Cerebral Hemispheres Research Articles

Neurometabolic Profile in Obese Patients: A Cerebral Multi-Voxel Magnetic Resonance Spectroscopy Study.

Background and Objectives: Obesity-related chronic inflammation may lead to neuroinflammation and neurodegeneration. This study aimed to evaluate the neurometabolic profile of obese patients using cerebral multivoxel magnetic resonance spectroscopy (mvMRS) and assess correlations between brain metabolites and obesity markers, including body mass index (BMI), waist circumference, waist-hip ratio, body fat percentage, and indicators of metabolic syndrome (e.g., triglycerides, HDL cholesterol, fasting blood glucose, insulin, and insulin resistance index (HOMA-IR)). Materials and Methods: This prospective study involved 100 participants, stratified into two groups: 50 obese individuals (BMI ≥ 30 kg/m2) and 50 controls (18.5 ≤ BMI < 25 kg/m2). Anthropometric measurements, body fat percentage, and biochemical markers were evaluated. All subjects underwent long- and short-echo mvMRS analysis of the frontal and parietal supracallosal subcortical and deep white matter, as well as the cingulate gyrus, analyzing NAA/Cr, Cho/Cr, and mI/Cr ratios, along with absolute concentrations of NAA and Cho. Results: Obese participants exhibited significantly decreased NAA/Cr and Cho/Cr ratios in the deep white matter of the right cerebral hemisphere (p < 0.001), while absolute concentrations of NAA and Cho did not differ significantly between groups (p > 0.05). NAA levels showed negative correlations with more reliable obesity parameters (waist circumference and waist-to-hip ratio) but not with BMI, particularly in the deep frontal white matter and dorsal anterior cingulate gyrus of the left cerebral hemisphere. Notably, insulin demonstrated a significant negative impact on NAA (ρ = -0.409 and ρ = -0.410; p < 0.01) and Cho levels (ρ = -0.403 and ρ = -0.392; p < 0.01) at these locations in obese individuals. Conclusions: Central obesity and hyperinsulinemia negatively affect specific brain regions associated with cognitive and emotional processing, while BMI is not a reliable parameter for assessing brain metabolism.

Heschl’s gyrus and the temporal pole: The cortical lateralization of language

The left lateralization of language has been attributed to hemispheric specialization for processing rapidly changing information. While interhemispheric differences in auditory cortex organization support this view, the macrostructure of the entire cerebral cortex has not been thoroughly examined from this perspective. This study investigated hemispheric asymmetries in cortical surface area and thickness and their relationship to pronunciation scores from oral reading using the Human Connectome Project Young Adult dataset (N=1113). Heschl’s gyrus had the most left-lateralized surface area, while the temporal pole showed the strongest right-lateralization in thickness. These areas correspond to the core components of speech: sound and meaning. Notably, their structural features were the only ones also yielding a significant correlation with pronunciation scores. Additionally, Broca’s area’s posterior region (pars opercularis), involved in articulatory phonological processing, showed leftward lateralization, contrasting with the right-lateralized anterior portions. Left-hemisphere language areas were largely thinner and more extended than their right-sided homologs with a larger white-to-gray matter ratio. Cortical thickness was inversely related to surface area. The lateralization of auditory-related language areas and their structure’s correlation with pronunciation in oral reading supports a genetically based auditory foundation for language. A thinner, more efficient cortex with larger surface areas and increased myelination likely underlies the left-hemispheric dominance of language. Thinner, more extended brain areas have been linked to more myelination and wider cortical columns and intercolumnar space. This provides the potential for a fast network of interconnected, discrete information units able to support language’s demands of rapid categorical processing.

Assessment of Post-COVID-19 Changes in Brain-Clinical and Imaging Evaluation Using MRI Vessel Wall Imaging and Complementary MRI Methods.

