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Humphreys CA, Smith C, Wardlaw JM. Correlations in post-mortem imaging-histopathology studies of sporadic human cerebral small vessel disease: A systematic review. Neuropathol Appl Neurobiol 2021; 47:910-930. [PMID: 34037264 DOI: 10.1111/nan.12737] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/29/2021] [Accepted: 05/02/2021] [Indexed: 11/30/2022]
Abstract
AIMS Sporadic human cerebral small vessel disease (SVD) commonly causes stroke and dementia but its pathogenesis is poorly understood. There are recognised neuroimaging and histopathological features. However, relatively few studies have examined the relationship between the radiological and pathological correlates of SVD; better correlation would promote greater insight into the underlying biological changes. METHODS We performed a systematic review to collate and appraise the information derived from studies that correlated histological with neuroimaging-defined SVD lesions. We searched for studies describing post-mortem imaging and histological tissue examination in adults, extracted data from published studies, categorised the information and compiled this narrative. RESULTS We identified 38 relevant studies, including at least 1146 subjects, 342 of these with SVD: 29 studies focussed on neuroradiological white matter lesions (WML), six on microinfarcts and three on dilated perivascular spaces (PVS) and lacunes. The histopathology terminology was diverse with few robust definitions. Reporting and methodology varied widely between studies, precluding formal meta-analysis. PVS and 'oedema' were frequent findings in WML, being described in at least 94 and 18 radiological WML, respectively, in addition to myelin pallor. Histopathological changes extended beyond the radiological lesion margins in at least 33 radiological WML. At least 43 radiological lesions not seen pathologically and at least 178 histological lesions were not identified on imaging. CONCLUSIONS Histopathological assessment of human SVD is hindered by inconsistent methodological approaches and unstandardised definitions. The data from this systematic review will help to develop standardised definitions to promote consistency in human SVD research.
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Affiliation(s)
| | - Colin Smith
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute at The University of Edinburgh, Edinburgh, UK.,Row Fogo Centre for Research into Ageing and the Brain, Edinburgh, UK
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2
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Stringer MS, Lee H, Huuskonen MT, MacIntosh BJ, Brown R, Montagne A, Atwi S, Ramirez J, Jansen MA, Marshall I, Black SE, Zlokovic BV, Benveniste H, Wardlaw JM. A Review of Translational Magnetic Resonance Imaging in Human and Rodent Experimental Models of Small Vessel Disease. Transl Stroke Res 2020; 12:15-30. [PMID: 32936435 PMCID: PMC7803876 DOI: 10.1007/s12975-020-00843-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/16/2020] [Accepted: 08/19/2020] [Indexed: 12/29/2022]
Abstract
Cerebral small vessel disease (SVD) is a major health burden, yet the pathophysiology remains poorly understood with no effective treatment. Since much of SVD develops silently and insidiously, non-invasive neuroimaging such as MRI is fundamental to detecting and understanding SVD in humans. Several relevant SVD rodent models are established for which MRI can monitor in vivo changes over time prior to histological examination. Here, we critically review the MRI methods pertaining to salient rodent models and evaluate synergies with human SVD MRI methods. We found few relevant publications, but argue there is considerable scope for greater use of MRI in rodent models, and opportunities for harmonisation of the rodent-human methods to increase the translational potential of models to understand SVD in humans. We summarise current MR techniques used in SVD research, provide recommendations and examples and highlight practicalities for use of MRI SVD imaging protocols in pre-selected, relevant rodent models.
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Affiliation(s)
- Michael S Stringer
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Mikko T Huuskonen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Bradley J MacIntosh
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Rosalind Brown
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Axel Montagne
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sarah Atwi
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Joel Ramirez
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Maurits A Jansen
- Edinburgh Preclinical Imaging, Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Ian Marshall
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Sandra E Black
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Joanna M Wardlaw
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK. .,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK.
