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Webb AJS, Paolucci M, Mazzucco S, Li L, Rothwell PM. Confounding of Cerebral Blood Flow Velocity by Blood Pressure During Breath Holding or Hyperventilation in Transient Ischemic Attack or Stroke. Stroke 2019; 51:468-474. [PMID: 31884903 PMCID: PMC7004447 DOI: 10.1161/strokeaha.119.027829] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose- Breath holding (BH) and hyperventilation are used to assess abnormal cerebrovascular reactivity, often in relation to severity of small vessel disease and risk of stroke with carotid stenosis, but responses may be confounded by blood pressure (BP) changes. We compared effects of BP and end-tidal carbon dioxide (etCO2) on middle cerebral artery mean flow velocity (MFV) in consecutive transient ischemic attack and minor stroke patients. Methods- In the population-based, prospective OXVASC (Oxford Vascular Study) phenotyped cohort, change in MFV on transcranial Doppler ultrasound (ΔMFV, DWL-DopplerBox), beat-to-beat BP (Finometer), and etCO2 was measured during 30 seconds of BH or hyperventilation. Two blinded reviewers independently assessed recording quality. Dependence of ΔMFV on ΔBP and ΔetCO2 was determined by general linear models, stratified by quartiles. Results- Four hundred eighty-eight of 602 (81%) patients with adequate bone windows had high-quality recordings, more often in younger participants (64.6 versus 68.7 years; P<0.01), whereas 426 had hyperventilation tests (70.7%). During BH, ΔMFV was correlated with a rise in mean blood pressure (MBP; r2=0.15, P<0.001) but not ΔCO2 (r2=0.002, P=0.32), except in patients with ΔMBP <10% (r2=0.13, P<0.001). In contrast during hyperventilation, the fall in MFV was similarly correlated with reduction in CO2 and reduction in MBP (ΔCO2: r2=0.13, P<0.001; ΔMBP: r2=0.12, P<0.001), with a slightly greater effect of ΔCO2 when ΔMBP was <10% (r2=0.15). Stratifying by quartile, MFV increased linearly during BH across quartiles of ΔMBP, with no increase with ΔetCO2. In contrast, during hyperventilation, MFV decreased linearly with ΔetCO2, independent of ΔMBP. Conclusions- In older patients with recent transient ischemic attack or minor stroke, cerebral blood flow responses to BH were confounded by BP changes but reflected etCO2 change during hyperventilation. Correct interpretation of cerebrovascular reactivity responses to etCO2, including in small vessel disease and carotid stenosis, requires concurrent BP measurement.
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Affiliation(s)
- Alastair J S Webb
- From the Department of Clinical Neuroscience, Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, United Kingdom (A.J.S.W., S.M., L.L., P.M.R.)
| | - Matteo Paolucci
- Headache and Neurosonology Unit, Neurology Department, Università Campus Bio-Medico, Rome, Italy (M.P.)
| | - Sara Mazzucco
- From the Department of Clinical Neuroscience, Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, United Kingdom (A.J.S.W., S.M., L.L., P.M.R.)
| | - Linxin Li
- From the Department of Clinical Neuroscience, Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, United Kingdom (A.J.S.W., S.M., L.L., P.M.R.)
| | - Peter M Rothwell
- From the Department of Clinical Neuroscience, Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, United Kingdom (A.J.S.W., S.M., L.L., P.M.R.)
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Smith EE, Biessels GJ, De Guio F, de Leeuw FE, Duchesne S, Düring M, Frayne R, Ikram MA, Jouvent E, MacIntosh BJ, Thrippleton MJ, Vernooij MW, Adams H, Backes WH, Ballerini L, Black SE, Chen C, Corriveau R, DeCarli C, Greenberg SM, Gurol ME, Ingrisch M, Job D, Lam BY, Launer LJ, Linn J, McCreary CR, Mok VC, Pantoni L, Pike GB, Ramirez J, Reijmer YD, Romero JR, Ropele S, Rost NS, Sachdev PS, Scott CJ, Seshadri S, Sharma M, Sourbron S, Steketee RM, Swartz RH, van Oostenbrugge R, van Osch M, van Rooden S, Viswanathan A, Werring D, Dichgans M, Wardlaw JM. Harmonizing brain magnetic resonance imaging methods for vascular contributions to neurodegeneration. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2019; 11:191-204. [PMID: 30859119 PMCID: PMC6396326 DOI: 10.1016/j.dadm.2019.01.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Many consequences of cerebrovascular disease are identifiable by magnetic resonance imaging (MRI), but variation in methods limits multicenter studies and pooling of data. The European Union Joint Program on Neurodegenerative Diseases (EU JPND) funded the HARmoNizing Brain Imaging MEthodS for VaScular Contributions to Neurodegeneration (HARNESS) initiative, with a focus on cerebral small vessel disease. METHODS Surveys, teleconferences, and an in-person workshop were used to identify gaps in knowledge and to develop tools for harmonizing imaging and analysis. RESULTS A framework for neuroimaging biomarker development was developed based on validating repeatability and reproducibility, biological principles, and feasibility of implementation. The status of current MRI biomarkers was reviewed. A website was created at www.harness-neuroimaging.org with acquisition protocols, a software database, rating scales and case report forms, and a deidentified MRI repository. CONCLUSIONS The HARNESS initiative provides resources to reduce variability in measurement in MRI studies of cerebral small vessel disease.
