FLAIR Hyperintensity Research Articles

SURG-29. EXTENDED RESECTION IMPROVES PATIENT SURVIVAL OUTCOMES AFTER GROSS-TOTAL RESECTION OF GLIOBLASTOMA

Abstract In recent years, the effectiveness of extended resection (ER) beyond the contrast-enhanced (CE) lesion has been reported as a surgical strategy for glioblastoma. This study was to determine whether ER of FLAIR-hyperintense area beyond the CE tumor affected the overall survival (OS) and progression-free survival (PFS) of patients with glioblastoma after gross-total resection (GTR). From October 2019 to March 2022, a total of 62 patients who underwent resection of glioblastoma (GBM) at Kobe University Hospital were retrospectively examined. Volumetric measurements of the CE area and surrounding FLAIR-hyperintense area were performed, and clinical variables related with OS and PFS were analyzed. In total, 33 patients with GBM who underwent GTR of the CE tumor met the inclusion criteria. The mean volume of CE tumor and FLAIR hyperintensity area before resection was 36.5 cm3 and 77.2 cm3 respectively. The mean excision rate of FLAIR-hyperintense area was 18.2%. Removal rates of 20% or more in the FLAIR-hyperintense region significantly increased OS and PFS (p=0.040 and 0.026, respectively). In multivariate analysis, age ≥ 65 years (HR 2.73; 95% CI 1.09–7.22; p=0.032) were associated with shorter OS, but ER ≥ 20% (HR 0.41; 95% CI 0.17–0.99; p=0.049) and MGMT promotor methylation (HR 0.36; 95% CI 0.15–0.85; p=0.020) were associated with longer OS. ER of FLAIR-hyperintense lesions of 20% or more in glioblastoma contributed to prolonging patient survival. It is necessary to validate the effect of ER in prospective clinical trials.

TMIC-29. IMMUNE SPECIFIC IMAGING TECHNIQUES IN GLIOBLASTOMA: SELFI MRI IDENTIFIES AGGRESSIVE AND IMMUNOSUPPRESSIVE BIOLOGICAL FEATURES THAT CONTRIBUTE TO THERAPEUTIC RESISTANCE

Abstract Gadolinium (Gd) enhanced MRI is nonspecific for identifying aggressive glioblastoma biology. Glioblastoma-associated macrophages (GAMs) are pivotal in regrowth. Segregation and Extravascular Localization of Ferumoxytol Imaging (SELFI) is a quantitative immune specific MRI technique. SELFI+ values quantify M2 GAMs by phagocytized Ferumoxytol (Fe), while SELFI- values delineate intravascular Fe, cerebral blood volume. The relationship between SELFI and biology driving therapeutic resistance remains unknown. We aimed to determine if SELFI identified immunosuppressive GAMs and biology contributing to poor outcomes, a capability not yet achievable in clinical practice. This prospective study included four patients with glioblastoma. All underwent preoperative Gd and Fe (7 mg/kg up to 510 mg) enhanced MRI allowing for image guided biopsy based on Gd enhancement and FLAIR hyperintensity. RNA was analyzed on GeneChip Clariom Arrays. Intraoperative biopsy location was referenced to MRI for placement of volumes of interest (VOIs). VOIs quantified MRI phenotype and SELFI values. Gene Set Enrichment Analysis (GSEA) assessed differential expression between MRI features. T-test assessed differences in SELFI (p <0.05) and GSEA significance was assessed by normalized enrichment score (NES) and false discovery rate (FDR) q-value. Four patients provided 36 image guided tissue samples with sufficient quality to assess the causal relationships between MRI features and transcriptomics. Stratification by patient MGMT methylation status (N= 3 unmethylated) demonstrated Gd+ regions had significantly elevated SELFI+ values (Mean±SD, Gd+ = 0.24±0.17, Gd- = 0.08±0.09, P<0.01). GSEA demonstrated that tissues with elevated SELFI+ and lowered SELFI- values were comprised of significantly upregulated hypoxia and transforming growth factor-beta (TGFβ) signaling; among others (NES>1.5, FDR q-value<0.05). SELFI MRI uniquely quantifies glioblastoma by localizing sites of biological aggressiveness known to contribute to therapeutic resistance and disease recurrence. Patient enrollment continues to further define the causal relationships between SELFI, GAMs, and glioblastoma biology.

