2021. We analyzed physical health (PH) summary scores to determine optimal thresholds for predicting length of stay (LOS), discharge disposition (DD), and 30-day readmission. Bivariate analyses were conducted to examine the distribution of PH scores based on patient characteristics. Multivariate logistic regression models were employed to assess the association between preoperative PH scores and short-term postoperative outcomes. Results Among 157 patients (mean age 55.4 years, 58.0% female), 14.6% exhibited low PH summary scores. Additionally, 5.7% experienced prolonged LOS, 37.6% had nonroutine DDs, and 19.1% were readmitted within 30 days. Bivariate analyses indicated that patients with low PH summary scores, indicating poorer baseline PH, were more likely to have malignant tumors, nonelective admissions, and adverse outcomes. In multivariate analysis, low PH summary scores independently predicted increased odds of prolonged LOS (odds ratio [OR] = 6.09, p = 0.003), nonroutine DD (OR = 4.25, p = 0.020), and 30-day readmission (OR = 3.93, p = 0.020). Conclusion The PROMIS-29 PH summary score serves as a valuable predictor of short-term postoperative outcomes in brain tumor patients. Integrating this score into clinical practice can enhance the ability to anticipate meaningful postoperative results.

P.127 Quality of life (QoL) using EORTC QoL-C30 and BN20 among patients who underwent brain tumor resection in a tertiary hospital in Saudi Arabia

Background: Quality of life (QoL) is the awareness of individuals’ well-being in life in physical, personal, mental and social wellbeing and needs to be addressed in brain tumor patients. Methods: A retrospective study conducted in 2017 in a single academic center that included patients diagnosed with brain tumors in a 10 year period. The assessment of the QoL was done using the European Organization for Research and Treatment of Cancer (EORTC), a standardized model (QLQ-C30) that assess several domains (Global Health, Physical function, Role functioning, Emotional Functioning, Cognitive functioning, social functioning and symptoms domain) and Brain cancer model (BN20) to assess symptoms to evaluate all aspects of wellbeing. Results: The total number of patients included in this study is 76 patients with no gender predilection. The most common brain tumor was meningioma by 40% followed by glioma/ others. More than half of the brain tumor patients had a WHO grade I (65%), intermediate grading grade II (15%) and higher grading grade III/IV (20%). The scales and measurements of functioning in life were low in all types of brain tumors. Conclusions: Quality of life in brain tumor patients seemed poor regardless of the type. Further prospective studies are needed to assess QoL worldwide.

Rapid DNA methylation-based classification of pediatric brain tumors from ultrasonic aspirate specimens

BackgroundAlthough cavitating ultrasonic aspirators are commonly used in neurosurgical procedures, the suitability of ultrasonic aspirator-derived tumor material for diagnostic procedures is still controversial. Here, we explore the feasibility of using ultrasonic aspirator-resected tumor tissue to classify otherwise discarded sample material by fast DNA methylation-based analysis using low pass nanopore whole genome sequencing.MethodsUltrasonic aspirator-derived specimens from pediatric patients undergoing brain tumor resection were subjected to low-pass nanopore whole genome sequencing. DNA methylation-based classification using a neural network classifier and copy number variation analysis were performed. Tumor purity was estimated from copy number profiles. Results were compared to microarray (EPIC)-based routine neuropathological histomorphological and molecular evaluation.Results19 samples with confirmed neuropathological diagnosis were evaluated. All samples were successfully sequenced and passed quality control for further analysis. DNA and sequencing characteristics from ultrasonic aspirator-derived specimens were comparable to routinely processed tumor tissue. Classification of both methods was concordant regarding methylation class in 17/19 (89%) cases. Application of a platform-specific threshold for nanopore-based classification ensured a specificity of 100%, whereas sensitivity was 79%. Copy number variation profiles were generated for all cases and matched EPIC results in 18/19 (95%) samples, even allowing the identification of diagnostically or therapeutically relevant genomic alterations.ConclusionMethylation-based classification of pediatric CNS tumors based on ultrasonic aspirator-reduced and otherwise discarded tissue is feasible using time- and cost-efficient nanopore sequencing.

