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Background: MRI magnetization-prepared rapid acquisition (MPRAGE) is an easily available imaging modality for dementia diagnosis. Previous studies suggested that volumetric analysis plays a crucial role in various stages of dementia classification. In this study, volumetry, radiomics and demographics were integrated as inputs to develop an artificial intelligence model for various stages, including Alzheimer's disease (AD), mild cognitive decline (MCI) and cognitive normal (CN) dementia classifications. Method: The Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset was separated into training and testing groups, and the Open Access Series of Imaging Studies (OASIS) dataset was used as the second testing group. The MRI MPRAGE image was reoriented via statistical parametric mapping (SPM12). Freesurfer was employed for brain segmentation, and 45 regional brain volumes were retrieved. The 3D Slicer software was employed for 107 radiomics feature extractions from within the whole brain. Data on patient demographics were collected from the datasets. The feed-forward neural network (FFNN) and the other most common artificial intelligence algorithms, including support vector machine (SVM), ensemble classifier (EC) and decision tree (DT), were used to build the models using various features. Results: The integration of brain regional volumes, radiomics and patient demographics attained the highest overall accuracy at 76.57% and 73.14% in ADNI and OASIS testing, respectively. The subclass accuracies in MCI, AD and CN were 78.29%, 89.71% and 85.14%, respectively, in ADNI testing, as well as 74.86%, 88% and 83.43% in OASIS testing. Balanced sensitivity and specificity were obtained for all subclass classifications in MCI, AD and CN. Conclusion: The FFNN yielded good overall accuracy for MCI, AD and CN categorization, with balanced subclass accuracy, sensitivity and specificity. The proposed FFNN model is simple, and it may support the triage of patients for further confirmation of the diagnosis. [ABSTRACT FROM AUTHOR]

Background The aim of this study is to address the paucity of epidemiological data regarding the characteristics, treatment patterns and survival outcomes of Chinese glioblastoma patients. Methods This was a population-level study of Hong Kong adult (> 18 years) Chinese patients with newly diagnosed histologically confirmed glioblastoma between 2006 and 2019. The age standardized incidence rate (ASIR), patient-, tumor- treatment-related characteristics, overall survival (OS) as well as its predictors were determined. Results One thousand and ten patients with a median follow-up of 10.0 months were reviewed. The ASIR of glioblastoma was 1.0 per 100 000 population with no significant change during the study period. The mean age was 57 + 14 years. The median OS was 10.6 months (IQR: 5.2–18.4). Independent predictors for survival were: Karnofsky performance score > 80 (adjusted OR: 0.8; 95% CI: 0.6–0.9), IDH-1 mutant (aOR: 0.7; 95% CI: 0.5–0.9) or MGMT methylated (aOR: 0.7; 95% CI: 0.5–0.8) glioblastomas, gross total resection (aOR: 0.8; 95% CI: 0.5–0.8) and temozolomide chemoradiotherapy (aOR 0.4; 95% CI: 0.3–0.6). Despite the significant increased administration of temozolomide chemoradiotherapy from 39% (127/326) of patients in 2006–2010 to 63% (227/356) in 2015–2019 (P -value <.001), median OS did not improve (2006–2010: 10.3 months vs 2015–2019: 11.8 months) (OR: 1.1; 95% CI: 0.9–1.3). Conclusions The incidence of glioblastoma in the Chinese general population is low. We charted the development of neuro-oncological care of glioblastoma patients in Hong Kong during the temozolomide era. Although there was an increased adoption of temozolomide chemoradiotherapy, a corresponding improvement in survival was not observed. [ABSTRACT FROM AUTHOR]

QUASAR arterial spin labeling (ASL) was used to investigate the role of vascular impairment in Alzheimer's disease (AD). We hypothesized that the hemodynamic parameters monitoring cerebrovascular integrity, i.e., cerebral blood flow (CBF), arterial blood volume (aBV), and arterial transit time (aTT), would be affected. 