Bilateral Occipital Research Articles

Videofluoroscopic Swallowing Study Features and Resting-State Functional MRI Brain Activity for Assessing Swallowing Differences in Patients with Mild Cognitive Impairment and Risk of Dysphagia.

To examine the swallowing characteristics in patients with mild cognitive impairment (MCI) and dysphagia risk and explore brain activity changes using regional homogeneity (ReHo) with resting-state functional magnetic resonance imaging (rs-fMRI). We included 28 patients with MCI and dysphagia risk and 17 age-matched older adults. All participants underwent neurological, cognitive examinations, and a videofluoroscopic swallowing study (VFSS). We quantitatively analyzed the VFSS temporal and kinetic parameters of the 5- and 10-mL swallows. The participants underwent rs-fMRI, and the ReHo values were calculated. Differences in the swallowing physiology and rs-fMRI findings between participants with MCI and controls were analyzed. Correlation analyses were also conducted. Compared to the control group, patients with MCI and dysphagia risk had lower global cognition scores, longer 10-mL oral transit times (OTTs), and lower executive function scores. ReHo in the bilateral inferior occipital lobes (IOLs) and left prefrontal lobe decreased in patients with MCI and dysphagia risk compared to participants in the control group. In patients with MCI, the 10-mL OTT was negatively correlated with the Montreal Cognitive Assessment (MoCA) score, and the ReHo values were positive correlated with quantitative temporal swallowing measurements using canonical correlation analysis. Mediation analysis revealed that the ReHo values of the left and right IOL acted as significant mediators between the MoCA score and the 10-mL OTT. We found that individuals with MCI and dysphagia risk, verified by reduced MoCA scores, demonstrated prolonged OTTs when swallowing larger boluses compared with age-matched controls. There was a negative correlation between the MoCA score and 10-mL OTT, which was partially mediated by the left and right IOL ReHo values, suggesting that functional changes in the IOLs and left prefrontal lobe associated with oral swallowing status and cognitive level in individuals with MCI and dysphagia risk.

EEG-based investigation of the impact of room size and window placement on cognitive performance

This study investigated changes in scalp electroencephalography (EEG) features associated with short-term exposure to four virtual classroom designs, with different window placement and room dimensions. Participants engaged in five cognitive tests in each design condition: the Stroop Test, the Digit Span Test, the Benton Test, a Visual Memory Test, and an Arithmetic Test. Performance on the cognitive tests and EEG data were analyzed by contrasting various classroom design conditions. The cognitive test performance results showed no significant differences related to the design changes in the room studied. We computed frequency band-power and connectivity EEG features to identify changes in neural patterns associated to the different design conditions. A leave-one-out machine-learning classification scheme was implemented to assess the robustness of the EEG features, with the classification accuracy evaluation of the trained model iteratively performed against an unseen participant’s data for the test set. The feature selection and classification results located consistent differences in the EEG features that held predictive power (p<0.003) across participants in the different classroom design conditions: a. Neural vs One-Window, b. Neutral vs Two-Windows, c. Neutral vs Wide room. This effect was observed for the tasks that required short-term memory encoding, including the Digit Span Test (median test set classification accuracy: a. 53.8%, b. 51.3%), the Benton Test (a. 61.3%, b. 56.3%), and the Visual Memory Test (a. 55.0%, b. 57.5%, c. 61.3%). The most discriminative EEG features were primarily frequency band-power features, observed in bilateral occipital, parietal, and frontal regions in the theta (4-8 Hz) and alpha (8-12 Hz) frequency bands. The connectivity features reinforced these findings by showing that there were changes in the transfer of information from centro-parietal to frontal electrodes in the different classroom conditions. This study provides rigorous evidence that brain activity features during cognitive tasks are affected by the design elements of window placement and room dimensions in a virtual classroom. The ongoing development of this EEG-based approach has the potential to strengthen evidence-based design through evaluation of robust neurophysiological evidence.

Early neural activity changes associated with stimulus detection during visual conscious perception.