NCMP-09. SPONTANEOUS RESOLUTION OF PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY (PML) DEVELOPED AFTER RITUXIMAB TREATMENT FOR LOW-GRADE B-CELL LYMPHOMA

Abstract Progressive multifocal leukoencephalopathy (PML) is a rare viral infection caused by the reactivation of the JC virus, which causes significant morbidity and mortality. Rituximab, a CD20 inhibitor used for B-cell neoplasms as well as autoimmune diseases, is associated with the development of PML. Here, we report a case of a 74-year-old woman with a history of low-grade B-cell lymphoma with biopsy-proven PML with spontaneous immune reconstitution with clinical and radiographic improvement. For her low-grade B-cell lymphoma, she received six cycles of rituximab and bendamustine, followed by one cycle of maintenance rituximab, which was discontinued due to intolerance. Ten months later, she developed progressive left-sided paresthesias, paresis, and incoordination. Brain MRI revealed a large right subcortical frontal-parietal FLAIR hyperintense and peripherally enhancing lesion with leading-edge diffusion restriction. CSF studies revealed elevated protein (385 mg/dL) and negative JCV PCR. A brain biopsy was performed with tissue staining positive for SV40, consistent with PML. Her CD4 count was 88 cells/mm3. A repeat CSF sample one month later showed near normalization CSF protein (47 mg/dL) and negative CSF JCV PCR. MRI of the brain one month later demonstrated complete enhancement resolution and decreased FLAIR abnormality, which correlated with subjective and objective clinical improvement. Her serum CD4 also increased to 134 cells/mm3. This highlights a rare case of PML related to rituximab with spontaneous improvement, which may help guide clinicians in counseling patients who may also develop this complication. Furthermore, this supports the biological rationale for continued investigation of T-cell therapies to achieve immune reconstitution.

NIMG-35. IMPACT OF RESECTION AT TIME OF FIRST RECURRENCE IN WHO GRADE 2 IDH-MUTANT GLIOMAS

Abstract INTRODUCTION Maximal safe resection standard of care treatment of IDH-mutant gliomas and is associated with improved overall survival (OS). However, the impact of extent of resection (EOR) at first recurrence is not well established and there are no data on its impact on prognosis. METHODS We retrospectively collected clinical data on patients with IDH-mutant WHO grade 2 astrocytoma and oligodendroglioma treated at our institution from 1997 to 2023. To assess the impact of EOR at first recurrence, we excluded patients who exclusively underwent diagnostic biopsy. Dates of progression were determined by the treating neuro-oncologist or tumor board consensus. Volumetric measurements of contrast-enhancing (CE) tumor and total T2/FLAIR pre- and post second surgery were obtained with BrainLab SmartBrush tool. RESULTS One-hundred patients with recurrent astrocytoma and 35 patients with recurrent oligodendroglioma were identified, of whom 57 and 25, respectively, underwent a second resection and had imaging available for volumetric analysis. In patients with astrocytoma, 13/57 had CE at diagnosis, and 28/57 at first recurrence. EOR of T2/FLAIR and CE volume correlated with improved OS. In multivariate regression analyses, T2/FLAIR EOR at first recurrence correlated with improved OS adjusted for gender, preoperative T2/FLAIR volume, prior radiotherapy or chemotherapy, and initial CE (HR 0.977, p< 0.001). In patients with CE, contrast-EOR correlated with OS adjusted for gender, initial CE, preoperative contrast volume, and prior radiotherapy or chemotherapy (HR 0.929, p< 0.001). Conversely, in patients with WHO grade 2 oligodendroglioma, T2/FLAIR EOR did not significantly impact OS (EOR> 90% p= 0.92, EOR> 20% p= 0.13). Only 5/25 patients had CE at first recurrence precluding further analysis. CONCLUSIONS The EOR of CE and total FLAIR hyperintensity at first recurrence appears to positively impact prognosis in patients with WHO grade 2 astrocytoma but not in oligodendroglioma. These findings should be evaluated in prospective trials.