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Affiliation(s)
- Eric E. Smith
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
| | - Geert Jan Biessels
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | - François De Guio
- Department of Neurology, Lariboisière Hospital, University Paris Diderot, Paris, France
| | - Frank Erik de Leeuw
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Donders Center for Medical Neuroscience, Radboud University Medical Center, Nijmegen, Netherlands
| | - Simon Duchesne
- CERVO Research Center, Quebec Mental Health Institute, Québec, Canada
- Radiology Department, Université Laval, Québec, Canada
| | - Marco Düring
- Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig-Maximilians-Universität LMU, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE, Munich), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Richard Frayne
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
- Seaman Family MR Centre, Foothills Medical Centre, Calgary, Alberta, Canada
| | - M. Arfan Ikram
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Eric Jouvent
- Department of Neurology, Lariboisière Hospital, University Paris Diderot, Paris, France
| | - Bradley J. MacIntosh
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Department of Medical Biophysics, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
| | - Michael J. Thrippleton
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Meike W. Vernooij
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Hieab Adams
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Walter H. Backes
- Department of Radiology & Nuclear Medicine, School for Mental Health & Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Lucia Ballerini
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Sandra E. Black
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Toronto, Ontario, Canada
- Department of Medicine (Neurology), Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Christopher Chen
- Memory Aging and Cognition Centre, Department of Pharmacology, National University of Singapore, Singapore
| | - Rod Corriveau
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Charles DeCarli
- Department of Neurology and Center for Neuroscience, University of California at Davis, Davis, CA, USA
| | - Steven M. Greenberg
- J. Philip Kistler Stroke Research Center, Stroke Service and Memory Disorders Unit, Massachusetts General Hospital, Boston, MA, USA
| | - M. Edip Gurol
- J. Philip Kistler Stroke Research Center, Stroke Service and Memory Disorders Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Michael Ingrisch
- Department of Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
| | - Dominic Job
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Bonnie Y.K. Lam
- Therese Pei Fong Chow Research Centre for Prevention of Dementia, Gerald Choa Neuroscience Centre, Lui Che Woo Institute of Innovative Medicine, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | - Lenore J. Launer
- National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer Linn
- Institute of Neuroradiology, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Cheryl R. McCreary
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Centre, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Vincent C.T. Mok
- Therese Pei Fong Chow Research Centre for Prevention of Dementia, Gerald Choa Neuroscience Centre, Lui Che Woo Institute of Innovative Medicine, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | - Leonardo Pantoni
- Luigi Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - G. Bruce Pike
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
| | - Joel Ramirez
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Department of Medical Biophysics, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Yael D. Reijmer
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jose Rafael Romero
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Framingham Heart Study, Framingham, MA, USA
| | - Stefan Ropele
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Natalia S. Rost
- J. Philip Kistler Stroke Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Perminder S. Sachdev
- Centre for Healthy Brain Ageing, University of New South Wales, Sydney, Australia
| | - Christopher J.M. Scott
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Department of Medical Biophysics, Sunnybrook Research Institute, University of Toronto, Ontario, Canada
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Sudha Seshadri
- Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases, University of Texas Health Sciences Center, San Antonio, TX, USA
| | - Mukul Sharma
- Population Health Research Institute, Hamilton, Ontario, Canada
- Department of Medicine (Neurology) McMaster University, Hamilton, Ontario, Canada
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Rebecca M.E. Steketee
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Richard H. Swartz
- Department of Medicine (Neurology), University of Toronto, Toronto, Canada
- Hurvitz Brain Sciences Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada
| | - Robert van Oostenbrugge
- Department of Neurology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Matthias van Osch
- C.J. Gorter Center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Sanneke van Rooden
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Anand Viswanathan
- J. Philip Kistler Stroke Research Center, Stroke Service and Memory Disorders Unit, Massachusetts General Hospital, Boston, MA, USA
| | - David Werring
- University College London Queen Square institute of Neurology, London, UK
| | - Martin Dichgans
- Institute for Stroke and Dementia Research (ISD), University Hospital, Ludwig-Maximilians-Universität LMU, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE, Munich), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Joanna M. Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
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Chen X, Huang L, Ye Q, Yang D, Qin R, Luo C, Li M, Zhang B, Xu Y. Disrupted functional and structural connectivity within default mode network contribute to WMH-related cognitive impairment. NEUROIMAGE-CLINICAL 2019; 24:102088. [PMID: 31795048 PMCID: PMC6861557 DOI: 10.1016/j.nicl.2019.102088] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/07/2019] [Accepted: 11/09/2019] [Indexed: 11/23/2022]
Abstract
Disconnective DMN contribute to impaired cognition
Aims The prevalence of white matter hyperintensities (WMH) rises dramatically with aging. Both the progression of WMH and changing patterns of default mode network (DMN) have been proven to be closely associated with cognitive function. The present study hypothesized that changes in functional connectivity and structural connectivity of DMN contributed to WMH related cognitive impairment. Methods A total of 116 subjects were enrolled from the Cerebral Small Vessel Disease Register in Drum Tower Hospital of Nanjing University, and were distributed across three categories according to Fazekas rating scale: WMH I (n = 57), WMH II (n = 34), and WMH III(n = 25). All participants underwent neuropsychological tests and multimodal MRI scans, including diffusion tensor imaging and resting-state fMRI imaging. The alterations of functional connectivity and structural connectivity within the DMN were further explored. Results Age and hypertension were risk factors for WMH progression. Subjects with a higher WMH burden displayed higher DMN functional connectivity in the medial frontal gyrus, while lower DMN functional connectivity in the thalamus. After adjusting for aging, gender, and education, the increased DMN functional connectivity in the medial frontal gyrus, and the increased mean diffusivity of the white matter tracts between the hippocampus and posterior cingulate cortex were independent indicators of worse performance in memory. Moreover, the decreased DMN functional connectivity in the thalamus and increased mean diffusivity of the white matter tracts between the thalamus and posterior cingulate cortex were independent risk factors for a slower processing speed. Conclusion The changes in functional connectivity and structural connectivity within the DMN attributed to WMH progression were responsible for the development of cognitive impairment.
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Affiliation(s)
- Xin Chen
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Lili Huang
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Qing Ye
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Dan Yang
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Ruomeng Qin
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Caimei Luo
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Mengchun Li
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China
| | - Bing Zhang
- Department of Radiology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, 210008, China
| | - Yun Xu
- Department of Neurology, Affiliated Drum Tower Hospital, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, 210008, China; Jiangsu Province Stroke Center for Diagnosis and Therapy, Nanjing, 210008, China; Nanjing Neuropsychiatry Clinic Medical Center, Nanjing, 210008, China.
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Wardlaw JM, Smith C, Dichgans M. Small vessel disease: mechanisms and clinical implications. Lancet Neurol 2019; 18:684-696. [DOI: 10.1016/s1474-4422(19)30079-1] [Citation(s) in RCA: 500] [Impact Index Per Article: 100.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 02/01/2019] [Accepted: 02/07/2019] [Indexed: 02/06/2023]
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Kim MS, Park DG, Yoon JH. Impaired endothelial function may predict treatment response in restless legs syndrome. J Neural Transm (Vienna) 2019; 126:1051-1059. [PMID: 31218470 DOI: 10.1007/s00702-019-02031-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 06/14/2019] [Indexed: 12/17/2022]
Abstract
While dopaminergic dysfunction is believed to be a crucial role in restless legs syndrome (RLS), changes in peripheral microvasculature system such as peripheral hypoxia and altered skin temperature, have been found. This study aimed to investigate whether patients with RLS would have a cerebral and peripheral endothelial dysfunction, and this may have association with treatment responsiveness. We evaluated cerebral endothelial function using breath-holding index (BHI) on transcranial Doppler in bilateral middle cerebral artery (MCA), posterior cerebral artery (PCA) and basilar artery (BA) and peripheral endothelial function using brachial flow-mediated dilation (FMD) in 34 patients with RLS compared with age and sex-matched controls. The values of BHI in both MCA and BA were significantly lower in RLS group than control group. The values of FMD also were significantly lower in RLS patients. There was a weak correlation between BHI and FMD (p = 0.038 in Rt MCA, p = 0.032 in Lt MCA, p = 0.362 in BA) in RLS, but not in controls. BHI differed according to treatment responsiveness. (p < 0.005). Our study suggests that RLS patients have poorer cerebral and peripheral endothelial function than controls, showing an underlying mechanism of RLS and further evidence of a possible association between RLS and cardiovascular disease.
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Affiliation(s)
- Min Seung Kim
- Department of Neurology, Ajou University School of Medicine, 5 San,Woncheon-dong, Yongtong-gu, Suwon-si, Kyunggi-do, 442-749, South Korea
| | - Dong Gyu Park
- Department of Neurology, Ajou University School of Medicine, 5 San,Woncheon-dong, Yongtong-gu, Suwon-si, Kyunggi-do, 442-749, South Korea
| | - Jung Han Yoon
- Department of Neurology, Ajou University School of Medicine, 5 San,Woncheon-dong, Yongtong-gu, Suwon-si, Kyunggi-do, 442-749, South Korea.