The earliest cortical neural signals following consciously perceived visual stimuli in humans are poorly understood. Using intracranial electroencephalography, we investigated neural activity changes associated with the earliest stages of stimulus detection during visual conscious perception. Participants (N = 10; 1,693 electrode contacts) completed a continuous performance task where subjects were asked to press a button when they saw a target letter among a series of nontargets. Broadband gamma power (40-115Hz) was analyzed as marker of cortical population neural activity. Regardless of target or nontarget letter type, we observed early gamma power changes within 30-180ms from stimulus onset in a network including increases in bilateral occipital, fusiform, frontal (including frontal eye fields), and medial temporal cortex; increases in left lateral parietal-temporal cortex; and decreases in the right anterior medial occipital cortex. No significant differences were observed between target and nontarget stimuli until >180ms post-stimulus, when we saw greater gamma power increases in left motor and premotor areas, suggesting a possible role in perceptual decision-making and/or motor responses with the right hand. The early gamma power findings support a broadly distributed cortical visual detection network that is engaged at early times tens of milliseconds after signal transduction from the retina.

Effects of Alzheimer and Lewy Body Disease Pathologies on Brain Metabolism.

This study aimed to determine the pattern of 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) related to postmortem Lewy body disease (LBD) pathology in clinical Alzheimer disease (AD). FDG-PET scans were analyzed in 62 autopsy-confirmed patients and 110 controls in the Alzheimer's Disease Neuroimaging Initiative. Based on neuropathologic evaluations on Braak stage for neurofibrillary tangle, Consortium to Establish a Registry for AD score for neuritic plaque, and Lewy-related pathology, subjects were classified into AD(-)/LBD(-), AD(-)/LBD(+), AD(+)/LBD(-), and AD(+)/LBD(+) groups. The association between postmortem LBD and AD pathologies and antemortem brain metabolism was evaluated. AD and LBD pathologies had significant interaction effects to decrease metabolism in the cerebellar vermis, bilateral caudate, putamen, basal frontal cortex, and anterior cingulate cortex in addition to the left side of the entorhinal cortex and amygdala, and significant interaction effects to increase metabolism in the bilateral parietal and occipital cortices. LBD pathology was associated with hypermetabolism in the cerebellar vermis, bilateral putamen, anterior cingulate cortex, and basal frontal cortex, corresponding to the Lewy body-related hypermetabolic patterns. AD pathology was associated with hypometabolism in the bilateral hippocampus, entorhinal cortex, and posterior cingulate cortex regardless of LBD pathology, whereas LBD pathology was associated with hypermetabolism in the bilateral putamen and anterior cingulate cortex regardless of AD pathology. Postmortem LBD and AD pathologies had significant interaction effects on the antemortem brain metabolism in clinical AD patients. Specific metabolic patterns related to AD and LBD pathologies could be elucidated when simultaneously considering the two pathologies. ANN NEUROL 2022;91:853-863.

Altered intrinsic brain activity in patients with CSF1R-related leukoencephalopathy.

CSF1R-related leukoencephalopathy is an adult-onset white matter disease with high disability and mortality, while little is known about its pathogenesis. This study introduced amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) based on resting-state functional magnetic resonance imaging(rsfMRI) to compare the spontaneous brain activities of patients and healthy controls, aiming to enhance our understanding of the disease. RsfMRI was performed on 16 patients and 23 healthy controls, and preprocessed for calculation of ALFF and ReHo. Permutation tests with threshold free cluster enhancement (TFCE) was applied for comparison (number of permutations = 5,000). The TFCE significance threshold was set at [Formula: see text] < 0.05. In addition, 10 was set as the minimum cluster size. Compared to healthy controls, the patient group showed decreased ALFF in right paracentral lobule, and increased ALFF in bilateral insula, hippocampus, thalamus, supramarginal and precentral gyrus, right inferior, middle and superior frontal gyrus, right superior and middle occipital gyrus, as well as left parahippocampal gyrus, fusiform, middle occipital gyrus and angular gyrus. ReHo was decreased in right supplementary motor area, paracentral lobule and precentral gyrus, while increased in right superior occipital gyrus and supramarginal gyrus, left parahippocampal gyrus, hippocampus, fusiform, middle occipital gyrus and angular gyrus, as well as bilateral middle occipital gyrus and midbrain. These results revealed altered spontaneous brain activities in CSF1R-related leukoencephalopathy, especially in limbic system and motor cortex, which may shed light on underlying mechanisms.

