Left Temporal Lobe Research Articles

20 Congenital Left Temporal Lobe Cyst: A Case Study of rs-fMRI and Cognitive Performance

Objective:Behavior is the product of interconnected brain regions that work together as networks. This case study examines whether there are differences between a participant with a large congenital left temporal lobe cyst, which impacted the volume of structures in the region, and control subjects of similar age on cognitive tasks and network connectivity as measured by resting-state functional magnetic resonance imaging (rs-fMRI).Participants and Methods:The case participant (CP; 71 year old female) and controls (CON; n = 25; 48% female) were recruited as part of a larger aging study. CON were chosen from the larger study population by age (+/- 10 years from CP; Range = 68-86 years). Cognitive tasks included: Shopping list memory task, Montreal Cognitive Assessment, WAIS-IV subtests: Digit Span, Digit-Symbol, Symbol Span, and Letter-Number Sequencing. For rs-fMRI, we administered four blood-oxygen level dependent (BOLD) functional connectivity (rs-fMRI) scans at 6 minutes each. Image processing was conducted using the CONN toolbox. Independent sample t-tests evaluated differences between CP and CON. Segregation was evaluated in the Auditory (Au), Cerebellar-basal ganglia (CBBG), Cingulo-Opercular Task Control (COTC), Dorsal Attention (DA), Default Mode (DMN), Fronto-Parietal Task Control (FPTC), Salience (Sa), Sensory Somatomotor Hand (SSH), Sensory Somatomotor Mouth (SSM), Visual (Vi), and Ventral Attention (VA) networks to assess CP’s functional segregation by network throughout the brain. Bonferroni correction was applied to account for multiple comparisons in cognitive testing (.05/7 for significance at p < 0.007) and network segregation (.05/11 for significance at p < .005).Results:Independent samples t-tests did not reveal significant differences across cognitive tasks (t(24) <1.04, p > .05). Network segregation did not reveal significant differences between CP and CON across networks examined (t(24) < 1.269, p > .005). However, DMN and DA segregation trended toward significance (t(24) = -2.724, p = .006 and t(24) =-2.006, p = .028), respectively) with CP demonstrating lower segregation as compared to CON.Conclusions:CP performed similarly on cognitive testing to CON, indicating that the congenital presence of a large temporal lobe cyst did not impact global cognition, list learning and memory, working memory, or processing speed. CP did not demonstrate significantly different segregation across networks of interest after Bonferroni correction. Our cognitive performance results are consistent with a similar case-study examining language, which revealed intact linguistic abilities (Tuckete et al., 2022). The lack of differences in cognitive performance and segregation highlight the capacity for plasticity in the human brain, even in the presence of a large structural abnormality. This also suggests that the processes of aging in this case are not markedly different from controls. In future research we intend to expand on this case study by evaluating right temporal to hippocampal seeds and language network seeds to delve deeper into memory and language functioning.

Alterations in the topological organization of the default-mode network in Tourette syndrome

BackgroundThe exact pathophysiology of TS is still elusive. Previous studies have identified default mode networks (DMN) abnormalities in patients with TS. However, these literatures investigated the neural activity during the tic suppression, not a true resting-state. Therefore, this study aimed to reveal the neural mechanism of Tourette's syndrome (TS) from the perspective of topological organization and functional connectivity within the DMN by electroencephalography (EEG) in resting-state.MethodsThe study was conducted by analyzing the EEG data of TS patients with graph theory approaches. Thirty children with TS and thirty healthy controls (HCs) were recruited, and all subjects underwent resting-state EEG data acquisition. Functional connectivity within the DMN was calculated, and network properties were measured.ResultsA significantly lower connectivity in the neural activity of the TS patients in the β band was found between the bilateral posterior cingulate cortex/retrosplenial cortex (t = -3.02, p < 0.05). Compared to HCs, the TS patients’ local topological properties (degree centrality) in the left temporal lobe in the γ band were changed, while the global topological properties (global efficiency and local efficiency) in DMN exhibited no significant differences. It was also demonstrated that the degree centrality of the left temporal lobe in the γ band was positively related to the Yale Global Tic Severity Scale scores (r = 0.369, p = 0.045).ConclusionsThe functional connectivity and topological properties of the DMN of TS patients were disrupted, and abnormal DMN topological property alterations might affect the severity of tic in TS patients. The abnormal topological properties of the DMN in TS patients may be due to abnormal functional connectivity alterations. The findings provide novel insight into the neural mechanism of TS patients.