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3
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McAleese KE, Graham S, Dey M, Walker L, Erskine D, Johnson M, Johnston E, Thomas AJ, McKeith IG, DeCarli C, Attems J. Extravascular fibrinogen in the white matter of Alzheimer's disease and normal aged brains: implications for fibrinogen as a biomarker for Alzheimer's disease. Brain Pathol 2019; 29:414-424. [PMID: 30485582 PMCID: PMC8028661 DOI: 10.1111/bpa.12685] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 11/16/2018] [Indexed: 12/11/2022] Open
Abstract
The blood-brain barrier (BBB) regulates cerebrovascular permeability and leakage of blood-derived fibrinogen. Dysfunction of the BBB has been associated with cerebral arteriolosclerosis small vessel disease (SVD) and white matter lesions (WML). Furthermore, BBB dysfunction is associated with the pathogenesis of Alzheimer's disease (AD) with the presence of CSF plasma proteins suggested to be a potential biomarker of AD. We aimed to determine if extravascular fibrinogen in the white matter was associated with the development of AD hallmark pathologies, i.e., hyperphosphorylated tau (HPτ) and amyloid-β (Aβ), as well as SVD, cerebral amyloid angiopathy (CAA) and measures of white matter damage. Using human post-mortem brains, parietal tissue from 20 AD and 22 non-demented controls was quantitatively assessed for HPτ, Aβ, white matter damage severity, axonal density, demyelination and the burden of extravascular fibrinogen in both WML and normal appearing white matter (NAWM). SVD severity was determined by calculating sclerotic indices. WML- and NAWM fibrinogen burden was not significantly different between AD and controls nor was it associated with the burden of HPτ or Aβ pathology, or any measures of white matter damage. Increasing severity of SVD was associated with and a predictor of both higher WML- and NAWM fibrinogen burden (all P < 0.05) in controls only. In cases with minimal SVD NAWM fibrinogen burden was significantly higher in the AD cases (P < 0.05). BBB dysfunction was present in both non-demented and AD brains and was not associated with the burden of AD-associated cortical pathologies. BBB dysfunction was strongly associated with SVD but only in the non-demented controls. In cases with minimal SVD, BBB dysfunction was significantly worse in AD cases possibly indicating the influence of CAA. In conclusion, extravascular fibrinogen is not associated with AD hallmark pathologies but indicates SVD, suggesting that the presence of fibrinogen in the CSF is not a surrogate marker for AD pathology.
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Affiliation(s)
| | - Sophie Graham
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | | | - Lauren Walker
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | - Daniel Erskine
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | - Mary Johnson
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | - Eleanor Johnston
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | - Alan J. Thomas
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | - Ian G. McKeith
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
| | | | - Johannes Attems
- Institute of NeuroscienceNewcastle UniversityNewcastle Upon TyneUK
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4
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Shaaban CE, Jorgensen DR, Gianaros PJ, Mettenburg J, Rosano C. Cerebrovascular disease: Neuroimaging of cerebral small vessel disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:225-255. [DOI: 10.1016/bs.pmbts.2019.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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5
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Dusek P, Madai VI, Huelnhagen T, Bahn E, Matej R, Sobesky J, Niendorf T, Acosta-Cabronero J, Wuerfel J. The choice of embedding media affects image quality, tissue R 2 * , and susceptibility behaviors in post-mortem brain MR microscopy at 7.0T. Magn Reson Med 2018; 81:2688-2701. [PMID: 30506939 DOI: 10.1002/mrm.27595] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/19/2018] [Accepted: 10/14/2018] [Indexed: 12/22/2022]
Abstract
PURPOSE The quality and precision of post-mortem MRI microscopy may vary depending on the embedding medium used. To investigate this, our study evaluated the impact of 5 widely used media on: (1) image quality, (2) contrast of high spatial resolution gradient-echo (T1 and T2 * -weighted) MR images, (3) effective transverse relaxation rate (R2 * ), and (4) quantitative susceptibility measurements (QSM) of post-mortem brain specimens. METHODS Five formaldehyde-fixed brain slices were scanned using 7.0T MRI in: (1) formaldehyde solution (formalin), (2) phosphate-buffered saline (PBS), (3) deuterium oxide (D2 O), (4) perfluoropolyether (Galden), and (5) agarose gel. SNR and contrast-to-noise ratii (SNR/CNR) were calculated for cortex/white matter (WM) and basal ganglia/WM regions. In addition, median R2 * and QSM values were extracted from caudate nucleus, putamen, globus pallidus, WM, and cortical regions. RESULTS PBS, Galden, and agarose returned higher SNR/CNR compared to formalin and D2 O. Formalin fixation, and its use as embedding medium for scanning, increased tissue R2 * . Imaging with agarose, D2 O, and Galden returned lower R2 * values than PBS (and formalin). No major QSM offsets were observed, although spatial variance was increased (with respect to R2 * behaviors) for formalin and agarose. CONCLUSIONS Embedding media affect gradient-echo image quality, R2 * , and QSM in differing ways. In this study, PBS embedding was identified as the most stable experimental setup, although by a small margin. Agarose and Galden were preferred to formalin or D2 O embedding. Formalin significantly increased R2 * causing noisier data and increased QSM variance.