Bony Surface-Matching Registration of Neuronavigation with Sectioned 3-Dimensional Skull in Prone Position

BackgroundNeuronavigation has become an essential system for brain tumor resections. It is sometimes difficult to obtain accurate registration of neuronavigation in prone position. The bony surface-matching registration should be more precise than skin surface-matching registration, however it is difficult to establish bony registration with limited exposed bone. We created a new bony surface-matching method to a section 3-dimensional (D) virtual skull in a neuronavigation system and register with a sectioned 3-D skull. In this study, the bony surface-matching with sectioned 3-D registration is applied to provide precise registration for brain tumor resections in prone position. MethodsFrom May 2023 to April 2024, 17 patients who underwent brain tumor resection in prone position were enrolled. The navigation system StealthStation S8 (Medtronic) was used. Bony surface-matching registration with a whole 3-D skull in a neuronavigation system was performed. Then, a sectioned 3-D skull was made according to surgical location to compare with whole 3-D skull registration. A phantom model was also used to validate between whole and sectioned 3-D skull registration. ResultsWhole 3-D skull registration was successful in only 2 (11.8%) patients, on the other hand, sectioned 3-D skull registration was successful in 16 (94.1%) patients. The examinations with a phantom skull model also showed superiority of sectioned 3-D skull registration to whole 3-D skull registration. ConclusionSectioned 3-D skull registration was superior to whole 3-D skull registration. Sectioned 3-D skull method could provide accurate registration with limited exposed bone.

Risk factors for postoperative ventriculoperitoneal shunt requirement in pediatric patients with brain tumors invading or adjacent to CSF circulation pathways.

Hydrocephalus is a common comorbidity of brain tumors in children that may persist following brain tumor resection. This study aimed to explore perioperative risk factors associated with postoperative ventriculoperitoneal shunt (VPS) placement for tumors located at or adjacent to the CSF circulation pathway. Patients aged 0-18 years with tumors invading or adjacent to the CSF circulation pathways who underwent brain tumor resection between October 2015 and September 2021 were included in this study. The outcome metric was whether patients underwent VPS placement within 6 months of tumor resection. Patients were followed up every 3-6 months after surgery. Demographic and perioperative imaging characteristics, clinical variables, and long-term treatments, including radiotherapy or chemotherapy, were included in the analysis. Two hundred sixty-five children were included in this study. Of these patients, 38 (14.34%) underwent VPS placement within 6 months of tumor resection. One hundred thirty-two patients (49.81%) presented with preoperative hydrocephalus. Results from the multivariate analysis showed that medulloblastoma (OR 4.15, 95% CI 1.74-9.91, p = 0.001), lateral/third ventricle tumors (OR 4.07, 95% CI 1.33-12.30, p = 0.014), postoperative intraventricular hematoma (OR 3.36, 95% CI 1.53-7.38, p = 0.003), and presence of subdural hygroma in the nonoperated area within 48 hours after tumor resection (OR 2.78, 95% CI 1.15-6.74, p = 0.024) were independent risk factors for postoperative VPS placement. Postoperative lateral/third ventricle hematoma and subdural hygroma in the nonoperated area, anatomical location, and tumor histology may be potential risk factors for a postoperative VPS after brain tumor resection.

Alterations in hypothalamic-pituitary axis (HPA) hormones 6 months after cranial radiotherapy in adult patients with primary brain tumors outside the HPA region.

