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Aamand R, Rasmussen PM, Andersen KS, de Paoli S, Weitzberg E, Christiansen M, Lund TE, Østergaard L. Cerebral microvascular changes in healthy carriers of the APOE-ɛ4 Alzheimer's disease risk gene. PNAS NEXUS 2024; 3:pgae369. [PMID: 39253395 PMCID: PMC11382292 DOI: 10.1093/pnasnexus/pgae369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 08/13/2024] [Indexed: 09/11/2024]
Abstract
APOE-ɛ4 is a genetic risk factor for Alzheimer's disease (AD). AD is associated with reduced cerebral blood flow (CBF) and with microvascular changes that limit the transport of oxygen from blood into brain tissue: reduced microvascular cerebral blood volume and high relative transit time heterogeneity (RTH). Healthy APOE-ɛ4 carriers reveal brain regions with elevated CBF compared with carriers of the common ɛ3 allele. Such asymptomatic hyperemia may reflect microvascular dysfunction: a vascular disease entity characterized by suboptimal tissue oxygen uptake, rather than limited blood flow per se. Here, we used perfusion MRI to show that elevated regional CBF is accompanied by reduced capillary blood volume in healthy APOE-ɛ4 carriers (carriers) aged 30-70 years compared with similarly aged APOE-ɛ3 carriers (noncarriers). Younger carriers have elevated hippocampal RTH and more extreme RTH values throughout both white matter (WM) and cortical gray matter (GM) compared with noncarriers. Older carriers have reduced WM CBF and more extreme GM RTH values than noncarriers. Across all groups, lower WM and hippocampal RTH correlate with higher educational attainment, which is associated with lower AD risk. Three days of dietary nitrate supplementation increased carriers' WM CBF but caused older carriers to score worse on two of six aggregate neuropsychological scores. The intervention improved late recall in younger carriers and in noncarriers. The APOE-ɛ4 gene is associated with microvascular changes that may impair tissue oxygen extraction. We speculate that vascular risk factor control is particularly important for APOE-ɛ4 carriers' healthy aging.
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Affiliation(s)
- Rasmus Aamand
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 8000 Aarhus, Denmark
| | - Peter M Rasmussen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 8000 Aarhus, Denmark
| | - Katrine Schilling Andersen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 8000 Aarhus, Denmark
| | - Stine de Paoli
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 8000 Aarhus, Denmark
| | - Eddie Weitzberg
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
- Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, 17177 Stockholm, Sweden
| | - Michael Christiansen
- Department for Congenital Disorders, Statens Serum Institut, 2300 Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Torben E Lund
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 8000 Aarhus, Denmark
| | - Leif Østergaard
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 8000 Aarhus, Denmark
- Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus, Denmark
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2
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Swinford CG, Risacher SL, Vosmeier A, Deardorff R, Chumin EJ, Dzemidzic M, Wu YC, Gao S, McDonald BC, Yoder KK, Unverzagt FW, Wang S, Farlow MR, Brosch JR, Clark DG, Apostolova LG, Sims J, Wang DJ, Saykin AJ. Amyloid and tau pathology are associated with cerebral blood flow in a mixed sample of nondemented older adults with and without vascular risk factors for Alzheimer's disease. Neurobiol Aging 2023; 130:103-113. [PMID: 37499587 PMCID: PMC10529454 DOI: 10.1016/j.neurobiolaging.2023.06.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 05/30/2023] [Accepted: 06/21/2023] [Indexed: 07/29/2023]
Abstract
Identification of biomarkers for the early stages of Alzheimer's disease (AD) is an imperative step in developing effective treatments. Cerebral blood flow (CBF) is a potential early biomarker for AD; generally, older adults with AD have decreased CBF compared to normally aging peers. CBF deviates as the disease process and symptoms progress. However, further characterization of the relationships between CBF and AD risk factors and pathologies is still needed. We assessed the relationships between CBF quantified by arterial spin-labeled magnetic resonance imaging, hypertension, APOEε4, and tau and amyloid positron emission tomography in 77 older adults: cognitively normal, subjective cognitive decline, and mild cognitive impairment. Tau and amyloid aggregation were related to altered CBF, and some of these relationships were dependent on hypertension or APOEε4 status. Our findings suggest a complex relationship between risk factors, AD pathologies, and CBF that warrants future studies of CBF as a potential early biomarker for AD.
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Affiliation(s)
- Cecily G Swinford
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Shannon L Risacher
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Aaron Vosmeier
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Rachael Deardorff
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Evgeny J Chumin
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Indiana University Network Science Institute, Bloomington, IN, USA; Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Mario Dzemidzic
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yu-Chien Wu
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Sujuan Gao
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Biostatistics and Health Data Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brenna C McDonald
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Karmen K Yoder
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Frederick W Unverzagt
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sophia Wang
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Martin R Farlow
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jared R Brosch
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - David G Clark
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Liana G Apostolova
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana University Network Science Institute, Bloomington, IN, USA
| | - Justin Sims
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Danny J Wang
- Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana University Network Science Institute, Bloomington, IN, USA.
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3
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Dounavi ME, Mak E, Swann P, Low A, Muniz-Terrera G, McKeever A, Pope M, Williams GB, Wells K, Lawlor B, Naci L, Malhotra P, Mackay C, Koychev I, Ritchie K, Su L, Ritchie CW, O’Brien JT. Differential association of cerebral blood flow and anisocytosis in APOE ε4 carriers at midlife. J Cereb Blood Flow Metab 2023; 43:1672-1684. [PMID: 37132287 PMCID: PMC10581239 DOI: 10.1177/0271678x231173587] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 05/04/2023]
Abstract
Cerebral hemodynamic alterations have been observed in apolipoprotein ε4 (APOE4) carriers at midlife, however the physiological underpinnings of this observation are poorly understood. Our goal was to investigate cerebral blood flow (CBF) and its spatial coefficient of variation (CoV) in relation to APOE4 and a measure of erythrocyte anisocytosis (red blood cell distribution width - RDW) in a middle-aged cohort. Data from 563 participants in the PREVENT-Dementia study scanned with 3 T MRI cross-sectionally were analysed. Voxel-wise and region-of-interest analyses within nine vascular regions were run to detect areas of altered perfusion. Within the vascular regions, interaction terms between APOE4 and RDW in predicting CBF were examined. Areas of hyperperfusion in APOE4 carriers were detected mainly in frontotemporal regions. The APOE4 allele differentially moderated the association between RDW and CBF, an association which was more prominent in the distal vascular territories (p - [0.01, 0.05]). The CoV was not different between the considered groups. We provide novel evidence that in midlife, RDW and CBF are differentially associated in APOE4 carriers and non-carriers. This association is consistent with a differential hemodynamic response to hematological alterations in APOE4 carriers.
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Affiliation(s)
- Maria-Eleni Dounavi
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Elijah Mak
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Peter Swann
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Audrey Low
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | | | - Anna McKeever
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Marianna Pope
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Guy B Williams
- Department of Clinical Neurosciences and Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Katie Wells
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - Brian Lawlor
- Institute of Neuroscience, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Lorina Naci
- Institute of Neuroscience, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Paresh Malhotra
- Division of Brain Science, Imperial College Healthcare NHS Trust, UK
| | - Clare Mackay
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Ivan Koychev
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Li Su
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- Department of Neuroscience, University of Sheffield, Sheffield, UK
| | - Craig W Ritchie
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - John T O’Brien
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
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4
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Palmer JM, Huentelman M, Ryan L. More than just risk for Alzheimer's disease: APOE ε4's impact on the aging brain. Trends Neurosci 2023; 46:750-763. [PMID: 37460334 DOI: 10.1016/j.tins.2023.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/16/2023] [Accepted: 06/12/2023] [Indexed: 08/18/2023]
Abstract
The apolipoprotein ε4 (APOE ε4) allele is most commonly associated with increased risk for late-onset Alzheimer's disease (AD). However, recent longitudinal studies suggest that these risks are overestimated; most ε4 carriers will not develop dementia in their lifetime. In this article, we review new evidence regarding the impact of APOE ε4 on cognition among healthy older adults. We discuss emerging work from animal models suggesting that ε4 impacts brain structure and function in multiple ways that may lead to age-related cognitive impairment, independent from AD pathology. We discuss the importance of taking an individualized approach in future studies by incorporating biomarkers and neuroimaging methods that may better disentangle the phenotypic influences of APOE ε4 on the aging brain from prodromal AD pathology.