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Reginold W, Sam K, Poublanc J, Fisher J, Crawley A, Mikulis DJ. The efficiency of the brain connectome is associated with cerebrovascular reactivity in persons with white matter hyperintensities. Hum Brain Mapp 2019; 40:3647-3656. [PMID: 31115127 DOI: 10.1002/hbm.24622] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 04/14/2019] [Accepted: 04/29/2019] [Indexed: 01/06/2023] Open
Abstract
The purpose of this study was to determine the relationship between the organization of the brain connectome and cerebrovascular reactivity (CVR) in persons with white matter hyperintensities. Diffusion tensor and CVR mapping 3T MRI scans were acquired in 31 participants with white matter hyperintensities. In each participant, the connectome was assessed by reconstructing all white matter tracts with tractography and segmenting the whole brain into multiple regions. Graph theory analysis was performed to quantify how effectively tracts connected brain regions by measuring the global and local efficiency of the connectome. CVR in white matter and gray matter was correlated with the global and local efficiency of the connectome, while adjusting for age, gender, and gray matter volume. For comparison, white matter hyperintensity volume was also correlated with global and local efficiency. White matter CVR was positively correlated with the global efficiency (coefficient: 23.3, p = .005) and local efficiency (coefficient: 2850, p = .004) of the connectome. Gray matter CVR was positively correlated with the global efficiency (coefficient: 21.3, p < .001) and local efficiency (coefficient: 2670, p < .001) of the connectome. White matter hyperintensity volume was negatively correlated with global efficiency (coefficient: -0.0002, p = .003) and local efficiency (coefficient: -0.024, p = .003) of the connectome. The association between CVR and the brain connectome suggests that impaired cerebrovascular function may be part of the pathophysiology of the disruption of the brain connectome in persons with white matter hyperintensities.
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Affiliation(s)
- William Reginold
- Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.,Division of Neuroradiology, Joint Department of Medical Imaging at the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Kevin Sam
- Russell H. Morgan Department of Radiology & Radiologic Science, The John Hopkins University School of Medicine, Baltimore, Maryland
| | - Julien Poublanc
- Division of Neuroradiology, Joint Department of Medical Imaging at the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Joe Fisher
- Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada
| | - Adrian Crawley
- Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.,Division of Neuroradiology, Joint Department of Medical Imaging at the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - David J Mikulis
- Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.,Division of Neuroradiology, Joint Department of Medical Imaging at the University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
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Václavů L, Meynart BN, Mutsaerts HJMM, Petersen ET, Majoie CBLM, VanBavel ET, Wood JC, Nederveen AJ, Biemond BJ. Hemodynamic provocation with acetazolamide shows impaired cerebrovascular reserve in adults with sickle cell disease. Haematologica 2019; 104:690-699. [PMID: 30523051 PMCID: PMC6442969 DOI: 10.3324/haematol.2018.206094] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/23/2018] [Indexed: 01/26/2023] Open
Abstract
Sickle cell disease is characterized by chronic hemolytic anemia and vascular inflammation, which can diminish the vasodilatory capacity of the small resistance arteries, making them less adept at regulating cerebral blood flow. Autoregulation maintains adequate oxygen delivery, but when vasodilation is maximized, the low arterial oxygen content can lead to ischemia and silent cerebral infarcts. We used magnetic resonance imaging of cerebral blood flow to quantify whole-brain cerebrovascular reserve in 36 adult patients with sickle cell disease (mean age, 31.9±11.3 years) and 11 healthy controls (mean age, 37.4±15.4 years), and we used high-resolution 3D FLAIR magnetic resonance imaging to determine the prevalence of silent cerebral infarcts. Cerebrovascular reserve was calculated as the percentage change in cerebral blood flow after a hemodynamic challenge with acetazolamide. Co-registered lesion maps were used to demonstrate prevalent locations for silent cerebral infarcts. Cerebral blood flow was elevated in patients with sickle cell disease compared to controls (median [interquartile range]: 82.8 [20.1] vs 51.3 [4.8] mL/100g/min, P<0.001). Cerebral blood flow was inversely associated with age, hemoglobin, and fetal hemoglobin, and correlated positively with bilirubin, and LDH, indicating that cerebral blood flow may reflect surrogates of hemolytic rate. Cerebrovascular reserve in sickle cell disease was decreased by half compared to controls (34.1 [33.4] vs 69.5 [32.4] %, P<0.001) and was associated with hemoglobin and erythrocyte count indicating anemia-induced hemodynamic adaptations. In total, 29/36 patients (81%) and 5/11 controls (45%) had silent cerebral infarcts (median volume of 0.34 vs 0.02 mL, P=0.03). Lesions were preferentially located in the borderzone. In conclusion, patients with sickle cell disease have a globally reduced cerebrovascular reserve as determined by arterial spin labeling with acetazolamide and reflects anemia-induced impaired vascular function in sickle cell disease. This study was registered at clinicaltrials.gov identifier 02824406.
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Affiliation(s)
- Lena Václavů
- Amsterdam UMC, Radiology and Nuclear Medicine, University of Amsterdam, the Netherlands
| | - Benoit N Meynart
- Amsterdam UMC, Radiology and Nuclear Medicine, University of Amsterdam, the Netherlands
| | - Henri J M M Mutsaerts
- Amsterdam UMC, Radiology and Nuclear Medicine, University of Amsterdam, the Netherlands
| | - Esben Thade Petersen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark
| | - Charles B L M Majoie
- Amsterdam UMC, Radiology and Nuclear Medicine, University of Amsterdam, the Netherlands
| | - Ed T VanBavel
- Amsterdam UMC, Biomedical Engineering and Physics, University of Amsterdam, the Netherlands
| | - John C Wood
- Cardiology and Radiology, Children's Hospital of Los Angeles, CA, USA
| | - Aart J Nederveen
- Amsterdam UMC, Radiology and Nuclear Medicine, University of Amsterdam, the Netherlands
| | - Bart J Biemond
- Amsterdam UMC, Hematology, Internal Medicine, University of Amsterdam, the Netherlands
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Abstract
Hypertension has emerged as a leading cause of age-related cognitive impairment. Long known to be associated with dementia caused by vascular factors, hypertension has more recently been linked also to Alzheimer disease-the major cause of dementia in older people. Thus, although midlife hypertension is a risk factor for late-life dementia, hypertension may also promote the neurodegenerative pathology underlying Alzheimer disease. The mechanistic bases of these harmful effects remain to be established. Hypertension is well known to alter in the structure and function of cerebral blood vessels, but how these cerebrovascular effects lead to cognitive impairment and promote Alzheimer disease pathology is not well understood. Furthermore, critical questions also concern whether treatment of hypertension prevents cognitive impairment, the blood pressure threshold for treatment, and the antihypertensive agents to be used. Recent advances in neurovascular biology, epidemiology, brain imaging, and biomarker development have started to provide new insights into these critical issues. In this review, we will examine the progress made to date, and, after a critical evaluation of the evidence, we will highlight questions still outstanding and seek to provide a path forward for future studies.
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Affiliation(s)
- Costantino Iadecola
- From the Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York (C.I.)