Evaluation of brain nerve function in ICU patients with Delirium by deep learning algorithm-based resting state MRI.

The purpose of this study was to explore the value of resting-state magnetic resonance imaging (MRI) based on the brain extraction tool (BET) algorithm in evaluating the cranial nerve function of patients with delirium in intensive care unit (ICU). A total of 100 patients with delirium in hospital were studied, and 20 healthy volunteers were used as control. All the subjects were examined by MRI, and the images were analyzed by the BET algorithm, and the convolution neural network (CNN) algorithm was introduced for comparison. The application effects of the two algorithms were analyzed, and the differences of brain nerve function between delirium patients and normal people were explored. The results showed that the root mean square error, high frequency error norm, and structural similarity of the BET algorithm were 70.4%, 71.5%, and 0.92, respectively, which were significantly higher than those of the CNN algorithm (P < 0.05). Compared with normal people, the ReHo values of pontine, hippocampus (right), cerebellum (left), midbrain, and basal ganglia in delirium patients were significantly higher. ReHo values of frontal gyrus, middle frontal gyrus, left inferior frontal gyrus, parietal lobe, and temporal lobe and anisotropy scores (FA) of cerebellums (left), frontal lobe, temporal lobe (left), corpus callosum, and hippocampus (left) decreased significantly. The average diffusivity (MD) of medial frontal lobe, superior temporal gyrus (right), the first half of cingulate gyrus, bilateral insula, and caudate nucleus (left) increased significantly (P < 0.05). MRI based on the deep learning algorithm can effectively improve the image quality, which is valuable in evaluating the brain nerve function of delirium patients. Abnormal brain structure damage and abnormal function can be used to help diagnose delirium.

Event-related potentials reveal visual episodic memory deficits in patients with temporal lobe epilepsy

ObjectiveTemporal lobe epilepsy (TLE) patients usually suffer from impaired episodic memory (EM), but its underlying electrophysiologic mechanism and impacted cognitive performance are unclear. We aim to investigate the association between episodic memory reserve and physiological measures of memory workload in TLE patients using Event-related potentials (ERP). MethodsA change detection task with image stimuli assesses visual episodic memory. During the memory encoding and decoding phases, the ERP signals were analyzed from twenty-nine TLE patients (twelve with left TLE patients, seventeen with TLE), and thirty healthy controls. Given that EM is a complex process involving many fundamental cognitive processes, the amplitudes and latencies of EM-related ERP (FN400, late positive potential (LPC), and late posterior negativity (LPN)), and the ERP reflecting the fundamental processes (P100, N100, P200, and P300) were calculated. Then we used a three-by-two factorial design on the ERP metrics for interaction and main effects. The correlation analysis among Wechsler Memory Scales-Chinese Revision (WMS-RC) results, behavioral data, and the ERPs was carried out. ResultsThe TLE patients performed worse in WMS-RC and the memory task. The increased P200 and decreased P300 amplitudes were observed in the TLE patients, and LPN was abnormal in only LTLE patients. For EM-related components, differences were observed in both the LTLE and RTLE patients: the lack of the FN400 effect, the lack of the reversed LPC effect, and the reduced FN400. No significant inter-group difference was detected for the latencies of all the ERPs. Additionally, there were significant correlations among WMS-RC scores, behaviors, and some ERP amplitudes. ConclusionsThe impaired EM is linked to the increased P200 and decreased P300 amplitudes. LPN seems to be sensitive to left temporal lobe dysfunction. More importantly, the abnormal old or new effects of the FN400 and LPC, and the reduced FN400 amplitude might be associated with the visual EM deficit in the TLE patients. These findings may assist in the deep understanding of the EM disorder and the evaluation of the side effects of antiepileptic drugs.

A - 114 Long Term Cognitive Sequela of Intracranial Radiation Therapy in a Pediatric Cerebellar Medulloblastoma Survivor.