Background/Objectives: The aim of the study was to evaluate the usefulness of vessel wall imaging and MRI in assessment of the post-COVID-19 changes in the brain. VWI is a progressive MRI technique that provides precise imaging of the pathological process in the wall of the vessel. It might help us to better understand the pathophysiology of COVID-19-related neurological lesions and may have an impact on management protocols. Methods: A total of 43 patients were included in the study; the post-COVID-19 group included 23 patients hospitalized for COVID-19 (mean age of the group: 53.52 years; 26% male, 74% female). The control group consisted of 20 patients from the general population who did not suffer from COVID-19 (mean age: 52.15 years; 35% male, 65% female). MRI examinations were performed on a 3T scanner (Biograph mMR, Siemens). The VW-MRI protocol included T1-weighted SPACE FS black-blood images, FLAIR images, SWI, and MRA. Results: Several radiological changes in post-COVID-19 patients were described: hyperintense foci in the white matter of the brain hemispheres, in the lower parts of the temporal lobes, and in the structures of the posterior cranial fossa; presence of engorgement of deep medullary veins or perivascular enhancement; presence of inflammatory vessel thickening in VWI images; changes in hippocampus size; presence of cortical atrophy; and thickening of the mucous membrane of the paranasal sinuses. The presence of atherosclerotic vessel thickening in VWI and the width of the third ventricle depended on the age of the patient. Conclusions: VWI and MRI may be useful in the assessment of post-COVID-19 lesions in the brain.

TREATMENT OPTIONS FOR RECURRENT MALIGNANT DIFFUSE ASTROCYTOMA (WHO GRADE IV)

Objectives We present the case of a 37-year-old female who underwent partial resection in 2018 for a diffuse fibrillary astrocytoma (WHO II) that invaded almost the entire right cerebral hemisphere. The patient followed conventional radiotherapy and chemotherapy. She presents after 6 years of regularly follow-ups with left hemiparesis, intracranial hypertension syndrome and tumor recurrence on MRI. The patient underwent another surgical intervention and the new histopathological diagnosis was diffuse astrocytoma grade IV. Therapeutic options for these patients are limited considering the fact that a gross total resection or a conventional re-irradiation could impact the quality of life. Therefore, exploring new therapeutic methods, such as targeted molecular therapy like EGFR antagonists or proteasome inhibitors, or proton therapy, should be considered. Material and Methods We conducted extensive research in two public medical databases for information related to the molecular pathways and management of primary and recurrent malignant astrocytoma and relevant articles were selected. Subsequently, we correlated this information with our direct experience in our case and discussed the observed results. Results Treatment modalities for these patients include reintervention, re-irradiation and second line chemotherapeutics. In relapsing cases the goal of reintervention is both to alleviate symptoms and obtain tumoral tissue for immunohistochemical analysis for identification of the new mutations. Conventional re-irradiation for large lesions carries high risks of producing both short-term and long-term side effects, impacting the quality of life. Alternatively, proton therapy minimizes the risk of adverse events due to Bragg peak reducing the irradiation of the surrounding tissue. Conclusions Genetic characterization of these lesions can facilitate targeted molecular therapy and help in establishing the prognosis. Re-irradiation of malignant astrocytomas with proton therapy is an effective treatment measure allowing for comparable tumor control to conventional radiotherapy.

Association of the Volumes of Limbic Brain Structures with the Development of Psychoneurological Disorders in Patients with Ischemic Stroke

Post-stroke depressive disorders (PSD) and post-stroke cognitive impairments (PCI) are frequent consequences of ischemic stroke (IS). The study was focused on exploring possible associations between relative volumes of cortical and limbic brain structures during the acute period of IS, and changes in biochemical indices of hypothalamic-pituitary-adrenal, sympathoadrenal medullary and inflammatory systems, with the development of PSD or PCI after mild or moderate IS. Patients developing PSD later on had significantly smaller relative volumes of the hippocampus, entorhinal cortex, and temporal pole versus patients without depressive symptoms. PCI development was associated with significantly smaller volumes of temporal pole and supramarginal gyrus versus patients without cognitive changes. Multiple logistic regression analysis showed higher likelihood of developing PSD in patients with smaller temporal pole volume (β0 =10.9; β = –4.27; p = 0.04) and in-creased salivary α-amylase activity (β0 = –3.55; β = 2.68e–05; p = 0.02). PCI likelihood was higher in patients with smaller supramarginal gyrus volume (β0 = 3.41; β = –0.99; p = 0.047), smaller temporal pole volume (β0 = 3.41; β = –3.12; p = 0.06), and increased hair cortisol concentration at admission (index of accumulated stress load within a month before IS; β0 = 3.41; β = –0.05; p = 0.08). The data support the hypothesis suggesting predisposition to PSD and PCI and multi hit scenarios of their pathogenesis with IS providing a final hit.

