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Fico BG, Miller KB, Rivera-Rivera LA, Corkery AT, Pearson AG, Eisenmann NA, Howery AJ, Rowley HA, Johnson KM, Johnson SC, Wieben O, Barnes JN. The Impact of Aging on the Association Between Aortic Stiffness and Cerebral Pulsatility Index. Front Cardiovasc Med 2022; 9:821151. [PMID: 35224051 PMCID: PMC8863930 DOI: 10.3389/fcvm.2022.821151] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/14/2022] [Indexed: 01/25/2023] Open
Abstract
The central arteries dampen the pulsatile forces from myocardial contraction, limiting the pulsatility that reaches the cerebral vasculature, although there are limited data on this relationship with aging in humans. The purpose of this study was to determine the association between aortic stiffness and cerebral artery pulsatility index in young and older adults. We hypothesized that cerebral pulsatility index would be associated with aortic stiffness in older adults, but not in young adults. We also hypothesized that both age and aortic stiffness would be significant predictors for cerebral pulsatility index. This study included 23 healthy older adults (aged 62 ± 6 years) and 33 healthy young adults (aged 25 ± 4 years). Aortic stiffness was measured using carotid-femoral pulse wave velocity (cfPWV), while cerebral artery pulsatility index in the internal carotid arteries (ICAs), middle cerebral arteries (MCAs), and basilar artery were assessed using 4D Flow MRI. Cerebral pulsatility index was calculated as (maximum flow - minimum flow) / mean flow. In the combined age group, there was a positive association between cfPWV and cerebral pulsatility index in the ICAs (r = 0.487; p < 0.001), MCAs (r = 0.393; p = 0.003), and basilar artery (r = 0.576; p < 0.001). In young adults, there were no associations between cfPWV and cerebral pulsatility index in any of the arteries of interest (ICAs: r = 0.253; p = 0.156, MCAs: r = -0.059; p = 0.743, basilar artery r = 0.171; p = 0.344). In contrast, in older adults there was a positive association between cfPWV and cerebral pulsatility index in the MCAs (r = 0.437; p = 0.037) and basilar artery (r = 0.500; p = 0.015). However, the relationship between cfPWV and cerebral pulsatility index in the ICAs of the older adults did not reach the threshold for significance (r = 0.375; p = 0.078). In conclusion, age and aortic stiffness are significant predictors of cerebral artery pulsatility index in healthy adults. This study highlights the importance of targeting aortic stiffness in our increasingly aging population to reduce the burden of age-related changes in cerebral hemodynamics.
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Affiliation(s)
- Brandon G. Fico
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Kathleen B. Miller
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Leonardo A. Rivera-Rivera
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States,Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Adam T. Corkery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Andrew G. Pearson
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Nicole A. Eisenmann
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Anna J. Howery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| | - Howard A. Rowley
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States,Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Kevin M. Johnson
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States,Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Sterling C. Johnson
- Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States,Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veteran's Hospital, Madison, WI, United States
| | - Oliver Wieben
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Jill N. Barnes
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States,*Correspondence: Jill N. Barnes
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Lombardi G, Crescioli G, Cavedo E, Lucenteforte E, Casazza G, Bellatorre A, Lista C, Costantino G, Frisoni G, Virgili G, Filippini G. Structural magnetic resonance imaging for the early diagnosis of dementia due to Alzheimer's disease in people with mild cognitive impairment. Cochrane Database Syst Rev 2020; 3:CD009628. [PMID: 32119112 PMCID: PMC7059964 DOI: 10.1002/14651858.cd009628.pub2] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Mild cognitive impairment (MCI) due to Alzheimer's disease is the symptomatic predementia phase of Alzheimer's disease dementia, characterised by cognitive and functional impairment not severe enough to fulfil the criteria for dementia. In clinical samples, people with amnestic MCI are at high risk of developing Alzheimer's disease dementia, with annual rates of progression from MCI to Alzheimer's disease estimated at approximately 10% to 15% compared with the base incidence rates of Alzheimer's disease dementia of 1% to 2% per year. OBJECTIVES To assess the diagnostic accuracy of structural magnetic resonance imaging (MRI) for the early diagnosis of dementia due to Alzheimer's disease in people with MCI versus the clinical follow-up diagnosis of Alzheimer's disease dementia as a reference standard (delayed verification). To