Cranial radiotherapy is a common treatment for brain tumors, but it can affect the hypothalamic-pituitary (H-P) axis and lead to hormonal disorders. This study aimed to compare serum levels of HPA hormones before and after cranial radiation. This study involved 27 adult patients who underwent brain tumor resection before the initiation of radiotherapy, and none had metastatic brain tumors. All participants had the HPA within the radiation field, and their tumors were located in brain areas outside from the HPA. Serum levels of HPA hormones were recorded both before and 6 months after cranial radiotherapy. A total of 27 adult patients, comprising 16 (59.3%) males and 11 (40.7%) females, with a mean age of 56.37 ± 11.38 years, were subjected to evaluation. Six months post-radiotherapy, serum levels of GH and TSH exhibited a significant decrease. Prior to radiotherapy, a substantial and direct correlation was observed between TSH and FSH (p = 0.005) as well as LH (p = 0.014). Additionally, a significant and direct relationship was noted between serum FSH and LH (p < 0.001) before radiotherapy. After radiotherapy, a significant and direct correlation persisted between TSH and FSH (p = 0.003) as well as LH (p = 0.005), along with a significant and direct relationship between serum FSH and LH (p < 0.001). Furthermore, a significant and direct association was identified between changes in serum GH levels and FSH (p = 0.04), as well as between serum LH and FSH (p < 0.001). Reduced serum levels of HPA hormones are a significant complication of cranial radiotherapy and should be evaluated in follow-up assessments.

Growth kinetics of benign neuroepithelial brain tumors in children with relapse

The problem of treating children with recurrent cerebral tumors cannot be solved without effective prediction of recurrent blastomatous growth. The main question will be, in addition to the possible risks of tumor recurrence, when should regrowth of the neoplasm be expected in time? In our opinion, one of the probable ways to solve this problem is to study the kinetics of tumor growth and create a mathematical model for it. The aim of the study was to analyze the kinetic features of the continued growth of benign neuroepithelial brain tumors in children after surgical treatment. The study included the results of an MRI of a 32 patients under the age of 17 years. All patients underwent brain tumor resection for the first time in the Department for Children Polenov Neurosurgical Institute (Almazov National Medical Research Centre). All patients had a relapse/continued tumor growth, as well as a benign nature of the neoplasm, which was confirmed pathomorphologically. To construct the kinetic curves, volumetric indicators of tumors obtained by virtual 3D-modeling were used. Depending on the histotype, the tumor growth rate was determined by the formula: v = (VT-VO)/T, and a graphical assessment of changes in the volume of the neoplasm was carried out – the construction of kinetic curves. Further, the most typical kinetic curves for each histological type of benign neuroepithelial tumors were identified.

Same-day discharge after craniotomy for brain tumor resection: enhancing patient selection through a prognostic scoring system.

Neurosurgery, among other surgical fields, is amid a shift in patient management with enhanced recovery and same-day discharge (SDD) protocols slowly becoming more popular and feasible. While such protocols reduce the risk of nosocomial complications and improve patient satisfaction, appropriate patient selection remains an area of debate. The authors aimed to better quantify selection criteria through a prospective follow-up study of patients undergoing brain tumor resection with SDD. Three arms of analysis were carried out. First, clinical data of SDD patients were prospectively collected between August 2021 and August 2022. In parallel, a retrospective analysis of patients who qualified for SDD but were excluded at surgeon clinical discretion over the same period was performed. Third, a comparative analysis of the pilot and follow-up studies was done from which a clinical scoring system for patient selection was derived. Over the duration of the study, 31 of 334 patients were selected for SDD while 59 qualified for SDD by previously defined criteria but were not selected at the surgeon's discretion. There was no difference in outcomes between the two groups, and there were no postoperative complications among the SDD group within 30 days of surgery. Preoperative clinical characteristics found to be significantly different between the two cohorts (left-sided lesion, extra-axial pathology, prior treatment of brain tumor, and tumor volume ≤ 11.75 cm3) were included in a predictive scoring system for successful SDD. The scoring system was found to significantly predict high or low likelihood for successful SDD when tested on the mixed prospective cohort. This study provides a straightforward clinical scoring system for appropriate selection of candidates for SDD after craniotomy for brain tumor resection. This clinical tool aims to aid clinicians in appropriate admission course selection and builds on the growing literature surrounding same-day and outpatient cranial neurosurgery.

Current State of Functional MRI in the Presurgical Planning of Brain Tumors.

