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Davies A, Gurung D, Ladthavorlaphatt K, Mankoo A, Panerai RB, Robinson TG, Minhas JS, Beishon LC. The effect of CO 2 on the age dependence of neurovascular coupling. J Appl Physiol (1985) 2024; 137:445-459. [PMID: 38961823 DOI: 10.1152/japplphysiol.00695.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 06/27/2024] [Accepted: 06/27/2024] [Indexed: 07/05/2024] Open
Abstract
Prior studies have identified variable effects of aging on neurovascular coupling (NVC). Carbon dioxide (CO2) affects both cerebral blood velocity (CBv) and NVC, but the effects of age on NVC under different CO2 conditions are unknown. Therefore, we investigated the effects of aging on NVC in different CO2 states during cognitive paradigms. Seventy-eight participants (18-78 yr), with well-controlled comorbidities, underwent continuous recordings of CBv by bilateral insonation of middle (MCA) and posterior (PCA) cerebral arteries (transcranial Doppler), blood pressure, end-tidal CO2, and heart rate during poikilocapnia, hypercapnia (5% CO2 inhalation), and hypocapnia (paced hyperventilation). Neuroactivation via visuospatial (VS) and attention tasks (AT) was used to stimulate NVC. Peak percentage and absolute change in MCAv/PCAv, were compared between CO2 conditions and age groups (≤30, 31-60, and >60 yr). For the VS task, in poikilocapnia, younger adults had a lower NVC response compared with older adults [mean difference (MD): -7.92% (standard deviation (SD): 2.37), P = 0.004], but comparable between younger and middle-aged groups. In hypercapnia, both younger [MD: -4.75% (SD: 1.56), P = 0.009] and middle [MD: -4.58% (SD: 1.69), P = 0.023] age groups had lower NVC responses compared with older adults. Finally, in hypocapnia, both older [MD: 5.92% (SD: 2.21), P = 0.025] and middle [MD: 5.44% (SD: 2.27), P = 0.049] age groups had greater NVC responses, compared with younger adults. In conclusion, the magnitude of NVC response suppression from baseline during hyper- and hypocapnia, did not differ significantly between age groups. However, the middle age group demonstrated a different NVC response while under hypercapnic conditions, compared with hypocapnia.NEW & NOTEWORTHY This study describes the effects of age on neurovascular coupling under altered CO2 conditions. We demonstrated that both hypercapnia and hypocapnia suppress neurovascular coupling (NVC) responses. Furthermore, that middle age exhibits an NVC response comparable with younger adults under hypercapnia, and older adults under hypocapnia.
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Affiliation(s)
- Aaron Davies
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Dewarkar Gurung
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Kannaphob Ladthavorlaphatt
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Alex Mankoo
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
| | - Thompson G Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
| | - Lucy C Beishon
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
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Tomoto T, Zhang R. Arterial Aging and Cerebrovascular Function: Impact of Aerobic Exercise Training in Older Adults. Aging Dis 2024; 15:1672-1687. [PMID: 38270114 PMCID: PMC11272215 DOI: 10.14336/ad.2023.1109-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/09/2023] [Indexed: 01/26/2024] Open
Abstract
Advanced age is the major risk factor for dementia including Alzheimer's disease. The clinical effects of recently developed anti-amyloid therapy for Alzheimer's disease were modest and the long-term outcome is unknown. Thus, an in-depth understanding of the mechanisms of brain aging is essential to develop preventive interventions to maintain cognitive health in late life. Mounting evidence suggests that arterial aging manifested as increases in central arterial stiffness is associated closely with cerebrovascular dysfunction and brain aging while improvement of cerebrovascular function with aerobic exercise training contributes to brain health in older adults. We summarized evidence in this brief review that 1) increases in central arterial stiffness and arterial pulsation with age are associated with increases in cerebrovascular resistance, reduction in cerebral blood flow, and cerebrovascular dysfunction, 2) aerobic exercise training improves cerebral blood flow by modifying arterial aging as indicated by reductions in cerebrovascular resistance, central arterial stiffness, arterial pulsation, and improvement in cerebrovascular function, and 3) improvement in cerebral blood flow and cerebrovascular function with aerobic exercise training may lead to improvement in cognitive function. These findings highlight the associations between arterial aging and cerebrovascular function and the importance of aerobic exercise in maintaining brain health in older adults.
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Affiliation(s)
- Tsubasa Tomoto
- Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA.
- Departments of Neurology,
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA.
- Departments of Neurology,
- Internal Medicine, and
- Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Sirant LW, Singh J, Martin S, Gaul CA, Stuart-Hill L, Candow DG, Mang C, Patrick Neary J. Long-term effects of multiple concussions on prefrontal cortex oxygenation during a hypercapnic challenge in retired contact sport athletes. Brain Res 2024; 1826:148735. [PMID: 38110074 DOI: 10.1016/j.brainres.2023.148735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 12/20/2023]
Abstract
This exploratory study aimed to investigate the long-term effects of multiple concussions on prefrontal cortex oxygenation during a five-minute hypercapnic challenge using Near Infrared Spectroscopy (NIRS). 55 physically active retired contact sport male athletes with three or more previous concussions (mTBI) were recruited along with 29 physically active males with no concussions history (CTRL). Participants completed five minutes of seated rest prior to the five-minute hypercapnic challenge (20-second breath-hold, 40-second recovery breathing; five times). NIRS measured right and left side oxygenated (O2Hb), deoxygenated (HHb), total (tHb) haemoglobin, and haemoglobin difference (HbDiff) with all parameters analysed through changes in average maximal and minimal values (ΔMAX), Z-scores, and standard deviations. Right prefrontal cortex HbDiff ΔMAX was significantly higher in the mTBI compared to CTRL (p = 0.045) group. Left prefrontal cortex O2Hb ΔMAX (p = 0.040), HHb Z-Scores (p = 0.008), and HbDiff ΔMAX(p = 0.014) were significantly higher in the mTBI group. Within-group right vs left analyses demonstrated significantly lower left HbDiff ΔMAX (p = 0.048) and HbDiff Z-scores (p = 0.002) in the mTBI group, while the CTRL group had significantly lower left HHb Z-scores (p = 0.003) and left tHb Z-scores (p = 0.042). This study provides preliminary evidence that athletes with a history of three or more concussions may have impaired prefrontal cortex oxygenation parameters during a hypercapnic challenge.
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Affiliation(s)
- Luke W Sirant
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada
| | - Jyotpal Singh
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada
| | - Steve Martin
- University of Victoria, School of Exercise Science, Physical and Health Education, Victoria, BC, Canada
| | - Catherine A Gaul
- University of Victoria, School of Exercise Science, Physical and Health Education, Victoria, BC, Canada
| | - Lynneth Stuart-Hill
- University of Victoria, School of Exercise Science, Physical and Health Education, Victoria, BC, Canada
| | - Darren G Candow
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada
| | - Cameron Mang
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada
| | - J Patrick Neary
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada.
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Corkery AT, Miller KB, Loeper CA, Tetri LH, Pearson AG, Loggie NA, Howery AJ, Eldridge MW, Barnes JN. Association between serum prostacyclin and cerebrovascular reactivity in healthy young and older adults. Exp Physiol 2023; 108:1047-1056. [PMID: 37170828 PMCID: PMC10524213 DOI: 10.1113/ep090903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 04/17/2023] [Indexed: 05/13/2023]
Abstract
NEW FINDINGS What is the central question of this study? What is the relationship between prostacyclin and cerebrovascular reactivity to hypercapnia before and after administration of a cyclooxygenase inhibitor, indomethacin, in healthy young and older adults? What is the main finding and importance? Serum prostacyclin was not related to cerebrovascular reactivity to hypercapnia before or after administration of indomethacin. However, in older adults, serum prostacyclin was related to the magnitude of change in cerebrovascular reactivity from before to after indomethacin administration. This suggests that older adults with higher serum prostacyclin may rely more on cyclooxygenase products to mediate cerebrovascular reactivity. ABSTRACT Platelet activation may contribute to age-related cerebrovascular dysfunction by interacting with the endothelial cells that regulate the response to vasodilatory stimuli. This study evaluated the relationship between a platelet inhibitor, prostacyclin, and cerebrovascular reactivity (CVR) in healthy young (n = 35; 25 ± 4 years; 17 women, 18 men) and older (n = 12; 62 ± 2 years; 8 women, 4 men) adults, who were not daily aspirin users, before and after cyclooxygenase inhibition. Prostacyclin was determined by levels of 6-keto-prostaglandin F1α (6-keto PGF1α) in the blood. CVR was assessed by measuring the middle cerebral artery blood velocity response to hypercapnia using transcranial Doppler ultrasound before (CON) and 90 min after cyclooxygenase inhibition with indomethacin (INDO). In young adults, there were no associations between prostacyclin and middle cerebral artery CVR during CON (r = -0.14, P = 0.415) or INDO (r = 0.27, P = 0.118). In older adults, associations between prostacyclin and middle cerebral artery CVR during CON (r = 0.53, P = 0.075) or INDO (r = -0.45, P = 0.136) did not reach the threshold for significance. We also evaluated the relationship between prostacyclin and the change in CVR between conditions (ΔCVR). We found no association between ΔCVR and prostacyclin in young adults (r = 0.27, P = 0.110); however, in older adults, those with higher baseline prostacyclin levels demonstrated significantly greater ΔCVR (r = -0.74, P = 0.005). In conclusion, older adults with higher serum prostacyclin, a platelet inhibitor, may rely more on cyclooxygenase products for cerebrovascular reactivity to hypercapnia.
