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Zhang L, Biessels GJ, Hilal S, Chong JSX, Liu S, Shim HY, Xu X, Chong EJY, Wong ZX, Loke YM, Venketasubramanian N, Yeow TB, Chen CLH, Zhou JH. Cerebral microinfarcts affect brain structural network topology in cognitively impaired patients. J Cereb Blood Flow Metab 2021; 41:105-115. [PMID: 31986957 PMCID: PMC7747167 DOI: 10.1177/0271678x20902187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cerebral microinfarcts (CMIs), a novel cerebrovascular marker, are prevalent in Alzheimer's disease (AD) and associated with cognitive impairment. Nonetheless, the underlying mechanism of how CMIs influence cognition remains uncertain. We hypothesized that cortical-CMIs disrupted structural connectivity in the higher-order cognitive networks, leading to cognitive impairment. We analyzed diffusion-MRI data of 92 AD (26 with cortical-CMIs) and 110 cognitive impairment no dementia patients (CIND, 28 with cortical-CMIs). We compared structural network topology between groups with and without cortical-CMIs in AD/CIND, and tested whether structural connectivity mediated the association between cortical-CMIs and cognition. Cortical-CMIs correlated with impaired structural network topology (i.e. lower efficiency/degree centrality in the executive control/dorsal attention networks in CIND, and lower clustering coefficient in the default mode/dorsal attention networks in AD), which mediated the association of cortical-CMIs with visuoconstruction dysfunction. Our findings provide the first in vivo human evidence that cortical-CMIs impair cognition in elderly via disrupting structural connectivity.
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Affiliation(s)
- Liwen Zhang
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore.,Department of Pharmacology, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Geert Jan Biessels
- Department of Neurology, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Saima Hilal
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Joanna Su Xian Chong
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore.,Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Siwei Liu
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore.,Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hee Youn Shim
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Xin Xu
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Eddie Jun Yi Chong
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Zi Xuen Wong
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Yng Miin Loke
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | | | | | - Christopher Li-Hsian Chen
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Juan Helen Zhou
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore.,Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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2
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Zhang L, Zuo XN, Ng KK, Chong JSX, Shim HY, Ong MQW, Loke YM, Choo BL, Chong EJY, Wong ZX, Hilal S, Venketasubramanian N, Tan BY, Chen CLH, Zhou JH. Distinct BOLD variability changes in the default mode and salience networks in Alzheimer's disease spectrum and associations with cognitive decline. Sci Rep 2020; 10:6457. [PMID: 32296093 PMCID: PMC7160203 DOI: 10.1038/s41598-020-63540-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 03/31/2020] [Indexed: 12/27/2022] Open
Abstract
Optimal levels of intrinsic Blood-Oxygenation-Level-Dependent (BOLD) signal variability (variability hereafter) are important for normative brain functioning. However, it remains largely unknown how network-specific and frequency-specific variability changes along the Alzheimer's disease (AD) spectrum and relates to cognitive decline. We hypothesized that cognitive impairment was related to distinct BOLD variability alterations in two brain networks with reciprocal relationship, i.e., the AD-specific default mode network (DMN) and the salience network (SN). We examined variability of resting-state fMRI data at two characteristic slow frequency-bands of slow4 (0.027-0.073 Hz) and slow5 (0.01-0.027 Hz) in 96 AD, 98 amnestic mild cognitive impairment (aMCI), and 48 age-matched healthy controls (HC) using two commonly used pre-processing pipelines. Cognition was measured with a neuropsychological assessment battery. Using both global signal regression (GSR) and independent component analysis (ICA), results generally showed a reciprocal DMN-SN variability balance in aMCI (vs. AD and/or HC), although there were distinct frequency-specific variability patterns in association with different pre-processing approaches. Importantly, lower slow4 posterior-DMN variability correlated with poorer baseline cognition/smaller hippocampus and predicted faster cognitive decline in all patients using both GSR and ICA. Altogether, our findings suggest that reciprocal DMN-SN variability balance in aMCI might represent an early signature in neurodegeneration and cognitive decline along the AD spectrum.