investigate sources of heterogeneity in accuracy, such as the use of qualitative visual assessment or quantitative volumetric measurements, including manual or automatic (MRI) techniques, or the length of follow-up, and age of participants. MRI was evaluated as an add-on test in addition to clinical diagnosis of MCI to improve early diagnosis of dementia due to Alzheimer's disease in people with MCI. SEARCH METHODS On 29 January 2019 we searched Cochrane Dementia and Cognitive Improvement's Specialised Register and the databases, MEDLINE, Embase, BIOSIS Previews, Science Citation Index, PsycINFO, and LILACS. We also searched the reference lists of all eligible studies identified by the electronic searches. SELECTION CRITERIA We considered cohort studies of any size that included prospectively recruited people of any age with a diagnosis of MCI. We included studies that compared the diagnostic test accuracy of baseline structural MRI versus the clinical follow-up diagnosis of Alzheimer's disease dementia (delayed verification). We did not exclude studies on the basis of length of follow-up. We included studies that used either qualitative visual assessment or quantitative volumetric measurements of MRI to detect atrophy in the whole brain or in specific brain regions, such as the hippocampus, medial temporal lobe, lateral ventricles, entorhinal cortex, medial temporal gyrus, lateral temporal lobe, amygdala, and cortical grey matter. DATA COLLECTION AND ANALYSIS Four teams of two review authors each independently reviewed titles and abstracts of articles identified by the search strategy. Two teams of two review authors each independently assessed the selected full-text articles for eligibility, extracted data and solved disagreements by consensus. Two review authors independently assessed the quality of studies using the QUADAS-2 tool. We used the hierarchical summary receiver operating characteristic (HSROC) model to fit summary ROC curves and to obtain overall measures of relative accuracy in subgroup analyses. We also used these models to obtain pooled estimates of sensitivity and specificity when sufficient data sets were available. MAIN RESULTS We included 33 studies, published from 1999 to 2019, with 3935 participants of whom 1341 (34%) progressed to Alzheimer's disease dementia and 2594 (66%) did not. Of the participants who did not progress to Alzheimer's disease dementia, 2561 (99%) remained stable MCI and 33 (1%) progressed to other types of dementia. The median proportion of women was 53% and the mean age of participants ranged from 63 to 87 years (median 73 years). The mean length of clinical follow-up ranged from 1 to 7.6 years (median 2 years). Most studies were of poor methodological quality due to risk of bias for participant selection or the index test, or both. Most of the included studies reported data on the volume of the total hippocampus (pooled mean sensitivity 0.73 (95% confidence interval (CI) 0.64 to 0.80); pooled mean specificity 0.71 (95% CI 0.65 to 0.77); 22 studies, 2209 participants). This evidence was of low certainty due to risk of bias and inconsistency. Seven studies reported data on the atrophy of the medial temporal lobe (mean sensitivity 0.64 (95% CI 0.53 to 0.73); mean specificity 0.65 (95% CI 0.51 to 0.76); 1077 participants) and five studies on the volume of the lateral ventricles (mean sensitivity 0.57 (95% CI 0.49 to 0.65); mean specificity 0.64 (95% CI 0.59 to 0.70); 1077 participants). This evidence was of moderate certainty due to risk of bias. Four studies with 529 participants analysed the volume of the total entorhinal cortex and four studies with 424 participants analysed the volume of the whole brain. We did not estimate pooled sensitivity and specificity for the volume of these two regions because available data were sparse and heterogeneous. We could not statistically evaluate the volumes of the lateral temporal lobe, amygdala, medial temporal gyrus, or cortical grey matter assessed in small individual studies. We found no evidence of a difference between studies in the accuracy of the total hippocampal volume with regards to duration of follow-up or age of participants, but the manual MRI technique was superior to automatic techniques in mixed (mostly indirect) comparisons. We did not assess the relative accuracy of the volumes of different brain regions measured by MRI because only indirect comparisons were available, studies were heterogeneous, and the overall accuracy of all regions was moderate. AUTHORS' CONCLUSIONS The volume of hippocampus or medial temporal lobe, the most studied brain regions, showed low sensitivity and specificity and did not qualify structural MRI as a stand-alone add-on test for an early diagnosis of dementia due to Alzheimer's disease in people with MCI. This is consistent with international guidelines, which recommend imaging to exclude non-degenerative or surgical causes of cognitive impairment and not to diagnose dementia due to Alzheimer's disease. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Future research should not focus on a single biomarker, but rather on combinations of biomarkers to improve an early diagnosis of Alzheimer's disease dementia.