Surgical resection of brain tumors is challenging because of the delicate balance between maximizing tumor removal and preserving vital brain functions. Functional MRI (fMRI) offers noninvasive preoperative mapping of widely distributed brain areas and is increasingly used in presurgical functional mapping. However, its impact on survival and functional outcomes is still not well-supported by evidence. Task-based fMRI (tb-fMRI) maps blood oxygen level-dependent (BOLD) signal changes during specific tasks, while resting-state fMRI (rs-fMRI) examines spontaneous brain activity. rs-fMRI may be useful for patients who cannot perform tasks, but its reliability is affected by tumor-induced changes, challenges in data processing, and noise. Validation studies comparing fMRI with direct cortical stimulation (DCS) show variable concordance, particularly for cognitive functions such as language; however, concordance for tb-fMRI is generally greater than that for rs-fMRI. Preoperative fMRI, in combination with MRI tractography and intraoperative DCS, may result in improved survival and extent of resection and reduced functional deficits. fMRI has the potential to guide surgical planning and help identify targets for intraoperative mapping, but there is currently limited prospective evidence of its impact on patient outcomes. This review describes the current state of fMRI for preoperative assessment in patients undergoing brain tumor resection. Keywords: MR-Functional Imaging, CNS, Brain/Brain Stem, Anatomy, Oncology, Functional MRI, Functional Anatomy, Task-based, Resting State, Surgical Planning, Brain Tumor © RSNA, 2023.

Development and validation of a prediction tool for intraoperative blood transfusion in brain tumor resection surgery: a retrospective analysis

Early identification of a patient with a high risk of blood transfusion during brain tumor resection surgery is difficult but critical for implementing preoperative blood-saving strategies. This study aims to develop and validate a machine learning prediction tool for intraoperative blood transfusion in brain tumor resection surgery. A total of 541 patients who underwent brain tumor resection surgery in our hospital from January 2019 to December 2021 were retrospectively enrolled in this study. We incorporated demographics, preoperative comorbidities, and laboratory risk factors. Features were selected using the least absolute shrinkage and selection operator (LASSO). Eight machine learning algorithms were benchmarked to identify the best model to predict intraoperative blood transfusion. The prediction tool was established based on the best algorithm and evaluated with discriminative ability. The data were randomly split into training and test groups at a ratio of 7:3. LASSO identified seven preoperative relevant factors in the training group: hemoglobin, diameter, prothrombin time, white blood cell count (WBC), age, physical status of the American Society of Anesthesiologists (ASA) classification, and heart function. Logistic regression, linear discriminant analysis, supporter vector machine, and ranger all performed better in the eight machine learning algorithms with classification errors of 0.185, 0.193, 0.199, and 0.196, respectively. A nomogram was then established, and the model showed a better discrimination ability [0.817, 95% CI (0.739, 0.895)] than hemoglobin [0.663, 95% CI (0.557, 0.770)] alone in the test group (P = 0.000). Hemoglobin, diameter, prothrombin time, WBC, age, ASA status, and heart function are risk factors of intraoperative blood transfusion in brain tumor resection surgery. The prediction tool established using the logistic regression algorithm showed a good discriminative ability than hemoglobin alone for predicting intraoperative blood transfusion in brain tumor resection surgery.

Pediatric Brain Tissue Segmentation Using a Snapshot Hyperspectral Imaging (sHSI) Camera and Machine Learning Classifier.

Pediatric brain tumors are the second most common type of cancer, accounting for one in four childhood cancer types. Brain tumor resection surgery remains the most common treatment option for brain cancer. While assessing tumor margins intraoperatively, surgeons must send tissue samples for biopsy, which can be time-consuming and not always accurate or helpful. Snapshot hyperspectral imaging (sHSI) cameras can capture scenes beyond the human visual spectrum and provide real-time guidance where we aim to segment healthy brain tissues from lesions on pediatric patients undergoing brain tumor resection. With the institutional research board approval, Pro00011028, 139 red-green-blue (RGB), 279 visible, and 85 infrared sHSI data were collected from four subjects with the system integrated into an operating microscope. A random forest classifier was used for data analysis. The RGB, infrared sHSI, and visible sHSI models achieved average intersection of unions (IoUs) of 0.76, 0.59, and 0.57, respectively, while the tumor segmentation achieved a specificity of 0.996, followed by the infrared HSI and visible HSI models at 0.93 and 0.91, respectively. Despite the small dataset considering pediatric cases, our research leveraged sHSI technology and successfully segmented healthy brain tissues from lesions with a high specificity during pediatric brain tumor resection procedures.