Cortical structural network characteristics in non-cognitive impairment end-stage renal disease.

Explore alterations in topological features of gray matter volume (GMV) and structural networks in non-cognitive impairment end-stage renal disease (Non-CI ESRD). Utilizing graph theory, we collected structural magnetic resonance imaging (sMRI) data from 38 Non-CI ESRD patients and 50 normal controls (NC). We compared, and extracted the GMV across subject groups, constructed corresponding structural covariance networks (SCNs), and investigated the alterations in SCNs feature parameters between groups. In Non-CI ESRD patients, The GMV were reduced in several brain regions, predominantly on the left side (p < 0.05, FWE correction). The small-world network characteristics of the patient group's brain networks showed a tendency toward regular. In a few densities, global network parameters, transitivity, (p < 0.05) was significantly increased in the ESRD group. Regional network measurements revealed inconsistent changes in regional efficiency across different brain areas. In the analysis of network hubs, the right temporal pole is likely a compensatory hub for Non-CI ESRD patients. The SCNs in Non-CI ESRD patients demonstrated reduced topological stability against targeted attacks. This study reveals that patients with renal failure exhibited subtle changes in brain network characteristics even before a decline in cognitive scores. These changes involve compensatory activation in certain brain regions, which enhances network transitivity to maintain the efficiency of whole-brain network information integration without significant loss. Additionally, the SCNs characteristics can serve as a neuroanatomical marker for brain alterations in Non-CI ESRD patients, offering new insights into the mechanisms of early brain injury in ESRD patients.

Deep Learning-Based Pediatric Brain Region Segmentation and Volumetric Analysis for General Growth Pattern in Healthy Children.

To establish a quantitative reference for brain structural changes in children with neurological disorders, we employed deep learning technique to brain region segmentation and volumetric analysis within a cohort of healthy children. In this study, we recruited 312 participants aged 1.5 to 14.5years (210 boys and 102 girls), dividing them into five age groups. High-resolution structural T1-weighted images were obtained, and an established toolkit utilizing deep learning algorithms was employed for brain region segmentation. For each age group, the volumes of gray matter and white matter, along with the thickness and surface area of the cortex, were calculated and compared between boys and girls. The results indicated that the volumes of gray matter and white matter in both bilateral cerebral hemispheres, as well as the total brain volume, increased with age. Furthermore, the volumes of the left and right hippocampus, amygdala, and thalamus also demonstrated an increase as age progressed. Conversely, cortical thickness and surface area decreased with age. Our findings provide a quantitative reference for understanding brain structural changes in children with neurological disorders.

Rasmussen Encephalitis: Clinical Features, Pathophysiology, and Management Strategies-A Comprehensive Literature Review.

Rasmussen encephalitis (RE) is a rare and progressive form of chronic encephalitis that typically affects one hemisphere of the brain and primarily occurs in pediatric individuals. The current study aims to narratively review the literature about RE, including historical information, pathophysiology, and management of this condition. RE often occurs in individuals with normal development, and it is estimated that only a few new cases are identified each year in epilepsy centers. Approximately 10% of cases also occur in adolescents and adults. The hallmark feature of RE is drug-resistant focal seizures that can manifest as epilepsia partialis continua. Also, patients with RE usually develop motor and cognitive impairment throughout the years. Neuroimaging studies show progressive damage to the affected hemisphere, while histopathological examination reveals T-cell-dominated encephalitis with activated microglial cells and reactive astrogliosis. The current therapy guidelines suggest cerebral hemispherotomy is the most recommended treatment for seizures in RE, although significant neurological dysfunction can occur. Another option is pharmacological management with antiseizure medications and immunomodulatory agents. No significant progress has been made in understanding the pathophysiology of this condition in the last decades, especially regarding genetics. Notably, RE diagnosis still depends on the criteria established by Bien et al., and the accuracy can be limited and include genetically different individuals, leading to unexpected responses to management.

Asymmetry of Directed Brain Connectivity at Birth in Low-Risk Full-Term Newborns.