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Affiliation(s)
- Adam T Corkery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Kathleen B Miller
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Carissa A Loeper
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Laura H Tetri
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Andrew G Pearson
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Nicole A Loggie
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Anna J Howery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Marlowe W Eldridge
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jill N Barnes
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
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Fico BG, Miller KB, Rivera-Rivera LA, Corkery AT, Pearson AG, Loggie NA, Howery AJ, Rowley HA, Johnson KM, Johnson SC, Wieben O, Barnes JN. Cerebral hemodynamics comparison using transcranial doppler ultrasound and 4D flow MRI. Front Physiol 2023; 14:1198615. [PMID: 37304825 PMCID: PMC10250020 DOI: 10.3389/fphys.2023.1198615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023] Open
Abstract
Introduction: Age-related changes in cerebral hemodynamics are controversial and discrepancies may be due to experimental techniques. As such, the purpose of this study was to compare cerebral hemodynamics measurements of the middle cerebral artery (MCA) between transcranial Doppler ultrasound (TCD) and four-dimensional flow MRI (4D flow MRI). Methods: Twenty young (25 ± 3 years) and 19 older (62 ± 6 years) participants underwent two randomized study visits to evaluate hemodynamics at baseline (normocapnia) and in response to stepped hypercapnia (4% CO2, and 6% CO2) using TCD and 4D flow MRI. Cerebral hemodynamic measures included MCA velocity, MCA flow, cerebral pulsatility index (PI) and cerebrovascular reactivity to hypercapnia. MCA flow was only assessed using 4D flow MRI. Results: MCA velocity between the TCD and 4D flow MRI methods was positively correlated across the normocapnia and hypercapnia conditions (r = 0.262; p = 0.004). Additionally, cerebral PI was significantly correlated between TCD and 4D flow MRI across the conditions (r = 0.236; p = 0.010). However, there was no significant association between MCA velocity using TCD and MCA flow using 4D flow MRI across the conditions (r = 0.079; p = 0.397). When age-associated differences in cerebrovascular reactivity using conductance were compared using both methodologies, cerebrovascular reactivity was greater in young adults compared to older adults when using 4D flow MRI (2.11 ± 1.68 mL/min/mmHg/mmHg vs. 0.78 ± 1.68 mL/min/mmHg/mmHg; p = 0.019), but not with TCD (0.88 ± 1.01 cm/s/mmHg/mmHg vs. 0.68 ± 0.94 cm/s/mmHg/mmHg; p = 0.513). Conclusion: Our results demonstrated good agreement between the methods at measuring MCA velocity during normocapnia and in response to hypercapnia, but MCA velocity and MCA flow were not related. In addition, measurements using 4D flow MRI revealed effects of aging on cerebral hemodynamics that were not apparent using TCD.
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Affiliation(s)
- Brandon G. Fico
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, University of Wisconsin-Madison, Madison, WI, United States
| | - Kathleen B. Miller
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, 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
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, University of Wisconsin-Madison, Madison, WI, United States
| | - Andrew G. Pearson
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, University of Wisconsin-Madison, Madison, WI, United States
| | - Nicole A. Loggie
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, University of Wisconsin-Madison, Madison, WI, United States
| | - Anna J. Howery
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, 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
- Department of Kinesiology, Bruno Balke Biodynamics Laboratory, University of Wisconsin-Madison, Madison, WI, United States
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Kecskés S, Menyhárt Á, Bari F, Farkas E. Nimodipine augments cerebrovascular reactivity in aging but runs the risk of local perfusion reduction in acute cerebral ischemia. Front Aging Neurosci 2023; 15:1175281. [PMID: 37181624 PMCID: PMC10174256 DOI: 10.3389/fnagi.2023.1175281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
Introduction The efficacy of cerebrovascular reactivity (CVR) is taken as an indicator of cerebrovascular health. Methods and Results We found that CVR tested with the inhalation of 10 % CO2 declined in the parietal cortex of 18-20-month-old rats. The CVR deficit in old rats was coincident with cerebrovascular smooth muscle cell and astrocyte senescence, revealed by the immuno-labeling of the cellular senescence marker p16 in these cells. In a next series of experiments, CVR was severely impaired in the acute phase of incomplete global forebrain ischemia produced by the bilateral occlusion of the common carotid arteries in young adult rats. In acute ischemia, CVR impairment often manifested as a perfusion drop rather than blood flow elevation in response to hypercapnia. Next, nimodipine, an L-type voltage-gated calcium channel antagonist was administered topically to rescue CVR in both aging, and cerebra ischemia. Nimodipine augmented CVR in the aged brain, but worsened CVR impairment in acute cerebral ischemia. Discussion A careful evaluation of benefits and side effects of nimodipine is recommended, especially in acute ischemic stroke.
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Affiliation(s)
- Szilvia Kecskés
- Cerebral Blood Flow and Metabolism Research Group, Hungarian Centre of Excellence for Molecular Medicine – University of Szeged, Szeged, Hungary
- Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Ákos Menyhárt
- Cerebral Blood Flow and Metabolism Research Group, Hungarian Centre of Excellence for Molecular Medicine – University of Szeged, Szeged, Hungary
- Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Eszter Farkas
- Cerebral Blood Flow and Metabolism Research Group, Hungarian Centre of Excellence for Molecular Medicine – University of Szeged, Szeged, Hungary
- Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- *Correspondence: Eszter Farkas,
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Razumovsky AY, Jahangiri FR, Balzer J, Alexandrov AV. ASNM and ASN joint guidelines for transcranial Doppler ultrasonic monitoring: An update. J Neuroimaging 2022; 32:781-797. [PMID: 35589555 DOI: 10.1111/jon.13013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/27/2022] [Accepted: 05/10/2022] [Indexed: 11/26/2022] Open
Abstract
Today, it seems prudent to reconsider how ultrasound technology can be used for providing intraoperative neurophysiologic monitoring that will result in better patient outcomes and decreased length and cost of hospitalization. An extensive and rapidly growing literature suggests that the essential hemodynamic information provided by transcranial Doppler (TCD) ultrasonography neuromonitoring (TCDNM) would provide effective monitoring modality for improving outcomes after different types of vascular, neurosurgical, orthopedic, cardiovascular, and cardiothoracic surgeries and some endovascular interventional or diagnostic procedures, like cardiac catheterization or cerebral angiography. Understanding, avoiding, and preventing peri- or postoperative complications, including neurological deficits following abovementioned surgeries, endovascular intervention, or diagnostic procedures, represents an area of great public and economic benefit for society, especially considering the aging population. The American Society of Neurophysiologic Monitoring and American Society of Neuroimaging Guidelines Committees formed a joint task force and developed updated guidelines to assist in the use of TCDNM in the surgical and intensive care settings. Specifically, these guidelines define (1) the objectives of TCD monitoring; (2) the responsibilities and behaviors of the neurosonographer during monitoring; (3) instrumentation and acquisition parameters; (4) safety considerations; (5) contemporary rationale for TCDNM; (6) TCDNM perspectives; and (7) major recommendations.
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Affiliation(s)
| | | | - Jeffrey Balzer
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Andrei V Alexandrov
- Department of Neurology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
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Abstract
UNLABELLED Exercise is associated with higher cognitive function and is a promising intervention to reduce the risk of dementia. With advancing age, there are changes in the vasculature that have important clinical implications for brain health and cognition. Primary aging and vascular risk factors are associated with increases in arterial stiffness and pulse pressure, and reductions in peripheral vascular function. OBJECTIVE The purpose is to discuss the epidemiological, observational, and mechanistic evidence regarding the link between age-related changes in vascular health and brain health. METHODS We performed a literature review and integrated with our published data. RESULTS Epidemiological evidence suggests a link between age-related increases in arterial stiffness and lower cognitive function, which may be mediated by cerebral vascular function, including cerebral vasoreactivity and cerebral pulsatility. Age-associated impairments in central arterial stiffness and peripheral vascular function have been attenuated or reversed through lifestyle behaviors such as exercise. Greater volumes of habitual exercise and higher cardiorespiratory fitness are associated with beneficial effects on both peripheral vascular health and cognition. Yet, the extent to which exercise directly influences cerebral vascular function and brain health, as well as the associated mechanisms remains unclear. CONCLUSION Although there is evidence that exercise positively impacts cerebral vascular function, more research is necessary in humans to optimize experimental protocols and address methodological limitations and physiological considerations. Understanding the impact of exercise on cerebral vascular function is important for understanding the association between exercise and brain health and may inform future intervention studies that seek to improve cognition.
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Zimmerman B, Rypma B, Gratton G, Fabiani M. Age-related changes in cerebrovascular health and their effects on neural function and cognition: A comprehensive review. Psychophysiology 2021; 58:e13796. [PMID: 33728712 PMCID: PMC8244108 DOI: 10.1111/psyp.13796] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/11/2021] [Accepted: 02/08/2021] [Indexed: 12/11/2022]
Abstract
The process of aging includes changes in cellular biology that affect local interactions between cells and their environments and eventually propagate to systemic levels. In the brain, where neurons critically depend on an efficient and dynamic supply of oxygen and glucose, age-related changes in the complex interaction between the brain parenchyma and the cerebrovasculature have effects on health and functioning that negatively impact cognition and play a role in pathology. Thus, cerebrovascular health is considered one of the main mechanisms by which a healthy lifestyle, such as habitual cardiorespiratory exercise and a healthful diet, could lead to improved cognitive outcomes with aging. This review aims at detailing how the physiology of the cerebral vascular system changes with age and how these changes lead to differential trajectories of cognitive maintenance or decline. This provides a framework for generating specific mechanistic hypotheses about the efficacy of proposed interventions and lifestyle covariates that contribute to enhanced cognitive well-being. Finally, we discuss the methodological implications of age-related changes in the cerebral vasculature for human cognitive neuroscience research and propose directions for future experiments aimed at investigating age-related changes in the relationship between physiology and cognitive mechanisms.