13 AD patients and 15 healthy control (HC) subjects underwent 3T MRI scanning. Two separate blood flow acquisitions were obtained with 1 slice overlap for whole brain coverage. CBF, aBV, and aTT maps were calculated using in-house software. Preprocessing and statistical analyses were performed on SPM5. Region-of-interest (ROI) studies of ten selected cerebral regions were also conducted. There were significant differences in mini mental status exam (MMSE) (AD: 16.3 ± 4.55, HC: 28.5 ± 2.00) and Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) scores (AD: 25.25 ± 9.64, HC: 5.51 ± 2.62) between the 2 groups (p < 0.001) but none in age (p = 0.068). CBF decreased significantly (p < 0.01) in AD compared to controls in the right middle cingulate, left cuneus, left inferior and middle frontal, right superior frontal, left inferior parietal, and right supramarginal gyri. ROI studies confirmed significant hemodynamic impairments in AD compared to HC (p < 0.05): CBF in middle and posterior cingulate, aBV in left superior temporal, right inferior parietal, and posterior cingulate, and aTT in left inferior frontal and middle cingulate gyri. CBF correlated positively while aTT correlated negatively to MMSE, and vice versa for ADAS-cog. Using QUASAR ASL, we found patterns of regional hemodynamic impairment typical of moderate AD, suggesting underlying vascular abnormality. As potential biomarkers, these hemodynamic parameters could differentiate patients from volunteers, and possibly indicate the conversion from healthy aging to mild cognitive impairment to AD. [ABSTRACT FROM AUTHOR]

Objective: To investigate the outcome of surgical resection of cerebral lesions near or at the motor cortex under general anaesthesia or in the awake condition. Methods: Patients undergoing motor cortical mapping for tumour surgery were recruited. Surgery was carried out according to the cortical mapping protocol of the centre. Tumour location, stimulation threshold, extent of resection and postoperative complications, including neurological deficits and seizure, were recorded. Results were categorized in the awake group and in the general anaesthesia (GA) group for analysis. Results: From February 2003 to July 2006, 28 patients suffering from brain tumour (24 glioma, two metastasis and two cavernoma) were indicated for motor cortical mapping to facilitate safe tumour removal. Eight patients were in the GA group. Five tumours were subcortical lesions, whereas three were cortical lesions. There were 20 patients in the awake group. Three tumours were subcortical, whereas 17 were cortical lesions. The mean stimulation threshold was 10.75 mA (5–16 mA) in the GA group and 7.7 mA (4–12 mA) in the awake group. There were four early postoperative seizures, two transient (3-month) deficits and four permanent deficits in the GA group. One early postoperative seizure, five transient deficits and no permanent deficits were recorded in the awake group. All the permanent deficits were associated with subcortical tumours and were in the GA group. Seventy five percent of the patients achieved radiological total removal and an average extent of resection of 94.15% was achieved in the awake group. Only 37.5% of patients achieved radiological total removal and the average of extent of resection was 64.1% in the GA group. Conclusions: General anaesthesia was associated with high postoperative permanent deficit despite the effort of motor cortical mapping. Higher rate of early postoperative seizure was also found in the GA group. Awake motor cortical mapping was safer and was associated with fewer complications. We suggest that awake motor cortical mapping is preferable to the general anaesthetic technique. [ABSTRACT FROM AUTHOR]

Background: There is growing evidence suggesting that the abnormal pituitary volume (PV) may be an essential deficit in schizophrenia spectrum disorders, and PV may change depending on the stage of the illness. However, previous studies assessing PV in schizophrenia spectrum disorders, especially in ultra-high risk individuals, were confounding. The present study aimed to assess whether there would be alteration of the PV in patients with first-episode schizophrenia and their non-affected first-degree relatives. Methods: This study recruited 147 subjects, including subjects with 62 first-episode schizophrenia (31 man, 31 female), 25 non-psychotic first-degree relatives (11 male, 14 female), and 60 healthy controls (30 male, 30 female). All of them underwent a T1 weighted image magnetic resonance imaging using 3T MRI Scanner (Siemens, Germany). All volumes were examined with the 3D-Slicer 4.10.1 (Surgical Planning Laboratory, Brigham and Women’s Hospital, USA; http://www. slicer.org/). The PV was traced in all coronal slices with well-defied boundaries (such as diaphragma sellae (superiorly), the sphenoid sinus (inferiorly), the cavernous sinuses(bilaterally)). The infundibular stalk was excluded while the bright posterior pituitary was included. All images were tranced manually by a trained rater who was blind to the participants’ group assignment. In a