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Affiliation(s)
- Petr Dusek
- Department of Neurology, Charles University, 1st Faculty of Medicine and General University Hospital in Prague, Praha, Czech Republic.,Department of Radiology, Charles University, 1st Faculty of Medicine and General University Hospital in Prague, Praha, Czech Republic
| | - Vince Istvan Madai
- Department of Neurology and Center for Stroke Research Berlin (CSB), Charité-Universitaetsmedizin, Berlin, Germany
| | - Till Huelnhagen
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Erik Bahn
- Institute of Neuropathology, University Medicine Göttingen, Göttingen, Germany
| | - Radoslav Matej
- Department of Pathology and Molecular Medicine, Thomayer Hospital, Praha, Czech Republic.,Department of Pathology, Charles University, 1st Faculty of Medicine and General University Hospital in Prague, Praha, Czech Republic
| | - Jan Sobesky
- Department of Neurology and Center for Stroke Research Berlin (CSB), Charité-Universitaetsmedizin, Berlin, Germany.,Experimental and Clinical Research Center (ECRC), Charité-Universitaetsmedizin and Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,Experimental and Clinical Research Center (ECRC), Charité-Universitaetsmedizin and Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Julio Acosta-Cabronero
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, University College London, London, United Kingdom.,German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Jens Wuerfel
- NeuroCure Clinical Research Center, Charité-Universitaetsmedizin, Berlin, Germany.,Medical Imaging Analysis Center AG, Basel, Switzerland.,Department of Biomedical Engineering, University Basel, Switzerland
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6
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Jorgensen DR, Shaaban CE, Wiley CA, Gianaros PJ, Mettenburg J, Rosano C. A population neuroscience approach to the study of cerebral small vessel disease in midlife and late life: an invited review. Am J Physiol Heart Circ Physiol 2018; 314:H1117-H1136. [PMID: 29393657 PMCID: PMC6032084 DOI: 10.1152/ajpheart.00535.2017] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 01/09/2018] [Accepted: 01/22/2018] [Indexed: 12/28/2022]
Abstract
Aging in later life engenders numerous changes to the cerebral microvasculature. Such changes can remain clinically silent but are associated with greater risk for negative health outcomes over time. Knowledge is limited about the pathogenesis, prevention, and treatment of potentially detrimental changes in the cerebral microvasculature that occur with advancing age. In this review, we summarize literature on aging of the cerebral microvasculature, and we propose a conceptual framework to fill existing research gaps and advance future work on this heterogeneous phenomenon. We propose that the major gaps in this area are attributable to an incomplete characterization of cerebrovascular pathology, the populations being studied, and the temporality of exposure to risk factors. Specifically, currently available measures of age-related cerebral microvasculature changes are indirect, primarily related to parenchymal damage rather than direct quantification of small vessel damage, limiting the understanding of cerebral small vessel disease (cSVD) itself. Moreover, studies seldom account for variability in the health-related conditions or interactions with risk factors, which are likely determinants of cSVD pathogenesis. Finally, study designs are predominantly cross-sectional and/or have relied on single time point measures, leaving no clear evidence of time trajectories of risk factors or of change in cerebral microvasculature. We argue that more resources should be invested in 1) developing methodological approaches and basic science models to better understand the pathogenic and etiological nature of age-related brain microvascular diseases and 2) implementing state-of-the-science population study designs that account for the temporal evolution of cerebral microvascular changes in diverse populations across the lifespan.
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Affiliation(s)
- Dana R Jorgensen
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - C Elizabeth Shaaban
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Clayton A Wiley
- Department of Pathology, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Peter J Gianaros
- Departments of Psychology and Psychiatry, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Joseph Mettenburg
- Department of Radiology, University of Pittsburgh, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Caterina Rosano
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh , Pittsburgh, Pennsylvania
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7
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Hase Y, Horsburgh K, Ihara M, Kalaria RN. White matter degeneration in vascular and other ageing-related dementias. J Neurochem 2018; 144:617-633. [DOI: 10.1111/jnc.14271] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/20/2017] [Accepted: 11/20/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Yoshiki Hase
- Neurovascular Research Group; Institute of Neuroscience; Newcastle University; Newcastle Upon Tyne UK
| | - Karen Horsburgh
- Centre for Neuroregeneration; University of Edinburgh; Edinburgh UK
| | - Masafumi Ihara
- Department of Neurology; National Cerebral and Cardiovascular Center; Suita Osaka Japan
| | - Raj N. Kalaria
- Neurovascular Research Group; Institute of Neuroscience; Newcastle University; Newcastle Upon Tyne UK
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8
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Lindemer ER, Greve DN, Fischl B, Augustinack JC, Salat DH. Differential Regional Distribution of Juxtacortical White Matter Signal Abnormalities in Aging and Alzheimer's Disease. J Alzheimers Dis 2017; 57:293-303. [PMID: 28222518 PMCID: PMC5534349 DOI: 10.3233/jad-161057] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND White matter signal abnormalities (WMSA) (also known as 'hyperintensities') on MRI are commonly seen in normal aging and increases have been noted in Alzheimer's disease (AD), but whether there is a spatial specificity to these increases is unknown. OBJECTIVE To discern whether or not there is a spatial pattern of WMSA in the brains of individuals with AD that differs from those who exhibit cognitively healthy aging. METHOD Structural MRI data from the Alzheimer's Disease Neuroimaging Initiative public database were used to quantify WMSA in 35 regions of interest (ROIs). Regional measures were compared between cognitively healthy older controls (OC; n = 107) and individuals with a clinical diagnosis of AD (n = 127). Regional WMSA volume was also assessed in individuals with mild cognitive impairment (MCI; n = 74) who were 6, 12, and 24 months away from AD conversion. RESULTS WMSA volume was significantly greater in AD compared to OC in 24 out of 35 ROIs after controlling for age, and nine were significantly higher after normalizing for total WMSA. Regions with greater WMSA volume in AD included rostral frontal, inferior temporal, and inferior parietal WM. In MCI, frontal and temporal regions demonstrated significantly greater WMSA volume with decreasing time-to-AD-conversion. DISCUSSION Individuals with AD have greater regional volume of WMSA compared to OC regardless of age or total WMSA volume. Accumulation of regional WMSA is linked to time to AD conversion in individuals with MCI. These findings indicate WMSA is an important pathological component of AD development.