Thrombotic Thrombocytopenic Purpura (ADAMTS13 [a Disintegrin and Metalloproteinase With a Thrombospondin Type 1 Motif, Member 13] Deficiency) as Cause of Recurrent Multiterritory Ischemic Strokes.

Thrombotic Thrombocytopenic Purpura (ADAMTS13 [a Disintegrin and Metalloproteinase With a Thrombospondin Type 1 Motif, Member 13] Deficiency) as Cause of Recurrent Multiterritory Ischemic Strokes.

Computed Tomography Density and β-Amyloid Deposition of Intraorbital Optic Nerve May Assist in Diagnosing Mild Cognitive Impairment and Alzheimer's Disease: A 18F-Flutemetamol Positron Emission Tomography/Computed Tomography Study.

ObjectiveThe aim was to study whether the computed tomography (CT) density and β-amyloid (Aβ) level of intraorbital optic nerve could assist in diagnosing mild cognitive impairment (MCI) and Alzheimer’s disease (AD).MethodsA total of sixty subjects were recruited in our study, including nine normal control (NC) subjects (i.e., 4 men and 5 women), twenty four MCI subjects (i.e., 11 men and 13 women), and twenty seven AD subjects (i.e., 14 men and 13 women). All subjects conducted 18F-flutemetamol amyloid positron emission tomography (PET)/CT imaging. Blinded to the clinical information of the subjects, two physicians independently measured and calculated the standardized uptake value ratio (SUVR) of the bilateral occipital cortex, SUVR of the bilateral intraorbital optic nerve, and CT density of the bilateral intraorbital optic nerve by using GE AW 4.5 Workstation.ResultsBetween AD and NC groups, the differences of the bilateral intraorbital optic nerve SUVR were statistically significant; between AD and MCI groups, the differences of the left intraorbital optic nerve SUVR were statistically significant. Between any two of the three groups, the differences in the bilateral intraorbital optic nerve density were statistically significant. The bilateral occipital SUVR was positively correlated with the bilateral intraorbital optic nerve SUVR and negatively correlated with the bilateral intraorbital optic nerve density. Bilateral intraorbital optic nerve SUVR was negatively correlated with the bilateral intraorbital optic nerve density. The area under the receiver operating characteristic (ROC) curve of multiple logistic regression was 0.9167 (for MCI vs. NC) and 0.8951 (for AD vs. MCI). The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores were positively associated with the intraorbital optic nerve density and were negatively associated with the intraorbital optic nerve SUVR. The regression equation of MoCA was y = 16.37-0.9734 × x1 + 0.5642 × x2-3.127 × x3 + 0.0275 × x4; the R2 was 0.848. The regression equation of MMSE was y = 19.57-1.633 × x1 + 0.4397 × x2-1.713 × x3 + 0.0424 × x4; the R2 was 0.827.ConclusionThe CT density and Aβ deposition of the intraorbital optic nerve were associated with Aβ deposition of the occipital cortex and the severity of cognitive impairment. The intraorbital optic nerve CT density and intraorbital optic nerve Aβ deposition could assist in diagnosing MCI and AD.