random subset of 24 cases, both the inter-rater reliability (intraclass correlation coefficient r=0.916, p<0.001) and the intra-rater reliability (intraclass correlation coefficient r=0.924 p<0.001) were high. We conducted MANCOVA with gender, and whole brain volumes (WBV) as covariates to compare the PV among the groups. Results: We found no significant differences in gender ratio, age, and WBV (p>0.05) among the three groups, but patients with first-episode schizophrenia showed shorter length of education than healthy controls (p<0.001). As expected, we found that male participants in general (Mean ± SD: 486.85 ± 100.24) exhibited a prominently smaller PV than female participants (Mean ± SD: 562.13 ± 102.90) after controlling for WBV (t=25.087, p<0.001). Findings from MANCOVA analysis showed that although first-episode schizophrenia patients (Mean ± SD: 523.81 ± 116.41) and healthy controls (Mean ± SD: 513.17 ± 103.57) showed no significant difference in PV (F=0.581, p=0.447), there was a trend of statistical significance in their non-psychotic first-degree relatives (Mean ± SD: 557.85 ± 93.58) compared with healthy controls (F=3.334, p=0.072). We also found a negative correlation between the duration of treatment and PV in female schizophrenia patients (r=-0.398, p=0.029), whose mean duration of treatment was 4.71 months (SD=2.18 months). No significant correlation was observed in in male patients. Discussion: Our findings found no alteration of PV in first-episode schizophrenia patients but a trend of enlargement was observed in their non-psychotic first-degree relatives. Moreover, female schizophrenia patients with longer duration of treatment exhibited smaller PV. These findings suggested that the enlarged PV might be an early detection signal for individuals with potentially high risk of developing into schizophrenia, and such an enlargement of PV might be responsive to antipsychotic medications. [ABSTRACT FROM AUTHOR]

Background: Neurological softs signs (NSS) are defined as subtle neurological abnormalities with manifestations of motor coordination, sensory integration and disinhibition. Evidence has suggested NSS as one of the most promising endophenotypes for schizophrenia spectrum disorders. Moreover, accumulating evidence also suggest that NSS may be associated with specific functional connectivity. The present study aimed to examine the cerebellar-cerebral resting-state functional connectivity (rsFC) of NSS in patients with first-episode schizophrenia (FES) and their unaffected siblings (SB). Methods: We administered the abridge version of the Cambridge Neurological Inventory (CNI) to 51 FES patients, 20 unaffected SB, and 50 healthy controls (HC) to assess the severity of NSS. All the participants also underwent a resting-state functional magnetic resonance imaging (MRI) scan. Ten regions of interest (ROIs) in the cerebellum were selected to represent cerebellar motor network (MN) and cerebellar executive control network (EN), which corresponded to the “sensorimotor-cognitive” dichotomy of NSS. rsFC between each ROI and the whole brain voxels were constructed, and the linear regression analysis was conducted to examine the cerebellar-cerebral rsFC patterns of NSS in each group. Results: Regarding the cerebellar MN, there were positive correlations observed between the rsFC of the cerebellar MN with the default mode network (DMN) and NSS in FES patients group (CNI total score and the motor coordination subscale) and the SB group (CNI total score and the motor coordination and sensory integration subscales). The rsFC of the cerebellar MN and the sensorimotor network were significantly and positively correlated with NSS (CNI total score and the motor coordination and sensory integration subscales) in the SB group. Regarding the cerebellar EN, we found that both the FES and the SB groups exhibited significantly negative correlations between NSS (CNI total score and the motor coordination subscale) and the rsFC of the cerebellar EN with the DMN. Moreover, the rsFC between the cerebellar EN and the sensorimotor network was positively correlated with NSS (CNI total score and the motor coordination and disinhibition subscales) in the SB group. Discussion: We found inverse correlations between NSS and the rsFC of the cerebellar EN/MN and the DMN in both FES patients and their unaffected SB, suggesting that altered cerebellar-cerebral rsFC between these networks is correlated with the NSS. Moreover, the SB group exhibited a unique correlational pattern that NSS were correlated with the cerebellarsensorimotor network rsFC, suggesting that such a network connectivity may serve as a potential biomarker for schizophrenia. [ABSTRACT FROM AUTHOR]