Intracranial radiation therapy (IRT) for pediatric brain tumors is associated with late delayed brain injury due to cerebrovascular abnormality, white matter necrosis, demyelination, and gliosis which are irreversible. As a result, persistent cognitive deficits in adulthood emerge which are aggravated by younger age at diagnosis, higher radiation dose, whole brain radiation (WBR), and concurrent chemotherapy. The case is a childhood brain tumor survivor seen 18years post treatment who displayed cognitive deficits reflecting the cognitive sequela of WBR that overlapped with the anatomical distribution of white matter damage sustained. 23-year-old Black male with a history of childhood cerebellar medulloblastoma diagnosed at age 4, tumor resection, WBR, chemotherapy, more recent seizure disorder and medullary stroke, diabetes, and hypertension was seen for a neuropsychological evaluation due to memory complaints. His neuroimaging showed white matter hyperintensities in bilateral temporal and occipital lobes, bilateral cerebellar hemispheres, bilateral frontal lobes, medial posterior right cerebellar cyst, and 10 x 5mm cyst in the left temporal lobe. Results showed FSIQ = 59 and deficits in language, processing speed, visuospatial abilities, executive functioning, and verbal memory. His auditory working memory and visual memory were preserved. Based on his numerous adaptive limitations, moderate intellectual development disorder diagnosis was given. Deficits across several cognitive domains were consistent with multi-focal white matter lesions seen in patient's neuroimaging which reflect radiographic findings related to long-term sequela of previous intracranial radiation. A unique finding was relatively preserved visual memory as findings related to asymmetrical memory dysfunction in childhood medulloblastoma survivors are scarce.

The neural correlates of sub-lexical semantics and its integration with the lexical meaning in reading Chinese characters

The semantic neural routes in contemporary models of visual word recognition are mainly constructed based on lexical-semantic processing. However, the neural bases of processing semantic cues embodied in sub-lexical units are less clear. The current fMRI study takes the ideographic property of Chinese characters (The semantic radical can provide a semantic cue for the character's meaning) to explore the brain mechanisms of sub-lexical semantic processing and its interaction with lexical-semantic processing in a lexical decision task. The GLM results and further ROI analysis revealed that the lexical-semantic processing relied on the left posterior Middle Temporal Gyrus (pMTG) and Angular Gyrus (AG); the sub-lexical semantic processing relied on the left middle MTG (mMTG) and AG; their integration relied on the left Anterior Temporal Lobe (ATL). It sheds light on investigating the neural circuit of the semantic processing in visual word reading.

Immediate neural impact and incomplete compensation after semantic hub disconnection

The human brain extracts meaning using an extensive neural system for semantic knowledge. Whether broadly distributed systems depend on or can compensate after losing a highly interconnected hub is controversial. We report intracranial recordings from two patients during a speech prediction task, obtained minutes before and after neurosurgical treatment requiring disconnection of the left anterior temporal lobe (ATL), a candidate semantic knowledge hub. Informed by modern diaschisis and predictive coding frameworks, we tested hypotheses ranging from solely neural network disruption to complete compensation by the indirectly affected language-related and speech-processing sites. Immediately after ATL disconnection, we observed neurophysiological alterations in the recorded frontal and auditory sites, providing direct evidence for the importance of the ATL as a semantic hub. We also obtained evidence for rapid, albeit incomplete, attempts at neural network compensation, with neural impact largely in the forms stipulated by the predictive coding framework, in specificity, and the modern diaschisis framework, more generally. The overall results validate these frameworks and reveal an immediate impact and capability of the human brain to adjust after losing a brain hub.

Cerebral perfusion in post-stroke aphasia and its relationship to residual language abilities.