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Affiliation(s)
- Liwen Zhang
- Department of Pharmacology, National University of Singapore, Singapore, Singapore.,Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore, Singapore.,Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Xi-Nian Zuo
- Research Centre for Lifespan Development of Mind and Brain (CLIMB), Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Kwun Kei Ng
- Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Joanna Su Xian Chong
- Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Hee Youn Shim
- Department of Pharmacology, National University of Singapore, Singapore, Singapore.,Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Marcus Qin Wen Ong
- Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Yng Miin Loke
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Boon Linn Choo
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Eddie Jun Yi Chong
- Department of Pharmacology, National University of Singapore, Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore, Singapore
| | - Zi Xuen Wong
- Department of Pharmacology, National University of Singapore, Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore, Singapore
| | - Saima Hilal
- Department of Pharmacology, National University of Singapore, Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore, Singapore
| | | | | | - Christopher Li-Hsian Chen
- Department of Pharmacology, National University of Singapore, Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore, Singapore
| | - Juan Helen Zhou
- Centre for Sleep and Cognition, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. .,Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore. .,Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University Health System, Singapore, Singapore.
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3
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Ching YY, Wang C, Tay T, Loke YM, Tang PH, Sng BL, Zhou J. Altered Sensory Insular Connectivity in Chronic Postsurgical Pain Patients. Front Hum Neurosci 2018; 12:483. [PMID: 30568586 PMCID: PMC6290251 DOI: 10.3389/fnhum.2018.00483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/19/2018] [Indexed: 12/03/2022] Open
Abstract
Chronic postsurgical pain (CPSP) occurs in up to 50% of individuals after surgeries and 32% after hysterectomy, leading to major adverse effects on quality of life and socioeconomic burden. Little is known about whether and how large-scale neural networks being affected in CPSP, particularly with regard to the functional connectivity (FC) of insula which is known to be the hub of the intrinsic neural network playing a critical role in pain processing. Here, we sought to examine the dynamics of insular FC in the context of noxious stimuli in CPSP patients. To this aim, resting state fMRI data were acquired, before and after acute heat pain stimulation, from 11 individuals with chronic post-hysterectomy pain (CPHP) and 22 age-matched healthy controls (HCs) who had a hysterectomy but without chronic post-surgical pain. We examined whole-brain FC were mapped by seeding at the sensorimotor and chemosensory subfields of the insula and found significant group × stimulation interaction effects. Specifically, the HC group had increased FC between the left sensorimotor insula and right angular and middle occipital gyrus (MOG) and increased FC between the left chemosensory insula and bilateral angular and MOG following pain stimulation. In contrast, such pain stimulation related FC changes were absent in the CPHP group. Furthermore, higher insular FC at baseline and smaller increased insular FC after pain stimulation correlated with clinical pain scores in CPHP patients. Our findings suggest that CPSP is associated with altered dynamics of large-scale functional networks anchored in the insula.
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Affiliation(s)
- Yin Ying Ching
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Chenhao Wang
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Terence Tay
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Yng Miin Loke
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Phua Hwee Tang
- KK Women's and Children's Hospital, Singapore, Singapore
| | - Ban Leong Sng
- KK Women's and Children's Hospital, Singapore, Singapore
| | - Juan Zhou
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Medical School, National University of Singapore, Singapore, Singapore.,Clinical Imaging Research Centre, The Agency for Science, Technology and Research and National University of Singapore, Singapore, Singapore
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4
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Vipin A, Loke YM, Liu S, Hilal S, Shim HY, Xu X, Tan BY, Venketasubramanian N, Chen CLH, Zhou J. Cerebrovascular disease influences functional and structural network connectivity in patients with amnestic mild cognitive impairment and Alzheimer's disease. Alzheimers Res Ther 2018; 10:82. [PMID: 30121086 PMCID: PMC6098837 DOI: 10.1186/s13195-018-0413-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/23/2018] [Indexed: 01/15/2023]
Abstract
