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Gudigar A, Kadri NA, Raghavendra U, Samanth J, Maithri M, Inamdar MA, Prabhu MA, Hegde A, Salvi M, Yeong CH, Barua PD, Molinari F, Acharya UR. Automatic identification of hypertension and assessment of its secondary effects using artificial intelligence: A systematic review (2013-2023). Comput Biol Med 2024; 172:108207. [PMID: 38489986 DOI: 10.1016/j.compbiomed.2024.108207] [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: 12/27/2023] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 03/17/2024]
Abstract
Artificial Intelligence (AI) techniques are increasingly used in computer-aided diagnostic tools in medicine. These techniques can also help to identify Hypertension (HTN) in its early stage, as it is a global health issue. Automated HTN detection uses socio-demographic, clinical data, and physiological signals. Additionally, signs of secondary HTN can also be identified using various imaging modalities. This systematic review examines related work on automated HTN detection. We identify datasets, techniques, and classifiers used to develop AI models from clinical data, physiological signals, and fused data (a combination of both). Image-based models for assessing secondary HTN are also reviewed. The majority of the studies have primarily utilized single-modality approaches, such as biological signals (e.g., electrocardiography, photoplethysmography), and medical imaging (e.g., magnetic resonance angiography, ultrasound). Surprisingly, only a small portion of the studies (22 out of 122) utilized a multi-modal fusion approach combining data from different sources. Even fewer investigated integrating clinical data, physiological signals, and medical imaging to understand the intricate relationships between these factors. Future research directions are discussed that could build better healthcare systems for early HTN detection through more integrated modeling of multi-modal data sources.
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Affiliation(s)
- Anjan Gudigar
- Department of Instrumentation and Control Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Nahrizul Adib Kadri
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - U Raghavendra
- Department of Instrumentation and Control Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India.
| | - Jyothi Samanth
- Department of Cardiovascular Technology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India
| | - M Maithri
- Department of Mechatronics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Mahesh Anil Inamdar
- Department of Mechatronics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Mukund A Prabhu
- Department of Cardiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Ajay Hegde
- Manipal Hospitals, Bengaluru, Karnataka, 560102, India
| | - Massimo Salvi
- Biolab, PolitoBIOMedLab, Department of Electronics and Telecommunications, Politecnicodi Torino, Turin, Italy
| | - Chai Hong Yeong
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, 47500, Subang Jaya, Malaysia
| | - Prabal Datta Barua
- Cogninet Brain Team, Cogninet Australia, Sydney, NSW, 2010, Australia; School of Business (Information Systems), Faculty of Business, Education, Law & Arts, University of Southern Queensland, Toowoomba, QLD, 4350, Australia; Faculty of Engineering and Information Technology, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Filippo Molinari
- Biolab, PolitoBIOMedLab, Department of Electronics and Telecommunications, Politecnicodi Torino, Turin, Italy
| | - U Rajendra Acharya
- School of Mathematics, Physics, and Computing, University of Southern Queensland, Springfield, QLD, 4300, Australia; Centre for Health Research, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
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2
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Robinson AC, Bin Rizwan T, Davidson YS, Minshull J, Tinkler P, Payton A, Mann DMA, Roncaroli F. Self-Reported Late-Life Hypertension Is Associated with a Healthy Cognitive Status and Reduced Alzheimer's Disease Pathology Burden. J Alzheimers Dis 2024; 98:1457-1466. [PMID: 38552117 DOI: 10.3233/jad-231429] [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] [Indexed: 04/20/2024]
Abstract
Background While mid-life hypertension represents a risk factor for the development of Alzheimer's disease (AD), the risk after the age of 65 is less certain. Establishing relationships between late life hypertension and the pathological changes of AD could be crucial in understanding the relevance of blood pressure as a risk factor for this disorder. Objective We investigated associations between self-reported late-life hypertension, cognitive status and AD pathology at death. The impact of antihypertensive medication was also examined. Methods Using the Cornell Medical Index questionnaire, we ascertained whether participants had ever reported hypertension. We also noted use of antihypertensive medication. The donated brains of 108 individuals were assessed for AD pathology using consensus guidelines. Statistical analysis aimed to elucidate relationships between hypertension and AD pathology. Results We found no associations between self-reported hypertension and cognitive impairment at death. However, those with hypertension were significantly more likely to exhibit lower levels of AD pathology as measured by Thal phase, Braak stage, CERAD score, and NIA-AA criteria-even after controlling for sex, level of education and presence of APOEɛ4 allele(s). No significant associations could be found when examining use of antihypertensive medications. Conclusions Our findings suggest that late-life hypertension is associated with less severe AD pathology. We postulate that AD pathology may be promoted by reduced cerebral blood flow.
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Affiliation(s)
- Andrew C Robinson
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience, The University of Manchester, Salford Royal Hospital, Salford, UK
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre (MAHSC), Manchester, UK
| | - Tawfique Bin Rizwan
- Faculty of Biology, Medicine and Health, School of Medical Sciences, School of Health Sciences, The University of Manchester, Manchester, UK
| | - Yvonne S Davidson
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience, The University of Manchester, Salford Royal Hospital, Salford, UK
| | - James Minshull
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience, The University of Manchester, Salford Royal Hospital, Salford, UK
| | - Phillip Tinkler
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience, The University of Manchester, Salford Royal Hospital, Salford, UK
| | - Antony Payton
- Faculty of Biology, Medicine and Health, School of Health Sciences, Division of Informatics, Imaging and Data Sciences, The University of Manchester, Manchester, UK
| | - David M A Mann
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience, The University of Manchester, Salford Royal Hospital, Salford, UK
| | - Federico Roncaroli
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience, The University of Manchester, Salford Royal Hospital, Salford, UK
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre (MAHSC), Manchester, UK
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Adams ZH, Blythe HC. The central chemoreflex in human hypertension: another piece of the sympathoexcitation puzzle? J Physiol 2023; 601:4263-4265. [PMID: 37634225 DOI: 10.1113/jp285338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023] Open
Affiliation(s)
- Zoe H Adams
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| | - Hazel C Blythe
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
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Hindenes LB, Ingebrigtsen T, Isaksen JG, Håberg AK, Johnsen LH, Herder M, Mathiesen EB, Vangberg TR. Anatomical variations in the circle of Willis are associated with increased odds of intracranial aneurysms: The Tromsø study. J Neurol Sci 2023; 452:120740. [PMID: 37517271 DOI: 10.1016/j.jns.2023.120740] [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: 02/20/2023] [Revised: 07/06/2023] [Accepted: 07/23/2023] [Indexed: 08/01/2023]
Abstract
PURPOSE Studies on patients suggest an association between anatomical variations in the Circle of Willis (CoW) and intracranial aneurysms (IA), but it is unclear whether this association is present in the general population. In this cross-sectional population study, we investigated the associations between CoW anatomical variations and IA. METHODS We included 1667 participants from a population sample with 3 T MRI time-of-flight angiography (40-84 years, 46.5% men). Saccular IAs were defined as protrusions in the intracranial arteries ≥2 mm, while variants of the CoW were classified according to whether segments were missing or hypoplastic (< 1 mm). We used logistic regression, adjusting for age and IA risk factors, to assess whether participants with incomplete CoW variants had a greater prevalence of IA and whether participants with specific incomplete variants had a greater prevalence of IA. RESULTS Participants with an incomplete CoW had an increased prevalence of IA (OR, 2.3 [95% CI 1.05-5.04]). This was mainly driven by the variant missing all three communicating arteries (OR, 4.2 [95% CI 1.7-1 0.3]) and the variant missing the P1 segment of the posterior cerebral artery (OR, 3.6 [95% CI 1.2-10.1]). The combined prevalence of the two variants was 15.4% but accounted for 28% of the IAs. CONCLUSION The findings suggest that an incomplete CoW is associated with an increased risk of IA for adults in the general population.