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Affiliation(s)
- Justin M Palmer
- The University of Arizona, Tucson, AZ, USA; Arizona Alzheimer's Consortium, Phoenix, AZ, USA.
| | - Matthew Huentelman
- Translational Genomics Research Institute, Phoenix, AZ, USA; Arizona Alzheimer's Consortium, Phoenix, AZ, USA
| | - Lee Ryan
- The University of Arizona, Tucson, AZ, USA; Arizona Alzheimer's Consortium, Phoenix, AZ, USA.
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5
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Hays Weeks CC, Zlatar ZZ, Meloy MJ, Shin DD, Thomas L, Wierenga CE. APOE Genotype Modifies the Association of Fusiform Gyrus Cerebral Metabolic Rate of Oxygen Consumption and Object Naming Performance. J Alzheimers Dis 2023; 91:1371-1383. [PMID: 36641668 DOI: 10.3233/jad-220749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND The apolipoprotein E (APOE) ɛ4 allele confers risk for age and Alzheimer's disease related cognitive decline but the mechanistic link remains poorly understood. Blood oxygenation level dependent (BOLD) response in the fusiform gyrus (FG) during object naming appears greater among APOEɛ4 carriers even in the face of equivalent cognitive performance, suggesting neural compensation. However, BOLD is susceptible to known age and APOE-related vascular changes that could confound its interpretation. OBJECTIVE To address this limitation, we used calibrated fMRI during an object naming task and a hypercapnic challenge to obtain a more direct measure of neural function - percent change cerebral metabolic rate of oxygen consumption (%ΔCMRO2). METHODS Participants were 45 older adults without dementia (28 ɛ4-, 17 ɛ4+) between the ages of 65 and 85. We examined APOE-related differences in %ΔCMRO2 in the FG during object naming and the extent to which APOE modified associations between FG %ΔCMRO2 and object naming accuracy. Exploratory analyses also tested the hypothesis that %ΔCMRO2 is less susceptible to vascular compromise than are measures of %ΔCBF and %ΔBOLD. RESULTS We observed a modifying role of APOE on associations between FG %ΔCMRO2 and cognition, with ɛ4 carriers (but not non-carriers) demonstrating a positive association between right FG %ΔCMRO2 and object naming accuracy. CONCLUSION Results suggest that the relationship between neural function and cognition is altered among older adult APOEɛ4 carriers prior to the onset of dementia, implicating CMRO2 response as a potential mechanism to support cognition in APOE-related AD risk.
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Affiliation(s)
- Chelsea C Hays Weeks
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, UC San Diego, La Jolla, CA, USA
| | | | - M J Meloy
- VA San Diego Healthcare System, San Diego, CA, USA
| | | | - Liu Thomas
- Department of Radiology, UC San Diego, La Jolla, CA, USA
| | - Christina E Wierenga
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, UC San Diego, La Jolla, CA, USA
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6
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Vidoni ED, Morris JK, Palmer JA, Li Y, White D, Kueck PJ, John CS, Honea RA, Lepping RJ, Lee P, Mahnken JD, Martin LE, Billinger SA. Dementia risk and dynamic response to exercise: A non-randomized clinical trial. PLoS One 2022; 17:e0265860. [PMID: 35802628 PMCID: PMC9269742 DOI: 10.1371/journal.pone.0265860] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/18/2022] [Indexed: 11/25/2022] Open
Abstract
Background Physical exercise may support brain health and cognition over the course of typical aging. The goal of this nonrandomized clinical trial was to examine the effect of an acute bout of aerobic exercise on brain blood flow and blood neurotrophic factors associated with exercise response and brain function in older adults with and without possession of the Apolipoprotein epsilon 4 (APOE4) allele, a genetic risk factor for developing Alzheimer’s. We hypothesized that older adult APOE4 carriers would have lower cerebral blood flow regulation and would demonstrate blunted neurotrophic response to exercise compared to noncarriers. Methods Sixty-two older adults (73±5 years old, 41 female [67%]) consented to this prospectively enrolling clinical trial, utilizing a single arm, single visit, experimental design, with post-hoc assessment of difference in outcomes based on APOE4 carriership. All participants completed a single 15-minute bout of moderate-intensity aerobic exercise. The primary outcome measure was change in cortical gray matter cerebral blood flow in cortical gray matter measured by magnetic resonance imaging (MRI) arterial spin labeling (ASL), defined as the total perfusion (area under the curve, AUC) following exercise. Secondary outcomes were changes in blood neurotrophin concentrations of insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and brain derived neurotrophic factor (BDNF). Results Genotyping failed in one individual (n = 23 APOE4 carriers and n = 38 APOE4 non-carriers) and two participants could not complete primary outcome testing. Cerebral blood flow AUC increased immediately following exercise, regardless of APOE4 carrier status. In an exploratory regional analyses, we found that cerebral blood flow increased in hippocampal brain regions, while showing no change in cerebellum across both groups. Among high inter-individual variability, there were no significant changes in any of the 3 neurotrophic factors for either group immediately following exercise. Conclusions Our findings show that both APOE4 carriers and non-carriers show similar effects of exercise-induced increases in cerebral blood flow and neurotrophic response to acute aerobic exercise. Our results provide further evidence that acute exercise-induced increases in cerebral blood flow may be regional specific, and that exercise-induced neurotrophin release may show a differential effect in the aging cardiovascular system. Results from this study provide an initial characterization of the acute brain blood flow and neurotrophin responses to a bout of exercise in older adults with and without this known risk allele for cardiovascular disease and Alzheimer’s disease. Trial registration Dementia Risk and Dynamic Response to Exercise (DYNAMIC); Identifier: NCT04009629.
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Affiliation(s)
- Eric D. Vidoni
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
- * E-mail:
| | - Jill K. Morris
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Jacqueline A. Palmer
- Department of Physical Therapy, Rehabilitation Science and Athletic Training, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Yanming Li
- Department of Biostatistics and Data Science, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Dreu White
- Department of Physical Therapy, Rehabilitation Science and Athletic Training, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Paul J. Kueck
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Casey S. John
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Robyn A. Honea
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Rebecca J. Lepping
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Phil Lee
- Department of Radiology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Jonathan D. Mahnken
- Department of Biostatistics and Data Science, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Laura E. Martin
- Department of Population Health, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Sandra A. Billinger
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States of America
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7
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Huang CJ, Zhou X, Yuan X, Zhang W, Li MX, You MZ, Zhu XQ, Sun ZW. Contribution of Inflammation and Hypoperfusion to White Matter Hyperintensities-Related Cognitive Impairment. Front Neurol 2022; 12:786840. [PMID: 35058875 PMCID: PMC8763977 DOI: 10.3389/fneur.2021.786840] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/22/2021] [Indexed: 01/15/2023] Open
Abstract
White matter hyperintensities (WMHs) of presumed vascular origin are one of the most important neuroimaging markers of cerebral small vessel disease (CSVD), which are closely associated with cognitive impairment. The aim of this study was to elucidate the pathogenesis of WMHs from the perspective of inflammation and hypoperfusion mechanisms. A total of 65 patients with WMHs and 65 healthy controls were enrolled in this study. Inflammatory markers measurements [hypersensitive C-reactive protein (hsCRP) and lipoprotein-associated phospholipase A2 (Lp-PLA2)], cognitive evaluation, and pseudocontinuous arterial spin labeling (PCASL) MRI scanning were performed in all the subjects. The multivariate logistic regression analysis showed that Lp-PLA2 was an independent risk factor for WMHs. Cerebral blood flow (CBF) in the whole brain, gray matter (GM), white matter (WM), left orbital medial frontal gyrus [MFG.L (orbital part)], left middle temporal gyrus (MTG.L), and right thalamus (Tha.R) in the patients was lower than those in the controls and CBF in the left triangular inferior frontal gyrus [IFG.L (triangular part)] was higher in the patients than in the controls. There was a significant correlation between Lp-PLA2 levels and CBF in the whole brain (R = -0.417, p < 0.001) and GM (R = -0.278, p = 0.025), but not in the WM in the patients. Moreover, CBF in the MFG.L (orbital part) and the Tha.R was, respectively, negatively associated with the trail making test (TMT) and the Stroop color word test (SCWT), suggesting the higher CBF, the better executive function. The CBF in the IFG.L (triangular part) was negatively correlated with attention scores in the Cambridge Cognitive Examination-Chinese Version (CAMCOG-C) subitems (R = -0.288, p = 0.020). Our results revealed the vascular inflammation roles in WMHs, which may through the regulation of CBF in the whole brain and GM. Additionally, CBF changes in different brain regions may imply a potential role in the modulation of cognitive function in different domains.