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Affiliation(s)
- Benjamin Zimmerman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gabriele Gratton
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Monica Fabiani
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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Burley CV, Francis ST, Thomas KN, Whittaker AC, Lucas SJE, Mullinger KJ. Contrasting Measures of Cerebrovascular Reactivity Between MRI and Doppler: A Cross-Sectional Study of Younger and Older Healthy Individuals. Front Physiol 2021; 12:656746. [PMID: 33912073 PMCID: PMC8072486 DOI: 10.3389/fphys.2021.656746] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
Cerebrovascular reactivity (CVR) is used as an outcome measure of brain health. Traditionally, lower CVR is associated with ageing, poor fitness and brain-related conditions (e.g. stroke, dementia). Indeed, CVR is suggested as a biomarker for disease risk. However, recent findings report conflicting associations between ageing or fitness and CVR measures. Inconsistent findings may relate to different neuroimaging modalities used, which include transcranial Doppler (TCD) and blood-oxygen-level-dependant (BOLD) contrast magnetic resonance imaging (MRI). We assessed the relationship between CVR metrics derived from two common imaging modalities, TCD and BOLD MRI, within the same individuals and with expected significant differences (i.e., younger vs. older) to maximise the expected spread in measures. We conducted two serial studies using TCD- and MRI-derived measures of CVR (via inspired 5% CO2 in air). Study 1 compared 20 younger (24 ± 7 years) with 15 older (66 ± 7 years) participants, Study 2 compared 10 younger (22 ± 2 years) with 10 older (72 ± 4 years) participants. Combining the main measures across studies, no significant correlation (r = 0.15, p = 0.36) was observed between individual participant TCD- and BOLD-CVR measures. Further, these measures showed differential effects between age groups; with TCD-CVR higher in the older compared to younger group (4 ± 1 vs. 3 ± 1 %MCAv/mmHg P ET CO2; p < 0.05, Hedges' g = 0.75), whereas BOLD-CVR showed no difference (p = 0.104, Hedges' g = 0.38). In Study 2 additional measures were obtained to understand the origin of the discrepancy: phase contrast angiography (PCA) MRI of the middle cerebral artery, showed a significantly lower blood flow (but not velocity) CVR response in older compared with younger participants (p > 0.05, Hedges' g = 1.08). The PCA CVR metrics did not significantly correlate with the BOLD- or TCD-CVR measures. The differing CVR observations between imaging modalities were despite expected, correlated (r = 0.62-0.82), age-related differences in resting CBF measures across modalities. Taken together, findings across both studies show no clear relationship between TCD- and BOLD-CVR measures. We hypothesize that CVR differences between imaging modalities are in part due to the aspects of the vascular tree that are assessed (TCD:arteries; BOLD:venules/veins). Further work is needed to understand the between-modality CVR response differences, but caution is needed when comparing CVR metrics derived from different imaging modalities.
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Affiliation(s)
- Claire V. Burley
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
- Dementia Centre for Research Collaboration, School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Susan T. Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Kate N. Thomas
- Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Anna C. Whittaker
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Samuel J. E. Lucas
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| | - Karen J. Mullinger
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
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11
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Caldwell HG, Howe CA, Chalifoux CJ, Hoiland RL, Carr JMJR, Brown CV, Patrician A, Tremblay JC, Panerai RB, Robinson TG, Minhas JS, Ainslie PN. Arterial carbon dioxide and bicarbonate rather than pH regulate cerebral blood flow in the setting of acute experimental metabolic alkalosis. J Physiol 2021; 599:1439-1457. [DOI: 10.1113/jp280682] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- Hannah G. Caldwell
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Connor A. Howe
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Carter J. Chalifoux
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Ryan L. Hoiland
- Department of Anesthesiology Pharmacology and Therapeutics Vancouver General Hospital University of British Columbia Vancouver BC Canada
- Department of Cellular and Physiological Sciences University of British Columbia Vancouver BC Canada
| | - Jay M. J. R. Carr
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Courtney V. Brown
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Alexander Patrician
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Joshua C. Tremblay
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
| | - Ronney B. Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHIASM) Research Group Leicester Biomedical Research Centre University of Leicester Leicester UK
| | - Thompson G. Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHIASM) Research Group Leicester Biomedical Research Centre University of Leicester Leicester UK
| | - Jatinder S. Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHIASM) Research Group Leicester Biomedical Research Centre University of Leicester Leicester UK
| | - Philip N. Ainslie
- Centre for Heart, Lung and Vascular Health School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC Canada
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12
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Beishon L, Clough RH, Kadicheeni M, Chithiramohan T, Panerai RB, Haunton VJ, Minhas JS, Robinson TG. Vascular and haemodynamic issues of brain ageing. Pflugers Arch 2021; 473:735-751. [PMID: 33439324 PMCID: PMC8076154 DOI: 10.1007/s00424-020-02508-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 01/17/2023]
Abstract
The population is ageing worldwide, thus increasing the burden of common age-related disorders to the individual, society and economy. Cerebrovascular diseases (stroke, dementia) contribute a significant proportion of this burden and are associated with high morbidity and mortality. Thus, understanding and promoting healthy vascular brain ageing are becoming an increasing priority for healthcare systems. In this review, we consider the effects of normal ageing on two major physiological processes responsible for vascular brain function: Cerebral autoregulation (CA) and neurovascular coupling (NVC). CA is the process by which the brain regulates cerebral blood flow (CBF) and protects against falls and surges in cerebral perfusion pressure, which risk hypoxic brain injury and pressure damage, respectively. In contrast, NVC is the process by which CBF is matched to cerebral metabolic activity, ensuring adequate local oxygenation and nutrient delivery for increased neuronal activity. Healthy ageing is associated with a number of key physiological adaptations in these processes to mitigate age-related functional and structural declines. Through multiple different paradigms assessing CA in healthy younger and older humans, generating conflicting findings, carbon dioxide studies in CA have provided the greatest understanding of intrinsic vascular anatomical factors that may mediate healthy ageing responses. In NVC, studies have found mixed results, with reduced, equivalent and increased activation of vascular responses to cognitive stimulation. In summary, vascular and haemodynamic changes occur in response to ageing and are important in distinguishing “normal” ageing from disease states and may help to develop effective therapeutic strategies to promote healthy brain ageing.
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Affiliation(s)
- Lucy Beishon
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.
| | - Rebecca H Clough
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Meeriam Kadicheeni
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Tamara Chithiramohan
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Victoria J Haunton
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Jatinder S Minhas
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
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13
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Effects of Exercise on Cognitive Performance in Older Adults: A Narrative Review of the Evidence, Possible Biological Mechanisms, and Recommendations for Exercise Prescription. J Aging Res 2020; 2020:1407896. [PMID: 32509348 PMCID: PMC7244966 DOI: 10.1155/2020/1407896] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/02/2020] [Accepted: 04/13/2020] [Indexed: 01/11/2023] Open
Abstract
Physical activity and exercise have emerged as potential methods to improve brain health among older adults. However, there are currently no physical activity guidelines aimed at improving cognitive function, and the mechanisms underlying these cognitive benefits are poorly understood. The purpose of this narrative review is to present the current evidence regarding the effects of physical activity and exercise on cognition in older adults without cognitive impairment, identify potential mechanisms underlying these effects, and make recommendations for exercise prescription to enhance cognitive performance. The review begins with a summary of evidence of the effect of chronic physical activity and exercise on cognition. Attention then turns to four main biological mechanisms that appear to underlie exercise-induced cognitive improvement, including the upregulation of growth factors and neuroplasticity, inhibition of inflammatory biomarker production, improved vascular function, and hypothalamic-pituitary-adrenal axis regulation. The last section provides an overview of exercise parameters known to optimize cognition in older adults, such as exercise type, frequency, intensity, session duration, and exercise program duration.
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14
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Tomoto T, Riley J, Turner M, Zhang R, Tarumi T. Cerebral vasomotor reactivity during hypo- and hypercapnia across the adult lifespan. J Cereb Blood Flow Metab 2020; 40:600-610. [PMID: 30764704 PMCID: PMC7026853 DOI: 10.1177/0271678x19828327] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Age is the strongest risk factor for cerebrovascular disease; however, age-related changes in cerebrovascular function are still not well understood. The objective of this study was to measure cerebral vasomotor reactivity (CVMR) during hypo- and hypercapnia across the adult lifespan. One hundred fifty-three healthy participants (21-80 years) underwent measurements of cerebral blood flow velocity (CBFV) via transcranial Doppler, mean arterial pressure (MAP) via plethysmograph, and end-tidal CO2 (EtCO2) via capnography during hyperventilation (hypocapnia) and a modified rebreathing protocol (hypercapnia). Cerebrovascular conductance (CVCi) and resistance (CVRi) indices were calculated from the ratios of CBFV and MAP. CVMRs were assessed by the slopes of CBFV and CVCi in response to changes in EtCO2. The baseline CBFV and CVCi decreased and CVRi increased with age. Advanced age was associated with progressive declines in CVMR during hypocapnia indicating reduced cerebral vasoconstriction, but increases in CVMR during hypercapnia indicating increased vasodilation. A negative correlation between hypo- and hypercapnic CVMRs was observed across all subjects (CBFV%/ EtCO2: r = -0.419, CVCi%/ EtCO2: r = -0.442, P < 0.0001). Collectively, these findings suggest that aging is associated with decreases in CBFV, increases in cerebrovascular resistance, reduced vasoconstriction during hypocapnia, but increased vasodilatory responsiveness during hypercapnia.