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Affiliation(s)
- Emily R. Lindemer
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Douglas N. Greve
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Bruce Fischl
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Jean C. Augustinack
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - David H. Salat
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, MA, USA
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9
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Ince PG, Minett T, Forster G, Brayne C, Wharton SB. Microinfarcts in an older population-representative brain donor cohort (MRC CFAS): Prevalence, relation to dementia and mobility, and implications for the evaluation of cerebral Small Vessel Disease. Neuropathol Appl Neurobiol 2016; 43:409-418. [PMID: 27664944 PMCID: PMC5516203 DOI: 10.1111/nan.12363] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/22/2016] [Accepted: 09/24/2016] [Indexed: 01/14/2023]
Abstract
Introduction Microinfarcts, small ischaemic foci common in ageing brain, are associated with dementia and gait dysfunction. We determined their relationship with dementia, mobility and cerebrovascular disease in an older population‐representative brain donor cohort. These data on microinfarcts were evaluated in relation to pathological assessments of clinically significant cerebral small vessel disease (SVD). Methods Microinfarcts were assessed in the MRC Cognitive Function and Ageing Study (n = 331). Nine brain areas were staged according to the number of areas affected. Results 36% of brains showed at least 1 microinfarct. Higher cortical microinfarct stage was associated with dementia at death (OR 1.41, 95% CI 1.02; 1.96, P = 0.038), whilst cortical and subcortical microinfarct stages were associated with impaired mobility (OR 1.36, 95% CI 1.05–1.74; P 0.018) and falls (OR 1.96, 95% CI 1.11–3.43; P = 0.02). Adding data on microinfarcts to a definition of SVD, based on white matter lesions (WMLs), lacunes and significant arteriosclerosis, were assessed by comparing area under ROC curve (AUC) with and without microinfarcts. SVD was significantly related to dementia status with or without inclusion of microinfarcts. Modelling potential pathological definitions of SVD to predict dementia or impaired mobility indicated optimal prediction using combined assessment of WMLs, lacunes and microinfarcts. Conclusion Cortical (dementia) and subcortical microinfarcts (impaired mobility) are related to diverse clinical outcomes. Optimal pathological assessment of significant SVD in brain ageing is achieved based on WMLs, lacunes and microinfarcts and may not require subjective assessment of the extent and severity of arteriosclerosis.
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Affiliation(s)
- P G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - T Minett
- Institute of Public Health, University of Cambridge, Cambridge, UK.,Department of Radiology, University of Cambridge, Cambridge, UK
| | - G Forster
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - C Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - S B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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10
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McAleese KE, Alafuzoff I, Charidimou A, De Reuck J, Grinberg LT, Hainsworth AH, Hortobagyi T, Ince P, Jellinger K, Gao J, Kalaria RN, Kovacs GG, Kövari E, Love S, Popovic M, Skrobot O, Taipa R, Thal DR, Werring D, Wharton SB, Attems J. Post-mortem assessment in vascular dementia: advances and aspirations. BMC Med 2016; 14:129. [PMID: 27600683 PMCID: PMC5011905 DOI: 10.1186/s12916-016-0676-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 08/19/2016] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Cerebrovascular lesions are a frequent finding in the elderly population. However, the impact of these lesions on cognitive performance, the prevalence of vascular dementia, and the pathophysiology behind characteristic in vivo imaging findings are subject to controversy. Moreover, there are no standardised criteria for the neuropathological assessment of cerebrovascular disease or its related lesions in human post-mortem brains, and conventional histological techniques may indeed be insufficient to fully reflect the consequences of cerebrovascular disease. DISCUSSION Here, we review and discuss both the neuropathological and in vivo imaging characteristics of cerebrovascular disease, prevalence rates of vascular dementia, and clinico-pathological correlations. We also discuss the frequent comorbidity of cerebrovascular pathology and Alzheimer's disease pathology, as well as the difficult and controversial issue of clinically differentiating between Alzheimer's disease, vascular dementia and mixed Alzheimer's disease/vascular dementia. Finally, we consider additional novel approaches to complement and enhance current post-mortem assessment of cerebral human tissue. CONCLUSION Elucidation of the pathophysiology of cerebrovascular disease, clarification of characteristic findings of in vivo imaging and knowledge about the impact of combined pathologies are needed to improve the diagnostic accuracy of clinical diagnoses.