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Affiliation(s)
- Chao-Juan Huang
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xia Zhou
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xin Yuan
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Wei Zhang
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Ming-Xu Li
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Meng-Zhe You
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiao-Qun Zhu
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zhong-Wu Sun
- Department of Neurology, First Affiliated Hospital of Anhui Medical University, Hefei, China
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8
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Dounavi ME, Low A, McKiernan EF, Mak E, Muniz-Terrera G, Ritchie K, Ritchie CW, Su L, O’Brien JT. Evidence of cerebral hemodynamic dysregulation in middle-aged APOE ε4 carriers: The PREVENT-Dementia study. J Cereb Blood Flow Metab 2021; 41:2844-2855. [PMID: 34078163 PMCID: PMC8543665 DOI: 10.1177/0271678x211020863] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 11/22/2022]
Abstract
Accumulating evidence suggests vascular dysregulation in preclinical Alzheimer's disease. In this study, cerebral hemodynamics and their coupling with cognition in middle-aged apolipoprotein ε4 carriers (APOEε4+) were investigated. Longitudinal 3 T T1-weighted and arterial spin labelling MRI data from 158 participants (40-59 years old) in the PREVENT-Dementia study were analysed (125 two-year follow-up). Cognition was evaluated using the COGNITO battery. Cerebral blood flow (CBF) and cerebrovascular resistance index (CVRi) were quantified for the flow territories of the anterior, middle and posterior cerebral arteries. CBF was corrected for underlying atrophy and individual hematocrit. Hemodynamic measures were the dependent variables in linear regression models, with age, sex, years of education and APOEε4 carriership as predictors. Further analyses were conducted with cognitive outcomes as dependent variables, using the same model as before with additional APOEε4 × hemodynamics interactions. At baseline, APOEε4+ showed increased CBF and decreased CVRi compared to non-carriers in the anterior and middle cerebral arteries, suggestive of potential vasodilation. Hemodynamic changes were similar between groups. Interaction analysis revealed positive associations between CBF changes and performance changes in delayed recall (for APOEε4 non-carriers) and verbal fluency (for APOEε4 carriers) cognitive tests. These observations are consistent with neurovascular dysregulation in middle-aged APOEε4+.
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Affiliation(s)
- Maria-Eleni Dounavi
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Audrey Low
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Elizabeth F McKiernan
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Elijah Mak
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | | | - Karen Ritchie
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
- INSERM, Montpellier, France
| | - Craig W Ritchie
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - Li Su
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - John T. O’Brien
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK
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9
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Parsey CM, Bagger JE, Trittschuh EH, Hanson AJ. Utility of the iPad NIH Toolbox Cognition Battery in a clinical trial of older adults. J Am Geriatr Soc 2021; 69:3519-3528. [PMID: 34342879 DOI: 10.1111/jgs.17382] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/29/2021] [Accepted: 07/07/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND To demonstrate feasibility and utility of the iPad version of the NIH Toolbox Cognition Battery (NIHTB-CB) in a clinical trial of older adults. METHODS Fifty-one adults, aged 55 and older without dementia were tested twice on NIHTB-CB and more traditional paper-and-pencil neuropsychological measures after meal ingestion, with approximately a 4-week interval. We also compared performances at Time 1 and Time 2 for significant change. We also extracted the response times and errors for available NIHTB-CB subtests to determine subtle changes in performance. RESULTS Over the interval, improvement in fluid cognitive measures was noted at Time 2 (t = -3.07, p = 0.004), whereas crystallized measures were unchanged. Tests of fluid cognition negatively correlated with age, particularly for the second visit. Analysis of the average speed per item showed that, for two of the tests, speed increased at Time 2. Traditional neuropsychological tests correlated with many of the NIHTB-CB measures. Response times for all five timed tests decreased at Time 2, although only statistically significant for Picture Sequence and Picture Vocabulary. CONCLUSIONS The iPad version of the NIH Toolbox Cognition Battery appears to be an adequate measure to assess cognitive functioning in a clinical trial of older adults. Psychometric analyses suggest stability in measures of crystallized functioning, whereas measures of fluid abilities revealed improvements over the short time frame of the study. Response times and errors for individual tests revealed intriguing relationships that should be further evaluated to determine the utility in clinical sample analysis, as this could aid identification of subtle cognitive change over short periods. Additional studies with larger sample sizes will be helpful to understanding the reliability, sensitivity, and specificity of the NIHTB-CB sub-scores in older adults. In addition, further evaluations with clinical populations, including individuals with cognitive impairment, are warranted.
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Affiliation(s)
- Carolyn M Parsey
- Alzheimer's Disease Research Center, University of Washington, Seattle, Washington, USA.,School of Medicine (Neurology), University of Washington, Seattle, Washington, USA
| | - Justina E Bagger
- Alzheimer's Disease Research Center, University of Washington, Seattle, Washington, USA
| | - Emily H Trittschuh
- School of Medicine (Psychiatry and Behavioral Sciences), University of Washington, Seattle, Washington, USA.,VA Puget Sound Health Care System, GRECC, University of Washington, Seattle, Washington, USA
| | - Angela J Hanson
- Alzheimer's Disease Research Center, University of Washington, Seattle, Washington, USA.,School of Medicine (Geriatrics), University of Washington, Seattle, Washington, USA
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10
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Memel M, Staffaroni AM, Cobigo Y, Casaletto KB, Fonseca C, Bettcher BM, Yassa MA, Elahi FM, Wolf A, Rosen HJ, Kramer JH. APOE moderates the effect of hippocampal blood flow on memory pattern separation in clinically normal older adults. Hippocampus 2021; 31:845-857. [PMID: 33835624 PMCID: PMC8295213 DOI: 10.1002/hipo.23327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/25/2021] [Accepted: 03/07/2021] [Indexed: 11/10/2022]
Abstract
Pattern separation, the ability to differentiate new information from previously experienced similar information, is highly sensitive to hippocampal structure and function and declines with age. Functional MRI studies have demonstrated hippocampal hyperactivation in older adults compared to young, with greater task-related activation associated with worse pattern separation performance. The current study was designed to determine whether pattern separation was sensitive to differences in task-free hippocampal cerebral blood flow (CBF) in 130 functionally intact older adults. Given prior evidence that apolipoprotein E e4 (APOE e4) status moderates the relationship between CBF and episodic memory, we predicted a stronger negative relationship between hippocampal CBF and pattern separation in APOE e4 carriers. An interaction between APOE group and right hippocampal CBF was present, such that greater right hippocampal CBF was related to better lure discrimination in noncarriers, whereas the effect reversed directionality in e4 carriers. These findings suggest that neurovascular changes in the medial temporal lobe may underlie memory deficits in cognitively normal older adults who are APOE e4 carriers.