Stroke alters blood flow to the brain resulting in damaged tissue and cell death. Moreover, the disruption of cerebral blood flow (perfusion) can be observed in areas surrounding and distal to the lesion. These structurally preserved but suboptimally perfused regions may also affect recovery. Thus, to better understand aphasia recovery, the relationship between cerebral perfusion and language needs to be systematically examined. In the current study, we aimed to evaluate (i) how stroke affects perfusion outside of lesioned areas in chronic aphasia and (ii) how perfusion in specific cortical areas and perilesional tissue relates to language outcomes in aphasia. We analysed perfusion data from a large sample of participants with chronic aphasia due to left hemisphere stroke (n = 43) and age-matched healthy controls (n = 25). We used anatomically defined regions of interest that covered the frontal, parietal, and temporal areas of the perisylvian cortex in both hemispheres, areas typically known to support language, along with several control regions not implicated in language processing. For the aphasia group, we also looked at three regions of interest in the perilesional tissue. We compared perfusion levels between the two groups and investigated the relationship between perfusion levels and language subtest scores while controlling for demographic and lesion variables. First, we observed that perfusion levels outside the lesioned areas were significantly reduced in frontal and parietal regions in the left hemisphere in people with aphasia compared to the control group, while no differences were observed for the right hemisphere regions. Second, we found that perfusion in the left temporal lobe (and most strongly in the posterior part of both superior and middle temporal gyri) and inferior parietal areas (supramarginal gyrus) was significantly related to residual expressive and receptive language abilities. In contrast, perfusion in the frontal regions did not show such a relationship; no relationship with language was also observed for perfusion levels in control areas and all right hemisphere regions. Third, perilesional perfusion was only marginally related to language production abilities. Cumulatively, the current findings demonstrate that blood flow is reduced beyond the lesion site in chronic aphasia and that hypoperfused neural tissue in critical temporoparietal language areas has a negative impact on behavioural outcomes. These results, using perfusion imaging, underscore the critical and general role that left hemisphere posterior temporal regions play in various expressive and receptive language abilities. Overall, the study highlights the importance of exploring perfusion measures in stroke.

SAT058 Diabetes Complicated By DKA, Mucormycosis And Covid-19

Abstract Disclosure: A. Gordon: None. Background: Mucormycosis is an invasive opportunistic fungal infection, that although rare, has an estimated all-cause mortality of 54%. Even with aggressive treatment, significant tissue necrosis and bone destruction can occur. Risk factors include diabetes, acidosis (as in diabetic ketoacidosis), excess iron, transplant, malignancy, kidney and liver disease, immunosuppressant and corticosteroid use - and in more recent times, the Covid-19 infection. We present a case of invasive rhino-orbital cerebral mucormycosis in the setting of DKA, uncontrolled diabetes and Covid-19. Case: A 60-year-old female with history of uncontrolled type 2 diabetes (HbA1c 14.3%) presented after being found unresponsive. Her exam was significant for encephalopathy, complete left eye ophthalmoplegia and right-sided hemiparesis. She was hemodynamically stable without fever. Initial labs showed significant hyperglycemia with an elevated anion gap and beta-hydroxybutyrate indicative of diabetic ketoacidosis (DKA). She had a lumbar puncture which showed leukocytosis with neutrophilia (146 WBC, 39% neutrophils), elevated glucose and normal protein; CSF culture was negative for growth. She also tested positive for Covid-19 although CXR was unremarkable and she did not require treatment. Initial CT/CTA head/neck showed complete occlusion of the left cervical internal carotid artery with associated acute/subacute infarcts in the left frontal, parietal, temporal and occipital lobes. CT sinuses showed severe frontal, maxillary and ethmoid sinus mucosal wall thickening with left premaxillary soft tissue swelling and leftward nasal septum deviation. Finally, orbital imaging showed left cavernous sinus thrombosis, left superior ophthalmic vein thrombosis, and necrosis vs devascularization of the extraocular muscles. She was initially treated with fluids, an insulin infusion and broad-spectrum antibiotics and was evaluated by neurology, ophthalmology, infectious disease and otolaryngology. She underwent surgical debridement with left maxillary antrostomy, left total ethmoidectomies and septoplasty. Sinus cultures were positive for MSSA (methicillin sensitive staph aureus) and tissue pathology showed angioinvasive fungal disease compatible with Mucor/Rhizomucor species. Antimicrobial coverage was changed to intravenous Nafcillin and Amphotericin B, and she underwent further surgical debridement twice more. Repeat brain imaging to evaluate for disease progression is pending. Discussion: Early detection and aggressive treatment of Mucormycosis with surgical debridement and Amphotericin B can improve patient outcomes, however the mortality rate is still significant. Therefore, tight glycemic control in high risk groups is imperative, particularly in those with uncontrolled diabetes complicated by DKA and Covid-19 infection (with or without steroid treatment). Presentation: Saturday, June 17, 2023

Language MEG predicts postoperative verbal memory change in left mesial temporal lobe epilepsy