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Affiliation(s)
- Gemma Lombardi
- University of FlorenceDepartment of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)Largo Brambilla, 3FlorenceItaly50134
| | - Giada Crescioli
- University of FlorenceDepartment of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)Largo Brambilla, 3FlorenceItaly50134
| | - Enrica Cavedo
- Pitie‐Salpetriere Hospital, Sorbonne UniversityAlzheimer Precision Medicine (APM), AP‐HP47 boulevard de l'HopitalParisFrance75013
| | - Ersilia Lucenteforte
- University of PisaDepartment of Clinical and Experimental MedicineVia Savi 10PisaItaly56126
| | - Giovanni Casazza
- Università degli Studi di MilanoDipartimento di Scienze Biomediche e Cliniche "L. Sacco"via GB Grassi 74MilanItaly20157
| | | | - Chiara Lista
- Fondazione I.R.C.C.S. Istituto Neurologico Carlo BestaNeuroepidemiology UnitVia Celoria, 11MilanoItaly20133
| | - Giorgio Costantino
- Ospedale Maggiore Policlinico, Università degli Studi di MilanoUOC Pronto Soccorso e Medicina D'Urgenza, Fondazione IRCCS Ca' GrandaMilanItaly
| | | | - Gianni Virgili
- University of FlorenceDepartment of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)Largo Brambilla, 3FlorenceItaly50134
| | - Graziella Filippini
- Carlo Besta Foundation and Neurological InstituteScientific Director’s Officevia Celoria, 11MilanItaly20133
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Rivera-Rivera LA, Schubert T, Turski P, Johnson KM, Berman SE, Rowley HA, Carlsson CM, Johnson SC, Wieben O. Changes in intracranial venous blood flow and pulsatility in Alzheimer's disease: A 4D flow MRI study. J Cereb Blood Flow Metab 2017; 37:2149-2158. [PMID: 27492950 PMCID: PMC5464708 DOI: 10.1177/0271678x16661340] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/16/2016] [Accepted: 06/23/2016] [Indexed: 01/09/2023]
Abstract
Cerebral blood flow, arterial pulsation, and vasomotion may be important indicators of cerebrovascular health in aging and diseases of aging such as Alzheimer's disease. Noninvasive markers that assess these characteristics may be helpful in the study of co-occurrence of these diseases and potential additive and interacting effects. In this study, 4D flow MRI was used to measure intra-cranial flow features with cardiac-gated phase contrast MRI in cranial arteries and veins. Mean blood flow and pulsatility index as well as the transit time of the peak flow from the middle cerebral artery to the superior sagittal sinus were measured in a total of 104 subjects comprising of four groups: (a) subjects with Alzheimer's disease, (b) age-matched controls, (c) subjects with mild cognitive impairment, and (d) a group of late middle-aged with parental history of sporadic Alzheimer's disease. The Alzheimer's disease group exhibited: a significant decrease in mean blood flow in the superior sagittal sinus, transverse sinus, middle cerebral artery, and internal carotid arteries; a significant decrease of the peak and end diastolic blood flow in the middle cerebral artery and superior sagittal sinus; a faster transmission of peak flow from the middle cerebral artery to the superior sagittal sinus and increased pulsatility index along the carotid siphon.