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Affiliation(s)
- Tsubasa Tomoto
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jonathan Riley
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
| | - Marcel Turner
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Takashi Tarumi
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
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15
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Abstract
Purpose of Review Risks for developing cardiovascular disease and cognitive decline increase with age. In women, these risks may be influenced by pregnancy history. This review provides an integrated evaluation of associations of pregnancy history with hypertension, brain atrophy, and cognitive decline in postmenopausal women. Recent Findings Atrophy in the occipital lobes of the brain was evident in women who had current hypertension and a history of preeclampsia. Deficits in visual memory in women with a history of preeclampsia are consistent with these brain structural changes. The blood velocity response to chemical and sympathoexcitatory stimuli were altered in women with a history of preeclampsia linking impairments in cerebrovascular regulation to the structural and functional changes in the brain. Summary Having a history of preeclampsia should require close monitoring of blood pressure and initiation of anti-hypertensive treatment in perimenopausal women. Mechanisms by which preeclampsia affects cerebrovascular structure and function require additional study.
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Affiliation(s)
- Kathleen B Miller
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Virginia M Miller
- Department of Surgery, Mayo Clinic, Medical Sci Bldg 421, 200 First St SW, Rochester, MN, 55905, USA.
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Medical Sci Bldg 421, 200 First St SW, Rochester, MN, 55905, USA.
| | - Jill N Barnes
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
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16
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Miller KB, Howery AJ, Rivera-Rivera LA, Johnson SC, Rowley HA, Wieben O, Barnes JN. Age-Related Reductions in Cerebrovascular Reactivity Using 4D Flow MRI. Front Aging Neurosci 2019; 11:281. [PMID: 31680935 PMCID: PMC6811507 DOI: 10.3389/fnagi.2019.00281] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022] Open
Abstract
Cerebrovascular reactivity (CVR), is important for determining future risk of cerebrovascular disease. It is unclear if primary aging is associated with reductions in CVR because previous studies often include participants with vascular risk factors. Additionally, the inconsistency in the literature may be due to the inherent difficulty in quantifying intracranial cerebral blood flow and CVR. To address these limitations, we determined the effect of age on CVR in the large intracranial vessels in adults with low vascular risk using state-of-the-art MRI techniques. We also determined if the effect of age on CVR was sex-specific. Young (n = 20; 25 ± 3 years) and older (n = 19; 61 ± 5 years) healthy, physically active adults participated in the study. CVR was measured in response to hypercapnia using 4D flow MRI, which allows for simultaneous angiographic and quantitative blood flow measurements in the intracranial arteries. Older adults had lower global CVR and CVR in multiple intracranial arteries [right and left internal carotid arteries (ICA), right and left middle cerebral arteries (MCA), and basilar artery (BA)] compared with young adults (p < 0.05 for all). In addition, the MCA dilated significantly in response to hypercapnia in young (p < 0.05), but not older adults. Young men demonstrated higher global CVR and CVR in multiple intracranial arteries (ICAs, MCAs, and BA) compared with young women and older men (p < 0.05 for both); however, CVR did not differ between young women and older women. Our results demonstrate that, using 4D flow MRI, primary aging is associated with lower CVR in adults with low vascular risk. In addition, the effect of age on CVR may be driven by men. The 4D flow MRI technique may provide a promising new alternative to measure cerebrovascular physiology without the limitations of commonly used techniques. Future studies could utilize this MRI technique to examine interventions to maintain CVR with advancing age. This study was registered under clinicaltrials.gov # NCT02840851.
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Affiliation(s)
- Kathleen B Miller
- 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
| | - Leonardo A Rivera-Rivera
- 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.,William S. Middleton Memorial Veterans Hospital, Geriatric Research Education and Clinical Center, Madison, WI, United States
| | - Howard A Rowley
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States.,Wisconsin Alzheimer's Disease Research Center, School of Medicine and Public Health, University of Wisconsin-Madison, 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
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17
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Determining differences between critical closing pressure and resistance-area product: responses of the healthy young and old to hypocapnia. Pflugers Arch 2019; 471:1117-1126. [DOI: 10.1007/s00424-019-02290-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/31/2019] [Accepted: 06/05/2019] [Indexed: 10/26/2022]
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18
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Hoiland RL, Fisher JA, Ainslie PN. Regulation of the Cerebral Circulation by Arterial Carbon Dioxide. Compr Physiol 2019; 9:1101-1154. [DOI: 10.1002/cphy.c180021] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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19
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Stefanidis KB, Askew CD, Klein T, Lagopoulos J, Summers MJ. Healthy aging affects cerebrovascular reactivity and pressure-flow responses, but not neurovascular coupling: A cross-sectional study. PLoS One 2019; 14:e0217082. [PMID: 31095646 PMCID: PMC6522028 DOI: 10.1371/journal.pone.0217082] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 05/05/2019] [Indexed: 01/28/2023] Open
Abstract
Background and purpose Aging leads to alterations in cerebrovascular function, and these are thought to contribute to cognitive decline/dementia. Disturbances to cerebral blood flow regulation have been reported, but the findings are inconsistent and to date no study has comprehensively tested the collective and independent contribution of these parameters in the same age range. Such lines of enquiry are vital since aging is a heterogeneous and complex process, with cerebrovascular parameters being differentially affected depending on the individual. A multicomponent comprehensive measure of cerebrovascular function, which accounts for such diversity, is needed to differentiate between healthy young and old adults. Methods We tested the effect of aging on cerebrovascular function by comparing healthy young adults aged 18–30 and older adults aged 60–75, without cognitive impairments. Cerebrovascular blood flow velocity was assessed using transcranial Doppler ultrasound. Parameters included resting middle cerebral artery velocity (MCAv), neurovascular coupling, cerebrovascular reactivity to CO2 (hypercapnia and hypocapnia), and the pressure-flow response during a sit-to-stand procedure. Results MANOVA revealed that collectively, the parameters discriminated the groups (p < .001). MCAv and pressure-flow responses were lower in the older group (p < .001). While there were no differences in hypercapnic responses (p = .908) and neurovascular coupling (p = .517), hypocapnic responses were elevated in the old (p = .002). Conclusions Collectively, cerebrovascular parameters can distinguish between healthy young and older adults, with aging leading to reductions in MCAv, and altering cerebrovascular reactivity and pressure-flow responses under hypotensive conditions.
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Affiliation(s)
- Kayla B. Stefanidis
- Sunshine Coast Mind and Neuroscience–Thompson Institute, University of the Sunshine Coast, Birtinya, Qld, Australia
- * E-mail:
| | - Christopher D. Askew
- Sunshine Coast Mind and Neuroscience–Thompson Institute, University of the Sunshine Coast, Birtinya, Qld, Australia
- School of Health & Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Timo Klein
- School of Health & Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Jim Lagopoulos
- Sunshine Coast Mind and Neuroscience–Thompson Institute, University of the Sunshine Coast, Birtinya, Qld, Australia
| | - Mathew J. Summers
- Sunshine Coast Mind and Neuroscience–Thompson Institute, University of the Sunshine Coast, Birtinya, Qld, Australia
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20
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Vestergaard MB, Larsson HB. Cerebral metabolism and vascular reactivity during breath-hold and hypoxic challenge in freedivers and healthy controls. J Cereb Blood Flow Metab 2019; 39:834-848. [PMID: 29099292 PMCID: PMC6498754 DOI: 10.1177/0271678x17737909] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The goal of the present study was to examine the cerebral metabolism and vascular reactivity during extended breath-holds (ranging from 2 min 32 s to 7 min 0 s) and during a hypoxic challenge in freedivers and non-diver controls. Magnetic resonance imaging was used to measure the global cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2), and magnetic resonance spectroscopy was used to measure the cerebral lactate, glutamate+glutamine, N-acetylaspartate and phosphocreatine+creatine concentrations in the occipital lobe. Fifteen freedivers and seventeen non-diver controls participated. The freedivers showed remarkable increases in CBF (107%) during the breath-holds, compensating for arterial desaturation, and sustained cerebral oxygen delivery (CDO2). CMRO2 was unaffected throughout the breath-holds. During the hypoxic challenge, the freedivers had larger increases in blood flow in the sagittal sinus than the non-divers, and could sustain normal CDO2. No differences were found in lactate production, global CBF or CMRO2. We conclude that the mechanism for sustaining brain function during breath-holding in freedivers involves an extraordinary increase in perfusion, and that freedivers present evidence for higher cerebrovascular reactivity, but not for higher lactate-producing glycolysis during a hypoxic challenge compared to controls.