A Case of Anton-Babinski Syndrome in an older adult: A case report

<h3>Introduction</h3> Anton-Babinski syndrome is a rare neuropsychiatric syndrome described by Gabriel Anton and Joseph Babinski early in the 19th century. This syndrome represents a rare differential that can mimic the advanced stages of dementia with similar apraxia, poor insight, while presenting different management needs and treatment response. Anton-Babinski syndrome results from damage to the non-dominant parietal lobe of the cerebral cortex and associated connections. It is the right-hemisphere equivalent of Gerstmann Syndrome and is to be distinguished from Anton's syndrome, caused by bilateral occipital cortical damage. Anton-Babinski syndrome presents with contralateral sensory neglect, anosognosia with anosodiaphoria (affective indifference), construction, and dressing apraxia. It can lead to significant functional impairment and a substantial risk of falls in affected subjects, as we present in our case. There is a relative paucity of data regarding this syndrome due to its remarkable rarity. <h3>Methods</h3> N/A <h3>Results</h3> N/A <h3>Conclusions</h3> Despite presenting initially for management of possible vascular major neurocognitive disorder with neuropsychiatric symptoms, detailed assessment and work-up revealed her presentation to be most consistent with the rare Anton-Babinski syndrome. Awareness of such disease entities can inform treatment planning. In her case, she will most likely benefit from deprescribing cognitive enhancers, which worsen her bradycardia and increase her fall risk, while optimizing occupational and physical therapy to improve her quality of life and home safety. <h3>This research was funded by</h3> None

Alterations in Cortical-Subcortical Metabolism in Temporal Lobe Epilepsy With Impaired Awareness Seizures.

ObjectiveThe features of cerebral metabolism associated with loss of consciousness in patients with temporal lobe epilepsy (TLE) have not been fully elucidated. We aim to investigate the alterations in cortical-subcortical metabolism in temporal lobe epilepsy with impaired awareness seizures (IAS).MethodsRegional cerebral metabolism was measured using fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in patients with TLE-IAS and healthy controls. All patients had a comprehensive evaluation to confirm their seizure origin and lateralization. Videos of all seizures were viewed and rated by at least two epileptologists to identify the state of consciousness when a seizure occurred. By synthesizing the seizure history, semeiology, and video EEG of all patients, as long as the patients had one seizure with impaired awareness, she/he will be included. 76 patients with TLE-IAS and 60 age-matched healthy controls were enrolled in this study. Regional cerebral metabolic patterns were analyzed for TLE-IAS and healthy control groups using statistical parametric mapping. Besides, we compared the MRI-negative patients and MRI-positive patients with healthy controls, respectively.ResultsThere were no significant differences in the age and sex of TLE-IAS patients and healthy control. TLE-IAS patients showed extensive bilateral hypermetabolism in the frontoparietal regions, cingulate gyrus, corpus callosum, occipital lobes, basal ganglia, thalamus, brainstem, and cerebellum. The region of metabolic change was more extensive in right TLE-IAS than that of the left, including extensive hypometabolism in the ipsilateral temporal, frontal, parietal, and insular lobes. And contralateral temporal lobe, bilateral frontoparietal regions, occipital lobes, the anterior and posterior regions of the cingulate gyrus, bilateral thalamus, bilateral basal ganglia, brainstem, and bilateral cerebellum showed hypermetabolism. The TLE patients with impaired awareness seizure showed hypermetabolism in the cortical-subcortical network including the arousal system. Additionally, 48 MRI-positive and 28 MRI-negative TLE-IAS patients were included in our study. TLE-IAS patients with MRI-negative and MRI-positive were both showed hypermetabolism in the cingulate gyrus. Hypometabolism in the bilateral temporal lobe was showed in the TLE-IAS with MRI-positive.ConclusionThese findings suggested that the repetitive consciousness impairing ictal events may have an accumulative effect on brain metabolism, resulting in abnormal interictal cortical-subcortical metabolic disturbance in TLE patients with impaired awareness seizure. Understanding these metabolic mechanisms may guide future clinical treatments to prevent seizure-related awareness deficits and improve quality of life in people with TLE.

Neural alterations in working memory of mild-moderate TBI: An fMRI study in Malaysia.