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Affiliation(s)
- Lars B Hindenes
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; PET Imaging Center, University Hospital of North Norway, Tromsø, Norway
| | - Tor Ingebrigtsen
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Neurosurgery, Ophthalmology, and Otorhinolaryngology, University Hospital of North Norway, Tromsø, Norway
| | - Jørgen G Isaksen
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Neurosurgery, Ophthalmology, and Otorhinolaryngology, University Hospital of North Norway, Tromsø, Norway
| | - Asta K Håberg
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Radiology and Nuclear Medicine, St. Olav University Hospital, Trondheim, Norway
| | - Liv-Hege Johnsen
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Radiology, University Hospital of North Norway, Tromsø, Norway
| | - Marit Herder
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Radiology, University Hospital of North Norway, Tromsø, Norway
| | - Ellisiv B Mathiesen
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Neurology, University Hospital of North Norway, Tromsø, Norway
| | - Torgil R Vangberg
- Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; PET Imaging Center, University Hospital of North Norway, Tromsø, Norway.
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Zhang T, Thakkar P, Emans TW, Fong D, Thampi S, Felippe ISA, Barrett CJ, Billing R, Campbell D, McBryde FD. Combined Arterial Hypertension and Ischemic Stroke Exaggerate Anesthesia-Related Hypotension and Cerebral Oxygenation Deficits: A Preclinical Study. Anesth Analg 2023; 137:440-450. [PMID: 36730724 DOI: 10.1213/ane.0000000000006263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Intraoperative arterial hypotension (IOH) is a common side effect of general anesthesia (GA), associated with poor outcomes in ischemic stroke. While IOH is more prevalent with hypertension, it is unknown whether IOH may differ when GA is induced during ischemic stroke, versus other clinical settings. This is important given that many stroke patients receive GA for endovascular thrombectomy. METHODS We evaluate the cardiovascular responses to volatile GA (isoflurane in 100% o2 ) before and during middle cerebral artery occlusion stroke in rats instrumented to record blood pressure (BP) and cerebral tissue oxygenation (p o2 ) in the projected penumbra, in clinically relevant cohorts of normotensive (Wistar rat, n = 10), treated hypertensive (spontaneously hypertensive [SH] + enalapril, n = 12), and untreated hypertensive (SH rat, n = 12). RESULTS During baseline induction of GA, IOH was similar in normotensive, treated hypertensive, and untreated hypertensive rats during the induction phase (first 10 minutes) (-24 ± 15 vs -28 ± 22 vs -48 ± 24 mm Hg; P > .05) and across the procedure (-24 ± 13 vs -30 ± 35 vs -39 ± 27 mm Hg; P > .05). Despite the BP reduction, cerebral p o2 increased by ~50% in all groups during the procedure. When inducing GA after 2 hours, all stroke groups showed a greater magnitude IOH compared to baseline GA induction, with larger falls in treated (-79 ± 24 mm Hg; P = .0202) and untreated(-105 ± 43 mm Hg; P < .001) hypertensive rats versus normotensives (-49 ± 21 mm Hg). This was accompanied by smaller increases in cerebral p o2 in normotensive rats (19% ± 32%; P = .0144 versus no-stroke); but a decrease in cerebral p o2 in treated (-11% ± 19%; P = .0048) and untreated (-12% ± 15%; P = .0003) hypertensive rats. Sham animals (normotensive and hypertensive) showed similar magnitude and pattern of IOH when induced with GA before and after sham procedure. CONCLUSIONS Our findings are the first demonstration that ischemic stroke per se increases the severity of IOH, particularly when combined with a prior history of hypertension; this combination appears to compromise penumbral perfusion.
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Affiliation(s)
- Tracy Zhang
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Pratik Thakkar
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Tonja W Emans
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Debra Fong
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Suma Thampi
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Igor S A Felippe
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Carolyn J Barrett
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Robyn Billing
- Department of Anaesthesia and Perioperative Medicine, Auckland City Hospital, Auckland, New Zealand
| | - Douglas Campbell
- Department of Anaesthesia and Perioperative Medicine, Auckland City Hospital, Auckland, New Zealand
| | - Fiona D McBryde
- From the Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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Washio T, Ogoh S. Point/counterpoint: Arterial blood pressure response to exercise does relate to exercise-induced improvement in cognitive function. J Cereb Blood Flow Metab 2023; 43:610-612. [PMID: 36704820 PMCID: PMC10063828 DOI: 10.1177/0271678x231153734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 12/22/2022] [Accepted: 12/29/2022] [Indexed: 01/28/2023]
Abstract
Exercise is a beneficial intervention to prevent cognitive dysfunction. However, an optimal exercise prescription for preventing dementia has not been established because the physiological mechanism(s) of exercise-induced improvements in cognitive function remains unclear. Interestingly, our recent study demonstrated that individuals with a higher exercise pressor response exhibit less exercise-induced cognitive improvement, suggesting that individual differences in cardiovascular responses to exercise or its associated physiological factors, may be related to exercise-induced alterations in cognitive function. Therefore, consideration of individual cardiovascular responses is warranted to develop appropriate exercise prescriptions for a given individual to prevent cognitive dysfunction.
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Affiliation(s)
- Takuro Washio
- Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
| | - Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, Kawagoe, Saitama, Japan
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7
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Mathew A, Mesa RA, Nahodyl L, Tremblay J, Rundek T, Zeki Al Hazzouri A, Elfassy T. Diastolic Blood Pressure and Cognitive Functioning: Differences by Systolic Blood Pressure Among US Adults. Am J Alzheimers Dis Other Demen 2023; 38:15333175231172283. [PMID: 37177903 PMCID: PMC10398835 DOI: 10.1177/15333175231172283] [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] [Indexed: 05/15/2023]
Abstract
BACKGROUND The role of diastolic blood pressure (DBP) with cognitive functioning is under-explored in relation to levels of systolic blood pressure (SBP). METHODS We studied 5466 participants from the National Health and Nutrition Examination Survey. Blood pressure was measured 3 times manually with a standardized sphygmomanometer and averaged. Cognitive functioning was measured using the digit symbol substitution test (DSST). RESULTS Participants were 60 years or older, 55% female, and 81% non-Hispanic White. Most participants had a DBP between 70 to <80 mmHg (33.7%), between 60 to <70 mmHg (29.3%), or <60 mmHg (18.8%). From multivariable linear regression analyses, each 5 mmHg increment of DBP was associated with significantly higher DSST scores among individuals with SBP <120 only (ß: 0.56, 95% CI: 0.09, 1.03). CONCLUSIONS Among older US adults, at non-elevated levels of SBP, higher DBP is associated with better cognitive performance.