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Affiliation(s)
- Molly Memel
- San Francisco VA Medical Center, San Francisco, California
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Adam M. Staffaroni
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Yann Cobigo
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Kaitlin B. Casaletto
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Corrina Fonseca
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Brianne M. Bettcher
- Department of Neurology, University of Colorado Anschutz Medical Campus, CU Alzheimer’s and Cognition Center, Aurora, Colorado
| | - Michael A. Yassa
- Department of Neurobiology and Behavior and Center for the Neurobiology of Learning and Memory, University of California, Irvine, California
| | - Fanny M. Elahi
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Amy Wolf
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Howard J. Rosen
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
| | - Joel H. Kramer
- Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California
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11
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White D, John CS, Kucera A, Truver B, Lepping RJ, Kueck PJ, Lee P, Martin L, Billinger SA, Burns JM, Morris JK, Vidoni ED. A methodology for an acute exercise clinical trial called dementia risk and dynamic response to exercise. Sci Rep 2021; 11:12776. [PMID: 34140586 PMCID: PMC8211849 DOI: 10.1038/s41598-021-92177-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 06/04/2021] [Indexed: 01/21/2023] Open
Abstract
Exercise likely has numerous benefits for brain and cognition. However, those benefits and their causes remain imprecisely defined. If the brain does benefit from exercise it does so primarily through cumulative brief, "acute" exposures over a lifetime. The Dementia Risk and Dynamic Response to Exercise (DYNAMIC) clinical trial seeks to characterize the acute exercise response in cerebral perfusion, and circulating neurotrophic factors in older adults with and without the apolipoprotein e4 genotype (APOE4), the strongest genetic predictor of sporadic, late onset Alzheimer's disease. DYNAMIC will enroll 60 older adults into a single moderate intensity bout of exercise intervention, measuring pre- and post-exercise cerebral blood flow (CBF) using arterial spin labeling, and neurotrophic factors. We expect that APOE4 carriers will have poor CBF regulation, i.e. slower return to baseline perfusion after exercise, and will demonstrate blunted neurotrophic response to exercise, with concentrations of neurotrophic factors positively correlating with CBF regulation. Preliminary findings on 7 older adults and 9 younger adults demonstrate that the experimental method can capture CBF and neurotrophic response over a time course. This methodology will provide important insight into acute exercise response and potential directions for clinical trial outcomes.ClinicalTrials.gov NCT04009629, Registered 05/07/2019.
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Affiliation(s)
- Dreu White
- University of Kansas Medical Center, Kansas City, KS, USA
| | - Casey S John
- University of Kansas Medical Center, Kansas City, KS, USA
| | - Ashley Kucera
- American Academy of Family Physicians, Leawood, KS, USA
| | - Bryce Truver
- University of Kansas Medical Center, Kansas City, KS, USA
| | | | - Paul J Kueck
- University of Kansas Medical Center, Kansas City, KS, USA
| | - Phil Lee
- University of Kansas Medical Center, Kansas City, KS, USA
| | - Laura Martin
- University of Kansas Medical Center, Kansas City, KS, USA
| | | | | | - Jill K Morris
- University of Kansas Medical Center, Kansas City, KS, USA
| | - Eric D Vidoni
- University of Kansas Medical Center, Kansas City, KS, USA.
- University of Kansas Alzheimer's Disease Center, 4350 Shawnee Mission Parkway, Fairway, KS, 60205, MS6002, USA.
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12
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Bangen KJ, Thomas KR, Sanchez DL, Edmonds EC, Weigand AJ, Delano-Wood L, Bondi MW. Entorhinal Perfusion Predicts Future Memory Decline, Neurodegeneration, and White Matter Hyperintensity Progression in Older Adults. J Alzheimers Dis 2021; 81:1711-1725. [PMID: 33967041 DOI: 10.3233/jad-201474] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Altered cerebral blood flow (CBF) has been linked to increased risk for Alzheimer's disease (AD). However, whether altered CBF contributes to AD risk by accelerating cognitive decline remains unclear. It also remains unclear whether reductions in CBF accelerate neurodegeneration and development of small vessel cerebrovascular disease. OBJECTIVE To examine associations between CBF and trajectories of memory performance, regional brain atrophy, and global white matter hyperintensity (WMH) volume. METHOD 147 Alzheimer's Disease Neuroimaging Initiative participants free of dementia underwent arterial spin labeling (ASL) magnetic resonance imaging (MRI) to measure CBF and serial neuropsychological and structural MRI examinations. Linear mixed effects models examined 5-year rate of change in memory and 4-year rate of change in regional brain atrophy and global WMH volumes as a function of baseline regional CBF. Entorhinal and hippocampal CBF were examined in separate models. RESULTS Adjusting for demographic characteristics, pulse pressure, apolipoprotein E ɛ4 positivity, cerebrospinal fluid p-tau/Aβ ratio, and neuronal metabolism (i.e., fluorodeoxyglucose standardized uptake value ratio), lower baseline entorhinal CBF predicted faster rates of decline in memory as well as faster entorhinal thinning and WMH progression. Hippocampal CBF did not predict cognitive or brain structure trajectories. CONCLUSION Findings highlight the importance of early cerebrovascular dysfunction in AD risk and suggest that entorhinal CBF as measured by noninvasive ASL MRI is a useful biomarker predictive of future cognitive decline and of risk of both.
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Affiliation(s)
- Katherine J Bangen
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Kelsey R Thomas
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Danielle L Sanchez
- Department of Psychology, San Diego State University, San Diego, CA, USA
| | - Emily C Edmonds
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Alexandra J Weigand
- San Diego Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California, San Diego, CA, USA
| | - Lisa Delano-Wood
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.,Psychology Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Mark W Bondi
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.,Psychology Service, VA San Diego Healthcare System, San Diego, CA, USA
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13
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Thomas KR, Osuna JR, Weigand AJ, Edmonds EC, Clark AL, Holmqvist S, Cota IH, Wierenga CE, Bondi MW, Bangen KJ. Regional hyperperfusion in older adults with objectively-defined subtle cognitive decline. J Cereb Blood Flow Metab 2021; 41:1001-1012. [PMID: 32615887 PMCID: PMC8054731 DOI: 10.1177/0271678x20935171] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/21/2020] [Accepted: 05/16/2020] [Indexed: 11/16/2022]
Abstract
Although cerebral blood flow (CBF) alterations are associated with Alzheimer's disease (AD), CBF patterns across prodromal stages of AD remain unclear. Therefore, we investigated patterns of regional CBF in 162 Alzheimer's Disease Neuroimaging Initiative participants characterized as cognitively unimpaired (CU; n = 80), objectively-defined subtle cognitive decline (Obj-SCD; n = 31), or mild cognitive impairment (MCI; n = 51). Arterial spin labeling MRI quantified regional CBF in a priori regions of interest: hippocampus, inferior temporal gyrus, inferior parietal lobe, medial orbitofrontal cortex, and rostral middle frontal gyrus. Obj-SCD participants had increased hippocampal and inferior parietal CBF relative to CU and MCI participants and increased inferior temporal CBF relative to MCI participants. CU and MCI groups did not differ in hippocampal or inferior parietal CBF, but CU participants had increased inferior temporal CBF relative to MCI participants. There were no CBF group differences in the two frontal regions. Thus, we found an inverted-U pattern of CBF signal across prodromal AD stages in regions susceptible to early AD pathology. Hippocampal and inferior parietal hyperperfusion in Obj-SCD may reflect early neurovascular dysregulation, whereby higher CBF is needed to maintain cognitive functioning relative to MCI participants, yet is also reflective of early cognitive inefficiencies that distinguish Obj-SCD from CU participants.
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Affiliation(s)
- Kelsey R Thomas
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Jessica R Osuna
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Alexandra J Weigand
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
- San Diego State University/University of California, San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA
| | - Emily C Edmonds
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Alexandra L Clark
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Sophia Holmqvist
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Isabel H Cota
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Christina E Wierenga
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Mark W Bondi
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
- Psychology Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Katherine J Bangen
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
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14
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Hays CC, Zlatar ZZ, Meloy MJ, Bondi MW, Gilbert PE, Liu T, Helm JL, Wierenga CE. Interaction of APOE, cerebral blood flow, and cortical thickness in the entorhinal cortex predicts memory decline. Brain Imaging Behav 2021; 14:369-382. [PMID: 32048144 DOI: 10.1007/s11682-019-00245-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The ε4 allele of the apolipoprotein E (APOE) gene, a risk factor for cognitive decline, is associated with alterations in medial temporal lobe (MTL) structure and function, yet little research has been dedicated to understanding how these alterations might interact to negatively impact cognition. To bridge this gap, the present study employed linear regression models to determine the extent to which APOE genotype (ε4+, ε4-) modifies interactive effects of baseline arterial spin labeling MRI-measured cerebral blood flow (CBF) and FreeSurfer-derived cortical thickness/volume (CT/Vo) in two MTL regions of interest (entorhinal cortex, hippocampus) on memory change in 98 older adults who were cognitively normal at baseline. Baseline entorhinal CBF was positively associated with memory change, but only among ε4 carriers with lower entorhinal CT. Similarly, baseline entorhinal CT was positively associated with memory change, but only among ε4 carriers with lower entorhinal CBF. Findings suggest that APOE ε4 carriers may experience concomitant alterations in neurovascular function and morphology in the MTL that interact to negatively affect cognition prior to the onset of overt clinical symptoms. Results also suggest the presence of distinct multimodal neural signatures in the entorhinal cortex that may signal relative risk for cognitive decline among this group, perhaps reflecting different stages of cerebrovascular compensation (early effective vs. later ineffective).