NIMG-59. COMPARATIVE ANALYSIS OF LONG-TERM GLIOBLASTOMA SURVIVORS USING MACHINE LEARNING GENERATED RADIO-PATHOMIC METRICS

Abstract BACKGROUND Glioblastoma (GBM) remains the most devastating central nervous system malignancy with poor overall survival (OS), even with gross total resection (GTR) and chemoradiation. Identifying factors associated with long-term survival (LTS) in GBM patients is challenging but crucial for improving prognostic models. This study compares an internal dataset of the top 10% long-term survivors of GBM (n=14) against a combined external cohort of 528 GBM patients who underwent GTR. METHODS We used a previously published machine learning-generated radio-pathomic model based on autopsy tissue as ground-truth to generate whole-brain maps of cell density and tumor probability maps (TPM) using conventional preoperative MRI sequences in both our internal dataset and a combined external cohort of GBM patients who underwent GTR from the UCSF-PDGM-v2 and UPenn-GBM databases. We then analyzed clinical and radio-pathomic metrics, including cell density and TPM values within contrast-enhancing (CE) and FLAIR hyperintense regions. Statistical comparisons were performed using t-tests. RESULTS Cell density metrics showed significant differences, with lower cell density in contrast-enhancing regions (t-value: 4.709, p<0.001; median: 1559 vs. 1959) and in FLAIR hyperintense regions (t-value: 3.585, p<0.001; median: 1356 vs. 1568) within the LTS group. TPM metrics also showed significant differences, with lower TPM values in contrast-enhancing regions (t-value: 3.312, p<0.001; median: 0.71 vs. 0.72) and in non-enhancing regions (t-value: 2.606, p<0.01; median: 0.68 vs. 0.69) in the LTS group. CONCLUSION Our comparative analysis reveals distinct radio-pathomic characteristics associated with long-term survival in GBM patients. Reduced cell density and lower TPM values in both contrast-enhancing and FLAIR hyperintense regions are significantly correlated with long-term survival. These findings suggest that integrating radio-pathomic data may enhance prognostic models and warrants further studies evaluating the relationship of these markers and OS.

The diagnostic challenge of differentiating Tumefactive Multiple Sclerosis (TMS) from other brain lesions: a case report and literature review on a rare subtype of MS

Introduction and Importance: This case report is a clinical diagnosis walk through of a rare subtype of Multiple sclerosis (MS). It gives an overview of how Tumefactive multiple sclerosis (TMS) is systematically narrowed down as the definitive diagnosis. Case Presentation: Our 29 year old male patient presented to the emergency department. He collapsed after experiencing pain over his right frontotemporal region followed by a seizure witnessed by his family. Magnetic Resonance Imaging of the brain displayed a diffuse enlargement and abnormal T2 weighted and FLAIR hyperintense signals in the diagnostic impressions described by the radiologist of the right temporoparietal region. Clinical Discussion: Liquefactive Multiple Sclerosis, also known as tumefactive multiple sclerosis or Marburg-type multiple sclerosis, is a rare subtype of the neurological disorder that can be difficult to diagnose. Unlike the traditional form of Multiple sclerosis (MS), Tumefactive multiple sclerosis (TMS) can present as a brain tumor and must be diagnosed with a biopsy rather than via magnetic resonance imaging (MRI) and clinical findings alone. Patients can typically present with headache, cognitive abnormalities, mental confusion, aphasia, apraxia, seizures, and weakness. Here, we discuss the presentation, disease diagnosis process and patient management. Conclusion: The patient was stabilized and discharged with a referral to the neurosurgery and neurology departments for outpatient consultation for future clinical management and treatment of their condition.

P10.24.B PREDICTION OF PCFDNA LEVELS, PROGRESSION-FREE SURVIVAL, AND OVERALL SURVIVAL THROUGH MACHINE-LEARNING MODELS BASED ON MRI-DERIVED RADIOMIC FEATURES IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA