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Affiliation(s)
- Leonardo A Rivera-Rivera
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Tilman Schubert
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Clinic of Radiology and Nuclear Medicine, Basel University Hospital, Basel, Switzerland
| | - Patrick Turski
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Kevin M Johnson
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Sara E Berman
- Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Howard A Rowley
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Cynthia M Carlsson
- Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Memorial VA Hospital, Madison, USA
- Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Sterling C Johnson
- Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Geriatric Research Education and Clinical Center, Wm. S. Middleton Memorial VA Hospital, Madison, USA
- Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Oliver Wieben
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, USA
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, USA
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4
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Turk M, Zaletel M, Pretnar-Oblak J. Ratio between carotid artery stiffness and blood flow - a new ultrasound index of ischemic leukoaraiosis. Clin Interv Aging 2016; 11:65-71. [PMID: 26869775 PMCID: PMC4734727 DOI: 10.2147/cia.s94163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Ischemic leukoaraiosis (ILA) is associated with cognitive decline and aging. Its pathophysiology is believed to be ischemic in origin due to its association with cerebrovascular risk factors and similarity in location to lacunar infarctions. ILA diagnosis is still based on magnetic resonance imaging (MRI) as well as exclusion of other causes of white matter hyperintensities. So far, there are no known confirming diagnostic tests of ILA. Ultrasound studies have recently shown increased large artery stiffness, increased cerebrovascular resistance, and lower cerebral blood flow in patients with ILA. Increased arterial stiffness and decreased blood flow could have a synergistic effect, and their ratio could be a useful diagnostic index of ILA. Methods In this post hoc analysis, we introduced new ILA indices (ILAi) that are ratios of the carotid stiffness parameters (pulse wave velocity beta [PWVβ], pressure–strain elasticity modulus [Ep], β index), and diastolic and mean blood flows in the internal carotid artery: Q-ICAd and Q-ICAm. We compared the ILAi of 52 patients with ILA and 44 sex- and risk factor-matched controls with normal MRI of the head. ILA diagnosis was based on MRI and exclusion of other causes of white matter hyperintensities. The diagnostic significance of ILAi for the prediction of ILA was analyzed. Results All ILAi significantly differed between the groups; the most significant were PWVβ/Q-ICAd (ILA group: 1.96±0.64 vs control group: 1.56±0.40, P=0.001) and PWVβ/Q-ICAm (ILA group: 1.13±0.32 vs control group: 0.94±0.25, P=0.003). All ILAi were significantly associated with ILA (P<0.01) and were significant independent predictors of ILA. All ILAi were also sensitive and specific for predicting ILA (area under the curve: 0.632–0.683, P<0.05). Conclusion The new ultrasound indices significantly differed between patients with ILA and the control group and were significant predictors of ILA. A combination of lower carotid blood flow and increased carotid stiffness represented as ILAi probably has a diagnostic value in patients with ILA.
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Affiliation(s)
- Monika Turk
- Department of Vascular Neurology and Intensive Neurological Therapy, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Marjan Zaletel
- Department of Vascular Neurology and Intensive Neurological Therapy, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Janja Pretnar-Oblak
- Department of Vascular Neurology and Intensive Neurological Therapy, University Medical Centre Ljubljana, Ljubljana, Slovenia
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Zhang R, Kadar T, Sirimanne E, MacGibbon A, Guan J. Age-related memory decline is associated with vascular and microglial degeneration in aged rats. Behav Brain Res 2012; 235:210-7. [PMID: 22889927 DOI: 10.1016/j.bbr.2012.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 08/01/2012] [Accepted: 08/02/2012] [Indexed: 12/16/2022]
Abstract
The hippocampus processes memory is an early target of aging-related biological and structural lesions, leading to memory decline. With absent neurodegeneration in the hippocampus, which identified in rodent model of normal aging the pathology underlying age-related memory impairment is not complete. The effective glial-vascular networks are the key for maintaining neuronal functions. The changes of glial cells and cerebral capillaries with age may contribute to memory decline. Thus we examined age associated changes in neurons, glial phenotypes and microvasculature in the hippocampus of aged rats with memory decline. Young adult (6 months) and aged (35 months) male rats (Fisher/Norway-Brown) were used. To evaluate memory, four days of acquisition phase of Morris water maze tasks were carried out in both age groups and followed by a probe trial 2 h after the acquisition. The brains were then collected for analysis using immunochemistry. The aged rats showed a delayed latency (p<0.001) and longer swimming path (p<0.001) to locate a hidden platform. They also spent less time in and made delayed and fewer entries into the correct quadrant during the probe trial. Without seen neuronal degeneration, the aged rats with memory impairments have displayed dopamine depletion, profound vascular and microglial degeneration with reduced vascular endothelial growth factor and elevated GFAP expression in the hippocampus. The data indicate the memory decline with age is associated with neuronal dysfunction, possibly due to impaired glial-vascular-neuronal networks, but not neuronal degeneration. Glial and vascular degeneration found in aged rats may represent early event of aging pathology prior to neuronal degeneration.