| | - Rebecca F Gottesman
- Departments of Neurology (R.F.G.), Johns Hopkins University, Baltimore, MD
- Epidemiology (R.F.G.), Johns Hopkins University, Baltimore, MD
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Atwi S, Shao H, Crane DE, da Costa L, Aviv RI, Mikulis DJ, Black SE, MacIntosh BJ. BOLD-based cerebrovascular reactivity vascular transfer function isolates amplitude and timing responses to better characterize cerebral small vessel disease. NMR IN BIOMEDICINE 2019; 32:e4064. [PMID: 30693582 DOI: 10.1002/nbm.4064] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 12/03/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
Cerebrovascular reactivity (CVR) is a dynamic measure of the cerebral blood vessel response to vasoactive stimulus. Conventional CVR measures amplitude changes in the blood-oxygenation-level-dependent (BOLD) signal per unit change in end-tidal CO2 (PET CO2 ), effectively discarding potential timing information. This study proposes a deconvolution procedure to characterize CVR responses based on a vascular transfer function (VTF) that separates amplitude and timing CVR effects. We implemented the CVR-VTF to primarily evaluate normal-appearing white matter (WM) responses in those with a range of small vessel disease. Comparisons between simulations of PET CO2 input models revealed that boxcar and ramp hypercapnia paradigms had the lowest relative deconvolution error. We used a T2 * BOLD-MRI sequence on a 3 T MRI scanner, with a boxcar delivery model of CO2 , to test the CVR-VTF approach in 18 healthy adults and three white matter hyperintensity (WMH) groups: 20 adults with moderate WMH, 12 adults with severe WMH, and 10 adults with genetic WMH (CADASIL). A subset of participants performed a second CVR session at a one-year follow-up. Conventional CVR, area under the curve of VTF (VTF-AUC), and VTF time-to-peak (VTF-TTP) were assessed in WM and grey matter (GM) at baseline and one-year follow-up. WMH groups had lower WM VTF-AUC compared with the healthy group (p < 0.0001), whereas GM CVR did not differ between groups (p > 0.1). WM VTF-TTP of the healthy group was less than that in the moderate WMH group (p = 0.016). Baseline VTF-AUC was lower than follow-up VTF-AUC in WM (p = 0.013) and GM (p = 0.026). The intraclass correlation for VTF-AUC in WM was 0.39 and coefficient of repeatability was 0.08 [%BOLD/mm Hg]. This study assessed CVR timing and amplitude information without applying model assumptions to the CVR response; this approach may be useful in the development of robust clinical biomarkers of CSVD.
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Affiliation(s)
- 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
| | - Han Shao
- Division of Engineering Science, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - David E Crane
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Leodante da Costa
- Division of Neurosurgery, Department of Surgery, Sunnybrook Hospital, University of Toronto, Toronto, ON, Canada
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Richard I Aviv
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - David J Mikulis
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, Canada
- Department of Medical Imaging, University of Toronto, Toronto, Canada
| | - 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
- Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada
- Rotman Research Institute, Baycrest Centre, Toronto, ON, Canada
- Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - 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
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Juttukonda MR, Donahue MJ. Neuroimaging of vascular reserve in patients with cerebrovascular diseases. Neuroimage 2019; 187:192-208. [PMID: 29031532 PMCID: PMC5897191 DOI: 10.1016/j.neuroimage.2017.10.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/01/2017] [Accepted: 10/07/2017] [Indexed: 12/21/2022] Open
Abstract
Cerebrovascular reactivity, defined broadly as the ability of brain parenchyma to adjust cerebral blood flow in response to altered metabolic demand or a vasoactive stimulus, is being measured with increasing frequency and may have a use for portending new or recurrent stroke risk in patients with cerebrovascular disease. The purpose of this review is to outline (i) the physiological basis of variations in cerebrovascular reactivity, (ii) available approaches for measuring cerebrovascular reactivity in research and clinical settings, and (iii) clinically-relevant cerebrovascular reactivity findings in the context of patients with cerebrovascular disease, including atherosclerotic arterial steno-occlusion, non-atherosclerotic arterial steno-occlusion, anemia, and aging. Literature references summarizing safety considerations for these procedures and future directions for standardizing protocols and post-processing procedures across centers are presented in the specific context of major unmet needs in the setting of cerebrovascular disease.
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Affiliation(s)
- Meher R Juttukonda
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J Donahue
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, USA.
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Non-alcoholic fatty liver disease and cerebral small vessel disease in Korean cognitively normal individuals. Sci Rep 2019; 9:1814. [PMID: 30755685 PMCID: PMC6372789 DOI: 10.1038/s41598-018-38357-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 12/15/2018] [Indexed: 12/18/2022] Open
Abstract
We aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD) and cerebral small vessel disease (CSVD) burden, especially according to the NAFLD severity. A total of 1,260 participants were included. The CSVD burden was assessed with white matter hyperintensities (WMH), lacunes, and microbleeds (MBs) on brain MRI. An ultrasound diagnosis of fatty liver was made based on standard criteria, and the Fibrosis-4 (FIB-4) index was used to classify participants with NAFLD with having a high-intermediate (FIB-4 ≥1.45) or low (FIB-4 < 1.45) probability of advanced fibrosis. A multivariable logistic regression analysis was used to assess the association between NAFLD and the presence of moderate to severe WMH, lacunes, and MBs. NAFLD had a significant association only with moderate to severe WMH (OR: 1.64, 95% CI: 1.10-2.42), even after controlling for cardiometabolic risk factors. A linear trend test showed a significant association between the severity of NAFLD fibrosis and the presence of moderate to severe WMH (p for trend <0.001). Our findings suggest that NAFLD, especially NAFLD with fibrosis, has a significant association with the presence of moderate to severe WMH in cognitively normal individuals, and NAFLD severity predicted more frequent moderate to severe WMH.
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White Matter Integrity and Early Outcomes After Acute Ischemic Stroke. Transl Stroke Res 2019; 10:630-638. [PMID: 30693424 DOI: 10.1007/s12975-019-0689-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/02/2019] [Accepted: 01/17/2019] [Indexed: 10/27/2022]
Abstract
Chronic white matter structural injury is a risk factor for poor long-term outcomes after acute ischemic stroke (AIS). However, it is unclear how white matter structural injury predisposes to poor outcomes after AIS. To explore this question, in 42 AIS patients with moderate to severe white matter hyperintensity (WMH) burden, we characterized WMH and normal-appearing white matter (NAWM) diffusivity anisotropy metrics in the hemisphere contralateral to acute ischemia in relation to ischemic tissue and early functional outcomes. All patients underwent brain MRI with dynamic susceptibility contrast perfusion and diffusion tensor imaging within 12 h and at day 3-5 post stroke. Early neurological outcomes were measured as the change in NIH Stroke Scale score from admission to day 3-5 post stroke. Target mismatch profile, percent mismatch lost, infarct growth, and rates of good perfusion were measured to assess ischemic tissue outcomes. NAWM mean diffusivity was significantly lower in the group with early neurological improvement (ENI, 0.79 vs. 0.82 × 10-3, mm2/s; P = 0.02). In multivariable logistic regression, NAWM mean diffusivity was an independent radiographic predictor of ENI (β = - 17.6, P = 0.037). Median infarct growth was 118% (IQR 26.8-221.9%) despite good reperfusion being observed in 65.6% of the cohort. NAWM and WMH diffusivity metrics were not associated with target mismatch profile, percent mismatch lost, or infarct growth. Our results suggest that, in AIS patients, white matter structural integrity is associated with poor early neurological outcomes independent of ischemic tissue outcomes.
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Paradoxical association between age and cerebrovascular reactivity in migraine: A cross-sectional study. J Neurol Sci 2019; 398:204-209. [PMID: 30709572 DOI: 10.1016/j.jns.2019.01.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 01/08/2019] [Accepted: 01/23/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND Previous studies reported an increased risk of ischemic stroke in younger migraineurs. We aimed to investigate the association between age and cerebrovascular reactivity (CVR) to vasodilatory stimuli in cerebral arteries in patients with migraine and normal controls. METHODS In this cross-sectional study, we recruited 248 patients with migraine and 105 normal controls at Samsung Medical Center between October 2015 and July 2018. CVR was measured interictally by using the transcranial Doppler breath-holding test. For the arteries which showed a correlation between age and CVR, we conducted univariable and multivariable linear regression analysis to assess the independent effect of age on CVR. The path analysis was performed to assess mediating effects of the age of onset and disease duration on the age-CVR association. RESULTS Patients had reduced CVR in all tested arteries compared to normal controls. A correlation between age and CVR was present in the posterior cerebral artery (PCA) only in patients (Pearson's correlation coefficient = 0.160, p = 0.012). In patients, younger age was independently associated with lower CVR in the PCA (multivariable B = 0.003, 95% CI = 0.0002-0.005, p = 0.033 adjusted for sex, migraine subtype, and headache frequencies). The path analysis showed that the age of onset fully mediated the effect of age on PCA CVR, while longer disease duration negatively modified the effect of age of onset (p for interaction = 0.018). CONCLUSIONS In migraineurs, younger age was associated with CVR reduction in the PCA. Younger age of onset may be a hidden risk factor mediating the paradoxical association between age and CVR. This association might explain an increased risk of stroke in younger migraineurs.