Abstract BACKGROUND Circulating cell-free DNA (ccfDNA) is a promising tool for monitoring patients with high-grade gliomas (HGGs) in addition to follow-up with conventional (cMRI) and advanced MRI (aMRI), which harbors an enormous amount of quantitative subvisual data that can be used to build models predicting disease behavior. Examining the relationship between ccfDNA levels and quantitative features extracted from cMRI and aMRI gives further insight into this novel biomarker, aiming to combine the biological value of ccfDNA and the spatial resolution of image biomarkers to improve HGGs monitoring. MATERIAL AND METHODS Features were extracted from each T1 post-contrast and FLAIR images by using the FLAIR hyperintensity and enhancement automatic segmentation tool (Pyradiomics software, v2.2.0). The radiomic dataset underwent Z-score normalization, feature reduction, and feature selection. Highly correlated features were excluded using a threshold of 0.9 person-correlation-coefficient. The ‘F_regression’ function was used to select the most important features concerning the ccfDNA concentration, Overall survival (OS), and progression-free survival (PFS). This dataset was used as input for four machine learning models: Linear Regression (LR), Support Vector Regression (SVR), Random Forest (RF), and least absolute shrinkage and selection operator (LASSO). Hyperparameter tuning was performed at the first training iteration of each model using a 4-fold cross-validation GridSearchCV and model-specific parameters. The train-test strategy involved randomizing datasets into 80% training and 20% testing subsets across 100 iterations, ensuring robustness and reducing biases. RMSE values of each run were averaged based on sample test frequencies. Root means square error (RMSE) was used to assess the model’s performance. RESULTS 405 features were successfully extracted from T1 post-contrast and FLAIR images from both tumoral masks. A total of 287 were found to be highly correlated and, therefore, removed from the dataset. The ‘F_regression’ with a 90-percentile threshold separates 12 features divided into 3 shapes features relative to FLAIR segmentation, 6 features relative to the T1 post-contrast image, and 3 features for the FLAIR image. The SVR achieves the best RMSE performances when compared to other models when predicting the ccfDNA concentration, reaching an RMSE of 8.58. An analogous strategy was used for the models built to predict PFS and OS reaching an RMSE of 5.89 and 6.77, respectively. CONCLUSION Machine-learning models based on radiomic features combined with clinical variables are valuable tools for predicting OS and PFS in HGGs’ patients. The radiomic signature provides additional information compared to the tumoral volume to forecast ccfDNA levels. Combining both techniques could provide more precise assessment of disease status.

DNA Methylation Profiling Confirms a Challenging Glioblastoma, Atypical Mesenchymal Type Which Mimics Intracranial Mesenchymal Tumor

Abstract Introduction/Objective Brain tumors exhibit distinct DNA methylation patterns that reflect their cellular origin, molecular subtype, and clinical behavior. DNA methylation signatures provide valuable insights into tumor heterogeneity, evolution, and treatment response, guiding personalized therapeutic strategies. Our case, glioblastoma, atypical mesenchymal type confirmed by DNA methylation profile and it reflects the clonal evolution of the glioblastoma metaplasia with minimal glial component which was histologically challenging. Methods/Case Report A 56-year-old gentleman presented with headaches. MRI brain demonstrated a heterogeneous enhancing mass with areas of central necrosis in the left temporal lobe, measuring approximately 49 x 34 mm, with surrounding T2 FLAIR hyperintensity extending into the left basal ganglia, causing compression of the left lateral ventricle and uncal herniation. He underwent left-sided craniotomy for tumor resection. Microscopic examination revealed hypercellular spindle cell neoplasm, forming fascicles. Brisk mitotic activity and geographic necrosis were evident. GFAP highlighted narrow margins of the tumor which could represent the entrapped glial tissue. CD99 stained the tumor cells, Other immunohistochemical stains for spindle cell work up, like S100, EMA, PR STAT6 and desmin were all negative. A diagnosis of intracranial mesenchymal tumor /sarcoma was considered. Methylation profiling results showed class calibrated scores of 0.9741, compatible with Glioblastoma, IDH-wildtype, atypical mesenchymal type with a cytogenetic profile including gain of chromosome 7 (including EGFR) and loss of chromosome 10 (including PTEN), and loss of CDKN2A/B. Results (if a Case Study enter NA) NA Conclusion Although histopathological examination and immunohistochemical study are fundamental in diagnosing brain tumors, the rapid development of cytogenetic and molecular diagnostic modalities has significantly contributed to diagnostic accuracy and the potential for targeted treatment. Particularly, DNA methylation profiling has proven valuable in diagnosing morphologically challenging cases with prognostic value. Eventually, DNA methylation profiling will be adopted as a major cancer diagnostic criterion and will become a standard procedure performed at major academic centers.

SREAT and Salty: Bitemporal FLAIR Hyperintensities in Steroid Responsive Encephalopathy in Autoimmune Thyroiditis

SREAT and Salty: Bitemporal FLAIR Hyperintensities in Steroid Responsive Encephalopathy in Autoimmune Thyroiditis

MR Imaging Findings in Anti-Leucine-Rich Glioma Inactivated Protein 1 Encephalitis: A Systematic Review and Meta-analysis.