To clarify the involvement of the cerebellum in impaired sensory integration in patients with schizophrenia, 52 first-episode patients with schizophrenia and 52 age- and sex-matched healthy controls underwent a verified sensory integration imaging task to examine the whole-brain dysfunction underlying impaired sensory integration. The familiality of cerebellar activation when integrating sensory stimuli was investigated in 25 siblings of the patients with schizophrenia, while the heritability of cerebellar activation was estimated in 56 monozygotic twins and 56 dizygotic twins. In addition, the functional connectivity between the cerebellum and the remaining regions of the whole brain was explored with psychophysiological interaction analysis. Relative to healthy controls, patients with schizophrenia showed reduced cerebellar activation when performing the sensory integration task in the whole-brain analysis. This reduced cerebellar activation was also found in the siblings of patients with schizophrenia, but to a lesser extent compared with schizophrenia patients. Cerebellar activation during sensory integration was also found to be significantly heritable. Furthermore, dysconnectivity within the cerebellum was found in patients with schizophrenia when integrating auditory and visual stimuli. These findings highlight the role of cerebellar dysfunction in the pathophysiology of schizophrenia symptoms and its potential role as an endophenotype of schizophrenia spectrum disorders. (PsycInfo Database Record (c) 2021 APA, all rights reserved). [ABSTRACT FROM AUTHOR]

Background: Cerebral microbleeds (CMB) are indicators of severe cerebral small vessel disease (CSVD) that can be identified through hemosiderin-sensitive sequences in MRI. Specifically, quantitative susceptibility mapping (QSM) and deep learning were applied to detect CMBs in MRI., Purpose: To automatically detect CMB on QSM, we proposed a two-stage deep learning pipeline., Study Type: Retrospective., Subjects: A total number of 1843 CMBs from 393 patients (69 ± 12) with cerebral small vessel disease were included in this study. Seventy-eight subjects (70 ± 13) were used as external testing., Field Strength/sequence: 3 T/QSM., Assessment: The proposed pipeline consisted of two stages. In stage I, 2.5D fast radial symmetry transform (FRST) algorithm along with a one-layer convolutional network was used to identify CMB candidate regions in QSM images. In stage II, the V-Net was utilized to reduce false positives. The V-Net was trained using CMB and non CMB labels, which allowed for high-level feature extraction and differentiation between CMBs and CMB mimics like vessels. The location of CMB was assessed according to the microbleeds anatomical rating scale (MARS) system., Statistical Tests: The sensitivity and positive predicative value (PPV) were reported to evaluate the performance of the model. The number of false positive per subject was presented., Results: Our pipeline demonstrated high sensitivities of up to 94.9% at stage I and 93.5% at stage II. The overall sensitivity was 88.9%, and the false positive rate per subject was 2.87. With respect to MARS, sensitivities of above 85% were observed for nine different brain regions., Data Conclusion: We have presented a deep learning pipeline for detecting CMB in the CSVD cohort, along with a semi-automated MARS scoring system using the proposed method. Our results demonstrated the successful application of deep learning for CMB detection on QSM and outperformed previous handcrafted methods., Level of Evidence: 2 TECHNICAL EFFICACY: Stage 2., (© 2023 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Background: Grey matter abnormalities and neurological soft signs (NSS) have been found in schizophrenia patients and their unaffected relatives. Evidence suggested that NSS are associated with grey matter morphometrical alterations in multiple regions in schizophrenia. However, the association between NSS and structural abnormalities at network level remains largely unexplored, especially in the schizophrenia and unaffected siblings., Method: We used source-based morphometry (SBM) to examine the association of structural brain network characteristics with NSS in 62 schizophrenia patients, 25 unaffected siblings, and 60 healthy controls., Results: Two components, namely the IC-5 (superior temporal gyrus, inferior frontal gyrus and insula network) and the IC-10 (parahippocampal gyrus, fusiform, thalamus and insula network) showed significant grey matter reductions in schizophrenia patients compared