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Lee MJ, Park BY, Cho S, Park H, Chung CS. Cerebrovascular reactivity as a determinant of deep white matter hyperintensities in migraine. Neurology 2019; 92:e342-e350. [PMID: 30610094 DOI: 10.1212/wnl.0000000000006822] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/27/2018] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE To evaluate the association between the cerebrovascular reactivity to carbon dioxide (CO2-CVR) and the deep white matter hyperintensity (WMH) burden in patients with migraine. METHODS A total of 86 nonelderly patients with episodic migraine without vascular risk factors and 35 headache-free controls underwent 3T MRI. Deep WMHs were quantified with a segmentation method developed for nonelderly migraineurs. The interictal CO2-CVR was measured with transcranial Doppler with the breath-holding method. The mean breath-holding index of the bilateral middle cerebral arteries (MCA-BHI) was square root transformed and analyzed with univariate and multivariate logistic regression models to determine its association with the highest tertiles of deep WMH burden (number and volume). RESULTS A low MCA-BHI was independently associated with the highest tertile of deep WMH number in patients with migraine (adjusted odds ratio [OR] 0.02, 95% confidence interval [CI] 0.0007-0.63, p = 0.026). In controls, the MCA-BHI was not associated with deep WMH number. Interaction analysis revealed that migraine modified the effect of MCA-BHI on deep WMH number (p for interaction = 0.029). The MCA-BHI was not associated with increased deep WMH volume in both patients and controls. Age was independently associated with deep WMH volume in patients (adjusted OR 1.07, 95% CI 1.004-1.15, p = 0.037). CONCLUSIONS In this study, we found a migraine-specific association between a reduced CVR to apnea and increased number of deep WMHs in healthy, nonelderly patients with migraine. A dysfunctional vascular response to apnea may predispose migraineurs to an increased risk of WMHs.
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Affiliation(s)
- Mi Ji Lee
- From the Department of Neurology (M.J.L., S.C., C.-S.C.), Samsung Medical Center, Sungkyunkwan University School of Medicine; Neuroscience Center (M.J.L., C.-S.C.), Samsung Medical Center, Seoul; Department of Electrical and Computer Engineering (B.-Y.P.) and School of Electronic and Electrical Engineering (H.P.), Sungkyunkwan University; and Center for Neuroscience Imaging Research (B.-Y.P., H.P.), Institute for Basic Science, Suwon, Korea
| | - Bo-Yong Park
- From the Department of Neurology (M.J.L., S.C., C.-S.C.), Samsung Medical Center, Sungkyunkwan University School of Medicine; Neuroscience Center (M.J.L., C.-S.C.), Samsung Medical Center, Seoul; Department of Electrical and Computer Engineering (B.-Y.P.) and School of Electronic and Electrical Engineering (H.P.), Sungkyunkwan University; and Center for Neuroscience Imaging Research (B.-Y.P., H.P.), Institute for Basic Science, Suwon, Korea
| | - Soohyun Cho
- From the Department of Neurology (M.J.L., S.C., C.-S.C.), Samsung Medical Center, Sungkyunkwan University School of Medicine; Neuroscience Center (M.J.L., C.-S.C.), Samsung Medical Center, Seoul; Department of Electrical and Computer Engineering (B.-Y.P.) and School of Electronic and Electrical Engineering (H.P.), Sungkyunkwan University; and Center for Neuroscience Imaging Research (B.-Y.P., H.P.), Institute for Basic Science, Suwon, Korea
| | - Hyunjin Park
- From the Department of Neurology (M.J.L., S.C., C.-S.C.), Samsung Medical Center, Sungkyunkwan University School of Medicine; Neuroscience Center (M.J.L., C.-S.C.), Samsung Medical Center, Seoul; Department of Electrical and Computer Engineering (B.-Y.P.) and School of Electronic and Electrical Engineering (H.P.), Sungkyunkwan University; and Center for Neuroscience Imaging Research (B.-Y.P., H.P.), Institute for Basic Science, Suwon, Korea.
| | - Chin-Sang Chung
- From the Department of Neurology (M.J.L., S.C., C.-S.C.), Samsung Medical Center, Sungkyunkwan University School of Medicine; Neuroscience Center (M.J.L., C.-S.C.), Samsung Medical Center, Seoul; Department of Electrical and Computer Engineering (B.-Y.P.) and School of Electronic and Electrical Engineering (H.P.), Sungkyunkwan University; and Center for Neuroscience Imaging Research (B.-Y.P., H.P.), Institute for Basic Science, Suwon, Korea.
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Fisher JA, Venkatraghavan L, Mikulis DJ. Magnetic Resonance Imaging–Based Cerebrovascular Reactivity and Hemodynamic Reserve. Stroke 2018; 49:2011-2018. [DOI: 10.1161/strokeaha.118.021012] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Joseph A. Fisher
- From the Department of Anesthesia and Pain Management and the Toronto General Hospital Research Institute (J.A.F., L.V.)
- Department of Anesthesiology (J.A.F., L.V.)
- Institute of Medical Sciences (J.A.F., D.J.M.)
- Department of Physiology (J.A.F.), University of Toronto, Canada
| | - Lashmi Venkatraghavan
- From the Department of Anesthesia and Pain Management and the Toronto General Hospital Research Institute (J.A.F., L.V.)
- Department of Anesthesiology (J.A.F., L.V.)
| | - David J. Mikulis
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory (D.J.M.), University Health Network, Toronto, Canada
- Institute of Medical Sciences (J.A.F., D.J.M.)
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New insights into cerebral small vessel disease and vascular cognitive impairment from MRI. Curr Opin Neurol 2018; 31:36-43. [PMID: 29084064 DOI: 10.1097/wco.0000000000000513] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW We review recent MRI research that addresses two important challenges in cerebral small vessel disease (SVD) research: early diagnosis, and linking SVD with cognitive impairment. First, we review studies of MRI measurements of blood flow and blood-brain barrier integrity. Second, we review MRI studies identifying neuroimaging correlates of SVD-related cognitive dysfunction, focusing on brain connectivity and white matter microarchitecture. This research is placed in context through discussion of recent recommendations for management of incidentally discovered SVD, and neuroimaging biomarker use in clinical trials. RECENT FINDINGS Cerebral perfusion, cerebrovascular reactivity (CVR), blood-brain barrier permeability, and white matter microarchitecture are measurable using MRI, and are altered in SVD. Lower cerebral blood flow predicts a higher future risk for dementia, whereas decreased CVR occurs at early stages of SVD and is associated with future white matter hyperintensity growth. Two new approaches to analyzing diffusion tensor imaging (DTI) data in SVD patients have emerged: graph theory-based analysis of networks of DTI connectivity between cortical nodes, and analysis of histograms of mean diffusivity of the hemispheric white matter. SUMMARY New, advanced quantitative neuroimaging techniques are not ready for routine radiological practice but are already being employed as monitoring biomarkers in the newest generation of trials for SVD.