BACKGROUND Patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) show functional and structural connectivity alterations in the default mode network (DMN) while cerebrovascular disease (CeVD) shows functional and structural connectivity changes in the executive control network (ECN). Such disruptions are associated with memory and executive function impairment, respectively. Concurrent AD and CeVD pathology is associated with a higher rate of cognitive decline and differential neurodegenerative patterns. Together, such findings are likely reflective of different underlying pathology in AD with and without CeVD. However, few studies have examined the effect of CeVD on network functional connectivity (task-free functional magnetic resonance imaging (fMRI)) and structural connectivity (diffusion MRI) of the DMN and ECN in aMCI and AD using a hypothesis-driven multiple seed-based approach. METHODS We examined functional and structural connectivity network changes in 39 aMCI, 50 aMCI+CeVD, 47 AD, 47 AD+CeVD, and 65 healthy controls (HCs) and their associations with cognitive impairment in the executive/attention and memory domains. RESULTS We demonstrate divergent DMN and ECN functional connectivity changes in CeVD and non-CeVD subjects. Compared with controls, intra-DMN hippocampal functional connectivity reductions were observed in both AD and AD+CeVD, while intra-DMN parietal and medial prefrontal-parietal functional connectivity was higher in AD+CeVD and aMCI+CeVD, but lower in AD. Intra-ECN frontal functional connectivity increases and fronto-parietal functional connectivity decreases occurred in CeVD but not non-CeVD subjects. Such functional connectivity alterations were related with cognitive impairment in a dissociative manner: intra-DMN functional connectivity changes were associated with worse cognition primarily in non-CeVD groups, while intra-ECN functional connectivity changes were associated with worse cognition primarily in CeVD groups. Additionally, CeVD and non-CeVD groups showed overlapping and distinct alterations in inter-network DMN-ECN functional connectivity depending on disease severity. In contrast to functional connectivity, CeVD groups had greater network structural connectivity damage compared with non-CeVD groups in both aMCI and AD patients. Network structural connectivity damage was associated with worse cognition. CONCLUSIONS We demonstrate differential functional and structural network changes between aMCI and AD patients with and without CeVD through diverging and deleterious network-based degeneration underlying domain-specific cognitive impairment.
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Affiliation(s)
- Ashwati Vipin
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Yng Miin Loke
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Siwei Liu
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Saima Hilal
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, Singapore.,Memory Aging and Cognition Centre, National University Health System, Singapore, Singapore
| | - Hee Youn Shim
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Xin Xu
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, Singapore.,Memory Aging and Cognition Centre, National University Health System, Singapore, Singapore
| | | | | | - Christopher Li-Hsian Chen
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, Singapore.,Memory Aging and Cognition Centre, National University Health System, Singapore, Singapore
| | - Juan Zhou
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore. .,Clinical Imaging Research Centre, The Agency for Science, Technology and Research and National University of Singapore, Singapore, Singapore.
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5
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Liu S, Poh JH, Koh HL, Ng KK, Loke YM, Lim JKW, Chong JSX, Zhou J. Carrying the past to the future: Distinct brain networks underlie individual differences in human spatial working memory capacity. Neuroimage 2018; 176:1-10. [DOI: 10.1016/j.neuroimage.2018.04.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 03/07/2018] [Accepted: 04/08/2018] [Indexed: 10/17/2022] Open
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Liu S, Ong YT, Hilal S, Loke YM, Wong TY, Chen CLH, Cheung CY, Zhou J. The Association Between Retinal Neuronal Layer and Brain Structure is Disrupted in Patients with Cognitive Impairment and Alzheimer's Disease. J Alzheimers Dis 2018; 54:585-95. [PMID: 27567815 DOI: 10.3233/jad-160067] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Both healthy and pathological aging due to Alzheimer's disease (AD) are associated with decreased brain grey matter volume (GMV) and disrupted white matter (WM) microstructure. Thinner macular ganglion cell-inner plexiform layer (GC-IPL) measured by spectral-domain optical coherence tomography has been reported in patients with AD and mild cognitive impairment. Emerging evidence suggested a link between thinner GC-IPL and lower GMV in subjects with no dementia using region-of-interest-based approach. However, it remains unknown whether GC-IPL thickness is associated with brain WM microstructure and how such association differed between normal and cognitively impaired subjects. Here, for subjects with no cognitive impairment (NCI), thinner GC-IPL was associated with lower WM microstructure integrity in the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, corticospinal tracts, anterior thalamic radiation, and cingulum regions, while it was weakly associated with lower GMV in visual cortex and cerebellum. Nevertheless, these retina-brain associations were disrupted in the presence of cognitive impairment. Correlations between GMV and GC-IPL were lost in patients with cognitive impairment but no dementia (CIND) and AD patients. GC-IPL was related to WM microstructural disruption in similar regions with decreased significance. In contrast, lower WM microstructure integrity in the fornix showed a trend of correlation with thinner GC-IPL in both CIND and AD but not NCI. Collectively, our findings suggest the possible physiological retina-brain relationship in healthy aging, which might be disrupted by disease-induced changes in patients with cognitive impairment. Longitudinal study with larger patient sample should follow to confirm the disease mechanism behind these retina-brain relationship changes.