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Affiliation(s)
- A Mathew
- Department of Public Health Sciences, University of Miami, Miami, FL, USA
| | - RA Mesa
- Department of Public Health Sciences, University of Miami, Miami, FL, USA
| | - L Nahodyl
- Department of Public Health Sciences, University of Miami, Miami, FL, USA
| | - J Tremblay
- Department of Public Health Sciences, University of Miami, Miami, FL, USA
| | - T Rundek
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - A Zeki Al Hazzouri
- Department of Epidemiology, Columbia University Mailman School of Public Health, New York, NY, USA
| | - T Elfassy
- Department of Medicine, Katz Family Division of Nephrology and Hypertension, University of Miami, Miami, FL, USA
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Tayler HM, MacLachlan R, Güzel Ö, Miners JS, Love S. Elevated late-life blood pressure may maintain brain oxygenation and slow amyloid-β accumulation at the expense of cerebral vascular damage. Brain Commun 2023; 5:fcad112. [PMID: 37113314 PMCID: PMC10128877 DOI: 10.1093/braincomms/fcad112] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 02/16/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
Hypertension in midlife contributes to cognitive decline and is a modifiable risk factor for dementia. The relationship between late-life hypertension and dementia is less clear. We have investigated the relationship of blood pressure and hypertensive status during late life (after 65 years) to post-mortem markers of Alzheimer's disease (amyloid-β and tau loads); arteriolosclerosis and cerebral amyloid angiopathy; and to biochemical measures of ante-mortem cerebral oxygenation (the myelin-associated glycoprotein:proteolipid protein-1 ratio, which is reduced in chronically hypoperfused brain tissue, and the level of vascular endothelial growth factor-A, which is upregulated by tissue hypoxia); blood-brain barrier damage (indicated by an increase in parenchymal fibrinogen); and pericyte content (platelet-derived growth factor receptor β, which declines with pericyte loss), in Alzheimer's disease (n = 75), vascular (n = 20) and mixed dementia (n = 31) cohorts. Systolic and diastolic blood pressure measurements were obtained retrospectively from clinical records. Non-amyloid small vessel disease and cerebral amyloid angiopathy were scored semiquantitatively. Amyloid-β and tau loads were assessed by field fraction measurement in immunolabelled sections of frontal and parietal lobes. Homogenates of frozen tissue from the contralateral frontal and parietal lobes (cortex and white matter) were used to measure markers of vascular function by enzyme-linked immunosorbent assay. Diastolic (but not systolic) blood pressure was associated with the preservation of cerebral oxygenation, correlating positively with the ratio of myelin-associated glycoprotein to proteolipid protein-1 and negatively with vascular endothelial growth factor-A in both the frontal and parietal cortices. Diastolic blood pressure correlated negatively with parenchymal amyloid-β in the parietal cortex. In dementia cases, elevated late-life diastolic blood pressure was associated with more severe arteriolosclerosis and cerebral amyloid angiopathy, and diastolic blood pressure correlated positively with parenchymal fibrinogen, indicating blood-brain barrier breakdown in both regions of the cortex. Systolic blood pressure was related to lower platelet-derived growth factor receptor β in controls in the frontal cortex and in dementia cases in the superficial white matter. We found no association between blood pressure and tau. Our findings demonstrate a complex relationship between late-life blood pressure, disease pathology and vascular function in dementia. We suggest that hypertension helps to reduce cerebral ischaemia (and may slow amyloid-β accumulation) in the face of increasing cerebral vascular resistance, but exacerbates vascular pathology.
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Affiliation(s)
- Hannah M Tayler
- Dementia Research Group, Institute of Clinical Neurosciences, Bristol Medical School, University of Bristol, Bristol, BS10 5NB, UK
| | - Robert MacLachlan
- Dementia Research Group, Institute of Clinical Neurosciences, Bristol Medical School, University of Bristol, Bristol, BS10 5NB, UK
| | - Özge Güzel
- Dementia Research Group, Institute of Clinical Neurosciences, Bristol Medical School, University of Bristol, Bristol, BS10 5NB, UK
| | - J Scott Miners
- Dementia Research Group, Institute of Clinical Neurosciences, Bristol Medical School, University of Bristol, Bristol, BS10 5NB, UK
| | - Seth Love
- Correspondence to: Seth Love South West Dementia Brain Bank, University of Bristol Learning & Research Level 1, Southmead Hospital, Bristol, BS10 5NB, UK E-mail:
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Christie IN, Windsor R, Mutsaerts HJMM, Tillin T, Sudre CH, Hughes AD, Golay X, Gourine AV, Hosford PS. Cerebral perfusion in untreated, controlled, and uncontrolled hypertension. J Cereb Blood Flow Metab 2022; 42:2188-2190. [PMID: 36113055 PMCID: PMC7613835 DOI: 10.1177/0271678x221124644] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/09/2022] [Accepted: 07/08/2022] [Indexed: 12/14/2022]
Abstract
This study evaluated the association between systemic arterial blood pressure and cerebral perfusion in 740 participants of the UK's largest tri-ethnic study with measurements of cerebral blood flow (CBF) performed using arterial spin labelling MRI. A significant negative correlation between blood pressure, age and CBF was observed across the patient cohort. The lowest CBF values were recorded in the group of patients with hypertension that were prescribed with anti-hypertensive drugs, but uncontrolled on medication. These findings confirm that hypertension is associated with reduced cerebral perfusion and highlight the importance of blood pressure control for the benefit of maintaining brain blood flow.
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Affiliation(s)
- Isabel N Christie
- Centre for Cardiovascular and Metabolic Neuroscience,
Neuroscience, Physiology and Pharmacology, University College London, London,
UK
| | - Rowan Windsor
- Centre for Cardiovascular and Metabolic Neuroscience,
Neuroscience, Physiology and Pharmacology, University College London, London,
UK
| | - Henk JMM Mutsaerts
- Department of Radiology and Nuclear Medicine, Amsterdam
University Medical Center, Amsterdam, The Netherlands
| | - Therese Tillin
- MRC Unit for Lifelong Health & Ageing, Population Science
& Experimental Medicine, Faculty of Population Health Sciences, University
College London, London, UK
| | - Carole H Sudre
- MRC Unit for Lifelong Health & Ageing, Population Science
& Experimental Medicine, Faculty of Population Health Sciences, University
College London, London, UK
| | - Alun D Hughes
- Institute of Cardiovascular Science, Population Science &
Experimental Medicine, Faculty of Population Health Sciences, University College
London, London, UK
| | - Xavier Golay
- Queen Square Institute of Neurology, University College London,
London, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience,
Neuroscience, Physiology and Pharmacology, University College London, London,
UK
| | - Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience,
Neuroscience, Physiology and Pharmacology, University College London, London,
UK
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10
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Xu M, Wu Q, Cheng Y, Zhang S, Tao W, Zhang S, Wang D, Liu M, Wu B. Circle of Willis Morphology in Primary Intracerebral Hemorrhage. Transl Stroke Res 2022; 13:736-744. [PMID: 35184272 PMCID: PMC9391241 DOI: 10.1007/s12975-022-00997-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/21/2022] [Accepted: 02/09/2022] [Indexed: 11/26/2022]
Abstract
We aimed to study the distribution of Circle of Willis (CoW) morphology and its association with intracerebral hemorrhage (ICH) etiology and cerebral small vessel disease (CSVD) burden. Patients with primary ICH who had brain MRIs were consecutively enrolled between March 2012 and January 2021. CoW morphology, CSVD features and the combined CSVD burden (including global CSVD burden, total hypertensive arteriopathy [HA] burden, and total cerebral amyloid angiopathy [CAA] burden) were assessed. CoW morphology included poor CoW (defined as CoW score 0-2), incomplete CoW, and complete fetal-variant of the posterior communicating artery (CFPcoA). Among 296 patients enrolled, 215 were included in the analysis. There was no significant difference among HA-, CAA-, and mixed-ICH in each CoW morphology. Exploratory subgroup analyses suggested that poor CoW was associated with a greater incidence of HA-ICH and low incidence of mixed ICH in patients aged < 60 years, while mixed ICH occurred more frequently in patients with CFPcoA, especially in those without hypertension history (all p < 0.050). Additionally, incomplete CoW was correlated with a larger incidence of lacunes (adjusted OR [adOR] 2.114, 95% CI 1.062-4.207), microbleeds ≥ 5 (adOR 2.437, 95% CI 1.187-5.002), and therefore the combined CSVD burden (adOR 1.194, 95% CI 1.004-1.419 for global CSVD burden, adOR 1.343, 95% CI 1.056-1.707 for total CAA burden), independent of modifiable vascular risk factors, but not age and sex. The CoW might therefore have a potential impact on ICH etiology and is associated with a greater CSVD burden. Our findings are novel, and need to be verified in future studies.