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Affiliation(s)
- Mark B Vestergaard
- 1 Department of Clinical Physiology, Nuclear Medicine and PET, Functional Imaging Unit, Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Henrik Bw Larsson
- 1 Department of Clinical Physiology, Nuclear Medicine and PET, Functional Imaging Unit, Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup, Denmark.,2 Institute of Clinical Medicine, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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21
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Miller KB, Howery AJ, Harvey RE, Eldridge MW, Barnes JN. Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults. Front Physiol 2018; 9:1096. [PMID: 30174609 PMCID: PMC6107836 DOI: 10.3389/fphys.2018.01096] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/23/2018] [Indexed: 12/28/2022] Open
Abstract
Reduced cerebrovascular reactivity to a vasoactive stimulus is associated with age-related diseases such as stroke and cognitive decline. Habitual exercise is protective against cognitive decline and is associated with reduced stiffness of the large central arteries that perfuse the brain. In this context, we evaluated the age-related differences in cerebrovascular reactivity in healthy adults who habitually exercise. In addition, we sought to determine the association between central arterial stiffness and cerebrovascular reactivity. We recruited 22 young (YA: age = 27 ± 5 years, range 18–35 years) and 21 older (OA: age = 60 ± 4 years, range 56–68 years) habitual exercisers who partake in at least 150 min of structured aerobic exercise each week. Middle cerebral artery velocity (MCAv) was recorded using transcranial Doppler ultrasound. In order to assess cerebrovascular reactivity, MCAv, end-tidal carbon dioxide (ETCO2), and mean arterial pressure (MAP) were continuously recorded at rest and during stepwise elevations of 2, 4, and 6% inhaled CO2. Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. Central arterial stiffness was assessed using carotid–femoral pulse wave velocity (PWV). Older adults had higher PWV (YA: 6.2 ± 1.2 m/s; OA: 7.5 ± 1.3 m/s; p < 0.05) compared with young adults. MCAv and CVCi reactivity to hypercapnia were not different between young and older adults (MCAv reactivity, YA: 2.0 ± 0.2 cm/s/mmHg; OA: 2.0 ± 0.2 cm/s/mmHg; p = 0.77, CVCi reactivity, YA: 0.018 ± 0.002 cm/s/mmHg2; OA: 0.015 ± 0.001 cm/s/mmHg2; p = 0.27); however, older adults demonstrated higher MAP reactivity to hypercapnia (YA: 0.4 ± 0.1 mmHg/mmHg; OA: 0.7 ± 0.1 mmHg/mmHg; p < 0.05). There were no associations between PWV and cerebrovascular reactivity (range: r = 0.00–0.39; p = 0.07–0.99). Our results demonstrate that cerebrovascular reactivity was not different between young and older adults who habitually exercise; however, MAP reactivity was augmented in older adults. This suggests an age-associated difference in the reliance on MAP to increase cerebral blood flow during hypercapnia.
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Affiliation(s)
- Kathleen B Miller
- 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
| | - Ronée E Harvey
- Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, United States
| | - Marlowe W Eldridge
- Division of Critical Care, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.,John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Jill N Barnes
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
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22
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Miyaji A, Ikemura T, Hayashi N. Aging decreases CO2 reactivity in the retinal artery, but not in the ocular choroidal vessels; a cross-sectional study. Clin Hemorheol Microcirc 2018; 70:231-240. [PMID: 29710683 DOI: 10.3233/ch-170332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The CO2 reactivity is often used to assess vascular function, but it is still unclear whether this reactivity is affected by aging. OBJECTIVE To investigate the effects of aging on the CO2 reactivity in ocular and cerebral vessels, both of which are highly sensitive to hypercapnia, we compared the CO2 reactivity in the retinal artery (RA), retinal and choroidal vessels (RCV), optic nerve head (ONH), and middle cerebral artery (MCA) between young and middle-aged subjects. METHODS We measured the CO2 reactivity in 14 young and 11 middle-aged males using laser-speckle flowgraphy during a 3-min inhalation of CO2-rich air. RESULTS The CO2 reactivity in the RA and ONH were lower in the middle-aged group than in the young group, but no significant effect of age was observed in the RCV or MCA. The CO2 reactivity in the RA and ONH were correlated significantly with age, whereas those in the RCV or MCA were not. CONCLUSIONS These findings suggest that there are regional differences in the effect of age on the CO2 reactivity among not only ocular and cerebral vessels, but also the retinal and choroidal vessels, even though these vessels are in neighboring areas.
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Affiliation(s)
- Akane Miyaji
- Division of Medical Nutrition, Faculty of Healthcare, Tokyo Healthcare University, Setagaya, Tokyo, Japan.,Graduate School of Decision Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo, Japan
| | - Tsukasa Ikemura
- Department of Management Information, Yokohama College of Commerce, Yokohama, Kanagawa, Japan
| | - Naoyuki Hayashi
- Graduate School of Decision Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo, Japan.,Institute for Liberal Arts, Tokyo Institute of Technology, Meguro, Tokyo, Japan
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23
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Barnes JN, Harvey RE, Miller KB, Jayachandran M, Malterer KR, Lahr BD, Bailey KR, Joyner MJ, Miller VM. Cerebrovascular Reactivity and Vascular Activation in Postmenopausal Women With Histories of Preeclampsia. Hypertension 2017; 71:110-117. [PMID: 29158356 DOI: 10.1161/hypertensionaha.117.10248] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/06/2017] [Accepted: 10/26/2017] [Indexed: 12/21/2022]
Abstract
Cerebrovascular reactivity (CVR) is reduced in patients with cognitive decline. Women with a history of preeclampsia are at increased risk for cognitive decline. This study examined an association between pregnancy history and CVR using a subgroup of 40 age- and parity-matched pairs of women having histories of preeclampsia (n=27) or normotensive pregnancy (n=29) and the association of activated blood elements with CVR. Middle cerebral artery velocity was measured by Doppler ultrasound before and during hypercapnia to assess CVR. Thirty-eight parameters of blood cellular elements, microvesicles, and cell-cell interactions measured in venous blood were assessed for association with CVR using principal component analysis. Middle cerebral artery velocity was lower in the preeclampsia compared with the normotensive group at baseline (63±4 versus 73±3 cm/s; P=0.047) and during hypercapnia (P=0.013-0.056). CVR was significantly lower in the preeclampsia compared with the normotensive group (2.1±1.3 versus 2.9±1.1 cm·s·mm Hg; P=0.009). Globally, the association of the 7 identified principal components with preeclampsia (P=0.107) and with baseline middle cerebral artery velocity (P=0.067) did not reach statistical significance. The interaction between pregnancy history and principal components with respect to CVR (P=0.084) was driven by a nominally significant interaction between preeclampsia and the individual principal component defined by blood elements, platelet aggregation, and interactions of platelets with monocytes and granulocytes (P=0.008). These results suggest that having a history of preeclampsia negatively affects the cerebral circulation years beyond the pregnancy and that this effect was associated with activated blood elements.
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Affiliation(s)
- Jill N Barnes
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN.
| | - Ronée E Harvey
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Kathleen B Miller
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Muthuvel Jayachandran
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Katherine R Malterer
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Brian D Lahr
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Kent R Bailey
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Michael J Joyner
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
| | - Virginia M Miller
- From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN
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24
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Puthon L, Bouzat P, Robach P, Favre-Juvin A, Doutreleau S, Verges S. Effect of ageing on hypoxic exercise cardiorespiratory, muscle and cerebral oxygenation responses in healthy humans. Exp Physiol 2017; 102:436-447. [DOI: 10.1113/ep085949] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 01/20/2017] [Indexed: 02/04/2023]
Affiliation(s)
- Lara Puthon
- U1042, INSERM, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- HP2 Laboratory, Université Grenoble Alpes, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- Acute Care Unit; Grenoble University Hospital; F-38042 Grenoble France
| | - Pierre Bouzat
- Acute Care Unit; Grenoble University Hospital; F-38042 Grenoble France
- Grenoble Institute of Neurosciences; INSERM U836, BP 217 F-38043 Grenoble France
| | - Paul Robach
- U1042, INSERM, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- HP2 Laboratory, Université Grenoble Alpes, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- National School for Mountain Sports (ENSM); F-74400 Chamonix France
| | - Anne Favre-Juvin
- U1042, INSERM, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- HP2 Laboratory, Université Grenoble Alpes, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
| | - Stéphane Doutreleau
- U1042, INSERM, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- HP2 Laboratory, Université Grenoble Alpes, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
| | - Samuel Verges
- U1042, INSERM, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
- HP2 Laboratory, Université Grenoble Alpes, Building Jean Roget; Faculty of Medicine; F-38042 Grenoble France
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25
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Coverdale NS, Badrov MB, Shoemaker JK. Impact of age on cerebrovascular dilation versus reactivity to hypercapnia. J Cereb Blood Flow Metab 2017; 37:344-355. [PMID: 26759432 PMCID: PMC5363751 DOI: 10.1177/0271678x15626156] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 12/02/2015] [Accepted: 12/10/2015] [Indexed: 01/02/2023]
Abstract
This study quantified the effect of age on cerebrovascular reactivity and cerebrovascular conductance while accounting for differences in grey matter volume in younger (YA: n = 12; 24 ± 4 years, six females) and older adults (OA: n = 10; 66 ± 7 years; five females). Cerebral blood flow velocity (CBFV; transcranial Doppler) in the middle cerebral artery (MCA), MCA cross-sectional area (CSA), intracranial volumes (magnetic resonance imaging), and mean arterial pressure (MAP; Finometer), were measured under normocapnic and hypercapnic (6% carbon dioxide) conditions. Cerebral blood flow (CBF) was quantified from CBFV and MCA CSA and normalized to grey matter volume. Grey matter volume was 719 ± 98 mL in YA and 622 ± 50 mL in OA (P = 0.009). Cerebrovascular reactivity (%ΔCBF/ΔPETCO2) was not different between YA and OA. In contrast, cerebrovascular conductance (CBF/MAP) in response to hypercapnia was reduced in OA (P = 0.02). Of note, MAP increased more with hypercapnia in OA compared with YA. Therefore, the central hemodynamic response to hypercapnia compensated for a diminished dilatory response downstream from the MCA so that the CBF response to hypercapnia per unit of brain mass was not affected by age. This impairment was not detected by traditional measures of cerebrovascular reactivity.