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Affiliation(s)
- Rong Zhang
- Liggins Institute, University of Auckland, Auckland, New Zealand
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Dubeau S, Desjardins M, Pouliot P, Beaumont E, Gaudreau P, Ferland G, Lesage F. Biophysical model estimation of neurovascular parameters in a rat model of healthy aging. Neuroimage 2011; 57:1480-91. [PMID: 21549843 DOI: 10.1016/j.neuroimage.2011.04.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 04/11/2011] [Accepted: 04/14/2011] [Indexed: 11/27/2022] Open
Abstract
Neuronal, vascular and metabolic factors result in a deterioration of the cerebral hemodynamic response with age. The interpretation of neuroimaging studies in the context of aging is rendered difficult due to the challenge in untangling the composite effect of these modifications. In this work we integrate multimodal optical imaging in biophysical models to investigate vascular and metabolic changes occurring in aging. Multispectral intrinsic optical imaging of an animal model of healthy aging, the LOU/c rat, is used in combination with somatosensory stimulation to study the modifications of the hemodynamic response with increasing age. Results are fitted with three macroscopic biophysical models to extract parameters, providing a phenomenological description of vascular and metabolic changes. Our results show that 1) biophysical parameters are estimable from multimodal data and 2) parameter estimates in this population change with aging.
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Affiliation(s)
- S Dubeau
- Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC, Canada
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Dubeau S, Ferland G, Gaudreau P, Beaumont E, Lesage F. Cerebrovascular hemodynamic correlates of aging in the Lou/c rat: a model of healthy aging. Neuroimage 2011; 56:1892-901. [PMID: 21497659 DOI: 10.1016/j.neuroimage.2011.03.076] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 03/07/2011] [Accepted: 03/28/2011] [Indexed: 11/18/2022] Open
Abstract
The LOU/c rat is an inbred strain considered a model of healthy aging. It exhibits a longer free disease lifespan and a low adiposity throughout life. While this animal model has been shown to maintain eating behavior and neuroendocrine, metabolic and cognitive functions with age, no study has yet investigated vascular correlates in this model of healthy aging. In the present work, multispectral optical imaging was used to investigate the hemodynamic response in the somatosensory cortex of LOU/c rats following forepaw stimulation in three age groups, 4, 24 and 40months. Results indicate reduced hemodynamic responses in the contralateral somatosensory cortex between young (4months) and older groups following stimulation. This decrease was associated with an increase in the spatial extent of activation. The ipsilateral response did not change with aging leading to decreased laterality. Estimations of the relative change in the local cerebral metabolic rate of oxygen during stimulation based on multimodal data showed no significant change with age. The exponent describing the relation between blood volume and blood flow changes, Grubb's parameter, did display a significant change with age which may suggest vessel compliance modifications. This work finds its relevance in recent findings underlying the importance of vascular changes with aging and its impact on neurodegenerative disease.
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Affiliation(s)
- S Dubeau
- Electrical Engineering Department, Ecole Polytechnique Montréal, Montreal, Quebec, Canada
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8
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Roher AE, Tyas SL, Maarouf CL, Daugs ID, Kokjohn TA, Emmerling MR, Garami Z, Belohlavek M, Sabbagh MN, Sue LI, Beach TG. Intracranial atherosclerosis as a contributing factor to Alzheimer's disease dementia. Alzheimers Dement 2011; 7:436-44. [PMID: 21388893 DOI: 10.1016/j.jalz.2010.08.228] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 06/30/2010] [Accepted: 08/06/2010] [Indexed: 01/12/2023]
Abstract
BACKGROUND A substantial body of evidence collected from epidemiologic, correlative, and experimental studies strongly associates atherosclerotic vascular disease (AVD) with Alzheimer's disease (AD). Depending on the precise interrelationship between AVD and AD, systematic application of interventions used to maintain vascular health and function as a component of standard AD therapy offers the prospect of mitigating the presently inexorable course of dementia. To assess this hypothesis, it is vital to rigorously establish the measures of AVD that are most strongly associated with an AD diagnosis. METHODS A precise neuropathological diagnosis was established for all subjects, using a battery of genetic, clinical, and histological methods. The severity of atherosclerosis in the circle of Willis was quantified by direct digitized measurement of arterial occlusion in postmortem specimens and was compared between AD and nondemented control groups by calculating a corresponding index of occlusion. RESULTS Atherosclerotic occlusion of the circle of Willis arteries was more extensive in the AD group than in the nondemented control group. Statistically significant differences were also observed between control and AD groups with regard to Braak stage, total plaque score, total neurofibrillary tangle score, total white matter rarefaction score, brain weight, Mini-Mental State Examination scores, and apolipoprotein E allelic frequencies. CONCLUSIONS Our results, combined with a consideration of the multifaceted effects of impaired cerebral circulation, suggest an immediate need for prospective clinical trials to assess the efficacy of AD prevention using antiatherosclerotic agents.