to healthy controls and unaffected siblings. Further association analysis demonstrated separate NSS-related grey matter covarying patterns in schizophrenia, unaffected siblings and healthy controls. Specifically, NSS were negatively associated with IC-1 (hippocampus, caudate and thalamus network) and IC-5 in schizophrenia, but with IC-3 (caudate, superior and middle frontal cortices network) in unaffected siblings and with IC-5 in healthy controls., Conclusion: Our results confirmed the key cortical and subcortical network abnormalities and NSS-related grey matter covarying patterns in the schizophrenia and unaffected siblings. Our findings suggest that brain regions implicating genetic liability to schizophrenia are partly separated from brain regions implicating neural abnormalities., Competing Interests: Declaration of competing interest All authors report no financial interest or conflict of interests., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Resting-state functional magnetic resonance imaging (rs-fMRI) has been actively used in the last decade to investigate brain functional connectivity alterations in Type 2 Diabetes Mellitus (T2DM) to understand the neuropathophysiology of T2DM in cognitive degeneration. Given the emergence of new analysis techniques, this scoping review aims to map the rs-fMRI analysis techniques that have been applied in the literature and reports the latest rs-fMRI findings that have not been covered in previous reviews. Graph theory, the contemporary rs-fMRI analysis, has been used to demonstrate altered brain topological organisations in people with T2DM, which included altered degree centrality, functional connectivity strength, the small-world architecture and network-based statistics. These alterations were correlated with T2DM patients' cognitive performances. Graph theory also contributes to identify unbiased seeds for seed-based analysis. The expanding rs-fMRI analytical approaches continue to provide new evidence that helps to understand the mechanisms of T2DM-related cognitive degeneration., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Apolipoprotein E ɛ4 allele (ApoE4) is the most common gene polymorphism related to Alzheimer's disease (AD). Impaired synaptic dysfunction occurs in ApoE4 carriers before any clinical symptoms. It remains unknown whether ApoE4 status affects the hippocampal neuromodulation, which further influences brain network topology., Purpose: To study the relationship of regional and global network properties by using graph theory analysis and glutamatergic (Glx) neuromodulation in the ApoE isoforms., Study Type: Prospective., Subjects: Eighty-four cognitively normal adults (26 ApoE4 and 58 non-ApoE4 carriers)., Field Strength/sequence: Gradient-echo echo-planar and point resolved spectroscopy sequence at 3 T., Assessment: Glx concentration in bilateral hippocampi were processed with jMRUI (4.0), and graph theory metrics (global: γ, λ, small-worldness in whole brain; regional: nodal clustering coefficient (C i ) and nodal characteristic path length (L i )) in top 20% highly connected hubs of subgroups (low-risk: non-ApoE4; high-risk: APOE4) were calculated and compared., Statistical Tests: Two-sample t test was used to compare metrics between subgroups. Correlations between regional properties and Glx by Pearson's partial correlation with false discovery rate correction., Results: Significant differences (P < 0.05) in C i between subgroups were found in hubs of left inferior frontal, bilateral inferior temporal, and bilateral precentral gyri, right parahippocampus, and bilateral precuneus. In addition, there was a significant correlation between Glx in the left hippocampus and C i in inferior frontal gyrus (r = -0.537, P = 0.024), right inferior temporal (r = -0.478, P = 0.043), right parahippocampus (r = -0.629, P = 0.016), left precentral (r = -0.581, P = 0.022), right precentral (r = -0.651, P = 0.003), left precuneus (r = -0.545, P = 0.024), and right precuneus (r = -0.567, P = 0.022); and L i in left precuneus (r = 0.575, P = 0.032) and right precuneus (r = 0.586, P = 0.032) in the high-risk group, but not in the low-risk group., Data Conclusion: Our results suggested that healthy ApoE4 carriers exhibit poorer local interconnectivity. Moreover, the close relationship between glutamate and small-world network properties in ApoE4 carriers might reflect a compensatory response to the impaired network efficiency., Evidence Level: 2 TECHNICAL EFFICACY: Stage 3., (© 2021 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC. on behalf of International Society for Magnetic Resonance in Medicine.)