Antibodies against leucine-rich glioma inactivated protein 1 (LGI1) constitute a common form of autoimmune encephalitis. On MR imaging, it may show T2 FLAIR hyperintensities of the medial temporal lobe (T2 FLAIR-MTL), involve the basal ganglia, or be unremarkable. We performed a systematic review and meta-analysis to obtain prevalence estimates of abnormal findings on MR imaging in anti-LGI1 encephalitis. A human brain map of the LGI1 microarray gene expression was derived from the Allen Human Brain Atlas. PubMed and Web of Science were searched with the terms "LGI1" and "encephalitis" from inception to April 7, 2022. Thirty-one research publications, encompassing case series and retrospective cohort and case-control studies, with >10 patients with anti-LGI1 encephalitis and MR imaging data were included. Pooled prevalence estimates were calculated using Freeman-Tukey double-arcsine transformation. Meta-analysis used DerSimonian and Laird random effects models. Of 1318 patients in 30 studies, T2 FLAIR-MTL hyperintensities were present in 54% (95% CI, 0.48-0.60; I2 = 76%). Of 394 patients in 13 studies, 27% showed bilateral (95% CI, 0.19-0.36; I2 = 71%) and 24% unilateral T2 FLAIR-MTL abnormalities (95% CI, 0.17-0.32; I2 = 61%). Of 612 patients in 15 studies, basal ganglia abnormalities were present in 10% (95% CI, 0.06-0.15; I2 = 67%). LGI1 expression was highest in the amygdala, hippocampus, and caudate nucleus. Only part of the spectrum of MR imaging abnormalities in anti-LGI1 encephalitis could be included in a meta-analysis. MR imaging findings were not the main outcomes in most studies, limiting available information. I2 values ranged from 62% to 76%, representing moderate-to-large heterogeneity. T2 FLAIR-MTL hyperintensities were present in around one-half of patients with anti-LGI1. The prevalence of unilateral and bilateral presentations was similar, suggesting unilaterality should raise the suspicion of this disease in the appropriate clinical context. Around 10% of patients showed basal ganglia abnormalities, indicating that special attention should be given to this region. LGI1 regional expression coincided with the most frequently reported abnormal findings on MR imaging. Regional specificity might be partially determined by expression levels of the target protein.

Clinical characteristics and multimodal imaging can help diagnosing and treating mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy.

Mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE) is a recently described, histopathologically and molecularly defined (SLC35A2-mutated) type of cortical malformation. Although increasingly recognized, the diagnosis of MOGHE remains a challenge. We present the characteristics of the first six patients diagnosed in Bulgaria, with the aim to facilitate identification, proper presurgical evaluation, and surgical treatment approach in this disease. Revision of histopathological specimens of 202 patients operated on for drug-resistant focal epilepsy identified four cases with MOGHE. Another two were suggested, based on clinical characteristics and subsequently, were histologically confirmed. Sanger SLC35A2 sequencing on paraffin-embedded or fresh-frozen brain tissue was performed. Analysis of seizure types, neuropsychological profiles, electroencephalographic (EEG), imaging features and epilepsy surgery outcomes was done. Three out of the six cases (50%) harbored pathogenic SLC35A2 mutations. One patient had a heterozygous somatic variant with uncertain significance. Clinical characteristics included epilepsy onset in infancy (in 100% under 3 years of age), multiple seizure types, and moderate or severe intellectual/developmental delay. Epileptic spasms with hypsarrhythmia on EEG were the initial seizure type in five patients. The subsequent seizure types resembled those in Lennox-Gastaut syndrome. The majority of the patients (n = 4) presented prominent and persisting autistic features. Magnetic resonance imaging (MRI) showed multilobar (n = 6) and bilateral (n = 3) lesions, affecting the frontal lobes (n = 5; bilaterally in three) and characterized by increased signal on T2/fluid-attenuated inversion recovery (FLAIR). Voxel-based morphometric MRI post-processing and positron emission tomography helped determining the localization and extent of the lesions and presumed epileptogenic zones. After surgery, four patients (66.7%) were seizure-free ≥2 years. Interestingly, all seizure-free patients carried somatic SLC35A2-alterations. Epileptic spasms, early prominent neuropsychological disturbances, MRI-T2/FLAIR hyperintense lesions with cortico-subcortical blurring, frequently multilobar and especially frontal, can preoperatively help to suspect MOGHE. Epilepsy surgery is still the only successful treatment option in MOGHE.