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Affiliation(s)
- Chelsea C Hays
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 9216, USA.,SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct, Suite 103, San Diego, CA, 92120, USA
| | - Zvinka Z Zlatar
- Department of Psychiatry, UC San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - M J Meloy
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 9216, USA.,Department of Psychiatry, UC San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Mark W Bondi
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 9216, USA.,SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct, Suite 103, San Diego, CA, 92120, USA.,Department of Psychiatry, UC San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Paul E Gilbert
- SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct, Suite 103, San Diego, CA, 92120, USA.,Department of Psychology, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182, USA
| | - Thomas Liu
- Department of Radiology, UC San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Jonathan L Helm
- SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct, Suite 103, San Diego, CA, 92120, USA.,Department of Psychology, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182, USA
| | - Christina E Wierenga
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 9216, USA. .,SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct, Suite 103, San Diego, CA, 92120, USA. .,Department of Psychiatry, UC San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA.
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15
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Østergaard L. Blood flow, capillary transit times, and tissue oxygenation: the centennial of capillary recruitment. J Appl Physiol (1985) 2020; 129:1413-1421. [PMID: 33031017 DOI: 10.1152/japplphysiol.00537.2020] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The transport of oxygen between blood and tissue is limited by blood's capillary transit time, understood as the time available for diffusion exchange before blood returns to the heart. If all capillaries contribute equally to tissue oxygenation at all times, this physical limitation would render vasodilation and increased blood flow insufficient means to meet increased metabolic demands in the heart, muscle, and other organs. In 1920, Danish physiologist August Krogh was awarded the Nobel Prize in Physiology or Medicine for his mathematical and quantitative, experimental demonstration of a solution to this conceptual problem: capillary recruitment, the active opening of previously closed capillaries to meet metabolic demands. Today, capillary recruitment is still mentioned in textbooks. When we suspect symptoms might represent hypoxia of a vascular origin, however, we search for relevant, flow-limiting conditions in our patients and rarely ascribe hypoxia or hypoxemia to short capillary transit times. This review describes how natural changes in capillary transit-time heterogeneity (CTH) and capillary hematocrit (HCT) across open capillaries during blood flow increases can account for a match of oxygen availability to metabolic demands in normal tissue. CTH and HCT depend on a number of factors: on blood properties, including plasma viscosity, the number, size, and deformability of blood cells, and blood cell interactions with capillary endothelium; on anatomical factors including glycocalyx, endothelial cells, basement membrane, and pericytes that affect the capillary diameter; and on any external compression. The review describes how risk factor- and disease-related changes in CTH and HCT interfere with flow-metabolism coupling and tissue oxygenation and discusses whether such capillary dysfunction contributes to vascular disease pathology.
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Affiliation(s)
- Leif Østergaard
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Neuroradiology Research Unit, Section of Neuroradiology, Department of Radiology, Aarhus University Hospital, Aarhus, Denmark
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16
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Sanchez DL, Thomas KR, Edmonds EC, Bondi MW, Bangen KJ. Regional Hypoperfusion Predicts Decline in Everyday Functioning at Three-Year Follow-Up in Older Adults without Dementia. J Alzheimers Dis 2020; 77:1291-1304. [PMID: 32831202 DOI: 10.3233/jad-200490] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Increasing evidence indicates that cerebrovascular dysfunction may precede cognitive decline in aging and Alzheimer's disease (AD). Reduced cerebral blood flow (CBF) is associated with cognitive impairment in older adults. However, less is known regarding the association between CBF and functional decline, and whether CBF predicts functional decline beyond cerebrovascular and metabolic risk factors. OBJECTIVE To examine the association between regional CBF and functional decline in nondemented older adults. METHOD One hundred sixty-six (N = 166) participants without dementia from the Alzheimer's Disease Neuroimaging Initiative underwent neuropsychological testing and neuroimaging. Pulsed arterial spin labeling magnetic resonance imaging was acquired to quantify resting CBF. Everyday functioning was measured using the Functional Assessment Questionnaire at baseline and annual follow-up visit across three years. RESULTS Adjusting for age, education, sex, cognitive status, depression, white matter hyperintensity volume, cerebral metabolism, and reference (precentral) CBF, linear mixed effects models showed that lower resting CBF at baseline in the medial temporal, inferior temporal, and inferior parietal lobe was significantly associated with accelerated decline in everyday functioning. Results were similar after adjusting for conventional AD biomarkers, including cerebrospinal fluid (CSF) amyloid-β (Aβ) and hyperphosphorylated tau (p-tau) and apolipoprotein E (APOE) ɛ4 positivity. Individuals who later converted to dementia had lower resting CBF in the inferior temporal and parietal regions compared to those who did not. CONCLUSION Lower resting CBF in AD vulnerable regions including medial temporal, inferior temporal, and inferior parietal lobes predicted faster rates of decline in everyday functioning. CBF has utility as a biomarker in predicting functional declines in everyday life and conversion to dementia.
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Affiliation(s)
- Danielle L Sanchez
- Department of Psychology, San Diego State University, San Diego, CA, USA
| | - Kelsey R Thomas
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Emily C Edmonds
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Mark W Bondi
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Psychology Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Katherine J Bangen
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
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17
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McKiernan EF, Mak E, Dounavi ME, Wells K, Ritchie C, Williams G, Su L, O'Brien J. Regional hyperperfusion in cognitively normal APOE ε4 allele carriers in mid-life: analysis of ASL pilot data from the PREVENT-Dementia cohort. J Neurol Neurosurg Psychiatry 2020; 91:861-866. [PMID: 32586852 DOI: 10.1136/jnnp-2020-322924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/01/2020] [Accepted: 05/27/2020] [Indexed: 01/28/2023]
Abstract
BACKGROUND Regional cerebral hypoperfusion is characteristic of Alzheimer's disease (AD). Previous studies report conflicting findings in cognitively normal individuals at high risk of AD. Understanding early preclinical perfusion alterations may improve understanding of AD pathogenesis and lead to new biomarkers and treatment targets. METHODS 3T arterial spin labelling MRI scans from 162 participants in the PREVENT-Dementia cohort were analysed (cognitively normal participants aged 40-59, stratified by future dementia risk). Cerebral perfusion was compared vertex-wise according to APOE ε4 status and family history (FH). Correlations between individual perfusion, age and cognitive scores (COGNITO battery) were explored. RESULTS Regional hyperperfusion was found in APOE ε4+group (left cingulate and lateral frontal and parietal regions p<0.01, threshold-free cluster enhancement, TFCE) and in FH +group (left temporal and parietal regions p<0.01, TFCE). Perfusion did not correlate with cognitive test scores. CONCLUSIONS Regional cerebral hyperperfusion in individuals at increased risk of AD in mid-life may be a very early marker of functional brain change related to AD. Increased perfusion may reflect a functional 'compensation' mechanism, offsetting the effects of early neural damage or may itself be risk factor for accelerating spread of degenerative pathology.