Working memory (WM) encompasses crucial cognitive processes or abilities to retain and manipulate temporary information for immediate execution of complex cognitive tasks in daily functioning such as reasoning and decision-making. The WM of individuals sustaining traumatic brain injury (TBI) was commonly compromised, especially in the domain of WM. The current study investigated the brain responses of WM in a group of participants with mild-moderate TBI compared to their healthy counterparts employing functional magnetic resonance imaging. All consented participants (healthy: n=26 and TBI: n=15) performed two variations of the n-back WM task with four load conditions (0-, 1-, 2-, and 3-back). The respective within-group effects showed a right hemisphere-dominance activation and slower reaction in performance for the TBI group. Random-effects analysis revealed activation difference between the two groups in the right occipital lobe in the guided n-back with cues, and in the bilateral occipital lobe, superior parietal region, and cingulate cortices in the n-back without cues. The left middle frontal gyrus was implicated in the load-dependent processing of WM in both groups. Further group analysis identified that the notable activation changes in the frontal gyri and anterior cingulate cortex are according to low and high loads. Though relatively smaller in scale, this study was eminent as it clarified the neural alterations in WM in the mild-moderate TBI group compared to healthy controls. It confirmed the robustness of the phenomenon in TBI with the reproducibility of the results in a heterogeneous non-Western sample.

From words to phrases: neural basis of social event semantic composition

Events are typically composed of at least actions and entities. Both actions and entities have been shown to be represented by neural structures respecting domain organizations in the brain, including those of social/animate (face and body; person-directed action) versus inanimate (man-made object or tool; object-directed action) concepts. It is unclear whether the brain combines actions and entities into events in a (relative) domain-specific fashion or via domain-general mechanisms in regions that have been shown to support semantic and syntactic composition. We tested these hypotheses in a functional magnetic resonance imaging experiment where two domains of verb-noun event phrases (social-person versus manipulation-artifact, e.g., “hug mother” versus “fold napkin”) and their component words were contrasted. We found a series of brain region supporting social-composition effects more strongly than the manipulation phrase composition—the bilateral inferior occipital gyrus (IOG), inferior temporal gyrus (ITG) and anterior temporal lobe (ATL)—which either showed stronger activation strength tested by univariate contrast, stronger content representation tested by representation similarity analysis, or stronger relationship between the neural activation patterns of phrases and synthesis (additive and multiplication) of the neural activity patterns of the word constituents. No regions were observed showing evidence of phrase composition for both domains or stronger effects of manipulation phrases. These findings highlight the roles of the visual cortex and ATL in social event compositions, suggesting a domain-preferring, rather than domain-general, mechanisms of verbal event composition.

Disassociated and concurrent structural and functional abnormalities in the drug-naïve first-episode early onset schizophrenia

Schizophrenia which is an abnormally developmental disease has been widely reported to show abnormal brain structure and function. Enhanced functional integration is a predominant neural marker for brain mature. Abnormal development of structure and functional integration may be a biomarker for early diagnosis of schizophrenia. Fifty-five patients with early onset schizophrenia (EOS) and 79 healthy controls were enrolled in this study. Voxel-based morphometry (VBM) and functional connectivity density (FCD) were performed to explore gray matter volume (GMV) lesion, abnormal functional integration, and concurrent structural and functional abnormalities in the brain. Furthermore, the relationships between abnormalities structural and function and clinical characteristics were evaluated in EOS. Compared with healthy controls, EOS showed significantly decreased GMV in the bilateral OFC, frontal, temporal, occipital, parietal and limbic system. EOS also showed decreased FCD in precuneus and increased FCD in cerebellum. Moreover, we found concurrent changes of structure and function in left lateral orbitofrontal cortex (lOFC). Finally, correlation analyses did not find significant correlation between abnormal neural measurements and clinical characteristic in EOS. The results reveal disassociated and bound structural and functional abnormalities patterns in EOS suggesting structural and functional measurements play different roles in delineating the abnormal patterns of EOS. The concurrent structural and functional changes in lOFC may be a biomarker for early diagnosis of schizophrenia. Our findings will deepen our understanding of the pathophysiological mechanisms in EOS.