Herpes simplex (HSV1) encephalitis in an infant: a case report study

Introduction and importance: The herpes simplex virus (HSV) is the most common cause of acute sporadic encephalitis, a severe and often fatal disease in humans. It is associated with high mortality and morbidity rates in untreated patients. Case presentation: An 11-month-old child was admitted to the hospital presenting with acute fever and seizures characterized by staring episodes and spastic movements affecting the left side of the body. Diagnostic workup revealed abnormal T2 flair hyperintense foci in bi-temporoparietal lobes and right thalamus, and bilateral otomastoiditis were detected. A positive result for HSV-1 was obtained through HSV type 1/2 PCR testing, leading to a diagnosis of herpes encephalitis. Clinical discussion: While acyclovir has proven to be an effective therapeutic option, mortality and neurological sequelae continue to be reported in a notable fraction of patients. HSV encephalitis is mainly caused by two strains of the herpes simplex virus: HSV-1, more frequently observed in children and adults, and HSV-2, commonly seen in neonates and those with compromised immune systems. MRI scans often reveal that the brain lesions are localized to certain areas, although temporal involvement may not always be evident. The symptoms of herpetic encephalitis can greatly vary, making early diagnosis and treatment vital for improving patient outcomes. Conclusion: this case report highlights the clinical presentation, diagnostic challenges, and treatment strategies for HSV-1 encephalitis and underscores the importance of early recognition and prompt initiation of antiviral therapy in suspected cases of HSV-1 encephalitis.

The safety and use of perioperative dexamethasone in the perioperative management of primary sporadic supratentorial meningiomas.

Despite the lack of prospective evidence for the perioperative use of dexamethasone in meningioma surgery, its use is well established in the daily routine of several centers. The present study evaluates the effect of dexamethasone on postoperative complications, peritumoral T2/FLAIR hyperintensity, and progression-free survival in patients with supratentorial meningiomas undergoing resection. A total of 148 patients who underwent resection of a primary sporadic supratentorial meningioma at the authors' institution between 2018 and 2020 were included in this retrospective cohort. Safety criteria were side effects of dexamethasone (e.g. hyperglycemia), surgical morbidities, length of stay, and mortality. The individual Karnofsky Performance Scales (KPS) were evaluated regarding the individual development and the delta of KPS at 3- and 12-months compared to baseline KPS was calculated. Longitudinal assessment of the peritumoral T2-/FLAIR hyperintensity changes was performed. The use of both pre- and postoperative dexamethasone did not influence the incidence rates of wound infections, infarctions, postoperative seizures, pulmonary embolism, postoperative hemorrhage, mortality, length of stay, new-onset hyperglycemia and new neurological deficits. Perioperative Dexamethasone use was associated with an improved Karnofsky performance development at 3- (delta of KPS 3.3 vs. -1.9, p=0.001) and 12-months (delta of KPS 3.8 vs. -1.1, p=0.008) compared to the preoperative Karnofsky performance status. Multivariable analysis revealed that perioperative dexamethasone use enhances the KPS improvement (OR: 3.65, 95% CI: 1.01-13.18, p=0.048). Persistent peritumoral T2/FLAIR hyperintensity changes were observed in 35 cases of 70 patients with available follow-up images and a baseline edema (50.0%). Perioperative dexamethasone use enhanced the reduction of the preoperative peritumoral T2-/FLAIR hyperintensity changes (mean reduction of maximum diameter: 1.8 cm vs. 1.1 cm, p=0.023). Perioperative dexamethasone use was independently associated with a lower risk for persistent peritumoral T2-/FLAIR hyperintensity changes (OR: 3.77, 95% CI: 1.05-13.54, p=0.042) The perioperative use of dexamethasone did not influence the progression-free survival time in Simpson grade I or II resected WHO grade 1 meningiomas (log-rank test: p=0.27). Perioperative dexamethasone use seems to be safe in surgery for primary supratentorial meningiomas. Dexamethasone use might enhance the functionality by reducing postoperative peritumoral T2-/FLAIR hyperintensities. These findings highlight the need for prospective data.