Functional connectivity hubs were previously identified at the source level in low-risk full-term newborns by high-density electroencephalography (HD-EEG). However, the directionality of information flow among hubs remains unclear. The aim of this study was to study the directionality of information flow among source level hubs in low-risk full-term newborns using HD-EEG. A retrospective analysis of HD-EEG collected from a prospective study. Subjects included 112 low-risk full-term (37-41 weeks' gestation) newborns born in a large delivery center and studied within 72 hours of life by HD-EEG. The directionality of information flow between hubs at the source level was quantified using the partial directed coherence in the delta frequency band. Descriptive statistics were used to identify the maximum and minimum information flow. Differences in information flow between cerebral hemispheres were assessed using Student t-test. There was higher information flow from the left hemisphere to the right hemisphere hubs (p < 0.05, t-statistic = 2). The brainstem had the highest information inflow and lowest outflow among all the hubs. The left putamen received the lowest information, and the right pallidum had the highest information outflow to other hubs. In low-risk full-term newborns, there is a significant information flow asymmetry already present, with left hemisphere dominance at birth. The relationship between these findings and the more prevalent left hemisphere dominance observed in full-term newborns, particularly in relation to language, warrants further study.

Peripheral molecular and brain structural profile implicated stress activation and hyperoxidation in methamphetamine use disorder.

Methamphetamine use disorders (MUDs) cause widespread disruptions in metabolomic and immunologic processes, highlighting the need for new therapeutic approaches. The purpose of this study was to find molecular and neuroimaging biomarkers for methamphetamine addiction. In this study, we recruited 231 patients with MUD at varying stages of withdrawal and 40 healthy controls to quantify the blood levels of 52 molecules using enzyme-linked immunosorbent assay. The overall molecular disruption caused by methamphetamine was inversely related to withdrawal time (P = 0.0008), with partial recovery observed after 1 year of follow-up (P = 2.20 × 10-5). Molecules related to stress, immune activation, oxidative products, and cardiac injury were significantly elevated in all MUD groups, while antioxidation enzymes were downregulated. Additionally, the blood level of brain-derived neurotrophic factor was significantly correlated with gray matter volumes in nine brain regions (fusiform gyrus, orbitofrontal cortex, temporal pole, caudate, cerebellum crus, and vermis, adjusted P < 0.05) among patients with MUD. These findings suggest that patients with MUD exhibit elevated levels of immune response, stress, and oxidative stress, which are associated with brain structural abnormalities.

The repeatability of behavioural laterality during nest building in zebra finches

Cerebral laterality is a widespread phenomenon across animals and refers to the specialization of the left and right hemispheres of the brain for perceptual, cognitive and behavioural tasks. Behavioural laterality occurs in several contexts, including foraging, mate selection, predator detection and tool manufacture. Behavioural laterality during nest building, however, has rarely been addressed. We conducted two experiments to examine (1) whether behavioural laterality occurs during nest building, (2) whether laterality correlates with nest-building speed, (3) whether laterality during nest building is repeatable, and (4) whether nest-building experience influences laterality. In Experiment 1, we scored individual laterality indices for 58 zebra finch (Taeniopygia guttata) males, the nest-building sex in this species, based on which eye he used to view then select the first 25 pieces of nest material. We calculated correlations between laterality strength and nest-building duration. In Experiment 2, to test the repeatability of laterality during nest building, we measured laterality for 20 males across five nests built by each male. Individuals varied both in the direction and the strength of behavioural laterality of material selection during nest building. Overall, however, males were not consistent in their laterality across the five nests. We found no correlation between laterality strength and nest-building duration in either experiment. Finally, we found evidence for building experience influencing the behavioural laterality of individuals: more building experience results in more predictable behavioural laterality during nest-material selection.

Cerebello-Cerebral Resting-State Functional Connectivity in Poststroke Aphasia.