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Affiliation(s)
| | - Elijah Mak
- Psychiatry, University of Cambridge, Cambridge, UK
| | | | - Katie Wells
- The Centre for Mental Health, Imperial College, London, UK
| | - Craig Ritchie
- Centre for Dementia Prevention, University of Edinburgh Centre for Clinical Brain Sciences, Edinburgh, Edinburgh, UK
| | - Guy Williams
- Wolfson Brain Imaging Centre, Cambridge University, Cambridge, UK
| | - Li Su
- Psychiatry, University of Cambridge, Cambridge, UK
| | - John O'Brien
- Psychiatry, University of Cambridge, Cambridge, UK
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18
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Mutsaerts HJMM, Mirza SS, Petr J, Thomas DL, Cash DM, Bocchetta M, de Vita E, Metcalfe AWS, Shirzadi Z, Robertson AD, Tartaglia MC, Mitchell SB, Black SE, Freedman M, Tang-Wai D, Keren R, Rogaeva E, van Swieten J, Laforce R, Tagliavini F, Borroni B, Galimberti D, Rowe JB, Graff C, Frisoni GB, Finger E, Sorbi S, de Mendonça A, Rohrer JD, MacIntosh BJ, Masellis M. Cerebral perfusion changes in presymptomatic genetic frontotemporal dementia: a GENFI study. Brain 2019; 142:1108-1120. [PMID: 30847466 PMCID: PMC6439322 DOI: 10.1093/brain/awz039] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/14/2018] [Accepted: 01/04/2019] [Indexed: 11/12/2022] Open
Abstract
Genetic forms of frontotemporal dementia are most commonly due to mutations in three genes, C9orf72, GRN or MAPT, with presymptomatic carriers from families representing those at risk. While cerebral blood flow shows differences between frontotemporal dementia and other forms of dementia, there is limited evidence of its utility in presymptomatic stages of frontotemporal dementia. This study aimed to delineate the cerebral blood flow signature of presymptomatic, genetic frontotemporal dementia using a voxel-based approach. In the multicentre GENetic Frontotemporal dementia Initiative (GENFI) study, we investigated cross-sectional differences in arterial spin labelling MRI-based cerebral blood flow between presymptomatic C9orf72, GRN or MAPT mutation carriers (n = 107) and non-carriers (n = 113), using general linear mixed-effects models and voxel-based analyses. Cerebral blood flow within regions of interest derived from this model was then explored to identify differences between individual gene carrier groups and to estimate a timeframe for the expression of these differences. The voxel-based analysis revealed a significant inverse association between cerebral blood flow and the expected age of symptom onset in carriers, but not non-carriers. Regions included the bilateral insulae/orbitofrontal cortices, anterior cingulate/paracingulate gyri, and inferior parietal cortices, as well as the left middle temporal gyrus. For all bilateral regions, associations were greater on the right side. After correction for partial volume effects in a region of interest analysis, the results were found to be largely driven by the C9orf72 genetic subgroup. These cerebral blood flow differences first appeared approximately 12.5 years before the expected symptom onset determined on an individual basis. Cerebral blood flow was lower in presymptomatic mutation carriers closer to and beyond their expected age of symptom onset in key frontotemporal dementia signature regions. These results suggest that arterial spin labelling MRI may be a promising non-invasive imaging biomarker for the presymptomatic stages of genetic frontotemporal dementia.
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Affiliation(s)
- Henri J M M Mutsaerts
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada
| | - Saira S Mirza
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada
| | - Jan Petr
- PET Center, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - David L Thomas
- Institute of Neurology, University College London, London, UK
| | - David M Cash
- Institute of Neurology, University College London, London, UK
| | | | - Enrico de Vita
- Institute of Neurology, University College London, London, UK
| | - Arron W S Metcalfe
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada
| | - Zahra Shirzadi
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada
| | - Andrew D Robertson
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada
| | - Maria Carmela Tartaglia
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada.,Memory Clinic, University Health Network, Toronto, Canada.,Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada
| | - Sara B Mitchell
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada.,Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,L.C. Campbell Cognitive Neurology Research Unit, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Sandra E Black
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada.,Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,L.C. Campbell Cognitive Neurology Research Unit, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Morris Freedman
- Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,Baycrest Centre for Geriatric Care, Toronto, Canada
| | - David Tang-Wai
- Memory Clinic, University Health Network, Toronto, Canada.,Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada
| | - Ron Keren
- Memory Clinic, University Health Network, Toronto, Canada
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - John van Swieten
- Department of Neurology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Robert Laforce
- Clinique Interdisciplinaire de Mémoire (CIME), Département des Sciences Neurologiques, CHU de Québec, Faculté de médecine, Université Laval, Québec, Canada
| | - Fabrizio Tagliavini
- Fondazione Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy
| | - Barbara Borroni
- Department of Medical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Daniela Galimberti
- Centro Dino Ferrari, Fondazione Ca' Granda IRCCS Ospedale Policlinico, University of Milan, Milan, Italy
| | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Caroline Graff
- Department of Geriatric Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Elizabeth Finger
- Department of Clinical Neurological Sciences, University of Western Ontario, London, Canada
| | - Sandro Sorbi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | | | | | - Bradley J MacIntosh
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada
| | - Mario Masellis
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, Canada.,Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.,L.C. Campbell Cognitive Neurology Research Unit, Sunnybrook Health Sciences Centre, Toronto, Canada.,Cognitive and Movement Disorders Clinic, Sunnybrook Health Sciences Centre, Toronto, Canada
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19
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APOE modifies the interaction of entorhinal cerebral blood flow and cortical thickness on memory function in cognitively normal older adults. Neuroimage 2019; 202:116162. [PMID: 31493534 DOI: 10.1016/j.neuroimage.2019.116162] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/14/2019] [Accepted: 09/03/2019] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE The ε4 allele of the apolipoprotein E (APOE) gene increases risk for cognitive decline in normal and pathologic aging. However, precisely how APOE ε4 exerts its negative impact on cognition is poorly understood. The present study aimed to determine whether APOE genotype (ε4+ vs. ε4-) modifies the interaction of medial temporal lobe (MTL) resting cerebral blood flow (CBF) and brain structure (cortical thickness [CT], volume [Vo]) on verbal memory performance. METHODS Multiple linear regression models were employed to investigate relationships between APOE genotype, arterial spin labeling MRI-measured CBF and FreeSurfer-based CT and Vo in four MTL regions of interest (left and right entorhinal cortex and hippocampus), and verbal memory performance among a sample of 117 cognitively normal older adults (41 ε4+, 76 ε4-) between the ages of 64 and 89 (mean age = 73). RESULTS Results indicated that APOE genotype modified the interaction of CBF and CT on memory in the left entorhinal cortex, such that the relationship between entorhinal CBF and memory was negative (lower CBF was associated with better memory) in non-carriers with higher entorhinal CT, positive (higher CBF was associated with better memory) in non-carriers with lower entorhinal CT, and negative (higher CBF was associated with worse memory) in ε4 carriers with lower entorhinal CT. CONCLUSIONS Findings suggest that older adult APOE ε4 carriers may experience vascular dysregulation and concomitant morphological alterations in the MTL that interact to negatively affect memory even in the absence overt clinical symptoms, providing potential insight into the mechanistic link between APOE ε4 and detriments in cognition. Moreover, findings suggest a distinct multimodal neural signature in ε4 carriers (higher CBF and lower CT in the entorhinal cortex) that could aid in the identification of candidates for future clinical trials aimed at preventing or slowing cognitive decline. Differential findings with respect to ε4 carriers and non-carriers are discussed in the context of neurovascular compensation.