ObjectiveTo clarify whether preoperative language magnetoencephalography (MEG) predicts postoperative verbal memory (VM) changes in left mesial temporal lobe epilepsy (LMTLE). MethodsWe reviewed 18 right-handed patients with LMTLE who underwent anterior temporal lobectomy or selective amygdala hippocampectomy, 12 with (HS+) and 6 without hippocampal sclerosis (HS−). Patients underwent neuropsychological assessment before and after surgery. MEG was measured with an auditory verbal learning task in patients preoperatively and in 15 right-handed controls. Dynamic statistical parametric mapping (dSPM) was used for source imaging of task-related activity. Language laterality index (LI) was calculated by z-score of dSPM in language-related regions. LI in the region of HS+ and HS− was compared to controls. The correlation between LI and postoperative VM change was assessed in HS+ and HS−. ResultsPreoperative LI in supramarginal gyrus showed greater right-shifted lateralization in both HS+ and HS− than in controls. Right-shifted LI in supramarginal gyrus was correlated with postoperative VM increase in HS+ (p = 0.019), but not in HS−. ConclusionsRight-shifted language lateralization in dSPM of MEG signals may predict favorable VM outcome in HS+ of LMTLE. SignificanceFindings warrant further investigation of the relation between regional language laterality index and postoperative verbal memory changes.

Effects of Transcranial Direct Current Stimulation on Graph Naming Function and Brain Connectivity in Postinfarction Aphasia Patients: An fMRI Study

Introduction: The study aimed to investigate the mechanisms of impairment and recovery in graph naming functions among patients with aphasia due to cerebral infarction. Specifically, the study compared immediate effects of transcranial direct current stimulation (tDCS) treatment in patients at different stages postinfarction: the acute phase (AP) and the recovery period (RP). Methods: Twenty-eight patients were selected, consisting of 16 in the AP and 12 in the RP, along with 18 healthy controls. Both patient groups underwent 2 weeks of tDCS treatment. Posttreatment changes in functional connectivity (FC) within language-related brain regions, as well as in graph naming abilities, were assessed in both patient groups. Results: Both AP and RP groups exhibited significant improvements in graph naming ability following tDCS treatment. Compared to healthy controls, patients showed decreased FC in multiple brain regions of both hemispheres, particularly in the dominant hemisphere. Posttreatment assessments revealed significant increases in FC within the bilateral frontotemporal lobes for both AP and RP groups, and within the bilateral temporo-occipital regions for the AP group. Moreover, the RP group demonstrated decreased FC in the left temporal lobe posttreatment, which had shown increased FC pre-treatment. Conclusions: This study suggests that tDCS can effectively enhance graph naming functions in patients with postinfarction aphasia. The therapeutic effects appear to be mediated by enhancing FC within bilateral frontotemporal lobes.

Dosage, time, and polytherapy dependent effects of different levetiracetam regimens on cognitive function

ObjectiveCognitive impairment is a potential drawback of antiseizure medications. This study aimed to evaluate the impact of different levetiracetam drug regimens on cognitive function. MethodsA retrospective analysis identified 221 patients diagnosed with seizures who underwent cognitive screening. Patients were categorized into four groups: no medications, non-levetiracetam medications, high and low dose levetiracetam. Composite scores determined low and high levetiracetam groups whereby one point was added for each increment in dosage, duration since uptake, and concurrent anti-seizure medication. Variables known to affect cognition were recorded and classified as demographic, seizure-related, diagnosis-related, and psychopathology. Logistic regression was used to identify variables associated with cognitive scores below cut-off. ResultsMultivariable analysis found being male, non-active in the community, less than 12 years of education, left temporal lobe epilepsy, high seizure frequency, and depression were associated with poor cognitive performance. In a final regression analysis, the high levetiracetam group exhibited a 4.5-fold higher likelihood of scoring below cut-off than the medication-free group (OR 4.5, CI 1.5–13.6, p<.08). Depression (OR 2.1, CI 1.1-3.9, p<.03), being male (OR 2.2, CI 1.1-4.3, p<.02), and not being active in the community (OR 3.8, 1.6-8.7, p <.003) remained significant contributors to the model. Language (p<.05), attention (p<.05), and delayed recall (p<.001) were the most affected cognitive domains. SignificanceWhen taken in small doses, for brief periods as monotherapy, levetiracetam minimally influences cognition.At higher doses, as part of long-term seizure management, in conjunction with multiple ASMs, LEV is associated with cognitive impairment.