Efficacy of Transcranial Direct Current Stimulation Over Dorsolateral Prefrontal Cortex in Patients With Minimally Conscious State

BackgroundThe treatment of patients in a minimally conscious state (MCS) remains challenging. Transcranial direct current stimulation (tDCS) is a non-invasive therapeutic method in treating neurologic diseases by regulating the cortical excitability. The aim is to investigate the effect of tDCS in patients with MCS in this study.MethodsEleven patients in MCS were enrolled in the study. All the patients received 5 daily sessions of 20-min sham tDCS, followed by 10 sessions of 20-min real tDCS. The anodal electrode and cathodal electrodes were placed over the left dorsolateral prefrontal cortex (DLPFC) and the right eyebrow, respectively. Assessment of Coma Recovery Scale-Revised (CRS-R) scores and resting-state functional MRI (rs-fMRI) scans was conducted three times in each patient: before tDCS (baseline, T0), post-sham tDCS at week 1 (T1), and post-real tDCS at week 2 (T2). The whole-brain functional connectivity (FC) was obtained by bilaterally computing FC from six seed regions: precuneus, middle frontal gyrus, supplemental motor area, angular gyrus, superior temporal gyrus, and occipital lobe. One-way repeated measure ANOVA was used to compare the differences of CRS-R scores and FC at T0, T1, and T2. The false discovery rate correction of p < 0.001 was adopted for controlling multiple comparisons in FC analysis.ResultsFive patients with MCS showed obvious clinical improvement represented by increased CRS-R scores post- 2-week real tDCS. The CRS-R scores did not change post- 1-week sham treatment. No side effects were reported during the study. The FC of the bilateral supplementary motor area, right angular gyrus, and right superior temporal gyrus were significantly enhanced after 2-week real tDCS compared with that after 1-week sham-tDCS. In addition, FC of bilateral occipital lobe and right precuneus were significantly enhanced post- 2-week real tDCS compared with the baseline.ConclusionOur findings indicated that tDCS over DLPFC could serve as a potentially effective therapy for improving the consciousness state in patients with MCS. The FC in rs-fMRI can be modulated by tDCS at both the stimulation site (left DLPFC) and the distant regions.

Medial prefrontal and occipito-temporal activity at encoding determines enhanced recognition of threatening faces after 1.5years.

Studies demonstrated that faces with threatening emotional expressions are better remembered than non-threatening faces. However, whether this memory advantage persists over years and which neural systems underlie such an effect remains unknown. Here, we employed an individual difference approach to examine whether the neural activity during incidental encoding was associated with differential recognition of faces with emotional expressions (angry, fearful, happy, sad and neutral) after a retention interval of > 1.5years (N = 89). Behaviorally, we found a better recognition for threatening (angry, fearful) versus non-threatening (happy and neutral) faces after a delay of > 1.5years, which was driven by forgetting of non-threatening faces compared with immediate recognition after encoding. Multivariate principal component analysis (PCA) on the behavioral responses further confirmed the discriminative recognition performance between threatening and non-threatening faces. A voxel-wise whole-brain analysis on the concomitantly acquired functional magnetic resonanceimaging (fMRI) data during incidental encoding revealed that neural activity in bilateral inferior occipital gyrus (IOG) and ventromedial prefrontal/orbitofrontal cortex (vmPFC/OFC) was associated with the individual differences in the discriminative emotional face recognition performance measured by an innovative behavioral pattern similarity analysis (BPSA). The left fusiform face area (FFA) was additionally determined using a regionally focused analysis. Overall, the present study provides evidence that threatening facial expressions lead to persistent face recognition over periods of > 1.5years, and thatdifferential encoding-related activity in the medial prefrontal cortex and occipito-temporal cortex may underlie this effect.

Characterizing multiscale modular structures in medication-free obsessive-compulsive disorder patients with no comorbidity.