Studies have shown the brain's rich-club organization may underpin brain function and be associated with various brain disorders. In this study, we aimed to investigate the relation between poststroke brain functions and functional recovery versus the rich-club organization of the structural brain network of patients after first-time acute ischemic stroke. A cohort of 16 acute ischemic stroke patients (11 males) was recruited. Structural brain networks were measured using diffusion tensor imaging within 1 week and at 1, 3 and 6 months after stroke. Motor impairment was assessed using the Upper-Extremity Fugl-Meyer motor scale and activities of daily living using the Barthel Index at the same time points as MRI. The rich-club regions that were stable over the course of stroke recovery included the bilateral dorsolateral superior frontal gyri, right supplementary motor area, and left median cingulate and paracingulate gyri. The network properties that correlated with poststroke brain functions were mainly the ratio between communication cost ratio and density ratio of rich-club, feeder and local connections. The recovery of both motor functions and activities of daily living were correlated with higher normalized rich club coefficients and a shorter length of local connections within a week after stroke. The communication cost ratio of feeder connections, the length of rich-club and local connections, and normalized rich club coefficients were found to be potential prognostic indicators of stroke recovery. Our results provide additional support to the notion that different types of network connections play different roles in brain functions as well as functional recovery., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system in which the immune system attacks the myelin and axons, consequently leading to demyelination and axonal injury. Magnetic resonance imaging (MRI) plays a pivotal role in the diagnosis of MS, and currently various types of MRI techniques have been used to detect the pathology of MS based on unique mechanisms. In this study, we applied the relayed nuclear Overhauser effect weighted (rNOEw) imaging to study human MS at clinical 3T. Three groups of subjects, including 20 normal control (NC) subjects, 14 neuromyelitis optica spectrum disorders (NMOSD) patients and 21 MS patients, were examined at a clinical 3T MRI scanner. Whole-brain rNOEw images of each subject were obtained by acquiring a control and a labeled image within four minutes. Significantly lower brain rNOEw contrast was detected in MS group compared to NC (P = 0.008) and NMOSD (P = 0.014) groups, while no significant difference was found between NC and NMOSD groups (P = 0.939). The lower rNOEw contrast of MS group compared to NC/NMOSD group was significant in white matter (P = 0.041/0.021), gray matter (P = 0.004/0.020) and brain parenchyma (P = 0.015/0.021). Moreover, MS lesions showed higher number and larger size but lower rNOEw contrast than NMOSD lesions (P = 0.002). Our proposed rNOEw imaging scheme has potential to serve as a new method for assisting MS diagnosis. Importantly, it may be used to identify MS from NMOSD., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

The link between non-demented type 2 diabetes mellitus (T2DM) and different types of cognitive impairment is controversial. By controlling for co-morbidities such as cerebral macrovascular and microvascular changes, cerebral atrophy, amyloid burden, hypertension or hyperlipidemia, the current study investigated the cerebral blood flow of T2DM individuals as compared to cognitively impaired subjects recruited from a memory clinic. 15 healthy control (71.8 ± 6.1 years), 18 T2DM (62.5 ± 3.7 years), as well as 8 Subjective Cognitive Decline (69.5 ± 7.5 years), 12 Vascular Dementia (79.3 ± 4.2 years) and 17 Alzheimer's Disease (75.1 ± 8.2 years) underwent multi-parametric MRI brain scanning. Subjects with T2DM and from the memory clinic also had 18-F Flutametamol PET-CT scanning to look for any amyloid burden. Pseudocontinuous Arterial Spin Labeling (PCASL), MR Angiography Head, 3D FLAIR and 3D T1-weighted sequences were used to quantify cerebral blood flow, cerebrovascular changes, white matter hyperintensities and brain atrophy respectively. Vascular risk factors were retrieved from the medical records. The 37 subjects from memory clinic were classified into subjective cognitive decline (SCD), vascular dementia (VD) and Alzheimer's disease (AD) subgroups by a multi-disciplinary panel consisting of a neuroradiologist, and 2 geriatricians. Absolute cortical CBF in our cohort of T2DM, SCD, VD and AD was significantly decreased (p < 0.01) as compared to healthy controls (HC) in both whole brain and eight paired brain regions, after age, normalized grey matter volume and gender adjustment and Bonferroni correction. Subgroup analysis between T2DM, SCD, VD, and AD revealed that CBF of T2DM was not significantly different