Dose Reductions to Critical Brain Organs-at-Risk and Better Cognition in Children with Medulloblastoma Receiving Proton Therapy

Our group previously demonstrated an improvement in cognition among children with medulloblastoma treated with proton therapy, as compared to photon therapy. However, the reason for this cognitive improvement was unclear. In this study, our aim was to determine whether dose to critical brain structures acted as a mediator of improved cognition in patients treated with proton therapy. In this retrospective study, a cohort of 75 children with medulloblastoma from two institutions was assembled (39 photon, 36 proton). Included patients were treated with similar radiation and cognitive follow-up protocols. Study endpoints were verbal comprehension (VCI), perceptual reasoning (PRI), working memory (WMI), processing speed (PSI) indices and full-scale IQ (FSIQ). Brain structures were segmented and dose comparisons by RT modality were compared using independent t-tests. Linear mixed effects models with random intercepts were created to evaluate cognitive endpoints using R version 4.2.2. Median follow-up from RT to last cognitive assessment was 4.8 years. Total dose, including RT boost, was slightly lower in the proton cohort than the photon cohort (mean, 54.6 Gy vs. 56.1 Gy, respectively, p < 0.001). Eleven children (31%) treated with proton therapy received 36 Gy CSI, while 6 children (15%) treated with photon therapy received 36 Gy CSI (p = 0.07). Children treated with proton therapy had reduced total doses to the brain (mean, D40), left and right temporal lobes (mean, D40, D50), and left and right hippocampi (mean, D40, D50 - see Table). After adjustment for age at RT and posterior fossa syndrome, higher whole brain mean dose and time since RT were associated with greater decrease in VCI (p = 0.033), higher left temporal D50 and time since RT with greater decrease in PRI (p = 0.031), higher whole brain D40 and time since RT with greater decrease in PSI (p < 0.001) and FSIQ (p = 0.030). Our study demonstrates that proton therapy for patients with medulloblastoma reduces dose to normal brain tissues, which is associated with better intellectual outcomes. Children with medulloblastoma who undergo RT should be treated with proton therapy, if available.

Negative association between DNA methylation in brain-derived neurotrophic factor exon VI and left superior parietal gyrification in major depressive disorder

ObjectiveWe have recently reported significantly higher DNA methylation in brain-derived neurotrophic factor (BDNF) exon VI in major depressive disorder (MDD). This study aimed to investigated cortical changes and their associations with DNA methylations in BDNF exon VI in MDD. MethodsData of 93 patients with MDD and 59 controls were involved in statistics. General linear regressions (GLM) were performed to analyze thickness and gyrification changes in MDD and their association with DNA methylation in BDNF exon VI in patients with MDD and controls. ResultsSignificantly decreased cortical thickness (CT) in left lateral orbitofrontal cortex (LOFC), left superior temporal lobe (ST) and right frontal pole (FP) and decreased local gyrification index (lGI) in left superior parietal lobe (SP) were found in MDD. The associations between DNA methylation in 3 CpG sites in BDNF exon VI and lGI in left SP were significantly different in patients and controls. DNA methylations in BDNF132 (β = –0.359, P < 0.001), BDNF137 (β = –0.214, P = 0.032), and BDNF151 (β = –0.223, P = 0.025) were significantly negatively associated with lGI in left SP in MDD. ConclusionThe negative association between BDNF exon VI methylation and lGI in left SP might imply a potential epigenetic marker associated with cortical gyrification reduction in patients with MDD.

Clinical Syndrome of Seizures, Headache, and Visual Blurring in Metastatic Carcinoma Colon

AbstractA 51-year-old lady diagnosed as a case of metastatic carcinoma colon stage IV involving lung and left adrenal metastasis was initiated with palliative chemotherapy with FOLFOX-6 chemotherapy infusion regimen that consisted of 5-flurouracil, calcium leucovorin, and oxaliplatin and injection bevacizumab was added to cycle seven of FOLFOX-6 chemotherapy. After 2 months of initiating bevacizumab, she was presented with one episode of generalized tonic clonic seizure, headache, and visual blurring of 2 days duration and magnetic resonance imaging brain T2 fluid-attenuated inversion recovery image revealed subcortical white matter edema in bilateral frontoparietal, occipital, left temporal lobes (Fig. 1A and B), and hyperintense edema with effacement of folia in both cerebellum with nodular areas of contrast enhancement suggestive of posterior reversible encephalopathy syndrome.