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Affiliation(s)
- Siwei Liu
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Yi-Ting Ong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Saima Hilal
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Aging & Cognition Centre, National University Health System, Singapore
| | - Yng Miin Loke
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Tien Y Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Christopher Li-Hsian Chen
- Department of Pharmacology, National University of Singapore, Singapore.,Memory Aging & Cognition Centre, National University Health System, Singapore
| | - Carol Y Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Juan Zhou
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Medical School, Singapore.,Clinical Imaging Research Centre, The Agency for Science, Technology and Research and National University of Singapore, Singapore
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Chong JSX, Liu S, Loke YM, Hilal S, Ikram MK, Xu X, Tan BY, Venketasubramanian N, Chen CLH, Zhou J. Influence of cerebrovascular disease on brain networks in prodromal and clinical Alzheimer's disease. Brain 2017; 140:3012-3022. [PMID: 29053778 PMCID: PMC5841199 DOI: 10.1093/brain/awx224] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/12/2017] [Indexed: 01/16/2023] Open
Abstract
Network-sensitive neuroimaging methods have been used to characterize large-scale brain network degeneration in Alzheimer’s disease and its prodrome. However, few studies have investigated the combined effect of Alzheimer’s disease and cerebrovascular disease on brain network degeneration. Our study sought to examine the intrinsic functional connectivity and structural covariance network changes in 235 prodromal and clinical Alzheimer’s disease patients with and without cerebrovascular disease. We focused particularly on two higher-order cognitive networks—the default mode network and the executive control network. We found divergent functional connectivity and structural covariance patterns in Alzheimer’s disease patients with and without cerebrovascular disease. Alzheimer’s disease patients without cerebrovascular disease, but not Alzheimer’s disease patients with cerebrovascular disease, showed reductions in posterior default mode network functional connectivity. By comparison, while both groups exhibited parietal reductions in executive control network functional connectivity, only Alzheimer’s disease patients with cerebrovascular disease showed increases in frontal executive control network connectivity. Importantly, these distinct executive control network changes were recapitulated in prodromal Alzheimer’s disease patients with and without cerebrovascular disease. Across Alzheimer’s disease patients with and without cerebrovascular disease, higher default mode network functional connectivity z-scores correlated with greater hippocampal volumes while higher executive control network functional connectivity z-scores correlated with greater white matter changes. In parallel, only Alzheimer’s disease patients without cerebrovascular disease showed increased default mode network structural covariance, while only Alzheimer’s disease patients with cerebrovascular disease showed increased executive control network structural covariance compared to controls. Our findings demonstrate the differential neural network structural and functional changes in Alzheimer’s disease with and without cerebrovascular disease, suggesting that the underlying pathology of Alzheimer’s disease patients with cerebrovascular disease might differ from those without cerebrovascular disease and reflect a combination of more severe cerebrovascular disease and less severe Alzheimer’s disease network degeneration phenotype.