Introduction: The influence of the cerebellum in poststroke aphasia recovery is poorly understood. Despite the right cerebellum being identified as a critical region involved in both language and cognitive functions, little is known about functional connections between the cerebellum and bilateral cortical hemispheres following stroke. This study investigated the relationship between chronic poststroke naming deficits and cerebello-cerebral resting-state functional connectivity (FC). Methods: Twenty-five cognitively normal participants and 42 participants with chronic poststroke aphasia underwent resting-state functional magnetic resonance imaging. Participants with aphasia also underwent language assessment. We conducted regions of interest (ROI)-to-ROI analyses to investigate the FC between the right cerebellar Crus I/II (seed ROI; Cereb1r/Cereb2r) and bilateral cortical language regions and compared these results to cognitively normal controls. Single-subject connectivity parameters were extracted and used as independent variables in a stepwise multiple linear regression model associating Boston Naming Test (BNT) score with FC measures. Results: FC analyses demonstrated correlations between the right cerebellar Crus I/II and both left and right cortical regions for both cognitively normal controls and stroke participants. Additionally, aphasia severity and lesion load had an effect on the cerebello-cerebral network connectivity in participants with aphasia. In a stepwise multiple linear regression, controlling for aphasia severity, time poststroke and lesion load, FC between the right Cereb2-left Cereb1 (standardized beta [std B]= -0.255, p < 0.004), right Cereb2-right anterior MTG (std B = 0.259, p < 0.004), and the right Cereb2-left anterior STG (std B = -0.208, p < 0.018) were significant predictors of BNT score. The overall model fit was R2 = 0.786 (p = 0.001). Conclusion: Functional connections between the right cerebellum and residual bilateral cerebral hemisphere regions may play a role in predicting naming ability in poststroke aphasia.

Resting-state functional connectome predicts sleep quality two months after the first negative COVID-19 antigen test

BackgroundThe COVID-19 pandemic has led to long-term neurological and psychological effects, including sleep disturbances. While prior studies have identified altered brain function post-COVID-19, specific functional connectivity (FC) patterns predicting sleep quality after recovery remain unclear. This study aims to identify FC patterns associated with sleep quality two months after the first negative COVID-19 antigen test. MethodsUsing a connectome-based predictive modeling (CPM) approach, we identified the functional connectome regulating sleep quality based on a 164-region parcellation. Significant connections were analyzed using mediation models to examine their role in the relationship between anxiety, depression, and sleep. ResultsFC between the right cerebellar peduncle and the left VIII of the cerebellum, and between the left middle temporal pole (MTP) and left ventral tegmental area (VTA), significantly predicted Pittsburgh Sleep Quality Index (PSQI) scores for sleep disturbances two months post-recovery (q2 = 0.059, MSE = 0.154, p = 0.017, r = 0.350). Mediation analysis showed a significant indirect effect of FC between the left MTP and VTA on the relationship between generalized anxiety and sleep disturbances (indirect effect = 0.013, 95% CI = [0.002, 0.03], pfdr <0.05). FC between the right dorsal raphe nucleus and ipsilateral regions—including occipital, parietal, and temporal areas—predicted PSQI scores for daytime dysfunction (q2 = 0.092, MSE = 0.678, p = 0.025, r = 0.342). ConclusionPost-COVID-19 brain connectivity and anxiety predict sleep quality. These findings highlight the potential for targeted therapeutic strategies to improve sleep and identify patients at risk for prolonged disturbances through FC biomarkers.

TMET-36. INCREASED METHIONINE CYCLE DRIVES PYRIMIDINE METABOLISM IN LETHAL PEDIATRIC EPENDYMOMAS

Abstract Supratentorial ependymomas (ST-EPN) are pediatric brain tumors found in the cerebral hemisphere, driven by the oncogenic fusion of ZFTA with RELA. Other than surgery and radiotherapy, these tumors do not have effective therapeutic options. Recurrent ST-EPN tumors are highly aggressive and hard to treat, which makes these tumors lethal. To understand the disease mechanism and potentially identify or develop therapeutic targets, we established patient-derived models and interrogated the genetic and metabolic dependencies using cutting-edge, near-genome-wide genetic screening and metabolomic tools. Our integrative transcriptomics and metabolic analysis identify that the ZFTA-RELA fusion drives methionine metabolic reprogramming in the cancer stem cells to regulate permissive epigenetic status and pyrimidine nucleotide synthesis to fuel tumor growth. Limiting methionine or inhibiting MAT2A, a rate-limiting enzyme of methionine metabolism in ST-EPN cells, results in profound cell cycle arrest and make the cells vulnerable to pyrimidine inhibitors compared to other pediatric brain tumors. Thus, for treatment, along with radiotherapy, blocking the methionine cycle by using the methionine limited diet or in combination with pyrimidine metabolism inhibitors can be a novel therapeutic strategy against the aggressive paediatric ST-EPN tumors.