A social-semantic working-memory account for two canonical language areas.

Language and social cognition are traditionally studied as separate cognitive domains, yet accumulative studies reveal overlapping neural correlates at the left ventral temporoparietal junction (vTPJ) and the left lateral anterior temporal lobe (lATL), which have been attributed to sentence processing and social concept activation. We propose a common cognitive component underlying both effects: social-semantic working memory. We confirmed two key predictions of our hypothesis using functional MRI. First, the left vTPJ and lATL showed sensitivity to sentences only when the sentences conveyed social meaning; second, these regions showed persistent social-semantic-selective activity after the linguistic stimuli disappeared. We additionally found that both regions were sensitive to the socialness of non-linguistic stimuli and were more tightly connected with the social-semantic-processing areas than with the sentence-processing areas. The converging evidence indicates the social-semantic working-memory function of the left vTPJ and lATL and challenges the general-semantic and/or syntactic accounts for the neural activity of these regions.

P11.11.A VOLUMETRIC AND SPATIAL ANALYSES OF TREATMENT-RELATED INJURY IN GLIOMA

Abstract BACKGROUND As diffuse glioma cannot yet be cured, benefits of therapeutic strategies should be carefully balanced against their burden. Postoperative ischemia is a relatively common adverse event of surgery, which can lead to serious neurological deficits. Radiation therapy (RT) can cause post-RT lesions, which may cause clinical symptoms and can create a therapeutic impasse since they mimic tumor progression. We aimed to explore the spatial and volumetric tumor and treatment characteristics in relation to development of treatment-related effects in glioma. Materials and METHODS We retrospectively included 144 WHO grade II-IV supratentorial glioma cases, which were resected from 2012 till 2014 and had early postoperative MRI with diffusion-weighted imaging (DWI). Tumors were delineated on preoperative contrast-enhanced T1 MRI for high grade gliomas and FLAIR for low grade gliomas. Postoperative ischemia was defined as new, confluent diffusion restriction on postoperative DWI. Post-RT injury was investigated in patients who received RT after first surgery and had at least 6 months of follow-up (FU), and was defined as new or increasing contrast-enhancement that subsequently stabilized or decreased during FU. After manual delineation and non-linear registration to MNI stereotaxic space, all lesions were investigated with regard to size and location of pre-operative tumor, resection cavity, residual tumor and extent of resection (EOR). Voxel-based analysis (VBA) was performed with family-wise error correction for multiple comparisons. RESULTS Postoperative ischemia occurred in 93 of 144 cases and was associated with a larger EOR (P=0.02). Ischemic volume was correlated with a larger preoperative tumor volume (P=0.009) and resection volume (P=0.001). Post-RT injury was found in 25 of 67 analyzed cases and was associated with a larger residual tumor volume (P=0.021) and a smaller EOR (P=0.005). VBA showed an association of the occurrence of post-RT lesions with a cluster of preoperative tumor voxels in the left temporal lobe and clusters of residual tumor voxels in the left temporal and right frontal region. No association in volume or location was found between postoperative ischemia and post-RT lesions. CONCLUSION Adverse events of glioma treatment may be influenced by tumor and treatment volumes. In our population, a larger EOR was associated with the occurrence of postoperative ischemia, and larger tumor and resection volumes were correlated with the volume of ischemia. Additionally, the occurrence of post-RT injury was associated with a larger residual tumor and a smaller EOR, as well as a left temporal preoperative tumor location and a right frontal or left temporal residual tumor location. A thorough examination of spatial and volumetric characteristics of the tumor, treatment and subsequent complications can help elucidate the etiology and guide treatment decisions.