from AD, VD or SCD. By controlling for co-morbidities, impaired cortical CBF in T2DM was not related to microangiopathy or amyloid deposition, but to the interaction of triple risk factors (such as diabetes mellitus, hypertension, and hyperlipidemia). There was statistically significant negative correlation (p ≤ 0.05) between adjusted CBF and HbA1c in all brain regions of T2DM and HC (with partial correlation ranging from -0.30 to -0.46). Taken together, altered cerebral blood flow in T2DM might be related to disruption of cerebrovascular autoregulation related to vascular risk factors, and such oligemia occurred before clinical manifestation due to altered glycemic control., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Schizophrenia has been characterized as a neurodevelopmental disorder of brain disconnectivity. However, whether disrupted integrity of white matter tracts in schizophrenia can potentially serve as individual discriminative biomarkers remains unclear., Methods: A random forest algorithm was applied to tractography-based diffusion properties obtained from a cohort of 65 patients with first-episode schizophrenia (FES) and 60 healthy individuals to investigate the machine-learning discriminative power of white matter disconnectivity. Recursive feature elimination was used to select the ultimate white matter features in the classification. Relationships between algorithm-predicted probabilities and clinical characteristics were also examined in the FES group., Results: The classifier was trained by 80% of the sample. Patients were distinguished from healthy individuals with an overall accuracy of 71.0% (95% confident interval: 61.1%, 79.6%), a sensitivity of 67.3%, a specificity of 75.0%, and the area under receiver operating characteristic curve (AUC) was 79.3% (χ2 p < 0.001). In validation using the held-up 20% of the sample, patients were distinguished from healthy individuals with an overall accuracy of 76.0% (95% confident interval: 54.9%, 90.6%), a sensitivity of 76.9%, a specificity of 75.0%, and an AUC of 73.1% (χ2 p = 0.012). Diffusion properties of inter-hemispheric fibres, the cerebello-thalamo-cortical circuits and the long association fibres were identified to be the most discriminative in the classification. Higher predicted probability scores were found in younger patients., Conclusions: Our findings suggest that the widespread connectivity disruption observed in FES patients, especially in younger patients, might be considered potential individual discriminating biomarkers., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Late stage Parkinson's disease (PD) patients were commonly observed with other non-motor comorbidities such as dementia and psychosis. While abnormal iron level in the substantia nigra was clinically accepted as a biomarker of PD, it was also suggested that the increased iron deposition could impair other brain regions and induce non-motor symptoms. A new Magnetic Resonance Imaging (MRI) called Quantitative Susceptibility Mapping (QSM) has been found to measure iron concentration in the grey matter reliably. In this study, we investigated iron level of different subcortical and limbic structures of Parkinson's disease (PD) patients with and without dementia by QSM. QSM and volumetric analysis by MRI were performed in 10 PD dementia (PDD) patients (73 ± 6 years), 31 PD patients (63 ± 8 years) and 27 healthy controls (62 ± 7 years). No significant differences were observed in the L-Dopa equivalent dosage for the two PD groups (p = 0.125). Putative iron content was evaluated in different subcortical and limbic structures of the three groups, as well as its relationship with cognitive performance. One-way ANCOVA with FDR adjustment at level of 0.05, adjusted for age and gender, showed significant group differences for left and right hippocampus (p = 0.015 & 0.032, respectively, BH-corrected for multiple ROIs) and right thalamus (p = 0.032, BH-corrected). Post-hoc test with Bonferroni's correction suggested higher magnetic susceptibility in PDD patients than healthy controls in the left and right hippocampus (p = 0.001 & 0.047, respectively, Bonferroni's corrected), while PD patients had higher magnetic susceptibility than the healthy controls in right hippocampus and right thalamus (p = 0.006 & 0.005, respectively, Bonferroni's corrected). PDD patients also had higher susceptibility than the non-demented PD patients in left hippocampus (p = 0.046, Bonferroni's corrected). The magnetic susceptibilities of the left and right hippocampus were negatively correlated with the Mini-Mental State Examination score ( r  = -0.329 & -0.386, respectively; p < 0.05). This study provides support for iron accumulation in limbic structures of PDD and PD patients and its correlation with cognitive performance, however, its putative involvement in development of non-motor cognitive dysfunction in PD pathogenesis remains to be elucidated.