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Affiliation(s)
- Mangmang Xu
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Qian Wu
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Yajun Cheng
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Shuting Zhang
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Wendan Tao
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Shihong Zhang
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Deren Wang
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Ming Liu
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Bo Wu
- Center of Cerebrovascular Diseases, Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
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Cheng H, Li G, Dai J, Zhang K, Xu T, Wei L, Zhang X, Ding D, Hou J, Li J, Zhuang J, Tan K, Guo R. A fluid-structure interaction model accounting arterial vessels as a key part of the blood-flow engine for the analysis of cardiovascular diseases. Front Bioeng Biotechnol 2022; 10:981187. [PMID: 36061431 PMCID: PMC9438578 DOI: 10.3389/fbioe.2022.981187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
According to the classical Windkessel model, the heart is the only power source for blood flow, while the arterial system is assumed to be an elastic chamber that acts as a channel and buffer for blood circulation. In this paper we show that in addition to the power provided by the heart for blood circulation, strain energy stored in deformed arterial vessels in vivo can be transformed into mechanical work to propel blood flow. A quantitative relationship between the strain energy increment and functional (systolic, diastolic, mean and pulse blood pressure) and structural (stiffness, diameter and wall thickness) parameters of the aorta is described. In addition, details of blood flow across the aorta remain unclear due to changes in functional and other physiological parameters. Based on the arterial strain energy and fluid-structure interaction theory, the relationship between physiological parameters and blood supply to organs was studied, and a corresponding mathematical model was developed. The findings provided a new understanding about blood-flow circulation, that is, cardiac output allows blood to enter the aorta at an initial rate, and then strain energy stored in the elastic arteries pushes blood toward distal organs and tissues. Organ blood supply is a key factor in cardio-cerebrovascular diseases (CCVD), which are caused by changes in blood supply in combination with multiple physiological parameters. Also, some physiological parameters are affected by changes in blood supply, and vice versa. The model can explain the pathophysiological mechanisms of chronic diseases such as CCVD and hypertension among others, and the results are in good agreement with epidemiological studies of CCVD.
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Affiliation(s)
- Heming Cheng
- Department of Mechanics, Kunming University of Science and Technology, Kunming, China
- *Correspondence: Heming Cheng, ; Ke Zhang,
| | - Gen Li
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Jifeng Dai
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Ke Zhang
- Department of Mechanics, Kunming University of Science and Technology, Kunming, China
- Department of Hydraulic Engineering, Kunming University of Science and Technology, Kunming, China
- *Correspondence: Heming Cheng, ; Ke Zhang,
| | - Tianrui Xu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Liuchuang Wei
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Xue Zhang
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Dongfang Ding
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Jie Hou
- Department of Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Jianyun Li
- Department of Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Jiangping Zhuang
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Kaijun Tan
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China
| | - Ran Guo
- Department of Mechanics, Kunming University of Science and Technology, Kunming, China
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12
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Effects of Diastolic Blood Pressure on Brain Structures and Cognitive Functions in Middle and Old Ages: Longitudinal Analyses. Nutrients 2022; 14:nu14122464. [PMID: 35745194 PMCID: PMC9229545 DOI: 10.3390/nu14122464] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 01/21/2023] Open
Abstract
Hypertension is a pervasive public health concern due to strong associations with cardiovascular diseases and stroke. Alternatively, the associations between hypertension and the risk of Alzheimer's disease are complex and recent large sample studies reported positive associations. In this paper, we examine the associations between diastolic blood pressure (BP) and subsequent changes in brain structure and cognitive function over several years by multiple regression analyses (with adjustment for a wide range of potential confounding variables) among a large cohort from the UK Biobank. Higher baseline diastolic BP was associated with a slightly smaller relative increase (relative improvements) in reaction time and a slightly greater reduction in depression scores. Higher baseline diastolic BP was also associated with a greater total gray matter volume (GMV) retention, while aging alone was associated with GMV reduction. White matter microstructural analyses revealed that a greater diastolic BP was associated with reduced longitudinal mean and regional fractional anisotropy, greater increases in mean and regional mean diffusivity, radial diffusivity, and axial diffusivity, a greater decline in mean intracellular volume fraction, and greater increases in mean and regional isotropic volume fraction. These white matter microstructural changes were consistent with those seen in the aging process. Additional analyses revealed a greater cheese intake level at baseline, which is associated with a subsequent decline in diastolic BP and a relative subsequent increase in depressive tendency together with a relative increase in fluid intelligence and visuospatial memory performance. These results are congruent with the view that a higher BP in the aging brain has a complex role.
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13
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Manghat NE, Robinson E, Mitrousi K, Rodrigues JCL, Hinton T, Paton JFR, Wise RG, Nightingale AK, Hart EC. Cerebrovascular Variants and the Role of the Selfish Brain in Young-Onset Hypertension. Hypertension 2022; 79:1265-1274. [PMID: 35291807 PMCID: PMC9093235 DOI: 10.1161/hypertensionaha.121.18612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Variants in the posterior anatomy of the cerebral circulation are associated with hypertension and lower cerebral blood flow in midlife (age ≈55 years); however, whether these variants are a result of aging or long-term exposure to high blood pressure is unclear. Additionally, the role these variants play in early onset of hypertension (<40 years) and poor cerebral perfusion in this population is unknown. METHODS We retrospectively examined whether specific cerebrovascular variants (vertebral artery hypoplasia and absent/hypoplastic posterior communicating arteries (an incomplete posterior circle of Willis) measured via magnetic resonance angiography) were associated with a diagnosis of hypertension in 220 young adults (<40 years; n=164 primary hypertensive [mean age±SD, 32±6 years] and n=56 [30±6 years] normotensive adults). Whether cerebrovascular variants were associated with lower cerebral blood flow (phase-contrast angiography) was measured in the hypertensive group only (n=146). RESULTS Binary logistic regression (adjusted for age, sex, and body mass index) showed that vertebral artery hypoplasia with an incomplete posterior circle of Willis was associated with hypertension diagnosis (P<0.001, odds ratio; 11.79 [95% CI, 3.34-41.58]). Vertebral artery hypoplasia plus an incomplete circle of Willis was associated with lower cerebral blood flow in young adults with hypertension (P=0.0172). CONCLUSIONS Vertebral artery hypoplasia plus an incomplete posterior circle of Willis independently predicts hypertension in young adults suggesting that this variant is not acquired with aging into midlife. Importantly this variant combination was associated with lower cerebral perfusion, which may have long-term consequences on cerebrovascular health in young adults with hypertension.