Longitudinal Volumetric Analysis of FLAIR Hyperintensity Following Radiation Therapy (RT) in Patients with Low-grade Glioma (LGG) (P4-5.019)

Longitudinal Volumetric Analysis of FLAIR Hyperintensity Following Radiation Therapy (RT) in Patients with Low-grade Glioma (LGG) (P4-5.019)

Assessment of PSR as a Novel Parameter in Perfusion Imaging for CNS Tumor Characterization: An Observational Study

Introduction: Magnetic resonance imaging (MRI) has emerged as the primary modality for diagnosing and evaluating central nervous system (CNS) tumors, transitioning from structural to functional assessment. Advanced MRI techniques, including MR spectroscopy and perfusion imaging, offer insights into functional, metabolic, and hemodynamic changes in addition to structural abnormalities. The study aims to assess the role of PSR (Post-Contrast Signal Recovery) alongside rCBV (Relative Cerebral Blood Volume) and rPSR (Relative Percentage of Signal Recovery) in differentiating grade IV glioma, solitary brain metastasis, and primary CNS lymphoma. Materials and Methods: An observational study was conducted on 38 patients with lymphoma, metastases, and grade IV glioma, utilizing DSC (Dynamic Susceptibility-Weighted Contrast-Enhanced) perfusion imaging and histopathology reports. Sociodemographic, clinical, and MRI parameters were collected. PSR measurements were obtained from perfusion maps using dedicated software. Statistical analysis was performed using SPSS version 27.0. Results: Among the study population, the mean age was 54.16±12.47, with male predominance (63.2%). Conventional imaging characteristics revealed significant differences, including T2 hypo intensity in lymphoma and FLAIR hyperintensity in all gliomas. Perfusion parameters showed higher rCBV in metastases and grade IV glioma compared to lymphoma, whereas PSR and rPSR were higher in lymphoma. PSR and rPSR effectively differentiated among the tumor types (p<0.001). Conclusion: Our study underscores the critical role of advanced MRI techniques, particularly DSC perfusion imaging, in differentiating between grade IV gliomas, solitary brain metastases, and primary CNS lymphomas. PSR emerges as a valuable parameter alongside rCBV and rPSR, demonstrating potential for accurate tumor characterization.

Anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated cortical encephalitis with low signal in subcortical white matter on MRI FLAIR imaging

A 32-year-old male presented with unilateral orbital-temporal pulsatile headache, followed by fever in the 38°C range and nausea. The patient experienced two episodes of transient dysarthria and tinnitus, each lasting several minutes. MRI revealed swelling of the left cerebral cortex, enhancement of the leptomeninges, dilation of the left middle cerebral artery, and subcortical FLAIR hypointensity. The clinical presentation and MRI findings raised suspicions of myelin oligodendrocyte glycoprotein (MOG) antibody-associated cortical encephalitis. After two courses of steroid pulse therapy, the patient's headache subsided, and there was a significant improvement in the swelling of the left cerebral cortex. Subsequently, serum MOG antibody positivity was confirmed. While unilateral cortical FLAIR hyperintensity and increased blood flow can be observed in various diseases, MOG antibody-associated cortical encephalitis is notably characterized by subcortical FLAIR hypointensity, a finding more frequently observed in this condition compared to other diseases. In this case, the findings were useful for early diagnosis and intervention.

Peripheral neuropathy associated with severe glial fibrillary acidic protein (GFAP) astrocytopathy: a case report

A 44-year-old man was admitted due to a fever. He developed unconsciousness and respiratory failure, necessitating mechanical ventilation. After the administration of methylprednisolone and intravenous immunoglobulin for suspected autoimmune encephalitis, his consciousness and respiratory state improved. However, he exhibited pronounced tetraparalysis and impaired sensation below the neck. A spinal MRI revealed swelling of the entire spinal cord, indicating myelitis. Deep tendon reflexes were diminished in all extremities, and a nerve conduction study confirmed motor-dominant axonal polyneuropathy. Subsequently, he developed a fever and headache. Brain MRI demonstrated FLAIR hyperintensities in the basal ganglia and brain stem. CSF analysis for anti-glial fibrillary acidic protein (GFAP) antibody turned out positive, leading to the diagnosis of GFAP astrocytopathy. Although the steroid re-administration improved muscle strength in his upper limbs and reduced the range of diminished sensation, severe hemiparalysis remained. Severe GFAP astrocytopathy can be involved with polyneuropathy. Early detection and therapeutic intervention for this condition may lead to a better prognosis.

Age-Related Decline in Brain Myelination: Quantitative Macromolecular Proton Fraction Mapping, T2-FLAIR Hyperintensity Volume, and Anti-Myelin Antibodies Seven Years Apart.