Background: Gamma-aminobutyric acid (GABA) dysfunction and its consequent imbalance are implicated in the pathophysiology of schizophrenia. Reduced GABA production would lead to a disinhibition of glutamatergic neurons and subsequently cause a disruption of the modulation between GABAergic interneurons and glutamatergic neurons. In this study, levels of GABA, Glx (summation of glutamate and glutamine), and other metabolites in the anterior cingulate cortex were measured and compared between first-episode schizophrenia subjects and healthy controls (HC). Diagnostic potential of GABA and Glx as upstream biomarkers for schizophrenia was explored., Methods: Nineteen first-episode schizophrenia subjects and fourteen HC participated in this study. Severity of clinical symptoms of patients was measured with Positive and Negative Syndrome Scale (PANSS). Metabolites were measured using proton magnetic resonance spectroscopy, and quantified using internal water as reference., Results: First-episode schizophrenia subjects revealed reduced GABA and myo-inositol (mI), and increased Glx and choline (Cho), compared to HC. No significant correlation was found between metabolite levels and PANSS scores. Receiver operator characteristics analyses showed Glx had higher sensitivity and specificity (84.2%, 92.9%) compared to GABA (73.7%, 64.3%) for differentiating schizophrenia patients from HC. Combined model of both GABA and Glx revealed the best sensitivity and specificity (89.5%, 100%)., Conclusion: This study simultaneously showed reduction in GABA and elevation in Glx in first-episode schizophrenia subjects, and this might provide insights on explaining the disruption of modulation between GABAergic interneurons and glutamatergic neurons. Elevated Cho might indicate increased membrane turnover; whereas reduced mI might reflect dysfunction of the signal transduction pathway. In vivo Glx and GABA revealed their diagnostic potential for schizophrenia., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This is a case report of a young healthy adult who had acute cerebral infarcts after a short-term visit to high-altitude area. He developed acute onset of right-sided limb weakness and right hemianopia a few hours after arrival at an altitude of 3600 m by train. He was initially treated for high-altitude cerebral oedema but later computed tomography and magnetic resonance imaging confirmed ischaemic infarcts in the medial left occipital lobe and left thalamus. Subsequent investigations, including laboratory tests and imaging including an echocardiogram, revealed no culpable predisposing factors.

This study examined the nature of deficits in mentalizing, the ability to read the mental state of other people, as measured by a faux pas task in people with medial frontal lesions. A total of 56 Mandarin-speaking Chinese individuals participated (9 participants with medial frontal lesions, 12 participants with lateral frontal lesions, 5 participants with non-frontal lesions, and 30 healthy controls). The faux pas test ascertained the participants' ability to identify and understand a social faux pas, and to understand the mental states of the characters (the speaker and the recipient in a conversation with a social faux pas). Although the participants with medial frontal lesions performed less well than the other clinical participants and the control participants on all aspects of the faux pas test, the most significant deficit was observed in understanding mental states and hence inferring the speaker's intentions. The performance on the various aspects of decoding a social faux pas by people with medial frontal lesions suggests that the cognitive processes, and hence the respective neural correlates subserving these various processes, may be different. Our results add to existing literature and illustrate the very nature of deficits of mentalizing, measured by a faux pas test, experienced by people with medial frontal lesions. The data have also prompted that future behavioral and neuroimaging studies may be applied to further decode both the neural mechanisms and the cognitive variables affecting "mentalizing"., (2010 Elsevier Ltd. All rights reserved.)

Purpose: We aimed to evaluate the relationships between primary tumour; maximum standardized uptake value (SUVmax), metabolic tumour volume (TV) and total lesion glycolysis (TLG) and tumour-node metastases (TNM) classification in nasopharyngeal carcinoma (NPC) patients., Methods: Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography scans of 57 consecutive newly diagnosed NPC patients (age range, 15-80 years) were retrospectively reviewed. SUVmax, TV and TLG were recorded. Two-tailed Spearman's correlation was used to analyse the relationships between the metabolic parameters and the TNM staging system., Results: Positive correlations were observed between SUVmax (P<0.001, R=0.516), TV (P<0.001, R=0.504) and TLG (P<0.001, R=0.620) and T-stage, and both TV and SUVmax were independent variables that significantly affected T-stage (P<0.001, adjusted R=0.370). No other significant correlations were found between the metabolic parameters and TNM classification system., Conclusion: The metabolic parameters derived from fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography were positively correlated with T-stage in primary NPC. Our findings may suggest a complementary role of these parameters to TNM staging in prognostication of NPC patients.