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Affiliation(s)
- Nathan E Manghat
- Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol and Weston NHS Foundation Trust, United Kingdom (N.E.M., E.R., K.M.).,Cardionomics Research Group, School of Physiology, Pharmacology and Neurosciences, University of Bristol, United Kingdom (N.E.M., K.M., T.H., A.K.N., E.C.H.)
| | - Elizabeth Robinson
- Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol and Weston NHS Foundation Trust, United Kingdom (N.E.M., E.R., K.M.)
| | - Konstantina Mitrousi
- Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol and Weston NHS Foundation Trust, United Kingdom (N.E.M., E.R., K.M.).,Cardionomics Research Group, School of Physiology, Pharmacology and Neurosciences, University of Bristol, United Kingdom (N.E.M., K.M., T.H., A.K.N., E.C.H.)
| | - Jonathan C L Rodrigues
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust (J.C.L.R.).,Department of Health, University of Bath, United Kingdom (J.C.L.R.)
| | - Thomas Hinton
- Cardionomics Research Group, School of Physiology, Pharmacology and Neurosciences, University of Bristol, United Kingdom (N.E.M., K.M., T.H., A.K.N., E.C.H.)
| | - Julian F R Paton
- Manaaki Manawa, The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, New Zealand (J.F.R.P.)
| | - Richard G Wise
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University (R.G.W.).,Department of Neuroscience, Imaging and Clinical Sciences (R.G.W.).,ITAB-Institute for Advanced Biomedical Technologies (R.G.W.)
| | - Angus K Nightingale
- Cardionomics Research Group, School of Physiology, Pharmacology and Neurosciences, University of Bristol, United Kingdom (N.E.M., K.M., T.H., A.K.N., E.C.H.).,"G. D'Annunzio" University of Chieti-Pescara, Italy. Clinical Research Facility, University Hospitals Bristol and Weston NHS Foundation Trust, United Kingdom (A.K.N., E.C.H.)
| | - Emma C Hart
- Cardionomics Research Group, School of Physiology, Pharmacology and Neurosciences, University of Bristol, United Kingdom (N.E.M., K.M., T.H., A.K.N., E.C.H.).,"G. D'Annunzio" University of Chieti-Pescara, Italy. Clinical Research Facility, University Hospitals Bristol and Weston NHS Foundation Trust, United Kingdom (A.K.N., E.C.H.)
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14
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Fan JL, Brassard P, Rickards CA, Nogueira RC, Nasr N, McBryde FD, Fisher JP, Tzeng YC. Integrative cerebral blood flow regulation in ischemic stroke. J Cereb Blood Flow Metab 2022; 42:387-403. [PMID: 34259070 PMCID: PMC8985438 DOI: 10.1177/0271678x211032029] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Optimizing cerebral perfusion is key to rescuing salvageable ischemic brain tissue. Despite being an important determinant of cerebral perfusion, there are no effective guidelines for blood pressure (BP) management in acute stroke. The control of cerebral blood flow (CBF) involves a myriad of complex pathways which are largely unaccounted for in stroke management. Due to its unique anatomy and physiology, the cerebrovascular circulation is often treated as a stand-alone system rather than an integral component of the cardiovascular system. In order to optimize the strategies for BP management in acute ischemic stroke, a critical reappraisal of the mechanisms involved in CBF control is needed. In this review, we highlight the important role of collateral circulation and re-examine the pathophysiology of CBF control, namely the determinants of cerebral perfusion pressure gradient and resistance, in the context of stroke. Finally, we summarize the state of our knowledge regarding cardiovascular and cerebrovascular interaction and explore some potential avenues for future research in ischemic stroke.
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Affiliation(s)
- Jui-Lin Fan
- Manaaki Mānawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec City, Canada.,Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec City, Canada
| | - Caroline A Rickards
- Department of Physiology & Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Ricardo C Nogueira
- Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.,Neurology Department, Hospital Nove de Julho, São Paulo, Brazil
| | - Nathalie Nasr
- Department of Neurology, Toulouse University Hospital, NSERM UMR 1297, Toulouse, France
| | - Fiona D McBryde
- Manaaki Mānawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - James P Fisher
- Manaaki Mānawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Yu-Chieh Tzeng
- Wellington Medical Technology Group, Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand.,Department of Surgery & Anaesthesia, Centre for Translational Physiology, University of Otago, Wellington, New Zealand
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15
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Toro EF, Celant M, Zhang Q, Contarino C, Agarwal N, Linninger A, Müller LO. Cerebrospinal fluid dynamics coupled to the global circulation in holistic setting: Mathematical models, numerical methods and applications. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3532. [PMID: 34569188 PMCID: PMC9285081 DOI: 10.1002/cnm.3532] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
This paper presents a mathematical model of the global, arterio-venous circulation in the entire human body, coupled to a refined description of the cerebrospinal fluid (CSF) dynamics in the craniospinal cavity. The present model represents a substantially revised version of the original Müller-Toro mathematical model. It includes one-dimensional (1D), non-linear systems of partial differential equations for 323 major blood vessels and 85 zero-dimensional, differential-algebraic systems for the remaining components. Highlights include the myogenic mechanism of cerebral blood regulation; refined vasculature for the inner ear, the brainstem and the cerebellum; and viscoelastic, rather than purely elastic, models for all blood vessels, arterial and venous. The derived 1D parabolic systems of partial differential equations for all major vessels are approximated by hyperbolic systems with stiff source terms following a relaxation approach. A major novelty of this paper is the coupling of the circulation, as described, to a refined description of the CSF dynamics in the craniospinal cavity, following Linninger et al. The numerical solution methodology employed to approximate the hyperbolic non-linear systems of partial differential equations with stiff source terms is based on the Arbitrary DERivative Riemann problem finite volume framework, supplemented with a well-balanced formulation, and a local time stepping procedure. The full model is validated through comparison of computational results against published data and bespoke MRI measurements. Then we present two medical applications: (i) transverse sinus stenoses and their relation to Idiopathic Intracranial Hypertension; and (ii) extra-cranial venous strictures and their impact in the inner ear circulation, and its implications for Ménière's disease.