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Affiliation(s)
- Kirsty E McAleese
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Irina Alafuzoff
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Andreas Charidimou
- Hemorrhagic Stroke Research Program, Department of Neurology, Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston, MA, USA
| | | | - Lea T Grinberg
- Departments of neurology and Pathology, University of California, San Francisco, USA.,Department of Pathology - LIM-22, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Atticus H Hainsworth
- Institute of Cardiovascular and Cell Sciences, St George's University of London, London, UK
| | - Tibor Hortobagyi
- Department of Neuropathology, University of Debrecen, Debrecen, Hungary
| | - Paul Ince
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | | | - Jing Gao
- Neurological Department, Peking Union Medical College Hospital, Beijing, China
| | - Raj N Kalaria
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Enikö Kövari
- Department of Mental Health and Psychiatry, University of Geneva, Geneva, Switzerland
| | - Seth Love
- Clincial Neurosciences, University of Bristol, Bristol, UK
| | - Mara Popovic
- Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Olivia Skrobot
- Clincial Neurosciences, University of Bristol, Bristol, UK
| | - Ricardo Taipa
- Unit of Neuropathology, Centro Hospitalar do Porto, University of Porto, Porto, Portugal
| | - Dietmar R Thal
- Department of Neuroscience, KU-Leuven and Department of Pathology, UZ-Leuven, Leuven, Belgium
| | - David Werring
- Institute of Neurology, University College London, London, UK
| | | | - Johannes Attems
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.
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11
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McAleese KE, Firbank M, Dey M, Colloby SJ, Walker L, Johnson M, Beverley JR, Taylor JP, Thomas AJ, O’Brien JT, Attems J. Cortical tau load is associated with white matter hyperintensities. Acta Neuropathol Commun 2015; 3:60. [PMID: 26419828 PMCID: PMC4589169 DOI: 10.1186/s40478-015-0240-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 09/17/2015] [Indexed: 12/24/2022] Open
Abstract
INTRODUCTION Cerebral white matter lesions (WML), visualized as white matter hyperintensities (WMH) on T2-weighted MRI, encompass structural damage and loss of integrity of the cerebral white matter (WM) and are commonly assumed to be associated with small vessel disease (SVD). However, it has been suggested that WM damage may also be the result of degenerative axonal loss that is secondary to cortical Alzheimer's disease (AD) pathologies i.e., hyperphosphorylated tau (HPτ) and amyloid-beta (Aβ). Here we investigate the influence of HPτ, Aβ and SVD on WMH severity. RESULTS 36 human post-mortem right fixed cerebral hemispheres (mean age 84.4 ± 7.7 years; male: 16, female: 20) containing varying amounts of AD-pathology (AD: 23, controls: 13) underwent T2- weighted MRI with WMH assessed according to the age related white matter change scale (ARWMC). After dissection, using tissue samples from the frontal, temporal, parietal and occipital regions from the right hemisphere, we quantitatively assessed cortical HPτ and Aβ pathology burden by measuring the percentage area covered by AT8 immunoreactivity (HPτ-IR) and 4G8 immunoreactivity (Aβ-IR), and assessed the severity of WM SVD by calculating the sclerotic index (SI) of WM arteries/arterioles. HPτ-IR, Aβ-IR, and SI were compared with ARWMC scores. HPτ-IR, Aβ-IR and WM ARWMC scores were all significantly higher in AD cases compared to controls, while SI values were similar between groups. ARWMC scores correlated with HPτ-IR, Aβ-IR and SI in various regions, however, linear regression revealed that only HPτ-IR was a significant independent predictor of ARWMC scores. CONCLUSIONS Here we have shown that increasing cortical HPτ burden independently predicted the severity of WMH indicating its potentially important role in the pathogenesis of WM damage. Moreover, our findings suggest that in AD patients the presence of WMH may indicate cortical AD-associated pathology rather than SVD. Further studies are warranted to elucidate the pathological processes that lead to WM damage and to clarify if WMH may serve as a general biomarker for cortical AD-associated pathology.