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Affiliation(s)
- Joanna Su Xian Chong
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Programme, Duke-National University of Singapore Medical School, Singapore
| | - Siwei Liu
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Programme, Duke-National University of Singapore Medical School, Singapore
| | - Yng Miin Loke
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Programme, Duke-National University of Singapore Medical School, Singapore
| | - Saima Hilal
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Mohammad Kamran Ikram
- Memory Ageing and Cognition Centre, National University Health System, Singapore.,Duke-National University of Singapore Medical School, Singapore
| | - Xin Xu
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | | | | | - Christopher Li-Hsian Chen
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore.,Memory Ageing and Cognition Centre, National University Health System, Singapore
| | - Juan Zhou
- Centre for Cognitive Neuroscience, Neuroscience and Behavioural Disorders Programme, Duke-National University of Singapore Medical School, Singapore.,Clinical Imaging Research Centre, The Agency for Science, Technology and Research and National University of Singapore, Singapore
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8
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Ji F, Pasternak O, Liu S, Loke YM, Choo BL, Hilal S, Xu X, Ikram MK, Venketasubramanian N, Chen CLH, Zhou J. Distinct white matter microstructural abnormalities and extracellular water increases relate to cognitive impairment in Alzheimer's disease with and without cerebrovascular disease. Alzheimers Res Ther 2017; 9:63. [PMID: 28818116 PMCID: PMC5561637 DOI: 10.1186/s13195-017-0292-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/24/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Mixed vascular and neurodegenerative dementia, such as Alzheimer's disease (AD) with concomitant cerebrovascular disease, has emerged as the leading cause of age-related cognitive impairment. The brain white matter (WM) microstructural changes in neurodegeneration well-documented by diffusion tensor imaging (DTI) can originate from brain tissue or extracellular free water changes. The differential microstructural and free water changes in AD with and without cerebrovascular disease, especially in normal-appearing WM, remain largely unknown. To cover these gaps, we aimed to characterize the WM free water and tissue microstructural changes in AD and mixed dementia as well as their associations with cognition using a novel free water imaging method. METHODS We compared WM free water and free water-corrected DTI measures as well as white matter hyperintensity (WMH) in patients with AD with and without cerebrovascular disease, patients with vascular dementia, and age-matched healthy control subjects. RESULTS The cerebrovascular disease groups had higher free water than the non-cerebrovascular disease groups. Importantly, besides the cerebrovascular disease groups, patients with AD without cerebrovascular disease also had increased free water in normal-appearing WM compared with healthy control subjects, reflecting mild vascular damage. Such free water increases in WM or normal-appearing WM (but not WMH) contributed to dementia severity. Whole-brain voxel-wise analysis revealed a close association between widespread free water increases and poorer attention, executive functioning, visual construction, and motor performance, whereas only left hemispheric free water increases were related to language deficits. Moreover, compared with the original DTI metrics, the free water-corrected DTI metric revealed tissue damage-specific (frontal and occipital) microstructural differences between the cerebrovascular disease and non-cerebrovascular disease groups. In contrast to both lobar and subcortical/brainstem free water increases, only focal lobar microstructural damage was associated with poorer cognitive performance. CONCLUSIONS Our findings suggest that free water analysis isolates probable mild vascular damage from WM microstructural alterations and underscore the importance of normal-appearing WM changes underlying cognitive and functional impairment in AD with and without cerebrovascular disease. Further developed, the combined free water and tissue neuroimaging assays could help in differential diagnosis, treatment planning, and disease monitoring of patients with mixed dementia.
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Affiliation(s)
- Fang Ji
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, 8 College Road, 06-15, Singapore, 169857, Singapore
| | - Ofer Pasternak
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Siwei Liu
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, 8 College Road, 06-15, Singapore, 169857, Singapore
| | - Yng Miin Loke
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, 8 College Road, 06-15, Singapore, 169857, Singapore
| | - Boon Linn Choo
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, 8 College Road, 06-15, Singapore, 169857, Singapore
| | - Saima Hilal
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, 117600, Singapore.,Memory Aging & Cognition Centre, National University Health System, National University of Singapore, Singapore, Singapore
| | - Xin Xu
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, 117600, Singapore.,Memory Aging & Cognition Centre, National University Health System, National University of Singapore, Singapore, Singapore
| | - Mohammad Kamran Ikram
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, 117600, Singapore.,Memory Aging & Cognition Centre, National University Health System, National University of Singapore, Singapore, Singapore
| | | | - Christopher Li-Hsian Chen
- Department of Pharmacology, Clinical Research Centre, National University Health System, National University of Singapore, Singapore, 117600, Singapore.,Memory Aging & Cognition Centre, National University Health System, National University of Singapore, Singapore, Singapore
| | - Juan Zhou
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, 8 College Road, 06-15, Singapore, 169857, Singapore. .,Clinical Imaging Research Centre, Agency for Science, Technology and Research, Singapore, Singapore.