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Affiliation(s)
| | - Morena Celant
- Department of MathematicsUniversity of TrentoTrentoItaly
| | - Qinghui Zhang
- Laboratory of Applied Mathematics, DICAMUniversity of TrentoTrentoItaly
| | | | | | - Andreas Linninger
- Department of BioengineeringUniversity of Illinois at ChicagoChicagoIllinoisUSA
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16
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Douglass A, Moffat G, Daly C. Using Confocal Microscopy to Generate an Accurate Vascular Model for Use in Patient Education Animation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1356:31-52. [PMID: 35146616 DOI: 10.1007/978-3-030-87779-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hypertension is a condition requiring lifelong medication, where patients often feel well with or without treatment. Uncontrolled hypertension, however, can lead to permanent remodelling processes that occur to the vascular structure, which are seldom understood by the public. As a result, a significant burden is placed on healthcare systems globally as a result of the effects of hypertension and lack of adherence to prescribed treatment.Improving patient education through well-designed interactive applications and animation is a known strategy that can improve adherence rates to medication. In the context of hypertension, little attention has been given to helping patients understand the unseen damage that occurs to vessels exposed to high blood pressure. However, generating an accurate representation of a vessel and the changes that occur can be challenging. Using microscopy data is one way for creating an anatomically correct model, but this often needs careful consideration as data cannot be directly imported. Here we describe methods for creating an accurate 3D model of a small artery using confocal microscopy data. This model can then be animated to demonstrate the substructures and pathological changes that occur in hypertensive conditions to better inform patients about the dangers of uncontrolled blood pressure.
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17
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Fong D, Gradon K, Barrett CJ, Guild SJ, Tzeng YC, Paton JFR, McBryde FD. A method to evaluate dynamic cerebral pressure-flow relationships in the conscious rat. J Appl Physiol (1985) 2021; 131:1361-1369. [PMID: 34498945 DOI: 10.1152/japplphysiol.00289.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The classic dogma of cerebral autoregulation is that cerebral blood flow is steadily maintained across a wide range of perfusion pressures. This has been challenged by recent studies suggesting little to no "autoregulatory plateau" in the relationship between cerebral blood flow and blood pressure (BP). Therefore, the mechanisms underlying the cerebral pressure-flow relationship still require further understanding. Here, we present a novel approach to examine dynamic cerebral autoregulation in conscious Wistar rats (n = 16) instrumented to measure BP and internal carotid blood flow (iCBF), as an indicator of cerebral blood flow. Transient reductions in BP were induced by occluding the vena cava via inflation of a chronically implanted intravascular silicone balloon. Falls in BP were paralleled by progressive decreases in iCBF, with no evidence of a steady-state plateau. No significant changes in internal carotid vascular resistance (iCVR) were observed. In contrast, intravenous infusions of the vasoactive drug sodium nitroprusside (SNP) produced a similar fall in BP but increases in iCBF and decreases in iCVR were observed. These data suggest a considerable confounding influence of vasodilatory drugs such as SNP on cerebrovascular tone in the rat, making them unsuitable to investigate cerebral autoregulation. We demonstrate that our technique of transient vena cava occlusion produced reliable and repeatable depressor responses, highlighting the potential for our approach to permit assessment of the dynamic cerebral pressure-flow relationship over time in conscious rats.NEW & NOTEWORTHY We present a novel technique to overcome the use of vasoactive agents when studying cerebrovascular dynamics in the conscious rat. Our method of vena cava occlusion to reduce BP was associated with decreased iCBF and no change in iCVR. In contrast, comparable BP falls with intravenous SNP increased iCBF and reduced iCVR. Thus, the dynamic cerebral pressure-flow relationship shows a narrower, less level autoregulatory plateau than conventionally thought. We confirm our method allows repeatable assessment of cerebrovascular dynamics in conscious rats.
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Affiliation(s)
- Debra Fong
- Manaaki Mānawa-The Centre for Heart Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Kelly Gradon
- Manaaki Mānawa-The Centre for Heart Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Carolyn J Barrett
- Manaaki Mānawa-The Centre for Heart Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Sarah-Jane Guild
- Manaaki Mānawa-The Centre for Heart Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Yu Chieh Tzeng
- Wellington Medical Technology Group, Centre for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Julian F R Paton
- Manaaki Mānawa-The Centre for Heart Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Fiona D McBryde
- Manaaki Mānawa-The Centre for Heart Research, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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18
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Muskat JC, Rayz VL, Goergen CJ, Babbs CF. Hemodynamic modeling of the circle of Willis reveals unanticipated functions during cardiovascular stress. J Appl Physiol (1985) 2021; 131:1020-1034. [PMID: 34264126 DOI: 10.1152/japplphysiol.00198.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The circle of Willis (CW) allows blood to be redistributed throughout the brain during local ischemia; however, it is unlikely that the anatomic persistence of the CW across mammalian species is driven by natural selection of individuals with resistance to cerebrovascular disease typically occurring in elderly humans. To determine the effects of communicating arteries (CoAs) in the CW on cerebral pulse wave propagation and blood flow velocity, we simulated young, active adult humans undergoing different states of cardiovascular stress (i.e., fear and aerobic exercise) using discrete transmission line segments with stress-adjusted cardiac output, peripheral resistance, and arterial compliance. Phase delays between vertebrobasilar and carotid pulses allowed bidirectional shunting through CoAs: both posteroanterior shunting before the peak of the pulse waveform and anteroposterior shunting after internal carotid pressure exceeded posterior cerebral pressure. Relative to an absent CW without intact CoAs, the complete CW blunted anterior pulse waveforms, although limited to 3% and 6% reductions in peak pressure and pulse pressure, respectively. Systolic rate of change in pressure (i.e., ∂P/∂t) was reduced 15%-24% in the anterior vasculature and increased 23%-41% in the posterior vasculature. Bidirectional shunting through posterior CoAs was amplified during cardiovascular stress and increased peak velocity by 25%, diastolic-to-systolic velocity range by 44%, and blood velocity acceleration by 134% in the vertebrobasilar arteries. This effect may facilitate stress-related increases in blood flow to the cerebellum (improving motor coordination) and reticular-activating system (enhancing attention and focus) via a nitric oxide-dependent mechanism, thereby improving survival in fight-or-flight situations.NEW & NOTEWORTHY Hemodynamic modeling reveals potential evolutionary benefits of the intact circle of Willis (CW) during fear and aerobic exercise. The CW equalizes pulse waveforms due to bidirectional shunting of blood flow through communicating arteries, which boosts vertebrobasilar blood flow velocity and acceleration. These phenomena may enhance perfusion of the brainstem and cerebellum via nitric oxide-mediated vasodilation, improving performance of the reticular-activating system and motor coordination in survival situations.
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Affiliation(s)
- J C Muskat
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - V L Rayz
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.,School of Mechanical Engineering, Purdue University, West Lafayette, Indiana
| | - C J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - C F Babbs
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
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19
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Pearson AG, Miller KB, Corkery AT, Eisenmann NA, Howery AJ, Carl AE, Eldridge MW, Barnes JN. Impact of age and cyclooxygenase inhibition on the hemodynamic response to acute cognitive challenges. Am J Physiol Regul Integr Comp Physiol 2021; 321:R208-R219. [PMID: 34161746 DOI: 10.1152/ajpregu.00048.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Structural and functional changes in the cerebral vasculature occur with advancing age, which may lead to impaired neurovascular coupling (NVC) and cognitive decline. Cyclooxygenase (COX) inhibition abolishes age-related differences in cerebrovascular reactivity, but it is unclear if COX inhibition impacts NVC. The purpose of this study was to examine the influence of aging on NVC before and after COX inhibition. Twenty-three young (age = 25 ± 4 yr) and 21 older (age = 64 ± 5 yr) adults completed two levels of difficulty of the Stroop and n-back tests before and after COX inhibition. Middle cerebral artery blood velocity (MCAv) was measured using transcranial Doppler ultrasound and mean arterial blood pressure (MAP) was measured using a finger cuff. Hemodynamic variables were measured at rest and in response to cognitive challenges. During the Stroop test, older adults demonstrated a greater increase in MCAv (young: 2.2 ± 6.8% vs. older: 5.9 ± 5.8%; P = 0.030) and MAP (young: 2.0 ± 4.9% vs. older: 4.8 ± 4.9%; P = 0.036) compared with young adults. There were no age-related differences during the n-back test. COX inhibition reduced MCAv by 30% in young and 26% in older adults (P < 0.001 for both). During COX inhibition, there were no age-related differences in the percent change in MCAv or MAP in response to the cognitive tests. Our results show that older adults require greater increases in MCAv and MAP during a test of executive function compared with young adults and that any age-related differences in NVC were abolished during COX inhibition. Collectively, this suggests that aging is associated with greater NVC necessary to accomplish a cognitive task.