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Affiliation(s)
- Nicole S Coverdale
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, ON, Canada
| | - Mark B Badrov
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, ON, Canada
| | - J Kevin Shoemaker
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, ON, Canada .,Department of Physiology and Pharmacology, Western University, London, ON, Canada
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26
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Bhogal AA, De Vis JB, Siero JCW, Petersen ET, Luijten PR, Hendrikse J, Philippens MEP, Hoogduin H. The BOLD cerebrovascular reactivity response to progressive hypercapnia in young and elderly. Neuroimage 2016; 139:94-102. [PMID: 27291492 DOI: 10.1016/j.neuroimage.2016.06.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 05/30/2016] [Accepted: 06/08/2016] [Indexed: 12/01/2022] Open
Abstract
Blood Oxygenation Level Dependent (BOLD) imaging in combination with vasoactive stimuli can be used to probe cerebrovascular reactivity (CVR). Characterizing the healthy, age-related changes in the BOLD-CVR response can provide a reference point from which to distinguish abnormal CVR from the otherwise normal effects of ageing. Using a computer controlled gas delivery system, we examine differences in BOLD-CVR response to progressive hypercapnia between 16 young (28±3years, 9 female) and 30 elderly subjects (66±4years, 13 female). Furthermore, we incorporate baseline T2* information to broaden our interpretation of the BOLD-CVR response. Significant age-related differences were observed. Grey matter CVR at 7mmHg above resting PetCO2 was lower amongst elderly (0.19±0.06%ΔBOLD/mmHg) as compared to young subjects (0.26±0.07%ΔBOLD/mmHg). White matter CVR at 7mmHg above baseline PetCO2 showed no significant difference between young (0.04±0.02%ΔBOLD/mmHg) and elderly subjects (0.05±0.03%ΔBOLD/mmHg). We saw no significant differences in the BOLD signal response to progressive hypercapnia between male and female subjects in either grey or white matter. The observed differences in the healthy BOLD-CVR response could be explained by age-related changes in vascular mechanical properties.
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Affiliation(s)
- Alex A Bhogal
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Jill B De Vis
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jeroen C W Siero
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Esben T Petersen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Hvidovre, Denmark
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Hans Hoogduin
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
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27
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Bain AR, Nybo L, Ainslie PN. Cerebral Vascular Control and Metabolism in Heat Stress. Compr Physiol 2016; 5:1345-80. [PMID: 26140721 DOI: 10.1002/cphy.c140066] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review provides an in-depth update on the impact of heat stress on cerebrovascular functioning. The regulation of cerebral temperature, blood flow, and metabolism are discussed. We further provide an overview of vascular permeability, the neurocognitive changes, and the key clinical implications and pathologies known to confound cerebral functioning during hyperthermia. A reduction in cerebral blood flow (CBF), derived primarily from a respiratory-induced alkalosis, underscores the cerebrovascular changes to hyperthermia. Arterial pressures may also become compromised because of reduced peripheral resistance secondary to skin vasodilatation. Therefore, when hyperthermia is combined with conditions that increase cardiovascular strain, for example, orthostasis or dehydration, the inability to preserve cerebral perfusion pressure further reduces CBF. A reduced cerebral perfusion pressure is in turn the primary mechanism for impaired tolerance to orthostatic challenges. Any reduction in CBF attenuates the brain's convective heat loss, while the hyperthermic-induced increase in metabolic rate increases the cerebral heat gain. This paradoxical uncoupling of CBF to metabolism increases brain temperature, and potentiates a condition whereby cerebral oxygenation may be compromised. With levels of experimentally viable passive hyperthermia (up to 39.5-40.0 °C core temperature), the associated reduction in CBF (∼ 30%) and increase in cerebral metabolic demand (∼ 10%) is likely compensated by increases in cerebral oxygen extraction. However, severe increases in whole-body and brain temperature may increase blood-brain barrier permeability, potentially leading to cerebral vasogenic edema. The cerebrovascular challenges associated with hyperthermia are of paramount importance for populations with compromised thermoregulatory control--for example, spinal cord injury, elderly, and those with preexisting cardiovascular diseases.
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Affiliation(s)
- Anthony R Bain
- Centre for Heart Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan Campus, Kelowna, Canada
| | - Lars Nybo
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Philip N Ainslie
- Centre for Heart Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan Campus, Kelowna, Canada
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28
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Arterial stiffness is associated with age-related differences in cerebrovascular conductance. Exp Gerontol 2016; 73:59-64. [DOI: 10.1016/j.exger.2015.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 10/31/2015] [Accepted: 11/10/2015] [Indexed: 11/23/2022]
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29
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Spencer MD, Tyndall AV, Davenport MH, Argourd L, Anderson TJ, Eskes GA, Friedenreich CM, Hogan DB, Leigh R, Meshi B, Smith EE, Wilson BJ, Wilton SB, Poulin MJ. Cerebrovascular Responsiveness to Hypercapnia Is Stable over Six Months in Older Adults. PLoS One 2015; 10:e0143059. [PMID: 26599343 PMCID: PMC4658173 DOI: 10.1371/journal.pone.0143059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/19/2015] [Indexed: 11/18/2022] Open
Abstract
The primary purpose of this Brain in Motion (BIM) sub-study was to determine the 6-month stability of resting blood flow velocity and cerebrovascular responsiveness to a euoxic hypercapnic challenge in a group of physically inactive community dwelling men and men aged ≥55 yrs (range 55–92 yrs). At baseline and 6 months later 88 women (65±6 yr) and 78 men (67±7 yr) completed a hypercapnic challenge (step changes from resting end-tidal PCO2 ((PETCO2) to +1, +5 and +8 mmHg above rest) while cerebral blood flow velocity was assessed using transcranial Doppler ultrasound. Peak velocity of the middle cerebral artery (MCAv) was increased (p<0.05) at the second visit during rest (51±2 vs. 52±4); however, these differences were abolished (p>0.05) when MCAv was normalized to PETCO2. During hypercapnia, MCAv tended to be increased at follow-up, but this finding was absent when MCAv/PETCO2 was compared across time. Cerebrovascular reactivity (i.e., ΔMCAv/ΔPETCO2) was similar (p>0.05) between testing occasions regardless of the approach taken (i.e., considering only the lower step [from +1 to +5 mmHg]; the upper step [+5 to +8 mmHg]; or the complete test taken together). In conclusion, this study has shown that cerebral blood flow and cerebrovascular responsiveness to acute euoxic hypercapnia are stable in older, healthy adults over a 6-month period. Modest changes in MCAv over time must be viewed in the context of underlying differences in PETCO2, an important finding with implications for future studies considering cerebral blood flow velocity.
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Affiliation(s)
- Matthew D. Spencer
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Amanda V. Tyndall
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Margie H. Davenport
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Laurie Argourd
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Todd J. Anderson
- Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Cardiac Science, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Gail A. Eskes
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 2E2 Canada
| | - Christine M. Friedenreich
- Department of Cancer Epidemiology and Prevention Research, Alberta Health Services, Cancer Control Alberta, Calgary, Alberta, T2S 3C3 Canada
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - David B. Hogan
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Richard Leigh
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary Alberta, T2N 4N1 Canada
| | - Bernard Meshi
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Eric E. Smith
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Ben J. Wilson
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Stephen B. Wilton
- Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
| | - Marc J. Poulin
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, T2N 1N4 Canada
- * E-mail:
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30
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Sobczyk O, Battisti-Charbonney A, Poublanc J, Crawley AP, Sam K, Fierstra J, Mandell DM, Mikulis DJ, Duffin J, Fisher JA. Assessing cerebrovascular reactivity abnormality by comparison to a reference atlas. J Cereb Blood Flow Metab 2015; 35:213-20. [PMID: 25388679 PMCID: PMC4426737 DOI: 10.1038/jcbfm.2014.184] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 09/25/2014] [Indexed: 11/09/2022]
Abstract
Attribution of vascular pathophysiology to reductions in cerebrovascular reactivity (CVR) is confounded by subjective assessment and the normal variation between anatomic regions. This study aimed to develop an objective scoring assessment of abnormality. CVR was measured as the ratio of the blood-oxygen-level-dependent magnetic resonance signal response divided by an increase in CO2, standardized to eliminate variability. A reference normal atlas was generated by coregistering the CVR maps from 46 healthy subjects into a standard space and calculating the mean and standard deviation (s.d.) of CVR for each voxel. Example CVR studies from 10 patients with cerebral vasculopathy were assessed for abnormality, by normalizing each patient's CVR to the same standard space as the atlas, and assigning a z-score to each voxel relative to the mean and s.d. of the corresponding atlas voxel. Z-scores were color coded and superimposed on their anatomic scans to form CVR z-maps. We found the CVR z-maps provided an objective evaluation of abnormality, enhancing our appreciation of the extent and distribution of pathophysiology compared with CVR maps alone. We concluded that CVR z-maps provide an objective, improved form of evaluation for comparisons of voxel-specific CVR between subjects, and across tests sites.