THE EFFECT OF NF-ΚB ON THE INTENSITY OF OXIDATIVE STRESS IN THE CEREBRAL CORTEX OF RATS UNDER THE COMBINED INFLUENCE OF THE LIGHT-DARK CYCLE, SYSTEMIC INFLAMMATORY RESPONSE, AND SODIUM GLUTAMATE ADMINISTRATION

To date, scientists have confirmed the link between the development of oxidative stress and disruptions in the light regime, as well as the systemic inflammatory response. The impact of monosodium glutamate on increasing oxidative damage to rat brain tissue has also been identified. The aim of this study was to investigate the role of the transcription factor NF-κB by examining the effect of its inhibitor, ammonium pyrrolidinedithiocarbamate, on the development of oxidative stress in the cerebral hemispheres of rats, in combination with acute desynchronosis, systemic inflammatory response, and monosodium glutamate administration. The study was conducted on 45 white Wistar rats weighing 150-200 g, divided into three groups: control (n=15), a group subjected to a combination of acute desynchronosis, systemic inflammatory response, and sodium glutamate administration (n=15), and a group exposed to the combination of acute desynchronosis, systemic inflammatory response, and received sodium glutamate and pyrrolidinedithiocarbamate (n=15). To induce acute desynchronosis, the rats were initially kept under a regular light-dark cycle (12 hours of light, 12 hours of darkness) for 3 weeks, followed by a shift in the light-dark phases by 6 hours back over the next 3 days. The systemic inflammatory response was modeled through intraperitoneal administration of Salmonella typhi lipopolysaccharide. During the first week, lipopolysaccharide was administered three times at a dose of 0.4 μg per 1 kg of body weight, and during the following seven weeks, it was given once a week. Sodium glutamate, at a dose of 30 mg/kg, dissolved in 0.5 ml of distilled water, was administered intragastrically for 20 days. The NF-kB activation inhibitor ammonium pyrrolidinedithiocarbamate (Sigma-Aldrich, Inc., USA) was administered at a dose of 76 mg/kg three times a week for 20 days. In a 10% homogenate of the cerebral hemispheres, the following were measured: the rate of superoxide anion radical production, the content of thiobarbituric acid-reactive substances (TBARS), the increase in these parameters, as well as the activity of catalase and superoxide dismutase. Administration of pyrrolidinedithiocarbamate in combination with acute desynchronosis, systemic inflammatory response, and sodium glutamate reduced the rate of basic superoxide anion radical production by 10%, NADPH-induced production by 17.6%, NADH-induced production by 13%, reduced the concentration and growth of TBC-active products by 6.6% and 14.6%, respectively, increased the activity of superoxide dismutase by 35.2%, catalase by 10.5% compared to the group exposed to the combination of acute desynchronosis, systemic inflammatory response, and sodium glutamate administration. Conclusion. The administration of pyrrolidinedithiocarbamate in combination with a systemic inflammatory response, acute desynchronosis and the action of sodium glutamate reduces the production of the superoxide anion radical, the concentration and increase in TBC-active products, enhances antioxidant protection that indicates the possible influence of the nuclear factor NF-κB on the development of oxidative processes in the cerebral hemispheres of rats.

TMOD-27. RECURRENT GLIOBLASTOMA AFTER LASER ABLATION OF THE PRIMARY TUMOR IN A PRECLINICAL ORTHOTOPIC MODEL EXHIBIT INCREASED GENETIC SIGNATURES OF CELL CYCLE AND CELL MOTILITY