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Rosenberg GA. Binswanger's disease: biomarkers in the inflammatory form of vascular cognitive impairment and dementia. J Neurochem 2018; 144:634-643. [PMID: 28902409 PMCID: PMC5849485 DOI: 10.1111/jnc.14218] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 08/17/2017] [Accepted: 08/30/2017] [Indexed: 12/13/2022]
Abstract
Vascular cognitive impairment and dementia (VCID) is a major public health concern because of the increased incidence of vascular disease in the aging population and the impact of vascular disease on Alzheimer's disease. VCID is a heterogeneous group of diseases for which there are no proven treatments. Biomarkers can be used to select more homogeneous populations. Small vessel disease is the most prevalent form of VCID and is the optimal form for treatment trials because there is a progressive course with characteristic pathological changes. Subcortical ischemic vascular disease of the Binswanger type (SIVD-BD) has a characteristic set of features that can be used both to identify patients and to follow treatment. SIVD-BD patients have clinical, neuropsychological, cerebrospinal fluid (CSF) and imaging features that can be used as biomarkers. No one feature is diagnostic, but a multimodal approach defines the SIVD-BD spectrum disorder. The most important features are large white matter lesions with axonal damage, blood-brain barrier disruption as shown by magnetic resonance imaging and CSF, and neuropsychological evidence of executive dysfunction. We have used these features to create a Binswanger Disease Scale and a probability of SIVD-BD, using a machine-learning algorithm. The patients discussed in this review are derived from published studies. Biomarkers not only aid in early diagnosis before the disease process has progressed too far for treatment, but also can indicate response to treatment. Refining the use of biomarkers will allow dementia treatment to enter the era of precision medicine. This article is part of the Special Issue "Vascular Dementia".
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Affiliation(s)
- Gary A Rosenberg
- Professor of Neurology, Neurosciences, and Cell Biology, UNM Memory and Aging Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
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68
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Thorin-Trescases N, de Montgolfier O, Pinçon A, Raignault A, Caland L, Labbé P, Thorin E. Impact of pulse pressure on cerebrovascular events leading to age-related cognitive decline. Am J Physiol Heart Circ Physiol 2018; 314:H1214-H1224. [PMID: 29451817 DOI: 10.1152/ajpheart.00637.2017] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Aging is a modern concept: human life expectancy has more than doubled in less than 150 yr in Western countries. Longer life span, however, reveals age-related diseases, including cerebrovascular diseases. The vascular system is a prime target of aging: the "wear and tear" of large elastic arteries exposed to a lifelong pulsatile pressure causes arterial stiffening by fragmentation of elastin fibers and replacement by stiffer collagen. This arterial stiffening increases in return the amplitude of the pulse pressure (PP), its wave penetrating deeper into the microcirculation of low-resistance, high-flow organs such as the brain. Several studies have associated peripheral arterial stiffness responsible for the sustained increase in PP, with brain microvascular diseases such as cerebral small vessel disease, cortical gray matter thinning, white matter atrophy, and cognitive dysfunction in older individuals and prematurely in hypertensive and diabetic patients. The rarefaction of white matter is also associated with middle cerebral artery pulsatility that is strongly dependent on PP and artery stiffness. PP and brain damage are likely associated, but the sequence of mechanistic events has not been established. Elevated PP promotes endothelial dysfunction that may slowly develop in parallel with the accumulation of proinflammatory senescent cells and oxidative stress, generating cerebrovascular damage and remodeling, as well as brain structural changes. Here, we review data suggesting that age-related increased peripheral artery stiffness may promote the penetration of a high PP to cerebral microvessels, likely causing functional, structural, metabolic, and hemodynamic alterations that could ultimately promote neuronal dysfunction and cognitive decline.
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Affiliation(s)
| | - Olivia de Montgolfier
- Montreal Heart Institute, Research Center , Montreal, Quebec , Canada.,Department of Pharmacology, Faculty of Medicine, Université de Montréal , Montreal, Quebec , Canada
| | - Anthony Pinçon
- Montreal Heart Institute, Research Center , Montreal, Quebec , Canada.,Department of Pharmacology, Faculty of Medicine, Université de Montréal , Montreal, Quebec , Canada
| | - Adeline Raignault
- Montreal Heart Institute, Research Center , Montreal, Quebec , Canada
| | - Laurie Caland
- Montreal Heart Institute, Research Center , Montreal, Quebec , Canada.,Department of Pharmacology, Faculty of Medicine, Université de Montréal , Montreal, Quebec , Canada
| | - Pauline Labbé
- Montreal Heart Institute, Research Center , Montreal, Quebec , Canada.,Department of Pharmacology, Faculty of Medicine, Université de Montréal , Montreal, Quebec , Canada
| | - Eric Thorin
- Montreal Heart Institute, Research Center , Montreal, Quebec , Canada.,Department of Pharmacology, Faculty of Medicine, Université de Montréal , Montreal, Quebec , Canada.,Department of Surgery, Faculty of Medicine, Université de Montréal , Montreal, Quebec , Canada
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Geurts LJ, Bhogal AA, Siero JCW, Luijten PR, Biessels GJ, Zwanenburg JJM. Vascular reactivity in small cerebral perforating arteries with 7 T phase contrast MRI - A proof of concept study. Neuroimage 2018; 172:470-477. [PMID: 29408324 PMCID: PMC5915583 DOI: 10.1016/j.neuroimage.2018.01.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 01/14/2018] [Accepted: 01/21/2018] [Indexed: 01/08/2023] Open
Abstract
Existing cerebrovascular reactivity (CVR) techniques assess flow reactivity in either the largest cerebral vessels or at the level of the parenchyma. We examined the ability of 2D phase contrast MRI at 7 T to measure CVR in small cerebral perforating arteries. Blood flow velocity in perforators was measured in 10 healthy volunteers (mean age 26 years) using a 7 T MR scanner, using phase contrast acquisitions in the semioval center (CSO), the basal ganglia (BG) and the middle cerebral artery (MCA). Changes in flow velocity in response to a hypercapnic breathing challenge were assessed, and expressed as the percentual increase of flow velocity as a function of the increase in end tidal partial pressure of CO2. The hypercapnic challenge increased (fit ± standard error) flow velocity by 0.7 ± 0.3%/mmHg in the CSO (P < 0.01). Moreover, the number of detected perforators (mean [range]) increased from 63 [27–88] to 108 [61–178] (P < 0.001). In the BG, the hypercapnic challenge increased flow velocity by 1.6 ± 0.5%/mmHg (P < 0.001), and the number of detected perforators increased from 48 [24–66] to 63 [32–91] (P < 0.01). The flow in the MCA increased by 5.2 ± 1.4%/mmHg (P < 0.01). Small vessel specific reactivity can now be measured in perforators of the CSO and BG, using 2D phase contrast at 7 T. We show that 2D phase contrast at 7T MRI is capable of measuring reactivity in small cerebral perforating arteries. Reactivity to hypercapnia was measured in perforating arteries of the semi-oval center and the basal ganglia. Both blood flow velocity and the number of detected perforating arteries increased during hypercapnia. The proposed method bridges the gap between current reactivity measurements in parenchyma and large arteries.