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Affiliation(s)
- Olivia Sobczyk
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Anne Battisti-Charbonney
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada
| | - Adrian P Crawley
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada
| | - Kevin Sam
- 1] Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada [2] Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jorn Fierstra
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Daniel M Mandell
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada
| | - David J Mikulis
- 1] Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada [2] Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada
| | - James Duffin
- 1] Department of Physiology, University of Toronto, Toronto, Ontario, Canada [2] Department of Anaesthesia and Pain Management University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Joseph A Fisher
- 1] Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada [2] Department of Physiology, University of Toronto, Toronto, Ontario, Canada [3] Department of Anaesthesia and Pain Management University Health Network, University of Toronto, Toronto, Ontario, Canada
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31
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Flück D, Braz ID, Keiser S, Hüppin F, Haider T, Hilty MP, Fisher JP, Lundby C. Age, aerobic fitness, and cerebral perfusion during exercise: role of carbon dioxide. Am J Physiol Heart Circ Physiol 2014; 307:H515-23. [DOI: 10.1152/ajpheart.00177.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Middle cerebral artery mean velocity (MCAvmean) is attenuated with increasing age both at rest and during exercise. The aim of this study was to determine the influence of the age-dependent reduction in arterial Pco2 (PaCO2) and physical fitness herein. We administered supplemental CO2 (CO2 trial) or no additional gas (control trial) to the inspired air in a blinded and randomized manner, and assessed middle cerebral artery mean flow velocity during graded exercise in 1) 21 young [Y; age 24 ± 3 yr (±SD)] volunteers of whom 11 were trained (YT) and 10 considered untrained (YUT), and 2) 17 old (O; 66 ± 4 yr) volunteers of whom 8 and 9 were considered trained (OT) and untrained (OUT), respectively. A resting hypercapnic reactivity test was also performed. MCAvmean and PaCO2 were lower in O [44.9 ± 3.1 cm/s and 30 ± 1 mmHg (±SE)] compared with Y (59.3 ± 2.3 cm/s and 34 ± 1 mmHg, P < 0.01) at rest, independent of aerobic fitness level. The age-related decreases in MCAvmean and PaCO2 persisted during exercise. Supplemental CO2 reduced the age-associated decline in MCAvmean by 50%, suggesting that PaCO2 is a major component in the decline. On the other hand, relative hypercapnic reactivity was neither influenced by age ( P = 0.46) nor aerobic fitness ( P = 0.36). Although supplemental CO2 attenuated exercise-induced reduction in cerebral oxygenation (near-infrared spectroscopy), this did not influence exercise performance. In conclusion, PaCO2 contributes to the age-associated decline in MCAvmean at rest and during exercise; however exercise capacity did not diminish this age effect.
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Affiliation(s)
- Daniela Flück
- Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
- Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Igor D. Braz
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Stefanie Keiser
- Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
- Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Fabienne Hüppin
- Exercise Physiology, Institute of Human Movement Sciences, ETH Zürich, Zürich, Switzerland
| | - Thomas Haider
- Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | - Matthias P. Hilty
- Medical Intensive Care Unit, University Hospital of Zürich, Zürich, Switzerland and
| | - James P. Fisher
- Exercise Physiology, Institute of Human Movement Sciences, ETH Zürich, Zürich, Switzerland
| | - Carsten Lundby
- Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
- Institute of Physiology, University of Zürich, Zürich, Switzerland
- Food and Nutrition and Sport Science, Gothenburg University, Gothenburg, Sweden
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32
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Flück D, Beaudin AE, Steinback CD, Kumarpillai G, Shobha N, McCreary CR, Peca S, Smith EE, Poulin MJ. Effects of aging on the association between cerebrovascular responses to visual stimulation, hypercapnia and arterial stiffness. Front Physiol 2014; 5:49. [PMID: 24600398 PMCID: PMC3928624 DOI: 10.3389/fphys.2014.00049] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 01/26/2014] [Indexed: 02/04/2023] Open
Abstract
Aging is associated with decreased vascular compliance and diminished neurovascular- and hypercapnia-evoked cerebral blood flow (CBF) responses. However, the interplay between arterial stiffness and reduced CBF responses is poorly understood. It was hypothesized that increased cerebral arterial stiffness is associated with reduced evoked responses to both, a flashing checkerboard visual stimulation (i.e., neurovascular coupling), and hypercapnia. To test this hypothesis, 20 older (64 ± 8 year; mean ± SD) and 10 young (30 ± 5 year) subjects underwent a visual stimulation (VS) and a hypercapnic test. Blood velocity through the posterior (PCA) and middle cerebral (MCA) arteries was measured concurrently using transcranial Doppler ultrasound (TCD). Cerebral and systemic vascular stiffness were calculated from the cerebral blood velocity and systemic blood pressure waveforms, respectively. Cerebrovascular (MCA: young = 76 ± 15%, older = 98 ± 19%, p = 0.004; PCA: young = 80 ± 16%, older = 106 ± 17%, p < 0.001) and systemic (young = 59 ± 9% and older = 80 ± 9%, p < 0.001) augmentation indices (AI) were higher in the older group. CBF responses to VS (PCA: p < 0.026) and hypercapnia (PCA: p = 0.018; MCA: p = 0.042) were lower in the older group. A curvilinear model fitted to cerebral AI and age showed AI increases until ~60 years of age, after which the increase levels off (PCA: R (2) = 0.45, p < 0.001; MCA: R (2) = 0.31, p < 0.001). Finally, MCA, but not PCA, hypercapnic reactivity was inversely related to cerebral AI (MCA: R (2) = 0.28, p = 0.002; PCA: R (2) = 0.10, p = 0.104). A similar inverse relationship was not observed with the PCA blood flow response to VS (R (2) = 0.06, p = 0.174). In conclusion, older subjects had reduced neurovascular- and hypercapnia-mediated CBF responses. Furthermore, lower hypercapnia-mediated blood flow responses through the MCA were associated with increased vascular stiffness. These findings suggest the reduced hypercapnia-evoked CBF responses through the MCA, in older individuals may be secondary to vascular stiffening.
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Affiliation(s)
- Daniela Flück
- Department of Biology, Institute of Human Movement Sciences and Sport, ETH Zurich Zurich, Switzerland ; Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Andrew E Beaudin
- Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Craig D Steinback
- Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Gopukumar Kumarpillai
- Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Nandavar Shobha
- Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Cheryl R McCreary
- Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Department of Radiology, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services Calgary, AB, Canada
| | - Stefano Peca
- Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services Calgary, AB, Canada
| | - Eric E Smith
- Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services Calgary, AB, Canada
| | - Marc J Poulin
- Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary Calgary, AB, Canada ; Faculty of Kinesiology, University of Calgary Calgary, AB, Canada ; The Libin Cardiovascular Institute of Alberta, Faculty of Medicine, University of Calgary Calgary, AB, Canada
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33
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Zhu YS, Tarumi T, Tseng BY, Palmer DM, Levine BD, Zhang R. Cerebral vasomotor reactivity during hypo- and hypercapnia in sedentary elderly and Masters athletes. J Cereb Blood Flow Metab 2013; 33:1190-6. [PMID: 23591649 PMCID: PMC3734768 DOI: 10.1038/jcbfm.2013.66] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 03/14/2013] [Accepted: 03/17/2013] [Indexed: 11/09/2022]
Abstract
Physical activity may influence cerebrovascular function. The objective of this study was to determine the impact of life-long aerobic exercise training on cerebral vasomotor reactivity (CVMR) to changes in end-tidal CO2 (EtCO2) in older adults. Eleven sedentary young (SY, 27±5 years), 10 sedentary elderly (SE, 72±4 years), and 11 Masters athletes (MA, 72±6 years) underwent the measurements of cerebral blood flow velocity (CBFV), arterial blood pressure, and EtCO2 during hypocapnic hyperventilation and hypercapnic rebreathing. Baseline CBFV was lower in SE and MA than in SY while no difference was observed between SE and MA. During hypocapnia, CVMR was lower in SE and MA compared with SY (1.87±0.42 and 1.47±0.21 vs. 2.18±0.28 CBFV%/mm Hg, P<0.05) while being lowest in MA among all groups (P<0.05). In response to hypercapnia, SE and MA exhibited greater CVMR than SY (6.00±0.94 and 6.67±1.09 vs. 3.70±1.08 CBFV1%/mm Hg, P<0.05) while no difference was observed between SE and MA. A negative linear correlation between hypo- and hypercapnic CVMR (R(2)=0.37, P<0.001) was observed across all groups. Advanced age was associated with lower resting CBFV and lower hypocapnic but greater hypercapnic CVMR. However, life-long aerobic exercise training appears to have minimal effects on these age-related differences in cerebral hemodynamics.
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Affiliation(s)
- Yong-Sheng Zhu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
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34
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Murrell CJ, Cotter JD, Thomas KN, Lucas SJE, Williams MJA, Ainslie PN. Cerebral blood flow and cerebrovascular reactivity at rest and during sub-maximal exercise: effect of age and 12-week exercise training. AGE (DORDRECHT, NETHERLANDS) 2013; 35:905-20. [PMID: 22669592 PMCID: PMC3636405 DOI: 10.1007/s11357-012-9414-x] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 04/17/2012] [Indexed: 05/05/2023]
Abstract
Chronic reductions in cerebral blood flow (CBF) and cerebrovascular reactivity to CO2 are risk factors for cerebrovascular disease. Higher aerobic fitness is associated with higher CBF at any age; however, whether CBF or reactivity can be elevated following an exercise training intervention in healthy individuals is unknown. The aim of this study was to assess the effect of exercise training on CBF and cerebrovascular reactivity at rest and during exercise in young and older individuals. Ten young (23 ± 5 years; body mass index (BMI), 26 ± 3 kg m(-2); [Formula: see text], 35 ± 5 ml kg(-1) min(-1)) and 10 older (63 ± 5 years; BMI, 25 ± 3.0 kg m(-2); [Formula: see text], 26 ± 4 ml kg(-1) min(-1)) previously sedentary individuals breathed 5 % CO2 for 3 min at rest and during steady-state cycling exercise (30 and 70 % heart rate range (HRR)) prior to and following a 12-week aerobic exercise intervention. Effects of training on middle cerebral artery blood velocity (MCAv) at rest were unclear in both age groups. The absolute MCAv response to exercise was greater in the young (9 and 9 cm s(-1) (30 and 70 % HRR, respectively) vs. 5 and 4 cm s(-1) (older), P < 0.05) and was similar following training. Cerebrovascular reactivity was elevated following the 12-week training at rest (2.87 ± 0.76 vs. 2.54 ± 1.12 cm s(-1) mm Hg(-1), P = 0.01) and during exercise, irrespective of age. The finding of a training-induced elevation in cerebrovascular reactivity provides further support for exercise as a preventative tool in cerebrovascular and neurological disease with ageing.