Disruptions in modular structure and network integration of language-related network predict language performance in temporal lobe epilepsy: Evidence from graph-based analysis

ObjectiveTemporal lobe epilepsy (TLE) is a network disorder that alters the total organization of the language-related network. Task-based functional magnetic resonance imaging (fMRI) aimed at functional connectivity is a direct method to investigate how the network is reorganized. However, such studies are scarce and represented mostly by the resting-state analysis of the individual connections between regions. To fill this gap, we used a graph-based analysis, which allows us to cover the total language-related network changes, such as disruptions in an integration/segregation balance, during a language task in TLE. MethodsWe collected task-based fMRI data with sentence completion from 19 healthy controls and 28 people with left TLE. Using graph-based analysis, we estimated how the language-related network segregated into modules and tested whether they differed between groups. We evaluated the total network integration and the integration within modules. To assess intermodular integration, we considered the number and location of connector hubs—regions with high connectivity. ResultsThe language-related network was differently segregated during language processing in the groups. While healthy controls showed a module consisting of left perisylvian regions, people with TLE exhibited a bilateral module formed by the anterior language-related areas and a module in the left temporal lobe, reflecting hyperconnectivity within the epileptic focus. As a consequence of this reorganization, there was a statistical tendency that the dominance of the intramodular integration over the total network integration was greater in TLE, which predicted language performance. The increase in the number of connector hubs in the right hemisphere, in turn, was compensatory in TLE. SignificanceOur study provides insights into the reorganization of the language-related network in TLE, revealing specific network changes in segregation and integration. It confirms reduced global connectivity and compensation across the healthy hemisphere, commonly observed in epilepsy. These findings advance the understanding of the network-based reorganizational processes underlying language processing in TLE.

Age of epilepsy onset as modulating factor for naming deficit after epilepsy surgery: a voxel-based lesion-symptom mapping study

Age at onset of epilepsy is an important predictor of deterioration in naming ability following epilepsy surgery. In 141 patients with left hemispheric epilepsy and language dominance who received epilepsy surgery at the Epilepsy Centre Erlangen, naming of objects (Boston naming test, BNT) was assessed preoperatively and 6 months postoperatively. Surgical lesions were plotted on postoperative MRI and normalized for statistical analysis using voxel-based lesion-symptom mapping (VBLSM). The correlation between lesion and presence of postoperative naming deterioration was examined varying the considered age range of epilepsy onsets. The VBLSM analysis showed that volumes of cortex areas in the left temporal lobe, which were associated with postoperative decline of naming, increased with each year of later epilepsy onset. In patients with later onset, an increasing left posterior temporobasal area was significantly associated with a postoperative deficit when included in the resection. For late epilepsy onset, the temporomesial expansion also included the left hippocampus. The results underline that early onset of epilepsy is a good prognostic factor for unchanged postoperative naming ability following epilepsy surgery. For later age of epilepsy onset, the extent of the area at risk of postoperative naming deficit at 6 months after surgery included an increasing left temporobasal area which finally also comprised the hippocampus.

Neuroplastic Changes Associated With Hybrid Exercise-Cognitive Training in Stroke Survivors With Mild Cognitive Decline: A Randomized Controlled Trial

Background Exercise and cognitive training have been shown to induce neuroplastic changes and modulate cognitive function following stroke. However, it remains unclear whether hybridized exercise-cognitive training facilitates cortical activity and further influences cognitive function after stroke. Objective The study aimed to investigate the effects of 2 hybridized exercise-cognitive trainings on neuroplastic changes and behavioral outcomes in stroke survivors with mild cognitive decline. Methods This study was a single-blind randomized controlled trial. Stroke survivors were randomly assigned to 1 of 3 groups: (1) sequential exercise-cognitive training (SEQ), (2) dual-task exercise-cognitive training (DUAL), or (3) control group (CON). All groups underwent training 60 min per day, 3 days per week, for a total of 12 weeks. The primary outcome was the resting-state (RS) functional connectivity (FC) in functional magnetic resonance imaging. Secondary behavioral outcomes included cognitive and physical functions. Results After 12 weeks of training, patients in the SEQ group (n = 21) exhibited increased RS FC between the left occipital lobe and posterior cingulate gyrus with right parietal lobe, compared to the DUAL (n = 22) and CON (n = 20) groups. Additionally, patients in the DUAL group showed increased FC of the left temporal lobe. However, changes in behavioral outcome measures were non-significant among the 3 groups (all P’s > .05). Conclusions This study highlights the distinct neuroplastic mechanisms associated with 2 types of exercise-cognitive hybridized trainings. The pre-post functional magnetic resonance imaging measurements illustrated the time course of neural mechanisms for cognitive recovery in stroke survivors following different exercise-cognitive training approaches. Trial registration. NCT03230253.