Abstract Image-guided laser interstitial thermal therapy (LITT) is a minimally invasive tumor cytoreductive treatment for recurrent gliomas and tumors in eloquent loci. We have adapted this technique to develop an image-guided glioblastoma (GBM) ablation model, its recurrence and have tested the efficacy of imaging biomarkers in evaluating tumor ablation and recurrence. The cytopathology and molecular signatures of the primary and recurrent tumors were compared. Immune-compromised female rats were implanted with U251N tumor cells in one brain hemisphere (n=20). Tumor growth was monitored using magnetic resonance imaging (MRI). When tumors reached about 4 mm in diameter, they were ablated using a clinical LITT system (Visualase®), under MRI guidance. Five other rats implanted with U251N tumors were used as unablated controls. MRI data were acquired at 24 h post-LITT, and at 2 and 4 weeks. Rats were sacrificed for histopathology at 2 and 4 weeks, and brain sections stained for hematoxylin and eosin, human major histocompatibility complex, Ki67, a cell proliferation marker and sex determining region Y)-box 2 (SOX2), a stem cell transcription factor. An additional cohort of rats with primary (n=4) and post-LITT recurrent (n=4) U251N tumors were used for analysis of their molecular composition using RNA-Seq approach. In the treated groups, MRI showed little tumor tissue at 24 h, evidence of recurrence at 2 weeks and significant tumor tissue at 4 weeks. Tumor DCE-MRI parameters showed elevated intra-tumoral vascular permeability (i.e., Ktrans) values at pre-LITT imaging, that shifted to peri-ablation periphery at 24 h. A trend of progressive decrease in Ktrans was seen until 1-week post-ablation. Increasing Ktrans values at 2 weeks and after 4 weeks coincided with tumor recurrence. RNA-Seq data showed that cell cycle, cellular movement and inflammatory disease genes were the most differentially expressed genes in the recurrent tumors suggesting increased infiltration may primarily underlie treatment resistance.

NCOG-08. A RARE PRIMARY CNS T-CELL LYMPHOMA CASE: 12-YEAR FOLLOW-UP AFTER CHEMOTHERAPY

Abstract INTRODUCTION Primary central nervous system (CNS) T-cell lymphoma (PCNSTL) is a rare hematological malignancy. There is mere literature to guide the treatment. CASE REPORT This study is an update on our previously reported case at SNO in 2012 after a 12-year follow-up, detailing the long-term outcome of our chemotherapy treatment for a case of PCNSTL. In 2011, a 26-year-old immunocompetent patient presented with severe headache, vomiting, and lethargy. The brain MRI found more than a dozen masses on his bilateral cerebral hemispheres. Brain biopsy discovered T-cell lymphoma. The patient was started biweekly high-dose-methotrexate (HD-MTX) in 2011. After three doses, there was no noticeable improvement on his brain MRI. His treatment was switched to HD-MTX plus high dose cytarabine regimen (Ferreri et al, The Lancet, 2009). The patient could not tolerate cytarabine; thus, was changed back to HD-MTX. The patient responded to the rest of HD-MTX well. He completed 8 doses of biweekly HD-MTX induction therapy and 2 doses of monthly HD-MTX maintenance therapy. His brain MRI showed complete resolution of enhancement on one-year follow-up image. The patient has been off-treatment and monitored under surveillance of brain MRIs since 2012. He has had no lymphoma recurrence over the past 12 years. His physical functions have been preserved with a Karnofsky Performance Status scale of 80%. Neuropsychological evaluations in 2015, 2018, and 2023 showed mild cognitive impairment with gradual improvements in his working memory and semantic fluency. His Mini-Mental Status Exam scores have remained stable to mild improvement, recording 27/30 in 2015, 26/30 in 2018, 27/30 in 2023 and 28/30 in 2024. DISCUSSION The patient, who is now 38 years old, has surpassed a 12-year survival mark. Our experience emphasizes the feasibility of treating PCNSTL through chemotherapy only, which might be potentially beneficial in surviving and preserving major aspects of brain function.