The Warburg effect in patients with brain tumors: a comprehensive analysis of clinical significance.

The Warburg Effect, referring to an elevation in serum lactate level attributable to increased tumor metabolism, is present in patients with brain tumors. This study comprehensively analyzes the Warburg effect in patients undergoing brain tumor resection. We retrospectively analyzed the baseline intraoperative serum lactate levels of 2,053 patients who underwent craniotomies, including 415 with cerebral aneurysms and 1,638 with brain tumors. The brain tumor group was divided into subgroups based on the tumor pathology (extra-axial and intra-axial tumor) and the WHO tumor grade (high-grade and low-grade). Serum lactate level was significantly higher in the tumor group than in the aneurysm group (1.98 ± 0.97 vs. 1.09 ± 0.57 mmol/L, p < 0.001). The hyperlactatemia incidence (serum lactate level > 2.2 mmol/L) was higher in the tumor group (33.5 vs. 3.1%, p < 0.001). Severe hyperlactatemia (serum lactate level > 4.4 mmol/L) was found in 34 patients (2.1%) of only the tumor group. In patients with intra-axial tumors, serum lactate level was greater in high- than low-grade tumors (2.10 ± 1.05 vs. 1.88 ± 0.92 mmol/L, p = 0.006). Factors predictive of hyperlactatemia included supratentorial tumor location (odds ratio[95%CI] 2.926[2.127-4.025], p < 0.001) and a long tumor diameter (1.071[1.007-1.139], p = 0.028). In high-grade intra-axial brain tumor patients, there was a significant difference in overall survival between patients with hyperlactatemia than those without (p = 0.048). Our results show that brain tumor patients exhibit the Warburg effect and serum lactate may be a useful diagnostic and prognostic biomarker in patients with high-grade intra-axial brain tumors.

The mFI-5 and Postoperative Outcomes in Brain Tumor Patients: A Bayesian Approach to Quantifying Uncertainty

To the best of our knowledge, prior research has not investigated the uncertainty in the relationship between patient frailty and postoperative outcomes afterbrain tumor surgery. The present study used Bayesian methods to quantify the statistical uncertainty betweenthe5-factor modified frailty index (mFI-5) and postoperative outcomes for patients undergoing brain tumor resection. The present study used retrospective data collected from patients undergoing brain tumor resection during a 2-year period (2017-2019). Posterior probability distributions were used to estimate the means of model parameters that are most likely given the priors and the data. Additionally, 95% credible intervals (CrIs) were constructed for each parameter estimate. Our patient cohort included 2519 patients with a mean age of 55.27 years. Our multivariate analysis demonstrated that each 1-point increase in the mFI-5 score was associated with an 18.76% (95% CrI, 14.35%-23.36%) increase in hospital length of stay and a 9.37% (CrI, 6.82%-12.07%) increase in hospital charges. We also noted an association between an increasing mFI-5 score and greater odds of a postoperative complication (odds ratio [OR], 1.58; CrI, 1.34-1.87) and a nonroutine discharge (OR, 1.54; CrI, 1.34-1.80). However, no meaningful statistical association was found between the mFI-5 score and 90-day hospital readmission (OR, 1.16; CrI, 0.98-1.36) or between the mFI-5 score and 90-day mortality (OR, 1.12; CrI, 0.83-1.50). Although mFI-5 scores might be able to effectively predict short-term outcomes such as length of stay, our results demonstrate no meaningful association between mFI-5 scores and 90-day readmission or 90-day mortality. Our study highlights the need for rigorously quantifying statistical uncertainty to safely risk-stratify neurosurgical patients.