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9
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Qiu Y, Liu S, Hilal S, Loke YM, Ikram MK, Xu X, Yeow Tan B, Venketasubramanian N, Chen CLH, Zhou J. Inter-hemispheric functional dysconnectivity mediates the association of corpus callosum degeneration with memory impairment in AD and amnestic MCI. Sci Rep 2016; 6:32573. [PMID: 27581062 PMCID: PMC5007647 DOI: 10.1038/srep32573] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 08/10/2016] [Indexed: 12/21/2022] Open
Abstract
Evidences suggested that both corpus callosum (CC) degeneration and alternations of homotopic inter-hemispheric functional connectivity (FC) are present in Alzheimer's disease (AD). However, the associations between region-specific CC degeneration and homotopic inter-hemispheric FC and their relationships with memory deficits in AD remain uncharacterized. We hypothesized that selective CC degeneration is associated with memory impairment in AD and amnestic mild cognitive impairment (aMCI), which is mediated by homotopic inter-hemispheric functional dysconnectivity. Using structural magnetic resonance imaging (MRI) and task-free functional MRI, we assessed the CC volume and inter-hemispheric FC in 66 healthy controls, 41 aMCI and 41 AD. As expected, AD had CC degeneration and attenuated inter-hemispheric homotopic FC. Nevertheless, aMCI had relatively less severe CC degeneration (mainly in mid-anterior, central, and mid-posterior) and no reduction in inter-hemispheric homotopic FC. The degeneration of each CC sub-region was associated with specific inter-hemispheric homotopic functional disconnections in AD and aMCI. More importantly, impairment of inter-hemispheric homotopic FC partially mediated the association between CC (particularly the central and posterior parts) degeneration and memory deficit. Notably, these results remained after controlling for hippocampal volume. Our findings shed light on how CC degeneration and the related inter-hemispheric FC impact memory impairment in early stage of AD.
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Affiliation(s)
- Yingwei Qiu
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore
| | - Siwei Liu
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore
| | - Saima Hilal
- Department of Pharmacology, National University Health System, Clinical Research Centre, Singapore
- Memory Aging & Cognition Centre, National University Health System, Singapore
| | - Yng Miin Loke
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore
| | - Mohammad Kamran Ikram
- Memory Aging & Cognition Centre, National University Health System, Singapore
- Duke-NUS Graduate Medical School, National University of Singapore, Singapore
| | - Xin Xu
- Department of Pharmacology, National University Health System, Clinical Research Centre, Singapore
- Memory Aging & Cognition Centre, National University Health System, Singapore
| | | | | | - Christopher Li-Hsian Chen
- Department of Pharmacology, National University Health System, Clinical Research Centre, Singapore
- Memory Aging & Cognition Centre, National University Health System, Singapore
| | - Juan Zhou
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore
- Clinical Imaging Research Centre, the Agency for Science, Technology and Research and National University of Singapore, Singapore
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Paulesu L, Bocci V, King A, Loke YM. Immunocytochemical localization of interferons in human trophoblast populations. J BIOL REG HOMEOS AG 1991; 5:81-5. [PMID: 1722381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It is known that Interferon (IFN) is present in normal body fluids and tissues during pregnancy. Using an immunohistochemical technique and a panel of monoclonal antibodies we have localized IFN-alpha, -beta and -gamma directly on formalin-fixed paraffin-embedded normal human placentae at different stages of pregnancy and in the hydatidiform mole. The results show that IFNs is mostly localized in villous syncytiotrophoblast and in extravillous interstitial-trophoblast. No reactivity was observed in villous cytotrophoblast or in cytotrophoblast cell columns. The most intense staining was observed for IFN-alpha and -beta, while IFN-gamma was rather weak. There is then a gradual diminution in IFN reactivity with increasing gestation age being almost imperceptible at term. These results suggest that IFN may deploy antiviral, immunomodulator and differentiation activities during normal human pregnancy.
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Affiliation(s)
- L Paulesu
- Institute of General Physiology, University of Siena, Italy
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