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Affiliation(s)
- Lennart J Geurts
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Alex A Bhogal
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jeroen C W Siero
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands; Spinoza Centre for Neuroimaging Amsterdam, Amsterdam, The Netherlands
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Geert Jan Biessels
- Department of Neurology and Neurosurgery, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Rane S, Koh N, Boord P, Madhyastha T, Askren MK, Jayadev S, Cholerton B, Larson E, Grabowski TJ. Quantitative cerebrovascular pathology in a community-based cohort of older adults. Neurobiol Aging 2018; 65:77-85. [PMID: 29452984 DOI: 10.1016/j.neurobiolaging.2018.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 02/07/2023]
Abstract
Cerebrovascular disease, especially small vessel pathology, is the leading comorbidity in degenerative disorders. We applied arterial spin labeling and cerebrovascular reserve (CVR) imaging to quantify small vessel disease and study its effect on cognitive symptoms in nondemented older adults from a community-based cohort. We evaluated baseline cerebral blood flow (CBF) using arterial spin labeling and percent signal change as a marker of CVR using blood-oxygen level-dependent imaging following a breath-hold stimulus. Measurements were performed in and near white matter hyperintensities, which are currently the standard to assess severity of vascular pathology. We show that similar to other studies (1) CBF and CVR are markedly reduced in the hyperintensities as well as in the tissue surrounding them, indicating susceptibility to infarction; (2) low CBF and CVR are significantly correlated with poor cognitive performance; and (3) in addition, compared to a 58.4% reduction in CBF, larger exhaustion (79.3%) of CVR was observed in the hyperintensities with a faster, nonlinear rate of decline. We conclude that CVR may be a more sensitive biomarker of small vessel disease than CBF.
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Affiliation(s)
- Swati Rane
- Radiology, University of Washington Medical Center, Seattle, WA, USA.
| | - Natalie Koh
- Radiology, University of Washington Medical Center, Seattle, WA, USA
| | - Peter Boord
- Radiology, University of Washington Medical Center, Seattle, WA, USA
| | - Tara Madhyastha
- Radiology, University of Washington Medical Center, Seattle, WA, USA
| | - Mary K Askren
- Radiology, University of Washington Medical Center, Seattle, WA, USA
| | - Suman Jayadev
- Radiology, University of Washington Medical Center, Seattle, WA, USA
| | - Brenna Cholerton
- Department of Pathology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Eric Larson
- Group Health Research Institute, Seattle, WA, USA
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Bright MG, Croal PL, Blockley NP, Bulte DP. Multiparametric measurement of cerebral physiology using calibrated fMRI. Neuroimage 2017; 187:128-144. [PMID: 29277404 DOI: 10.1016/j.neuroimage.2017.12.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/07/2023] Open
Abstract
The ultimate goal of calibrated fMRI is the quantitative imaging of oxygen metabolism (CMRO2), and this has been the focus of numerous methods and approaches. However, one underappreciated aspect of this quest is that in the drive to measure CMRO2, many other physiological parameters of interest are often acquired along the way. This can significantly increase the value of the dataset, providing greater information that is clinically relevant, or detail that can disambiguate the cause of signal variations. This can also be somewhat of a double-edged sword: calibrated fMRI experiments combine multiple parameters into a physiological model that requires multiple steps, thereby providing more opportunity for error propagation and increasing the noise and error of the final derived values. As with all measurements, there is a trade-off between imaging time, spatial resolution, coverage, and accuracy. In this review, we provide a brief overview of the benefits and pitfalls of extracting multiparametric measurements of cerebral physiology through calibrated fMRI experiments.
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Affiliation(s)
- Molly G Bright
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK; Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Paula L Croal
- IBME, Department of Engineering Science, University of Oxford, Oxford, UK
| | - Nicholas P Blockley
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Daniel P Bulte
- IBME, Department of Engineering Science, University of Oxford, Oxford, UK; FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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Chronic cerebral hypoperfusion: a key mechanism leading to vascular cognitive impairment and dementia. Closing the translational gap between rodent models and human vascular cognitive impairment and dementia. Clin Sci (Lond) 2017; 131:2451-2468. [PMID: 28963120 DOI: 10.1042/cs20160727] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/28/2017] [Accepted: 09/04/2017] [Indexed: 12/15/2022]
Abstract
Increasing evidence suggests that vascular risk factors contribute to neurodegeneration, cognitive impairment and dementia. While there is considerable overlap between features of vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD), it appears that cerebral hypoperfusion is the common underlying pathophysiological mechanism which is a major contributor to cognitive decline and degenerative processes leading to dementia. Sustained cerebral hypoperfusion is suggested to be the cause of white matter attenuation, a key feature common to both AD and dementia associated with cerebral small vessel disease (SVD). White matter changes increase the risk for stroke, dementia and disability. A major gap has been the lack of mechanistic insights into the evolution and progress of VCID. However, this gap is closing with the recent refinement of rodent models which replicate chronic cerebral hypoperfusion. In this review, we discuss the relevance and advantages of these models in elucidating the pathogenesis of VCID and explore the interplay between hypoperfusion and the deposition of amyloid β (Aβ) protein, as it relates to AD. We use examples of our recent investigations to illustrate the utility of the model in preclinical testing of candidate drugs and lifestyle factors. We propose that the use of such models is necessary for tackling the urgently needed translational gap from preclinical models to clinical treatments.
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Dadar M, Pascoal TA, Manitsirikul S, Misquitta K, Fonov VS, Tartaglia MC, Breitner J, Rosa-Neto P, Carmichael OT, Decarli C, Collins DL. Validation of a Regression Technique for Segmentation of White Matter Hyperintensities in Alzheimer's Disease. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:1758-1768. [PMID: 28422655 DOI: 10.1109/tmi.2017.2693978] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Segmentation and volumetric quantification of white matter hyperintensities (WMHs) is essential in assessment and monitoring of the vascular burden in aging and Alzheimer's disease (AD), especially when considering their effect on cognition. Manually segmenting WMHs in large cohorts is technically unfeasible due to time and accuracy concerns. Automated tools that can detect WMHs robustly and with high accuracy are needed. Here, we present and validate a fully automatic technique for segmentation and volumetric quantification of WMHs in aging and AD. The proposed technique combines intensity and location features frommultiplemagnetic resonance imaging contrasts and manually labeled training data with a linear classifier to perform fast and robust segmentations. It provides both a continuous subject specific WMH map reflecting different levels of tissue damage and binary segmentations. Themethodwas used to detectWMHs in 80 elderly/AD brains (ADC data set) as well as 40 healthy subjects at risk of AD (PREVENT-AD data set). Robustness across different scanners was validated using ten subjects from ADNI2/GO study. Voxel-wise and volumetric agreements were evaluated using Dice similarity index (SI) and intra-class correlation (ICC), yielding ICC=0.96 , SI = 0.62±0.16 for ADC data set and ICC=0.78 , SI=0.51±0.15 for PREVENT-AD data set. The proposed method was robust in the independent sample yielding SI=0.64±0.17 with ICC=0.93 for ADNI2/GO subjects. The proposed method provides fast, accurate, and robust segmentations on previously unseen data from different models of scanners, making it ideal to study WMHs in large scale multi-site studies.
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74
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Extracellular matrix inflammation in vascular cognitive impairment and dementia. Clin Sci (Lond) 2017; 131:425-437. [PMID: 28265034 DOI: 10.1042/cs20160604] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/15/2016] [Accepted: 12/19/2016] [Indexed: 12/16/2022]
Abstract
Vascular cognitive impairment and dementia (VCID) include a wide spectrum of chronic manifestations of vascular disease related to large vessel strokes and small vessel disease (SVD). Lacunar strokes and white matter (WM) injury are consequences of SVD. The main vascular risk factor for SVD is brain hypoperfusion from cerebral blood vessel narrowing due to chronic hypertension. The hypoperfusion leads to activation and degeneration of astrocytes with the resulting fibrosis of the extracellular matrix (ECM). Elasticity is lost in fibrotic cerebral vessels, reducing the response of stiffened blood vessels in times of increased metabolic need. Intermittent hypoxia/ischaemia activates a molecular injury cascade, producing an incomplete infarction that is most damaging to the deep WM, which is a watershed region for cerebral blood flow. Neuroinflammation caused by hypoxia activates microglia/macrophages to release proteases and free radicals that perpetuate the damage over time to molecules in the ECM and the neurovascular unit (NVU). Matrix metalloproteinases (MMPs) secreted in an attempt to remodel the blood vessel wall have the undesired consequences of opening the blood-brain barrier (BBB) and attacking myelinated fibres. This dual effect of the MMPs causes vasogenic oedema in WM and vascular demyelination, which are the hallmarks of the subcortical ischaemic vascular disease (SIVD), which is the SVD form of VCID also called Binswanger's disease (BD). Unravelling the complex pathophysiology of the WM injury-related inflammation in the small vessel form of VCID could lead to novel therapeutic strategies to reduce damage to the ECM, preventing the progressive damage to the WM.