SURG-40. PEDIATRIC LOWER GRADE GLIOMA SURGERY IN THE ERA OF GENOMIC MEDICINE

Abstract INTRODUCTION In the 2021 WHO Brain Tumor Classification, pediatric-type gliomas are distinctly categorized from their adult counterparts. The continual evolution of cancer genomics has significantly broadened the spectrum of available treatment options. Here we would like to consider surgery for pediatric low-grade gliomas. METHODS We retrospectively analyzed 41 cases of low-grade gliomas or glioneuronal tumors in pediatric patients who underwent surgery at our institute from 2002 to 2023. We discussed surgical strategies based on molecular classification. RESULTS Among the cases, there were 34 gliomas and 7 glioneuronal tumors. According to the new WHO classification, they corresponded to 1) Adult-type diffuse gliomas, 2) Pediatric-type diffuse low-grade gliomas, 3) Circumscribed astrocytic tumors, or 4) Glioneuronal and neuronal tumors. Cases without molecular diagnosis were also considered in light of the new WHO classification. Among molecularly diagnosed astrocytomas involving the cerebral hemisphere, brain stem, spinal cord, there were no cases of 1), and 2) 3) were the main cases. It is important in surgical selection to note that these cases generally have a more favorable prognosis compared to the adult type and have usefulness in diagnosing MAPK pathway abnormalities leading to the selection of molecularly targeted drugs. 3) includes pilocytic astrocytoma, subependymal giant cell astrocytoma, and pleomorphic xanthoastrocytoma. Among these, in the treatment of pilocytic astrocytoma of the visual tract and hypothalamus, biopsy is essential for molecular diagnosis and therapeutic agent selection. 4) is mainly an epilepsy-related tumor. While their removal contributes to genetic diagnosis and epileptic seizure control, total removal may not always be deemed necessary. CONCLUSION Based on the new WHO classification, a reevaluation of treatment strategies for pediatric brain tumors is necessary.

Changes in brain functional connectivity between on and off states and their relationship with cognitive impairment in Parkinson’s disease

Parkinson’s disease (PD) is characterized by motor and non-motor symptoms. Cognitive decline is crucial in disease progression and affect quality of life; however, their underlying mechanisms in PD remain unclear. We explored the relationship between cognitive impairment and functional connectivity (FC) using resting-state functional magnetic resonance imaging in 26 patients with sporadic PD, focusing on the changes in FC between on and off states. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) score. The correlation between MMSE scores and changes in FC values during on and off states was assessed using Pearson’s correlation coefficient. The correlation between changes in FC during the on and off periods and cognitive function differed for each cognitive function item. MMSE memory scores were positively correlated with FC between the brainstem and the left cerebral hemisphere. MMSE attention scores were positively correlated with FC between the bilateral thalamus and frontal lobes and negatively correlated with FC between the left cerebral hemispheres. These findings may facilitate our understanding of the neural correlates underlying cognitive impairment in PD and help develop treatment strategies to preserve cognitive function.

Changes in the functional connections of the brain in patients with hypersomnia in acute ischemic stroke

BACKGROUND: The Disorders of cerebral circulation and sleep are inextricably related, since sleep disorders, including hypersomnia, are closely intertwined with cardiovascular diseases and increase the risk of stroke. Research works on visualization of functional brain changes in patients with sleep disorders and acute ischemic stroke are very few and need more study. AIM: to determine the functional connections of the brain in hypersomnia in patients with acute ischemic stroke by performing functional magnetic resonance imaging at rest. A study of 40 patients with acute ischemic stroke and sleep disorders was performed on the basis of the Federal State Budgetary Institution Almazov Research Center of the Ministry of Health of the Russian Federation. All patients underwent neurological examination, assessment of sleepiness, worry and depression, magnetic resonance imaging was performed on tomographs with a magnetic field induction force of 1.5T, using a standard protocol and special pulse sequences of T-gradient echo 3D MPRAGE and BOLD. Functional magnetic resonance imaging of the brain at rest was used to assess functional connections. Postprocessing was performed using specialized CONN-TOOLBOX software with an appropriate graphical representation of quantitative results based on the selection of areas of interest. RESULTS: Among the examined patients, 23 had hypersomnolence; of these, 8 patients were diagnosed with secondary hypersomnia associated with sleep apnea syndrome. Thus, in the examined sample, post-stroke hypersomnolence was detected in 15 patients (34%). Patients with an unspecified subtype of stroke and right-sided lesions showed a high degree of drowsiness (p 0.05). With the help of functional magnetic resonance imaging of the brain at rest, changes in functional connections between the main nodes of the default mode network with the left temporal pole, cerebellum, central cerebral cortex on the left, angular gyrus on the left, with the dorsal attention network on the right are determined (p 0.05). CONCLUSION: The use of complex magnetic resonance imaging, which includes structural and functional magnetic resonance imaging in patients with acute ischemic stroke and sleep disorders, allows us to identify structural changes and changes in functional connectivity and identify neuroimaging markers of this pathology. Hypersomnolence is typical for patients with an unspecified subtype of ischemic stroke and damage to the right hemisphere of the brain.