Age-related myelination decrease is considered one of the likely mechanisms of cognitive decline. The present preliminary study is based on the longitudinal assessment of global and regional myelination of the normal adult human brain using fast macromolecular fraction (MPF) mapping. Additional markers were age-related changes in white matter (WM) hyperintensities on FLAIR-MRI and the levels of anti-myelin autoantibodies in serum. Eleven healthy subjects (33-60 years in the first study) were scanned twice, seven years apart. An age-related decrease in MPF was found in global WM, grey matter (GM), and mixed WM-GM, as well as in 48 out of 82 examined WM and GM regions. The greatest decrease in MPF was observed for the frontal WM (2-5%), genu of the corpus callosum (CC) (4.0%), and caudate nucleus (5.9%). The age-related decrease in MPF significantly correlated with an increase in the level of antibodies against myelin basic protein (MBP) in serum (r = 0.69 and r = 0.63 for global WM and mixed WM-GM, correspondingly). The volume of FLAIR hyperintensities increased with age but did not correlate with MPF changes and the levels of anti-myelin antibodies. MPF mapping showed high sensitivity to age-related changes in brain myelination, providing the feasibility of this method in clinics.

Acute Onset of Creutzfeldt-Jakob Disease Resembling Stroke in Absence of Diagnostic EEG Findings

We report a case of Creutzfeldt-Jakob disease with acute onset of symptoms with EEG negative for PSWC, resembling a cerebrovascular accident. The patient was diagnosed with sporadic CJD by positive RT-QUIC, positive 14-3-3 protein, T-Tau protein of 14560 pg/mL, brain magnetic resonance imaging (MRI) demonstrating restricted diffusion on DWI in bilateral frontal, temporal, occipital cortex, caudate and putaminal nuclei, as well as T2 FLAIR hyperintensities in the bilateral cerebral cortex and basal ganglia. The entire course of the disease from onset to death was 52 days.

Burden of cerebral small vessel disease modifies relationship between some plasma Abeta 42/40 assays, but not p‐tau181 assays, with amyloid PET

AbstractBackgroundWe aimed to determine if burden of cerebral small vessel disease (CSVD) modifies the relationship of plasma amyloid‐beta (Abeta) 42/40 ratio and/or plasma p‐tau 181 with amyloid PET.MethodWe studied N = 100 participants from the Alzheimer’s Disease Neuroimaging Initiative with 1) Abeta‐42/40 biomarker levels using Quanterix SIMOA (Quanterix), Washington University Mass Spectroscopy (WashU), Simoa HD‐X 4Plex, Roche Elecsys, Shimadzu Mass Spectroscopy, and Gothenburg Mass Spectroscopy, 2) p‐tau181 plasma biomarker levels using Lumipluse G, Roche Elecsys, Simoa p‐tau181V2 Advantage (Simoa Advntage), Simoa p‐tau181, 3) MRI brain, and 4) amyloid‐PET. We stratified by CSVD bruden tertile (calculated from total white matter FLAIR hyperintensity volume). Amyloid positivity was defined as standardized uptake value ratio ≥ 1.11 for florbetapir PET scans. We used box plots to visualize plasma Abeta‐42/40 and p‐tau181 levels stratified by Amyloid‐PET positivity and CSVD tertile. Using logistic regression models, we tested for an interaction between CSVD and plasma Abeta‐42/40 ratio or p‐tau181 on amyloid PET positivity in unadjusted models and models adjusted for age, Clinical Dementia Rating, and presence of ≥1 apolipoprotein E4 allele (ApoE4+).ResultThe cohort had an average age of 77 years, was 56% female, 50% cognitively normal, and 42% ApoE4+ (Table1). We found significant interactions between CSVD and plasma Abeta‐42/40 ratio on amyloid‐PET positivity for Quanterix (raw/adjusted: p = 0.035/p = 0.049), Simoa HD‐Plex (p = 0.047/p = 0.047), and Gothenburg assays (p = 0.026/p = 0.030), with worst discrimination between amyloid‐PET positivity among participants with highest CSVD burden (Figure1A). The Quanterix and Gothenburg assay demonstrated near total overlap between amyloid‐PET positive vs. negative groups at the highest tertile of CSVD. No significant interaction was found between CSVD and any plasma p‐tau181 assay on amyloid‐PET positivity (all p>0.2, Figure1B).ConclusionOur findings suggest that individuals with a high burden of CSVD are at risk for incorrect Abeta‐42/40 ratio on certain assay platforms but not others. No interaction was found between CSVD and any plasma p‐tau181 assay on amyloid‐PET positivity. Further research in diverse cohorts with a high burden of CSVD is warranted to inform appropriate use of these blood assays and unravel mechanisms of this unexpected finding.