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Affiliation(s)
- Alex E Roher
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, AZ, USA.
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Ferrer I. Cognitive impairment of vascular origin: neuropathology of cognitive impairment of vascular origin. J Neurol Sci 2010; 299:139-49. [PMID: 20846674 DOI: 10.1016/j.jns.2010.08.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 08/15/2010] [Accepted: 08/24/2010] [Indexed: 12/31/2022]
Abstract
The term cognitive impairment of vascular origin is used to designate global cognitive deficits as well as focal neurological deficits such as aphasia, apraxia and agnosia of vascular/circulatory origin. It has been useful for identifying early clinical and neuroradiological alterations that might permit therapeutic strategies geared to curbing the progression of cerebrovascular disease. Multi-infarct encephalopathy, infarcts in strategic areas, lacunae and lacunar status, Binswanger's encephalopathy, hippocampal sclerosis, cortical granular atrophy and watershed infarcts are common lesions. Hypertension and vascular diseases such as arteriosclerosis, small blood vessel disease, inflammatory diseases of the blood vessels, Sneddon syndrome, cerebral amyloid angiopathies, cerebral autosomic dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and Maeda's syndrome are causative of cognitive impairment of vascular origin. Other less common causes are hereditary endotheliopathy with retinopathy, neuropathy and strokes (HERNS), cerebro-retinian vasculopathy (CRV), hereditary vascular retinopathy (HVR) (all three linked to 3p21.1-p21.3), hereditary infantile hemiparesis with arteriolar retinopathy and leukoencephalopathy (HIHRATL) (not linked to 3p21), fibromuscular dysplasia, and moya-moya disease. Lack of uniformity of clinical manifestations, the variety of vascular diseases and circulatory factors, the diverse, but often convergent, neuropathological substrates, and the common association with unrelated neurodegenerative diseases in the elderly, make it hard to assume a single clinical approach in the diagnosis and treatment of cognitive impairment of vascular origin. Rather, environmental and genetic risk factors, underlying vascular diseases, associated systemic, metabolic and neurodegenerative diseases and identification of extent and distribution of lesions with morphological and functional neuroimaging methods should be applied in every individual patient.
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Affiliation(s)
- Isidre Ferrer
- Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, 08907 Hospitalet de LLobregat, Spain.
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de la Torre JC. Carotid artery ultrasound and echocardiography testing to lower the prevalence of Alzheimer's disease. J Stroke Cerebrovasc Dis 2009; 18:319-28. [PMID: 19560690 DOI: 10.1016/j.jstrokecerebrovasdis.2008.11.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 10/29/2008] [Accepted: 11/03/2008] [Indexed: 12/22/2022] Open
Abstract
The use of two clinic office techniques, carotid artery ultrasound and echocardiography (CAUSE), to detect deficient brain blood flow delivery in the healthy, cognitively normal, older individual is proposed. Evidence indicates that persistent heart-to-brain blood flow deficit involving low cardiac output or low ejection fraction and carotid artery narrowing can promote cognitive impairment and that such impairment may lead to Alzheimer's disease (AD) or vascular dementia (VaD). A number of independent epidemiologic studies reported cardiovascular and cerebrovascular disease to be risk factors to AD and VaD. The clinical rationale for CAUSE is to detect and prevent progression of cognitive dysfunction in elderly persons and is based on the general understanding that mild cognitive impairment is a preclinical threshold to AD or VaD with high conversion rates to either dementia. The use of CAUSE is anticipated to prevent or attenuate, by appropriate clinical management, mild cognitive impairment arising from persistent brain hypoperfusion, a condition implicated in the promotion of cognitive impairment in the elderly and a common preclinical feature seen in AD and VaD. As detection of lowered cerebral perfusion from cardiac and carotid artery pathology is achieved using these cost-effective, noninvasive, and relatively accurate ultrasound procedures, a significant reduction in the number of new AD and VaD cases would be anticipated after appropriate patient treatment. In this context, a brief summary is presented outlining recent medical and surgical treatments that may improve cerebral blood flow insufficiency. The merit of CAUSE in screening and treating mentally healthy elderly persons who are identified as being at risk of cognitive decline is that it could blunt the soaring socioeconomic impact that will hammer the health care system of many nations by the mounting dementia prevalence rate expected in the next 25 years. A 5- year delay in the onset of AD could reduce the prevalence of AD by 50%. We are making preparations to test the merit of CAUSE in a clinical study of a cognitively healthy elderly population.