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Affiliation(s)
- Andrew G Pearson
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kathleen B Miller
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Adam T Corkery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nicole A Eisenmann
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Anna J Howery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Alexandra E Carl
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Marlowe W Eldridge
- Division of Critical Care, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.,John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Jill N Barnes
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin.,Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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20
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Palmer JC, Tayler HM, Dyer L, Kehoe PG, Paton JFR, Love S. Zibotentan, an Endothelin A Receptor Antagonist, Prevents Amyloid-β-Induced Hypertension and Maintains Cerebral Perfusion. J Alzheimers Dis 2021; 73:1185-1199. [PMID: 31903990 PMCID: PMC7081103 DOI: 10.3233/jad-190630] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cerebral blood flow is reduced in Alzheimer’s disease (AD), which is associated with mid-life hypertension. In people with increased cerebral vascular resistance due to vertebral artery or posterior communicating artery hypoplasia, there is evidence that hypertension develops as a protective mechanism to maintain cerebral perfusion. In AD, amyloid-β (Aβ) accumulation may similarly raise cerebral vascular resistance by upregulation of the cerebral endothelin system. The level of endothelin-1 in brain tissue correlates positively with Aβ load and negatively with markers of cerebral hypoperfusion such as increased vascular endothelial growth factor. We previously showed that cerebroventricular infusion of Aβ40 exacerbated pre-existing hypertension in Dahl rats. We have investigated the effects of 28-day cerebral infusion of Aβ40 on blood pressure and heart rate and their variability; carotid flow; endothelin-1; and markers of cerebral oxygenation, in the (normotensive) Wistar rat, and the modulatory influence of the endothelin A receptor antagonist Zibotentan (ZD4054). Cerebral infusion of Aβ caused progressive rise in blood pressure (p < 0.0001) (paired t-test: increase of 3 (0.1–5.6) mmHg (p = 0.040)), with evidence of reduced baroreflex responsiveness, and accumulation of Aβ and elevated endothelin-1 in the vicinity of the infusion. Oral Zibotentan (3 mg/kg/d, administered for 31 d) abrogated the effects of Aβ40 infusion on baroreflex responsiveness and blood pressure, which declined, although without reduction in carotid blood flow, and Zibotentan caused uncoupling of the positive linear relationship between endothelin-1 and vascular endothelial growth factor, which as a sensor of tissue oxygenation would be expected to increase if there were hypoperfusion.
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Affiliation(s)
- Jennifer C Palmer
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Hannah M Tayler
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Laurence Dyer
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Patrick G Kehoe
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, New Zealand
| | - Seth Love
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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21
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Intracranial baroreflex is attenuated in an ovine model of renovascular hypertension. Sci Rep 2021; 11:5816. [PMID: 33712655 PMCID: PMC7955074 DOI: 10.1038/s41598-021-85278-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/26/2021] [Indexed: 11/08/2022] Open
Abstract
We have previously shown that elevations in intracranial pressure (ICP) within physiological ranges in normotensive animals increase arterial pressure; termed the intracranial baroreflex. Hypertension is associated with alterations in reflexes which maintain arterial pressure however, whether the intracranial baroreflex is altered is not known. Hence, in the present study, we tested the hypothesis that in hypertension, physiological increases in ICP would not be accompanied with an increase in arterial pressure. Renovascular hypertension was associated with no change in heart rate, renal blood flow or ICP levels compared to the normotensive group. ICV infusion of saline produced a ramped increase in ICP of 20 ± 1 mmHg. This was accompanied by an increase in arterial pressure (16 ± 2 mmHg) and a significant decrease in renal vascular conductance. ICV infusion of saline in the hypertensive group also increased ICP (19 ± 2 mmHg). However, the increase in arterial pressure was significantly attenuated in the hypertensive group (5 ± 2 mmHg). Ganglionic blockade abolished the increase in arterial pressure in both groups to increased ICP. Our data indicates that physiological increases in ICP lead to increases in arterial pressure in normotensive animals but this is severely attenuated in renovascular hypertension.
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22
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Blevins BL, Vinters HV, Love S, Wilcock DM, Grinberg LT, Schneider JA, Kalaria RN, Katsumata Y, Gold BT, Wang DJJ, Ma SJ, Shade LMP, Fardo DW, Hartz AMS, Jicha GA, Nelson KB, Magaki SD, Schmitt FA, Teylan MA, Ighodaro ET, Phe P, Abner EL, Cykowski MD, Van Eldik LJ, Nelson PT. Brain arteriolosclerosis. Acta Neuropathol 2021; 141:1-24. [PMID: 33098484 PMCID: PMC8503820 DOI: 10.1007/s00401-020-02235-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/04/2020] [Accepted: 10/05/2020] [Indexed: 12/14/2022]
Abstract
Brain arteriolosclerosis (B-ASC), characterized by pathologic arteriolar wall thickening, is a common finding at autopsy in aged persons and is associated with cognitive impairment. Hypertension and diabetes are widely recognized as risk factors for B-ASC. Recent research indicates other and more complex risk factors and pathogenetic mechanisms. Here, we describe aspects of the unique architecture of brain arterioles, histomorphologic features of B-ASC, relevant neuroimaging findings, epidemiology and association with aging, established genetic risk factors, and the co-occurrence of B-ASC with other neuropathologic conditions such as Alzheimer's disease and limbic-predominant age-related TDP-43 encephalopathy (LATE). There may also be complex physiologic interactions between metabolic syndrome (e.g., hypertension and inflammation) and brain arteriolar pathology. Although there is no universally applied diagnostic methodology, several classification schemes and neuroimaging techniques are used to diagnose and categorize cerebral small vessel disease pathologies that include B-ASC, microinfarcts, microbleeds, lacunar infarcts, and cerebral amyloid angiopathy (CAA). In clinical-pathologic studies that factored in comorbid diseases, B-ASC was independently associated with impairments of global cognition, episodic memory, working memory, and perceptual speed, and has been linked to autonomic dysfunction and motor symptoms including parkinsonism. We conclude by discussing critical knowledge gaps related to B-ASC and suggest that there are probably subcategories of B-ASC that differ in pathogenesis. Observed in over 80% of autopsied individuals beyond 80 years of age, B-ASC is a complex and under-studied contributor to neurologic disability.