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20
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van der Thiel M, Rodriguez C, Van De Ville D, Giannakopoulos P, Haller S. Regional Cerebral Perfusion and Cerebrovascular Reactivity in Elderly Controls With Subtle Cognitive Deficits. Front Aging Neurosci 2019; 11:19. [PMID: 30837863 PMCID: PMC6390712 DOI: 10.3389/fnagi.2019.00019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 01/21/2019] [Indexed: 12/27/2022] Open
Abstract
Background: Recent studies suggested that arterial spin labeling (ASL)-based measures of cerebral blood flow (CBF) as well as cerebral vasoreactivity to CO2 (CVR CO2) show significant alterations mainly in posterior neocortical areas both in mild cognitive impairment (MCI) and Alzheimer disease. It remains, however, unknown whether similar changes occur in at risk healthy elders without clinically overt symptoms. This longitudinal study investigated patterns of ASL perfusion and CVR CO2 as a function of the cognitive trajectories in asymptomatic elderly individuals. Methods: Seventy-nine community-dwelling subjects (mean age: 78.7 years, 34 male) underwent three neuropsychological assessments during a subsequent 3-year period. Individuals were classified as stable-stable (SS), variable (V), or progressive-progressive (PP). Between-group comparisons were conducted for ASL CBF and transit-time delay maps and β-maps of CO2 response. Spearman's rho maps assessed the correlation between ASL (respectively, CVR CO2 measures) and Shapes test for working memory, as well as Verbal fluency test for executive functions. Three group-with-continuous-covariate-interaction designs were implemented to investigate group-based differences on the association between neuropsychological scores and ASL or CO2 measures. Results: Comparison of CBF maps demonstrates significantly lower perfusion in the V-group as to PP-cases predominantly in parietal regions, including the precuneus and, to a lesser degree, in temporal and frontal cortex. A stronger CVR CO2 response was found in the PP-group in left parietal areas compared to the V-group. V-cases showed a stronger ASL-Shape value relationship than V-group in right temporoparietal junction and superior parietal lobule. CO2-Shape value correlation was significantly higher in both SS and PP-groups compared to the V-group in right insular and superior perisylvian regions. Conclusion: Our data indicate the presence of decreased ASL and CVR CO2 values mainly in parietal and fronto-temporal areas in cases with the first signs of cognitive instability (V-group). Importantly, the PP-group, at high risk for MCI transition, displays an increase of both parameters in the same areas. Clinicoradiologic correlations also indicate a clear distinction between the V-group and both PP and SS-cases. These data imply the presence of an inverted U-shape pattern of regional blood flow and CVR in old age that might predict subsequent cognitive fate.
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Affiliation(s)
- Merel van der Thiel
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Faculté de Médecine, Université de Genève, Geneva, Switzerland
| | - Cristelle Rodriguez
- Division of Institutional Measures, Geneva University Hospitals, Geneva, Switzerland
| | - Dimitri Van De Ville
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Faculté de Médecine, Université de Genève, Geneva, Switzerland
| | | | - Sven Haller
- Faculté de Médecine, Université de Genève, Geneva, Switzerland.,CIRD - Centre d'Imagerie Rive Droite, Geneva, Switzerland.,Department of Surgical Sciences, Division of Radiology, Uppsala University, Uppsala, Sweden
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21
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Deng H, Ordaz A, Upadhyayula PS, Gillis-Buck EM, Suen CG, Melhado CG, Mohammed N, Lam T, Yue JK. Apolipoprotein E Epsilon 4 Genotype, Mild Traumatic Brain Injury, and the Development of Chronic Traumatic Encephalopathy. Med Sci (Basel) 2018; 6:E78. [PMID: 30223506 PMCID: PMC6163513 DOI: 10.3390/medsci6030078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 09/04/2018] [Accepted: 09/12/2018] [Indexed: 12/14/2022] Open
Abstract
The annual incidence of mild traumatic brain injury (MTBI) is 3.8 million in the USA with 10⁻15% experiencing persistent morbidity beyond one year. Chronic traumatic encephalopathy (CTE), a neurodegenerative disease characterized by accumulation of hyperphosphorylated tau, can occur with repetitive MTBI. Risk factors for CTE are challenging to identify because injury mechanisms of MTBI are heterogeneous, clinical manifestations and management vary, and CTE is a postmortem diagnosis, making prospective studies difficult. There is growing interest in the genetic influence on head trauma and development of CTE. Apolipoprotein epsilon 4 (APOE-ε4) associates with many neurologic diseases, and consensus on the ε4 allele as a risk factor is lacking. This review investigates the influence of APOE-ε4 on MTBI and CTE. A comprehensive PubMed literature search (1966 to 12 June 2018) identified 24 unique reports on the topic (19 MTBI studies: 8 athletic, 5 military, 6 population-based; 5 CTE studies: 4 athletic and military, 1 leucotomy group). APOE-ε4 genotype is found to associate with outcomes in 4/8 athletic reports, 3/5 military reports, and 5/6 population-based reports following MTBI. Evidence on the association between APOE-ε4 and CTE from case series is equivocal. Refining modalities to aid CTE diagnosis in larger samples is needed in MTBI.
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Affiliation(s)
- Hansen Deng
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94122, USA.
| | - Angel Ordaz
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94122, USA.
| | - Pavan S Upadhyayula
- Department of Neurological Surgery, University of California San Diego, San Diego, CA 92093, USA.
| | - Eva M Gillis-Buck
- Department of Surgery, University of California San Francisco, San Francisco, CA 94122, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| | - Catherine G Suen
- Department of Neurology, University of Utah, Salt Lake City, UT 84112, USA.
| | - Caroline G Melhado
- Department of Surgery, University of California San Francisco, San Francisco, CA 94122, USA.
| | - Nebil Mohammed
- Department of Pathology, University of California San Francisco, San Francisco, CA 94122, USA.
| | - Troy Lam
- Department of Oral and Maxillofacial Surgery, University of California San Francisco, San Francisco, CA 94122, USA.
| | - John K Yue
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94122, USA.
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22
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Nylander R, Kilander L, Ahlström H, Lind L, Larsson EM. Small Vessel Disease on Neuroimaging in a 75-Year-Old Cohort (PIVUS): Comparison With Cognitive and Executive Tests. Front Aging Neurosci 2018; 10:217. [PMID: 30061827 PMCID: PMC6054972 DOI: 10.3389/fnagi.2018.00217] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/26/2018] [Indexed: 12/28/2022] Open
Abstract
Background and Purpose: Signs of small vessel disease (SVD) are commonly seen on magnetic resonance imaging (MRI) of the brain in cognitively healthy elderly individuals, and the clinical relevance of these are often unclear. We have previously described three different MRI manifestations of SVD as well as cerebral perfusion in a longitudinal study of non-demented 75-year-old subjects. The purpose of the present study was to evaluate the relationship of these findings to cognition and executive function at age 75 and changes after 5 years. Methods: In all, 406 subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study were examined with MRI of the brain at age 75 years. Two-hundred and fifty of the subjects were re-examined 5 years later. White matter hyperintensities (WMHs) and lacunar infarcts (LIs) were assessed on both occasions, but microbleeds (MBs) and perfusion only at age 75. Cognitive function was screened by the Mini Mental State Examination (MMSE). Trail Making Test A and B (TMT-A and TMT-B) were performed at baseline and at follow-up at age 80. Results: At baseline, 93% performed >27 points in the MMSE. The TMT-B at age 75 was significantly related to WMH visual scoring after adjustment for sex, education and cerebrovascular disease risk factors (+80 s (95% CI 0.3-161 s), P < 0.05 for grade 2-3 vs. grade 0). Neither MMSE nor TMT-A was significantly related to WMH scoring. There was no relation between any test performance and WMH volume, white matter volume, number of MBs or brain perfusion at age 75. Subjects who had sustained a new LI (n = 26) showed a greater increase of the time to perform TMT-A at the 5-year follow-up (+25 s vs. +4 s in LI-free subjects, P = 0.003). Changes in MMSE or TMT-A and -B test performance between ages 75 and 80 were not related to changes in WMH scoring or volume during the 5 years follow-up, or to brain perfusion at age 75. Conclusion: In this cognitively healthy community-based population, moderate-severe WMHs and incident LIs on brain MRI in individuals aged 75-80 years were associated with a mild impairment of processing speed and executive function.