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Affiliation(s)
- Jack C de la Torre
- Center for Alzheimer's Research, Sun Health Research Institute, Sun City, Arizona 85351, USA.
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Henry-Feugeas MC. Assessing cerebrovascular contribution to late dementia of the Alzheimer's type: the role of combined hemodynamic and structural MR analysis. J Neurol Sci 2009; 283:44-8. [PMID: 19268312 DOI: 10.1016/j.jns.2009.02.325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The critical question as to the respective role of Alzheimer's disease (AD) and cerebrovascular disease in dementia of the Alzheimer's type (DAT), the most common form of dementia, is still debated. But there has been considerable progress in understanding cerebral hemodynamics and the relationship between structural brain damage and cognitive decline, in routine neuro imaging techniques. These advances now allow the proposition of a novel MR classification of DAT including indicators of both cerebrovascular function and regional brain atrophy. MR indicators of windkessel function include the arterial pulsatility index, the intracranial blood stroke volume, the cerebral relative venous outflow rates and a relative index of craniospinal compliance. MR indicators of vascular conduct function include total arterial and superficial venous flow rates that are closely related to brain metabolism. Structural MR sequences allow the detection of structural markers of windkessel dysfunction and, beyond the non specific hippocampal atrophy, a more extensive AD-like MR pattern of atrophy. The first illustration of this MR classification in elderly patients that later progressed to dementia converges with recent neuropathological observations to suggest that the major enemy to combat in late-life dementia is not AD but cerebrovascular dysfunction.
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Affiliation(s)
- Marie Cécile Henry-Feugeas
- Department of Radiology, Bichat-Claude Bernard University Hospital, AP-HP, 46 rue Henri Huchard, 75877 Paris cedex 18, France.
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Henry-Feugeas MC, Roy C, Baron G, Schouman-Claeys E. Leukoaraiosis and pulse-wave encephalopathy: observations with phase-contrast MRI in mild cognitive impairment. J Neuroradiol 2009; 36:212-8. [PMID: 19250677 DOI: 10.1016/j.neurad.2009.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To test the pathogenic hypothesis of a breakdown in the vital buffering of the arterial pulsations behind leukoaraiosis (LA) in mild cognitive impairment (MCI). METHODS Seventy-one elderly patients with MCI underwent a combined structural and dynamic MR examination (3D T1-weighted and fast-FLAIR T2-weighted sequences, phase contrast sequences). Arterial indices of pulsatility (IP) and composite indicators of the amplitude transfer function between cerebrospinal fluid and cerebral venous flow (Icsf/veins) were used to assess the large artery stiffness and the intracranial compliance respectively. Cerebral total arterial blood flow (tCBF), superficial and deep venous flow rates were also measured. Intracranial dynamic parameters and potential confounders including age, gender and vascular risk factors were compared between two groups respectively with and without significant LA. RESULTS The only dynamic changes on multivariate analyse were an IP increase, a lowering of deep venous outflow and Icsf/veins in patients with LA. There was a significant interaction between IP and Icsf/veins in the logistic regression: as compared with patients with low IP (suggestive of high large artery compliance) and high Icsf/veins (suggestive of high intracranial compliance), the adjusted odds ratios for the presence of LA were 9 (95% CI 1-64, P=0.02) in cases of both high IP and Icsf/veins, 10 (95% CI 1-64, P=0.02) in cases of both high IP and low Icsf/veins and 19 (95% CI 3-127, P=0.002) in cases of both low IP and Icsf/veins. CONCLUSION LA may reflect an arteriosclerotic and/or resistive pulse wave encephalopathy in MCI.
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Affiliation(s)
- M-C Henry-Feugeas
- Department of Radiology, Bichat-Claude-Bernard University Hospital, AP-HP, 46, rue Henri-Huchard, 75877 Paris cedex 18, France.
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