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Blair GW, Hernandez MV, Thrippleton MJ, Doubal FN, Wardlaw JM. Advanced Neuroimaging of Cerebral Small Vessel Disease. CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2017. [PMID: 28620783 PMCID: PMC5486578 DOI: 10.1007/s11936-017-0555-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cerebral small vessel disease (SVD) is characterised by damage to deep grey and white matter structures of the brain and is responsible for a diverse range of clinical problems that include stroke and dementia. In this review, we describe advances in neuroimaging published since January 2015, mainly with magnetic resonance imaging (MRI), that, in general, are improving quantification, observation and investigation of SVD focussing on three areas: quantifying the total SVD burden, imaging brain microstructural integrity and imaging vascular malfunction. Methods to capture ‘whole brain SVD burden’ across the spectrum of SVD imaging changes will be useful for patient stratification in clinical trials, an approach that we are already testing. More sophisticated imaging measures of SVD microstructural damage are allowing the disease to be studied at earlier stages, will help identify specific factors that are important in development of overt SVD imaging features and in understanding why specific clinical consequences may occur. Imaging vascular function will help establish the precise blood vessel and blood flow alterations at early disease stages and, together with microstructural integrity measures, may provide important surrogate endpoints in clinical trials testing new interventions. Better knowledge of SVD pathophysiology will help identify new treatment targets, improve patient stratification and may in future increase efficiency of clinical trials through smaller sample sizes or shorter follow-up periods. However, most of these methods are not yet sufficiently mature to use with confidence in clinical trials, although rapid advances in the field suggest that reliable quantification of SVD lesion burden, tissue microstructural integrity and vascular dysfunction are imminent.
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Affiliation(s)
- Gordon W Blair
- Brain Research Imaging Centres, Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Maria Valdez Hernandez
- Brain Research Imaging Centres, Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Michael J Thrippleton
- Brain Research Imaging Centres, Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Fergus N Doubal
- Brain Research Imaging Centres, Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Joanna M Wardlaw
- Brain Research Imaging Centres, Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Chancellor's Building, Edinburgh, EH16 4SB, UK.
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Maillard P, Mitchell GF, Himali JJ, Beiser A, Fletcher E, Tsao CW, Pase MP, Satizabal CL, Vasan RS, Seshadri S, DeCarli C. Aortic Stiffness, Increased White Matter Free Water, and Altered Microstructural Integrity: A Continuum of Injury. Stroke 2017; 48:1567-1573. [PMID: 28473633 DOI: 10.1161/strokeaha.116.016321] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/20/2017] [Accepted: 03/29/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Previous reports from the Framingham Heart Study have identified cross-sectional associations of arterial stiffness, as reflected by carotid-femoral pulse wave velocity (CFPWV) and systolic blood pressure with vascular brain injury. The purpose of this study is to examine free water (FW), fractional anisotropy (FA), and white matter hyperintensities (WMH) in relation to arterial stiffness among subjects of the Framingham Offspring and Third-Generation cohorts. METHODS In 2422 participants aged 51.3±11.6 years, FA, FW, and WMH were related to CFPWV using voxel-based linear and generalized linear regressions, adjusting for relevant covariables. Mean FW, mean FA, and WMH burden (log transformed) were computed within white matter (WM) region and related to systolic blood pressure and CFPWV using multiple mediation analyses. RESULTS CFPWV was found to be associated with higher FW, lower FA, and higher WMH incidence in WM areas covering, respectively, 356.1, 211.8, and 10.9 mL of the WM mask. Mediation analyses revealed that the effect of systolic blood pressure on FW was mediated by CFPWV (direct and indirect effects: a=0.040; P<0.001, and a'=0.020; P>0.05). Moreover, the effect of CFPWV on FA was mediated by FW (direct and indirect effects: b=-0.092; P<0.001, and b'=0.012; P>0.05), whose effect on WMH was, in turn, mediated by FA (direct and indirect effects: c=0.246; P<0.001, and c'=0.116; P>0.05). CONCLUSIONS From these data, we propose a biomechanical hypothesis designed for future research experiments to explain how hemodynamic alteration may lead to WM injury by impacting cerebral water content and more subtly WM integrity, to finally lead to WMH development.
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Affiliation(s)
- Pauline Maillard
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.).
| | - Gary F Mitchell
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Jayandra J Himali
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Alexa Beiser
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Evan Fletcher
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Connie W Tsao
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Matthew P Pase
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Claudia L Satizabal
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Ramachandran S Vasan
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Sudha Seshadri
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
| | - Charles DeCarli
- From the Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA (P.M., E.F., C.D.); Department of Neurology and Center for Neurosciences, University of California, Davis (P.M., E.F., C.D.); Cardiovascular Engineering, Inc, Norwood, MA (G.F.M.); The Framingham Heart Study, MA (J.J.H., A.B., M.P.P., C.L.S., S.S.); Department of Neurology (J.J.H., A.B., M.P.P., C.L.S., S.S.) and Department of Medicine (R.S.V.), Boston University School of Medicine, MA; Department of Biostatistics, Boston University School of Public Health, MA (J.J.H., A.B.); Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (C.W.T.); and Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia (M.P.P.)
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Pathogenesis of white matter changes in cerebral small vessel diseases: beyond vessel-intrinsic mechanisms. Clin Sci (Lond) 2017; 131:635-651. [DOI: 10.1042/cs20160380] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 01/04/2017] [Accepted: 01/16/2017] [Indexed: 01/08/2023]
Abstract
Cerebral small vessel diseases (SVDs) are a leading cause of age and hypertension-related stroke and dementia. The salient features of SVDs visible on conventional brain magnetic resonance images include white matter hyperintensities (WMHs) on T2-weighted images, small infarcts, macrohemorrhages, dilated perivascular spaces, microbleeds and brain atrophy. Among these, WMHs are the most common and often the earliest brain tissue changes. Moreover, over the past two decades, large population- and patient-based studies have established the clinical importance of WMHs, notably with respect to cognitive and motor disturbances. Here, we seek to provide a new and critical look at the pathogenesis of SVD-associated white matter (WM) changes. We first review our current knowledge of WM biology in the healthy brain, and then consider the main clinical and pathological features of WM changes in SVDs. The most widely held view is that SVD-associated WM lesions are caused by chronic hypoperfusion, impaired cerebrovascular reactivity (CVR) or blood–brain barrier (BBB) leakage. Here, we assess the arguments for and against each of these mechanisms based on population, patient and experimental model studies, and further discuss other potential mechanisms. Specifically, building on two recent seminal studies that have uncovered an anatomical and functional relationship between oligodendrocyte progenitor cells and blood vessels, we elaborate on how small vessel changes might compromise myelin remodelling and cause WM degeneration. Finally, we propose new directions for future studies on this hot research topic.
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