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Affiliation(s)
- Ruta Nylander
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | - Lena Kilander
- Department of Public Health and Caring Sciences, Geriatrics, Uppsala University, Uppsala, Sweden
| | - Håkan Ahlström
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | - Lars Lind
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Elna-Marie Larsson
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
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23
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Bayram E, Caldwell JZK, Banks SJ. Current understanding of magnetic resonance imaging biomarkers and memory in Alzheimer's disease. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2018; 4:395-413. [PMID: 30229130 PMCID: PMC6140335 DOI: 10.1016/j.trci.2018.04.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Alzheimer's disease (AD) is caused by a cascade of changes to brain integrity. Neuroimaging biomarkers are important in diagnosis and monitoring the effects of interventions. As memory impairments are among the first symptoms of AD, the relationship between imaging findings and memory deficits is important in biomarker research. The most established magnetic resonance imaging (MRI) finding is hippocampal atrophy, which is related to memory decline and currently used as a diagnostic criterion for AD. While the medial temporal lobes are impacted early by the spread of neurofibrillary tangles, other networks and regional changes can be found quite early in the progression. Atrophy in several frontal and parietal regions, cortical thinning, and white matter alterations correlate with memory deficits in early AD. Changes in activation and connectivity have been detected by functional MRI (fMRI). Task-based fMRI studies have revealed medial temporal lobe hypoactivation, parietal hyperactivation, and frontal hyperactivation in AD during memory tasks, and activation patterns of these regions are also altered in preclinical and prodromal AD. Resting state fMRI has revealed alterations in default mode network activity related to memory in early AD. These studies are limited in part due to the historic inclusion of patients who had suspected AD but likely did not have the disorder. Modern biomarkers allow for more diagnostic certainty, allowing better understanding of neuroimaging markers in true AD, even in the preclinical stage. Larger patient cohorts, comparison of candidate imaging biomarkers to more established biomarkers, and inclusion of more detailed neuropsychological batteries to assess multiple aspects of memory are needed to better understand the memory deficit in AD and help develop new biomarkers. This article reviews MRI findings related to episodic memory impairments in AD and introduces a new study with multimodal imaging and comprehensive neuropsychiatric evaluation to overcome current limitations.
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Affiliation(s)
- Ece Bayram
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, USA
| | - Jessica Z K Caldwell
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, USA
| | - Sarah J Banks
- Department of Neurology, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, USA
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24
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Subjective Cognitive Decline Modifies the Relationship Between Cerebral Blood Flow and Memory Function in Cognitively Normal Older Adults. J Int Neuropsychol Soc 2018; 24:213-223. [PMID: 28974274 PMCID: PMC5837810 DOI: 10.1017/s135561771700087x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Subjective cognitive decline (SCD), or self-reported cognitive decline despite normal neuropsychological test performance, is a risk factor for objective cognitive decline and Alzheimer's disease (AD). While brain mechanisms contributing to SCD are not well defined, studies show associations with vascular risk factors and altered cerebral blood flow (CBF), raising the hypothesis that those with SCD might be experiencing vascular dysregulation, or a disruption in the normal relationship between CBF and cognition. We examined whether the association between CBF and verbal memory performance differs between those with SCD (SCD+) and those without SCD (SCD-). METHODS Linear mixed-effects models were used to investigate whether the voxel-wise relationship between arterial spin labeling (ASL) MRI-measured CBF and verbal memory performance was modified by SCD among a group of 70 cognitively normal older adults (35 SCD+, 35 SCD-; mean age=72) matched on age, gender, and symptoms of depression. RESULTS Results indicated that the SCD- group exhibited positive associations between verbal memory and CBF within the posterior cingulate cortex, middle temporal gyrus, and inferior frontal gyrus, whereas the SCD+ group displayed negative associations between verbal memory and CBF within the posterior cingulate cortex, middle temporal gyrus, hippocampus, fusiform gyrus, and inferior frontal gyrus. CONCLUSIONS Findings suggest that, while higher CBF is supportive of memory function in those without SCD, higher CBF may no longer support memory function in those presenting with SCD, perhaps reflecting neurovascular dysregulation. (JINS, 2018, 24, 213-223).
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25
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Yue JK, Robinson CK, Burke JF, Winkler EA, Deng H, Cnossen MC, Lingsma HF, Ferguson AR, McAllister TW, Rosand J, Burchard EG, Sorani MD, Sharma S, Nielson JL, Satris GG, Talbott JF, Tarapore PE, Korley FK, Wang KK, Yuh EL, Mukherjee P, Diaz‐Arrastia R, Valadka AB, Okonkwo DO, Manley GT. Apolipoprotein E epsilon 4 (APOE-ε 4) genotype is associated with decreased 6-month verbal memory performance after mild traumatic brain injury. Brain Behav 2017; 7:e00791. [PMID: 28948085 PMCID: PMC5607554 DOI: 10.1002/brb3.791] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 06/28/2017] [Accepted: 07/02/2017] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION The apolipoprotein E (APOE) ε4 allele associates with memory impairment in neurodegenerative diseases. Its association with memory after mild traumatic brain injury (mTBI) is unclear. METHODS mTBI patients (Glasgow Coma Scale score 13-15, no neurosurgical intervention, extracranial Abbreviated Injury Scale score ≤1) aged ≥18 years with APOE genotyping results were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Cohorts determined by APOE-ε4(+/-) were assessed for associations with 6-month verbal memory, measured by California Verbal Learning Test, Second Edition (CVLT-II) subscales: Immediate Recall Trials 1-5 (IRT), Short-Delay Free Recall (SDFR), Short-Delay Cued Recall (SDCR), Long-Delay Free Recall (LDFR), and Long-Delay Cued Recall (LDCR). Multivariable regression controlled for demographic factors, seizure history, loss of consciousness, posttraumatic amnesia, and acute intracranial pathology on computed tomography (CT). RESULTS In 114 mTBI patients (APOE-ε4(-)=79; APOE-ε4(+)=35), ApoE-ε4(+) was associated with long-delay verbal memory deficits (LDFR: B = -1.17 points, 95% CI [-2.33, -0.01], p = .049; LDCR: B = -1.58 [-2.63, -0.52], p = .004), and a marginal decrease on SDCR (B = -1.02 [-2.05, 0.00], p = .050). CT pathology was the strongest predictor of decreased verbal memory (IRT: B = -8.49, SDFR: B = -2.50, SDCR: B = -1.85, LDFR: B = -2.61, LDCR: B = -2.60; p < .001). Seizure history was associated with decreased short-term memory (SDFR: B = -1.32, p = .037; SDCR: B = -1.44, p = .038). CONCLUSION The APOE-ε4 allele may confer an increased risk of impairment of 6-month verbal memory for patients suffering mTBI, with implications for heightened surveillance and targeted therapies. Acute intracranial pathology remains the driver of decreased verbal memory performance at 6 months after mTBI.
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Affiliation(s)
- John K. Yue
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Caitlin K. Robinson
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - John F. Burke
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Ethan A. Winkler
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Hansen Deng
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Maryse C. Cnossen
- Department of Public HealthErasmus Medical CenterRotterdamThe Netherlands
| | - Hester F. Lingsma
- Department of Public HealthErasmus Medical CenterRotterdamThe Netherlands
| | - Adam R. Ferguson
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | | | - Jonathan Rosand
- Program in Medical and Population GeneticsThe Broad Institute at MIT and HarvardCambridgeMAUSA
- Department of NeurologyHarvard Medical SchoolBostonMAUSA
| | - Esteban G. Burchard
- Department of Bioengineering and Therapeutic SciencesUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Marco D. Sorani
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Sourabh Sharma
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Stritch School of Medicine at Loyola UniversityMaywoodILUSA
| | - Jessica L. Nielson
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Gabriela G. Satris
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Jason F. Talbott
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
- Department of RadiologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Phiroz E. Tarapore
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
| | - Frederick K. Korley
- Department of Emergency MedicineUniversity of Michigan at Ann ArborAnn ArborMIUSA
| | - Kevin K.W. Wang
- Departments of Psychiatry and NeuroscienceUniversity of FloridaGainesvilleFLUSA
| | - Esther L. Yuh
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Department of RadiologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Pratik Mukherjee
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Department of RadiologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | | | - Alex B. Valadka
- Department of Neurological SurgeryVirginia Commonwealth UniversityRichmondVAUSA
| | - David O. Okonkwo
- Department of Neurological SurgeryUniversity of Pittsburgh Medical CenterPittsburghPAUSA
| | - Geoffrey T. Manley
- Department of Neurological SurgeryUniversity of California, San FranciscoSan FranciscoCAUSA
- Brain and Spinal Injury CenterSan Francisco General HospitalSan FranciscoCAUSA
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