Brain networks exhibit signatures of modular structure, which maintains a fine trade‐off between wiring cost and efficiency of information transmission. Alterations in modular structure have been found in patients with obsessive–compulsive disorder (OCD). However, previous studies were focused on a single scale (i.e., modularity or intra/intermodular connectivity) for investigation. Here, we recruited 92 OCD patients and 90 healthy controls. A comprehensive analysis was performed on modular architecture alterations in the voxelwise functional connectome at the “global” (modularity), “meso” (modular segregation and within‐ and between‐module connections), and “local” (participation coefficients, PC) scales. We also examined the correlation between modular structure metrics and clinical symptoms. The findings revealed that (1) there was no significant group difference in global modularity; (2) both primary modules (visual network, sensorimotor network) and high‐order modules (dorsal attention network, frontoparietal network) exhibited lower modular segregation in OCD patients, which was mainly driven by increased numbers of between‐module connections; and (3) OCD patients showed higher PC in several connectors including the bilateral middle occipital gyri, left medial orbital frontal gyrus, left superior frontal gyrus, left posterior cingulate gyrus, right superior temporal gyrus and right middle frontal gyrus, and lower PC in the right lingual gyrus. Moreover, these alterations in modular structure were associated with clinical symptoms in patients. Our findings provide further insights into the involvement of different modules in functional network dysfunction in OCD from a connectomic perspective and suggest a synergetic mechanism of module interactions that may be related to the pathophysiology of OCD.

Cerebral Blood Flow Alterations in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Arterial Spin Labeling Studies

ObjectiveArterial spin labeling (ASL) studies have revealed inconsistent regional cerebral blood flow (CBF) alterations in patients with type 2 diabetes mellitus (T2DM). The aim of this systematic review and meta-analysis was to identify concordant regional CBF alterations in T2DM.MethodsA systematic review was conducted to the published literatures comparing cerebral perfusion between patients with T2DM and healthy controls using ASL. The seed-based d mapping (SDM) was further used to perform quantitative meta-analysis on voxel-based literatures and to estimate the regional CBF alterations in patients with T2DM. Metaregression was performed to explore the associations between clinical characteristics and cerebral perfusion alterations.ResultsA total of 13 studies with 14 reports were included in the systematic review and 7 studies with 7 reports were included in the quantitative meta-analysis. The qualitative review found widespread CBF reduction in cerebral lobes in T2DM. The meta-analysis found increased regional CBF in right supplementary motor area and decreased regional CBF in bilateral middle occipital gyrus, left caudate nucleus, right superior parietal gyrus, and left calcarine fissure/surrounding cortex in T2DM.ConclusionThe patterns of cerebral perfusion alterations, characterized by the decreased CBF in occipital and parietal lobes, might be the neuropathology of visual impairment and cognitive aging in T2DM.

Differentiating Melancholic and Non-melancholic Major Depressive Disorder Using Fractional Amplitude of Low-Frequency Fluctuations.

BackgroundMelancholic major depressive disorder (MDD) is a network-based brain disorder. However, whether or not network-based changes can be applied to differentiate melancholic (MEL) from non-melancholic (NMEL) MDD remains unclear.MethodsThirty-one MEL patients, 28 NMEL patients, and 32 matched healthy controls (HCs) were scanned using resting-state functional magnetic resonance imaging. Patients were assessed by the Chinese version of Snaith–Hamilton Pleasure Scale (SHAPS-C) and Temporal Experience of Pleasure Scale (TEPS). Fractional amplitude of low-frequency fluctuations (fALFF) and correlation analysis were used to analyze the data.ResultsCompared with HCs, the MEL group had significantly higher fALFF values in the bilateral inferior frontal gyrus and right supplementary motor area (SMA) and significantly lower fALFF values in the right inferior occipital gyrus (IOG), right middle temporal gyrus (MTG)/left IOG, and bilateral superior occipital gyrus (SOG)/MTG. On the other hand, the NMEL group showed significantly higher fALFF values in the bilateral SMA and significantly lower fALFF values in the bilateral posterior cingulate cortex/precuneus relative to HCs. Compared with the NMEL group, the MEL group showed significantly lower fALFF values in the left anterior cingulate cortex (ACC). A correlation was found between the fALFF values of the right SMA and the SHAPS-C in the MEL group. In addition, correlations were observed between the fALFF values of the left ACC and the TEPS contextual consummatory and total scores in all patients.ConclusionOur study uncovered that MDD exhibited altered brain activity in extensive brain networks, including the default-mode network, frontal-striatal network, reward system, and frontal-limbic network. Decreased fALFF in the left ACC might be applied to differentiate the two subtypes of MDD.