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Affiliation(s)
| | - James D. Cotter
- />School of Physical Education, University of Otago, Dunedin, New Zealand
| | - Kate N. Thomas
- />Department of Physiology, University of Otago, Dunedin, New Zealand
| | | | | | - Philip N. Ainslie
- />School of Health and Exercise Sciences, University of British Columbia, Okanagan Campus, Kelowna, Canada
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35
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Miller VM, Garovic VD, Kantarci K, Barnes JN, Jayachandran M, Mielke MM, Joyner MJ, Shuster LT, Rocca WA. Sex-specific risk of cardiovascular disease and cognitive decline: pregnancy and menopause. Biol Sex Differ 2013; 4:6. [PMID: 23537114 PMCID: PMC3623746 DOI: 10.1186/2042-6410-4-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 03/05/2013] [Indexed: 12/26/2022] Open
Abstract
Understanding the biology of sex differences is integral to personalized medicine. Cardiovascular disease and cognitive decline are two related conditions, with distinct sex differences in morbidity and clinical manifestations, response to treatments, and mortality. Although mortality from all-cause cardiovascular diseases has declined in women over the past five years, due in part to increased educational campaigns regarding the recognition of symptoms and application of treatment guidelines, the mortality in women still exceeds that of men. The physiological basis for these differences requires further research, with particular attention to two physiological conditions which are unique to women and associated with hormonal changes: pregnancy and menopause. Both conditions have the potential to impact life-long cardiovascular risk, including cerebrovascular function and cognition in women. This review draws on epidemiological, translational, clinical, and basic science studies to assess the impact of hypertensive pregnancy disorders on cardiovascular disease and cognitive function later in life, and examines the effects of post-menopausal hormone treatments on cardiovascular risk and cognition in midlife women. We suggest that hypertensive pregnancy disorders and menopause activate vascular components, i.e., vascular endothelium and blood elements, including platelets and leukocytes, to release cell-membrane derived microvesicles that are potential mediators of changes in cerebral blood flow, and may ultimately affect cognition in women as they age. Research into specific sex differences for these disease processes with attention to an individual's sex chromosomal complement and hormonal status is important and timely.
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Affiliation(s)
- Virginia M Miller
- Departments of Surgery and Physiology and Biomedical Engineering, 200 1st St SW, Rochester, MN 55905, USA
| | - Vesna D Garovic
- Division of Nephrology and Hypertension, 200 1st St SW, Rochester, MN 55905, USA
| | - Kejal Kantarci
- Department of Radiology, 200 1st St SW, Rochester, MN 55905, USA
| | - Jill N Barnes
- Department of Anesthesiology, 200 1st St SW, Rochester, MN 55905, USA
| | - Muthuvel Jayachandran
- Department of Physiology and Biomedical Engineering, 200 1st St SW, Rochester, MN 55905, USA
| | - Michelle M Mielke
- Department of Health Science Research, Division of Epidemiology, 200 1st St SW, Rochester, MN 55905, USA
| | - Michael J Joyner
- Department of Anesthesiology, 200 1st St SW, Rochester, MN 55905, USA
| | - Lynne T Shuster
- Department of Internal Medicine, Women’s Health Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Walter A Rocca
- Department of Health Science Research, Division of Epidemiology, and Neurology, College of Medicine, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
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36
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Barnes JN, Schmidt JE, Nicholson WT, Joyner MJ. Cyclooxygenase inhibition abolishes age-related differences in cerebral vasodilator responses to hypercapnia. J Appl Physiol (1985) 2012; 112:1884-90. [PMID: 22442028 DOI: 10.1152/japplphysiol.01270.2011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Blood flow and vasodilatory responses are altered by age in a number of vascular beds, including the cerebral circulation. To test the role of prostaglandins as regulators of cerebral vascular function, we examined cerebral vasodilator responses to CO(2) (cerebrovascular reactivity) in young (26 ± 5 yr; 6 males/6 females) and older (65 ± 6 yr, 5 males/5 females) healthy humans before and after cyclooxygenase inhibition (using indomethacin). Middle cerebral artery velocity (MCAv) responses to stepped hypercapnia were measured before and 90 min after indomethacin. Changes in MCAv during the recovery from hypercapnia (vasoconstrictor responses) were also evaluated before and after indomethacin. Cerebrovascular reactivity was calculated using linear regression between MCAv and end-tidal CO(2). Young adults demonstrated greater MCAv (55 ± 6 vs. 39 ± 5 cm/s: P < 0.05) and MCAv reactivity (1.67 ± 0.20 vs. 1.09 ± 0.19 cm·s(-1)·mmHg(-1); P < 0.05) to hypercapnia compared with older adults (P < 0.05). In both groups MCAv and MCAv reactivity decreased between control and indomethacin. Furthermore, the age-related differences in these cerebrovascular variables were abolished by indomethacin. During the recovery from hypercapnia, there were no age-related differences in MCAv reactivity; however, indomethacin significantly reduced the MCAv reactivity in both groups. Taken together, these results suggest that cerebral blood flow velocity and cerebrovascular reactivity are attenuated in aging humans, and may be due to a loss of prostaglandin-mediated vasodilation.
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Affiliation(s)
- Jill N Barnes
- Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905, USA.
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37
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de Paula VR, Rocha LP, Tiveron GC, de Oliveira Guimarães CS, Dos Reis MA, Tavares BB, Corrêa RRM. Carotid angiodysplasia complicated by the use of anti-hypertensive drugs during pregnancy: a case report. J Med Case Rep 2011; 5:415. [PMID: 21867546 PMCID: PMC3174930 DOI: 10.1186/1752-1947-5-415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 08/25/2011] [Indexed: 11/14/2022] Open
Abstract
Introduction Hypertensive syndromes in pregnancy are one of the leading causes of obstetric admissions into intensive care units. They are related to changes in the central nervous system caused by a decrease in cerebral perfusion pressure, indicated by an increase in intracranial pressure. These changes in pressure usually result from acute injuries or a decrease in the mean arterial pressure due to iatrogenic action or shock. However, other vascular disorders may contribute to similar occurrences. Case presentation A 15-year-old girl was admitted to our hospital complaining of severe headaches since the eighth month of pregnancy, and presented with an arterial blood pressure of 180/120 mmHg. The diagnostic hypothesis was pre-eclampsia. Our patient's blood pressure levels remained elevated, and she was submitted to a cesarean section. After the procedure, she was referred to our infirmary, presenting with a blank distant look and with no interaction with the environment, dyslalia, and labial and upper and lower right limb paresis. She was confused and unable to speak, but responded to painful stimuli as she conveyed abdominal pain at superficial and deep palpation. The hypothesis of post-partum psychosis was suggested. She was then transferred to our intensive care unit, maintaining an impassive attitude in bed but reacting to external stimuli. Results of a computed tomography scan revealed ischemic infarction of the territory of her left middle cerebral artery. A selective cerebral arteriography showed bilateral occlusion of her internal carotid artery in the intracranial position, prebifurcation and angiodysplasia in the cervical segments of her internal carotid artery. Sixteen days after hospital admission, our patient died. Conclusion This data shows the need for careful monitoring of hypertensive syndromes in pregnancy cases, especially in cases with a history of chronic hypertension or with vascular alterations, It also highlights the need for constant supervision of blood pressure levels during the use of anti-hypertensive medications.
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Affiliation(s)
- Viviane Ribeiro de Paula
- Discipline of General Pathology, Department of Biological Sciences, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
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38
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Rolita L, Verghese J. Neurovascular coupling: Key to gait slowing in aging? Ann Neurol 2011; 70:189-91. [DOI: 10.1002/ana.22503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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39
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Willie CK, Colino FL, Bailey DM, Tzeng YC, Binsted G, Jones LW, Haykowsky MJ, Bellapart J, Ogoh S, Smith KJ, Smirl JD, Day TA, Lucas SJ, Eller LK, Ainslie PN. Utility of transcranial Doppler ultrasound for the integrative assessment of cerebrovascular function. J Neurosci Methods 2011; 196:221-37. [PMID: 21276818 DOI: 10.1016/j.jneumeth.2011.01.011] [Citation(s) in RCA: 397] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 01/05/2011] [Accepted: 01/06/2011] [Indexed: 01/05/2023]
Abstract
There is considerable utility in the use of transcranial Doppler ultrasound (TCD) to assess cerebrovascular function. The brain is unique in its high energy and oxygen demand but limited capacity for energy storage that necessitates an effective means of regional blood delivery. The relative low cost, ease-of-use, non-invasiveness, and excellent temporal resolution of TCD make it an ideal tool for the examination of cerebrovascular function in both research and clinical settings. TCD is an efficient tool to access blood velocities within the cerebral vessels, cerebral autoregulation, cerebrovascular reactivity to CO(2), and neurovascular coupling, in both physiological states and in pathological conditions such as stroke and head trauma. In this review, we provide: (1) an overview of TCD methodology with respect to other techniques; (2) a methodological synopsis of the cerebrovascular exam using TCD; (3) an overview of the physiological mechanisms involved in regulation of the cerebral blood flow; (4) the utility of TCD for assessment of cerebrovascular pathology; and (5) recommendations for the assessment of four critical and complimentary aspects of cerebrovascular function: intra-cranial blood flow velocity, cerebral autoregulation, cerebral reactivity, and neurovascular coupling. The integration of these regulatory mechanisms from an integrated systems perspective is discussed, and future research directions are explored.
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Affiliation(s)
- C K Willie
- Department of Human Kinetics, Faculty of Health and Social Development, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC, Canada V1V 1V7.
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