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Wharton SB, Simpson JE, Brayne C, Ince PG. Age-associated white matter lesions: the MRC Cognitive Function and Ageing Study. Brain Pathol 2015; 25:35-43. [PMID: 25521175 DOI: 10.1111/bpa.12219] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 10/08/2014] [Indexed: 12/11/2022] Open
Abstract
Cerebral white matter lesions (WML) are common in the aging brain and are associated with dementia and depression. They are associated with vascular risk factors and small vessel disease, suggesting an ischemic origin, but recent pathology studies suggest a more complex pathogenesis. Studies using samples from the population-representative Medical Research Council Cognitive Function and Ageing Study neuropathology cohort used post-mortem magnetic resonance imaging to identify WML for further study. Expression of hypoxia-related molecules and other injury and protective cellular pathways in candidate immunohistochemical and gene expression microarray studies support a role for hypoxia/ischemia. However, these approaches also suggest that immune activation, blood-brain barrier dysfunction, altered cell metabolic pathways and glial cell injury contribute to pathogenesis. These abnormalities are not confined to WML, but are also found in apparently normal white matter in brains with lesions, suggesting a field effect of white matter abnormality within which lesions arise. WML are an active pathology with a complex pathogenesis that may potentially offer a number of primary and secondary intervention targets.
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Affiliation(s)
- Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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Love S, Miners JS. White matter hypoperfusion and damage in dementia: post-mortem assessment. Brain Pathol 2015; 25:99-107. [PMID: 25521180 DOI: 10.1111/bpa.12223] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 10/08/2014] [Indexed: 01/19/2023] Open
Abstract
Neuroimaging has revealed a range of white matter abnormalities that are common in dementia, some that predict cognitive decline. The abnormalities may result from structural diseases of the cerebral vasculature, such as arteriolosclerosis and amyloid angiopathy, but can also be caused by nonstructural vascular abnormalities (eg, of vascular contractility or permeability), neurovascular instability or extracranial cardiac or vascular disease. Conventional histopathological assessment of the white matter has tended to conflate morphological vascular abnormalities with changes that reflect altered interstitial fluid dynamics or white matter ischemic damage, even though the latter may be of extracranial or nonstructural etiology. However, histopathology is being supplemented by biochemical approaches, including the measurement of proteins involved in the molecular responses to brain ischemia, myelin proteins differentially susceptible to ischemic damage, vessel-associated proteins that allow rapid measurement of microvessel density, markers of blood-brain barrier dysfunction and axonal injury, and mediators of white matter damage. By combining neuroimaging with histopathology and biochemical analysis, we can provide reproducible, quantitative data on the severity of white matter damage, and information on its etiology and pathogenesis. Together these have the potential to inform and improve treatment, particularly in forms of dementia to which white matter hypoperfusion makes a significant contribution.
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Affiliation(s)
- Seth Love
- Dementia Research Group, Institute of Clinical Neurosciences, University of Bristol, Learning and Research Level 2, Southmead Hospital, Bristol, UK
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Frontotemporal lobar degeneration FTLD-tau: preclinical lesions, vascular, and Alzheimer-related co-pathologies. J Neural Transm (Vienna) 2015; 122:1007-18. [PMID: 25556950 DOI: 10.1007/s00702-014-1360-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 12/22/2014] [Indexed: 02/01/2023]
Abstract
Frontotemporal lobar degeneration with τ pathology (FTLD-tau) is one of a group of neurodegenerative diseases that manifests with cognitive decline. Alzheimer (AD) and cerebrovascular lesions are commonly noted in the brains of most elderly individuals, begging the question as to whether (a) coexisting AD and vascular pathology or age contribute to the development of FTLD-tau disorders and vice versa and (b) FTLD-tau-like pathology can be found in non-diseased individuals. We studied brains of FTLD-tau cases exhibiting (a) argyrophilc grain disease (AGD), (b) progressive supranuclear palsy (PSP), (c) corticobasal degeneration (CBD), or (d) Pick's disease (PiD) for coexisting AD and vascular pathology for comparison with that of non-diseased individuals and AD patients. We confirmed that AGD lowered the threshold for AD pathology to cause dementia. Such an effect was not seen in PSP, CBD, or PiD. In PiD, white matter degeneration and demyelination was observed in the frontal and temporal lobes in association with small vessel disease (SVD)-related changes in white matter arteries. Age at death varied among the four types of FTLD-tau. PiD cases were youngest at death followed by CBD, PSP, and finally AGD. In 9.8% of non-diseased controls, we found grains, coiled bodies, and/or τ-positive astrocytes mimicking an AGD-like pattern. Moreover, the prevalence of FTLD-tau pathology in non-diseased individuals increased with age. In summary, this study demonstrates that age impacts of the diversity of neuropathological changes in FTLD-tau. The age-related coexistence of AD-related pathology is, thereby, associated with AGD but not with PSP, CBD, and PiD. Moreover, severe SVD and white matter demyelination is associated with PiD indicating a role of vascular copathology in this type of FTLD-tau. Finally, our finding that FTLD-tau-related pathological lesions occur in non-diseased individuals suggests that preclinical stages of FTLD-tau exist. As such, our results indicate that age, together with vascular and AD-related copathology, contributes to the morphological appearance of FTLD-tau.