Reducing postoperative delirium in brain tumor patients through frailty-originated early rehabilitation: Findings from a prospective randomized study

ObjectiveThis study aims to examine the effects of frailty-originated, evidence-based early activity training on postoperative delirium in patients who have undergone brain tumor resection. MethodsA randomized controlled trial was carried out at the Second Affiliated Hospital of Zhejiang University School of Medicine from July 2019 to June 2020. Data encompassing patients’ general information, delirium incidence and duration, hospitalization period, and daily activities were collected. Starting from the day after surgery, patients were randomly assigned to either the traditional care group or the group receiving frailty-originated rehabilitation tailored for intracranial tumors using distinct evidence (FORTITUDE). Non-parametric, chi-square, and log-rank tests were employed to compare the onset time and duration of postoperative delirium, as well as daily activities, between the two groups. ResultsThe study involved a total of 291 patients, with 150 in the control group and 141 in the FORTITUDE group. Patients in the FORTITUDE group exhibited a lower occurrence of postoperative delirium (15.6% vs. 28.7%, P = 0.007), delayed onset of delirium (Z = −2.108, P = 0.035), shorter duration of postoperative delirium (χ2; = 26.67, P < 0.001), reduced hospital stay (Z = −2.037, P = 0.042), and higher scores in activities of daily living at one week (Z = −2.304, P = 0.021) and one month (Z = −2.724, P = 0.006) post-surgery in comparison to the control group. ConclusionsThe FORTITUDE program demonstrated both safety and effectiveness in diminishing the incidence and duration of postoperative delirium while enhancing the quality of life for patients who underwent brain tumor resection.

Variables associated with cortical motor mapping thresholds: A retrospective data review with a unique case of interlimb motor facilitation.

Intraoperative neuromonitoring (IONM) is crucial to preserve eloquent neurological functions during brain tumor resections. We observed a rare interlimb cortical motor facilitation phenomenon in a patient with recurrent high-grade glioma undergoing craniotomy for tumor resection; the patient's upper arm motor evoked potentials (MEPs) increased in amplitude significantly (up to 44.52 times larger, p < 0.001) following stimulation of the ipsilateral posterior tibial nerve at 2.79 Hz. With the facilitation effect, the cortical MEP stimulation threshold was reduced by 6 mA to maintain appropriate continuous motor monitoring. It likely has the benefit of reducing the occurrence of stimulation-induced seizures and other adverse events associated with excessive stimulation. We conducted a retrospective data review including 120 patients who underwent brain tumor resection with IONM at our center from 2018 to 2022. A broad range of variables collected pre-and intraoperatively were reviewed. The review aimed to determine: (1) whether we overlooked this facilitation phenomenon in the past, (2) whether this unique finding is related to any specific demographic information, clinical presentation, stimulation parameter (s) or anesthesia management, and (3) whether it is necessary to develop new techniques (such as facilitation methods) to reduce cortical stimulation intensity during intraoperative functional mapping. There is no evidence suggesting that clinical presentation, stimulation configuration, or intraoperative anesthesia management of the patient with the facilitation effect were significantly different from our general patient cohort. Even though we did not identify the same facilitation effect in any of these patients, we were able to determine that stimulation thresholds for motor mapping are significantly associated with the location of stimulation (p = 0.003) and the burst suppression ratio (BSR) (p < 0.001). Stimulation-induced seizures, although infrequent (4.05%), could occur unexpectedly even when the BSR was 70%. We postulated that functional reorganization and neuronal hyperexcitability induced by glioma progression and repeated surgeries were probable underlying mechanisms of the interlimb facilitation phenomenon. Our retrospective review also provided a practical guide to cortical motor mapping in brain tumor patients under general anesthesia. We also underscored the need for developing new techniques to reduce the stimulation intensity and, hence, seizure occurrence.

Preoperative Laboratory Values Are Predictive of Adverse Postoperative Outcomes in Patients Older Than 65 Years Undergoing Brain Tumor Resection: A National Surgical Quality Improvement Program Study