Sex Differences of Cerebellum and Cerebrum: Evidence from Graph Convolutional Network.

This work aims to exploit a novel graph neural network to predict the sex of the brain topological network, and to find the sex differences in the cerebrum and cerebellum. A two-branch multi-scale graph convolutional network (TMGCN) is designed to analyze the sex differences of the brain. Two complementary templates are used to construct cerebrum and cerebellum networks, respectively, followed by a two-branch sub-network with multi-scale filters and a trainable weighted fusion strategy for the final prediction. Finally, a trainable graph topk-pooling layer is utilized in our model to visualize key brain regions relevant to the prediction. The proposed TMGCN achieves a prediction accuracy of 84.48%. In the cerebellum, the bilateral Crus I-II, lobule VI and VIIb, and the posterior vermis (VI-X) are discriminative for this task. As for the cerebrum, the discriminative brain regions consist of the bilateral inferior temporal gyrus, the bilateral fusiform gyrus, the bilateral parahippocampal gyrus, the bilateral cingulate gyrus, the bilateral medial ventral occipital cortex, the bilateral lateral occipital cortex, the bilateral amygdala, and the bilateral hippocampus. This study tackles the sex prediction problem from a more comprehensive view, and may provide the resting-state fMRI evidence for further study of sex differences in the cerebellum and cerebrum.

Multiple Cerebral infarction Associated with Heat Stroke

Heat stroke is a condition of severe heat injury characterized by hyperthermia, multiorgan failure and central nervous system dysfunction. A 79-year-old woman was brought to our hospital in a semicomatose state. She was found lying unconscious on her house yard at a hot summer day. Her body temperature was 40.3°C. Laboratory findings were consistent with multiorgan failure and rhabdomyolysis. Brain magnetic resonance imaging showed multifocal infarctions in the bilateral basal ganglia, cerebellum, and occipital lobe. Despite cooling therapy and supportive treatment, her mentality was not recovered. This case suggests that multiple cerebral infarction may occur as a complication of heat stroke and prompt treatment is crucial.

Posterior reversible encephalopathy syndrome seen in a case of acu tepost-streptococcal glomerulonephritis: a case report

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological condition that involves the acute onset of headache, confusion, optical impairments, and seizures with accompanying vasogenic edema on brain imaging. Here is a 12 years old male patient presented with complaints of swelling in the face and legs, headache and vomitings. He had a history of fever, sore throat and tonsillitis 12 days back. On physical examination weight and height of the patient was between 25-50th percentile, BP was 142/92 mmHg (&gt;99th centile), he had pretibial +2 edema and periorbitol edema. At presentation urine analysis showed haematuria, proteinuria at nephritic level, elevated urea and creatinine, increased ASO titre, low C3 and C4 levels. After admission, he had an episode of convulsion when BP was 162/98 mm hg. Magnetic resonance imaging brain showed bilateral occipital, parietal, frontal cortex and subcortical white matter T2/Fluid-attenuated inversion recovery (FLAIR) hyperintensitie, suggestive of PRES. EEG was found to be normal. MRI was found to be normal in the first month after starting on antihypertensive and anticonvulsive treatment. In the first year of the follow-up, the blood pressure, neurological examination and urinalysis findings were found to be normal. Thus, it is suggested that early diagnosis of PRES in patients with clinical features and prompt treatment will prevent permanent neurologic sequale.