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Shim YS, Yang DW, Roe CM, Coats MA, Benzinger TL, Xiong C, Galvin JE, Cairns NJ, Morris JC. Pathological correlates of white matter hyperintensities on magnetic resonance imaging. Dement Geriatr Cogn Disord 2015; 39:92-104. [PMID: 25401390 PMCID: PMC4312498 DOI: 10.1159/000366411] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/04/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS We investigated the histopathological correlates of white matter hyperintensities (WMHs) in participants with Alzheimer's disease (AD) or cerebrovascular disease, and in aged controls. METHODS We reviewed 57 participants who had neuropathology and in whom neuroimaging was done. In addition to AD pathology, cortical microinfarcts, lacunes, and cerebral hemorrhages were assessed. Small-vessel disease included arteriolosclerosis and cerebral amyloid angiopathy. Postmortem brain tissue corresponding to regions of WMHs was investigated in 14 participants. The variables included: demyelination of the deep and periventricular white matter (WM), atrophy of the ventricular ependyma, and thickness of blood vessels. Partial Spearman's rank test and linear regression analysis, adjusted for age at the clinical evaluation and the duration to death, were performed. RESULTS The severity of arteriosclerosis was correlated with the volume of periventricular hyperintensity (PVH) estimated by magnetic resonance imaging. Deep white matter hyperintensity (DWMH) volume was correlated with the presence of cortical microinfarcts and cerebral hemorrhages. The severity of the breakdown of the ventricular lining was correlated with PVHs, and DWMHs correlated with the severity of deep WM demyelination. The diameter of small blood vessels was not associated with WMHs. CONCLUSION WMHs are consistent with small-vessel disease and increase the tissue water content. We found no association between WMHs and the thickness of small blood vessels.
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Affiliation(s)
- Yong S. Shim
- Department of Neurology, The Catholic University of Korea College of Medicine, Seoul, South Korea,Correspondence to: Yong S. Shim, The Catholic University of Korea Bucheon St. Mary's Hospital, 2 Sosa-dong, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-717, South Korea (Tel: +82-32-340-7094, Fax: +82-32-340-2669, ) Co-Correspondence: John C. Morris, Knight ADRC, Washington University School of Medicine, 4488 Forest Park Avenue, St. Louis, MO 63108, USA (Tel: +1-314-286-2881, Fax: +1-314-286-2448, )
| | - Dong-Won Yang
- Department of Neurology, The Catholic University of Korea College of Medicine, Seoul, South Korea
| | - Catherine M. Roe
- Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Mary A. Coats
- Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Tammie L. Benzinger
- Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Chengjie Xiong
- Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - James E. Galvin
- Departments of Neurology, Psychiatry and Population Health, New York University Langone Medical Center, New York, NY, USA
| | - Nigel J. Cairns
- Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
| | - John C. Morris
- Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA,Correspondence to: Yong S. Shim, The Catholic University of Korea Bucheon St. Mary's Hospital, 2 Sosa-dong, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-717, South Korea (Tel: +82-32-340-7094, Fax: +82-32-340-2669, ) Co-Correspondence: John C. Morris, Knight ADRC, Washington University School of Medicine, 4488 Forest Park Avenue, St. Louis, MO 63108, USA (Tel: +1-314-286-2881, Fax: +1-314-286-2448, )
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Abstract
The spectrum of mixed brain pathologies expands beyond accompanying vascular pathology in brains with Alzheimer's disease-related pathology. Co-occurrence of neurodegenerative non-Alzheimer's disease-type proteinopathies is increasingly recognized to be a frequent event in the brains of symptomatic and asymptomatic patients, particularly in older people. Owing to the evolving concept of neurodegenerative diseases, clinical and neuropathological diagnostic criteria have changed during the last decades. Autopsy-based studies differ in the selection criteria and also in the applied staining methods used. The present review summarizes the prevalence of mixed brain pathologies reported in recent community-based studies. In these cohorts, irrespective of the clinical symptoms, the frequency of Alzheimer's disease-related pathology is between 19 and 67%, of Lewy body pathology is between 6 and 39%, of vascular pathologies is between 28 and 70%, of TDP-43 proteinopathy is between 13 and 46%, of hippocampal sclerosis is between 3 and 13% and, finally, of mixed pathologies is between 10 and 74%. Some studies also mention tauopathies. White-matter pathologies are not discussed specifically in all studies, although these lesions may be present in more than 80% of the aging brains. In summary, community-based neuropathology studies have shown that complex constellations of underlying pathologies may lead to cognitive decline, and that the number of possible combinations increases in the aging brain. These observations have implications for the prediction of the prognosis, for the development of biomarkers or therapy targets, or for the stratification of patient cohorts for genome-wide studies or, eventually, for therapy trials.