In this study, we used a large national database to assess the effect of preoperative laboratory value (PLV) derangements on postoperative outcomes in patients older than 65 years undergoing brain tumor resection. Data was collected for patients >65 years old undergoing brain tumor resection from 2015 to 2019 (N= 10,525). Univariate and multivariate analysis were performed for 11 PLVs and 6 postoperative outcomes. Hypernatremia (odds ratio [OR], 4.707; 95% confidence interval [CI], 1.695-13.071; P < 0.01) and increased creatinine level (OR, 2.556; 95% CI, 1.291-5.060; P < 0.01) were the most significant predictors of 30-day mortality. The most significant predictor of Clavien-Dindo grade IV complications was increased creatinine level (OR, 1.667; 95% CI, 1.064-2.613; P < 0.05), whereas, significant predictors of major complications were hypoalbuminemia (OR, 1.426; 95% CI, 1.132-1.796; P < 0.05) and leukocytosis (OR, 1.347; 95% CI, 1.075-1.688; P < 0.05). Predictors of readmission were anemia (OR, 1.326; 95% CI, 1.047-1.680; P < 0.05) and thrombocytopenia (OR, 1.387; 95% CI, 1.037-1.856; P < 0.05), whereas, hypoalbuminemia (OR, 1.787; 95% CI, 1.280-2.495; P < 0.001) was predictive of reoperation. Increased partial thromboplastin time and hypoalbuminemia were predictors of extended length of stay (OR, 2.283, 95% CI, 1.360-3.834, P < 0.01 and OR, 1.553, 95% CI, 1.553-1.966, P < 0.001, respectively). Hypernatremia (OR, 2.115; 95% CI, 1.181-3.788; P < 0.05) and hypoalbuminemia (OR, 1.472; 95% CI, 1.239-1.748; P < 0.001) were the most significant predictors of NHD. Seven of 11 PLVs were associated with adverse postoperative outcomes. PLV derangements were significantly associated with adverse postoperative outcomes in patients older than 65 years undergoing brain tumor resection. The most significant predictors of adverse postoperative outcomes were hypoalbuminemia and leukocytosis.

Intraoperative Hypotension and Postoperative Stroke in Older Patients Who Had Brain Tumor Resections: A Retrospective Cohort Analysis

At some level, intraoperative hypotension causes strokes. Elderly neurosurgical patients are presumably at especially high risk. We tested the primary hypothesis that intraoperative hypotension is associated with postoperative stroke in older patients undergoing brain tumor resection. Patients >65 years old who had elective craniotomy for tumor resections were included. The primary exposure was the area under the threshold of intraoperative hypotension. The primary outcome was newly diagnosed ischemic stroke within 30 days, confirmed by scheduled brain imaging. Among 724 eligible patients, 98 (13.5%) had strokes within 30 days after surgery, 86% of which were clinically silent. Curves of lowest mean arterial pressure versus stroke incidence suggested a threshold at 75 mm Hg. Area under the threshold of mean arterial pressure below 75 mm Hg was therefore incorporated into multivariable modeling. There was no association of area below 75 mm Hg and stroke (adjusted odds ratio, 1.00; 95% confidence interval, 1.00-1.00). The adjusted odds ratio for area below 75 mm Hg between 1 and 148 mm Hg× minutes was 1.21 (95% confidence interval, 0.23-6.23). When the area below 75 mm Hg exceeded 1117 mm Hg× minutes, the association remained insignificant. In contrast, malignant tumor and history of previous stroke or myocardial ischemia were associated with strokes. Postoperative strokes were common in older patients who underwent brain tumor resection, with about 14% having ischemic cerebrovascular events within 30 days, of which 86% were clinically silent. Malignant brain tumors and previous ischemic vascular events were associated with postoperative strokes, but area under 75 mm Hg was not.

A Framework for Integrating Speech-Language Pathology in an Interdisciplinary Awake Craniotomy Program for Brain Tumor Resection

Purpose: The aim of this work was to detail the interdisciplinary awake craniotomy program model at The University of Texas MD Anderson Cancer Center integrating speech-language pathology and neuropsychology in the pre-, intra-, and postoperative settings to monitor and maximize expressive and receptive language skills among patients undergoing brain tumor resection. Conclusions: This report outlines the MD Anderson clinical protocols and procedures, with focus on the clinical methods of the speech-language pathologist in pre-, intra-, and postoperative interventions. Case examples are summarized to illustrate dynamic features of implementing this protocol. An intradisciplinary team approach to treatment of patients with brain tumor and specifically those undergoing awake craniotomy may improve care and quality of life.