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Affiliation(s)
- Jasmin Rahimi
- Institute of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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Attems J, Jellinger KA. The overlap between vascular disease and Alzheimer's disease--lessons from pathology. BMC Med 2014; 12:206. [PMID: 25385447 PMCID: PMC4226890 DOI: 10.1186/s12916-014-0206-2] [Citation(s) in RCA: 475] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/07/2014] [Indexed: 12/15/2022] Open
Abstract
Recent epidemiological and clinico-pathological data indicate considerable overlap between cerebrovascular disease (CVD) and Alzheimer's disease (AD) and suggest additive or synergistic effects of both pathologies on cognitive decline. The most frequent vascular pathologies in the aging brain and in AD are cerebral amyloid angiopathy and small vessel disease. Up to 84% of aged subjects show morphological substrates of CVD in addition to AD pathology. AD brains with minor CVD, similar to pure vascular dementia, show subcortical vascular lesions in about two-thirds, while in mixed type dementia (AD plus vascular dementia), multiple larger infarcts are more frequent. Small infarcts in patients with full-blown AD have no impact on cognitive decline but are overwhelmed by the severity of Alzheimer pathology, while in early stages of AD, cerebrovascular lesions may influence and promote cognitive impairment, lowering the threshold for clinically overt dementia. Further studies are warranted to elucidate the many hitherto unanswered questions regarding the overlap between CVD and AD as well as the impact of both CVD and AD pathologies on the development and progression of dementia.
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Affiliation(s)
- Johannes Attems
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK.
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Valdés Hernández MC, Piper RJ, Bastin ME, Royle NA, Maniega SM, Aribisala BS, Murray C, Deary IJ, Wardlaw JM. Morphologic, distributional, volumetric, and intensity characterization of periventricular hyperintensities. AJNR Am J Neuroradiol 2013; 35:55-62. [PMID: 23811980 DOI: 10.3174/ajnr.a3612] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE White matter hyperintensities are characteristic of old age and identifiable on FLAIR and T2-weighted MR imaging. They are typically separated into periventricular or deep categories. It is unclear whether the innermost segment of periventricular white matter hyperintensities is truly abnormal or is imaging artifacts. MATERIALS AND METHODS We used FLAIR MR imaging from 665 community-dwelling subjects 72-73 years of age without dementia. Periventricular white matter hyperintensities were visually allocated into 4 categories: 1) thin white line; 2) thick rim; 3) penetrating toward or confluent with deep white matter hyperintensities; and 4) diffuse ill-defined, labeled as "subtle extended periventricular white matter hyperintensities." We measured the maximum intensity and width of the periventricular white matter hyperintensities, mapped all white matter hyperintensities in 3D, and investigated associations between each category and hypertension, stroke, diabetes, hypercholesterolemia, cardiovascular disease, and total white matter hyperintensity volume. RESULTS The intensity patterns and morphologic features were different for each periventricular white matter hyperintensity category. Both the widths (r = 0.61, P < .001) and intensities (r = 0.51, P < .001) correlated with total white matter hyperintensity volume and with each other (r = 0.55, P < .001) for all categories with the exception of subtle extended periventricular white matter hyperintensities, largely characterized by evidence of erratic, ill-defined, and fragmented pale white matter hyperintensities (width: r = 0.02, P = .11; intensity: r = 0.02, P = .84). The prevalence of hypertension, hypercholesterolemia, and neuroradiologic evidence of stroke increased from periventricular white matter hyperintensity categories 1 to 3. The mean periventricular white matter hyperintensity width was significantly larger in subjects with hypertension (mean difference = 0.5 mm, P = .029) or evidence of stroke (mean difference = 1 mm, P < .001). 3D mapping revealed that periventricular white matter hyperintensities were discontinuous with deep white matter hyperintensities in all categories, except only in particular regions in brains with category 3. CONCLUSIONS Periventricular white matter hyperintensity intensity levels, distribution, and association with risk factors and disease suggest that in old age, these are true tissue abnormalities and therefore should not be dismissed as artifacts. Dichotomizing periventricular and deep white matter hyperintensities by continuity from the ventricle edge toward the deep white matter is possible.
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