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Affiliation(s)
- Brittney L Blevins
- Department of Neuroscience, University Kentucky, Lexington, KY, 40536, USA
| | - Harry V Vinters
- Department of Pathology and Laboratory Medicine, David Geffen SOM at UCLA and Ronald Reagan UCLA Medical Center, Los Angeles, CA, 90095-1732, USA
| | - Seth Love
- University of Bristol and Southmead Hospital, Bristol, BS10 5NB, UK
| | - Donna M Wilcock
- Sanders-Brown Center on Aging, Department of Neuroscience, University Kentucky, Lexington, KY, 40536, USA
| | - Lea T Grinberg
- Department of Neurology and Pathology, UCSF, San Francisco, CA, USA
- Global Brain Health Institute, UCSF, San Francisco, CA, USA
- LIM-22, Department of Pathology, University of Sao Paulo Medical School, São Paulo, Brazil
| | - Julie A Schneider
- Departments of Neurology and Pathology, Rush University Medical Center, Chicago, IL, 60612, USA
| | - Rajesh N Kalaria
- Translational and Clinical Research Institute, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Yuriko Katsumata
- Sanders-Brown Center on Aging, Department of Biostatistics, University Kentucky, Lexington, KY, 40536, USA
| | - Brian T Gold
- Sanders-Brown Center on Aging, Department of Neuroscience, University Kentucky, Lexington, KY, 40536, USA
| | - Danny J J Wang
- Laboratory of FMRI Technology (LOFT), USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Samantha J Ma
- Laboratory of FMRI Technology (LOFT), USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Lincoln M P Shade
- Sanders-Brown Center on Aging, Department of Biostatistics, University Kentucky, Lexington, KY, 40536, USA
| | - David W Fardo
- Sanders-Brown Center on Aging, Department of Biostatistics, University Kentucky, Lexington, KY, 40536, USA
| | - Anika M S Hartz
- Sanders-Brown Center on Aging, Department of Pharmacology and Nutritional Sciences, University Kentucky, Lexington, KY, 40536, USA
| | - Gregory A Jicha
- Sanders-Brown Center on Aging, Department of Neurology, University Kentucky, Lexington, KY, 40536, USA
| | | | - Shino D Magaki
- Department of Pathology and Laboratory Medicine, David Geffen SOM at UCLA and Ronald Reagan UCLA Medical Center, Los Angeles, CA, 90095-1732, USA
| | - Frederick A Schmitt
- Sanders-Brown Center on Aging, Department of Neurology, University Kentucky, Lexington, KY, 40536, USA
| | - Merilee A Teylan
- Department of Epidemiology, University Washington, Seattle, WA, 98105, USA
| | | | - Panhavuth Phe
- Sanders-Brown Center on Aging, University Kentucky, Lexington, KY, 40536, USA
| | - Erin L Abner
- Sanders-Brown Center on Aging, Department of Epidemiology, University Kentucky, Lexington, KY, 40536, USA
| | - Matthew D Cykowski
- Departments of Pathology and Genomic Medicine and Neurology, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Linda J Van Eldik
- Sanders-Brown Center on Aging, Department of Neuroscience, University Kentucky, Lexington, KY, 40536, USA
| | - Peter T Nelson
- Sanders-Brown Center on Aging, Department of Pathology, University of Kentucky, Lexington, KY, 40536, USA.
- Rm 311 Sanders-Brown Center on Aging, University of Kentucky, 800 S. Limestone Avenue, Lexington, KY, 40536, USA.
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Incognito AV, Samora M, Shepherd AD, Cartafina RA, Guimarães GMN, Daher M, Vianna LC, Millar PJ. Sympathetic arterial baroreflex hysteresis in humans: different patterns during low- and high-pressure levels. Am J Physiol Heart Circ Physiol 2020; 319:H787-H792. [PMID: 32857604 DOI: 10.1152/ajpheart.00505.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fluctuations in diastolic pressure modulate muscle sympathetic nerve activity (MSNA) through the arterial baroreflex. A higher sympathetic baroreflex sensitivity (sBRS) to pressure falls compared with rises has been reported; however, the underlying mechanisms are unclear. We assessed whether beat-to-beat falling and rising diastolic pressures operate on two distinct baroreflex response curves. Twenty-two men (32 ± 8 yr) underwent sequential bolus injections of nitroprusside and phenylephrine (modified Oxford test) with continuous recording of heart rate, blood pressure, and MSNA. The weighted negative linear regression slope between falling or rising diastolic pressure and MSNA burst incidence quantified sBRSfall and sBRSrise, respectively. The diastolic pressure evoking a MSNA burst incidence of 50 (T50) was calculated. sBRSfall was greater than sBRSrise (-6.24 ± 2.80 vs. -4.34 ± 2.16 bursts·100 heartbeats-1·mmHg-1, P = 0.01) and had a narrower operating range (14 ± 8 vs. 20 ± 10 mmHg, P = 0.01) that was shifted rightward (T50, 75 ± 9 and 70 ± 11 mmHg, P < 0.001). At diastolic pressures below baseline, sBRSfall was less than sBRSrise (-1.81 ± 1.31 vs. -3.59 ± 1.70 bursts·100 heartbeats-1·mmHg-1, P = 0.003) as low absolute pressures operated closer to the saturation plateau on the falling, compared with the rising pressure curve. At pressures above baseline, sBRSfall was greater than sBRSrise (-5.23 ± 1.94 and -3.79 ± 1.67 bursts·100 heartbeats-1·mmHg-1, P = 0.03). These findings demonstrate that the sympathetic arterial baroreflex possesses two response curves for processing beat-to-beat diastolic pressure falls and rises. The falling pressure curve is rightward shifted, which reduces sensitivity to falling pressure at low absolute pressures. This demonstrates that the direction of the hysteresis is influenced by the prevailing pressure level relative to each baroreflex response curve.NEW & NOTEWORTHY The findings show that the arterial baroreflex processes diastolic pressure dependent on the direction of pressure change from the previous beat, yielding two distinct baroreflex response curves to falling and rising pressure. Overall, the falling pressure curve is rightward shifted and more sensitive. The rightward shift caused a hysteresis reversal at hypotensive pressures as the falling pressure saturation plateau of the sigmoid response curve occurred at higher pressures than the rising pressure curve.
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Affiliation(s)
- Anthony V Incognito
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.,NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Milena Samora
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Andrew D Shepherd
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Roberta A Cartafina
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | | | - Mauricio Daher
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Lauro C Vianna
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Philip J Millar
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Brognara F, Felippe ISA, Salgado HC, Paton JFR. Autonomic innervation of the carotid body as a determinant of its sensitivity: implications for cardiovascular physiology and pathology. Cardiovasc Res 2020; 117:1015-1032. [PMID: 32832979 DOI: 10.1093/cvr/cvaa250] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/01/2020] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
The motivation for this review comes from the emerging complexity of the autonomic innervation of the carotid body (CB) and its putative role in regulating chemoreceptor sensitivity. With the carotid bodies as a potential therapeutic target for numerous cardiorespiratory and metabolic diseases, an understanding of the neural control of its circulation is most relevant. Since nerve fibres track blood vessels and receive autonomic innervation, we initiate our review by describing the origins of arterial feed to the CB and its unique vascular architecture and blood flow. Arterial feed(s) vary amongst species and, unequivocally, the arterial blood supply is relatively high to this organ. The vasculature appears to form separate circuits inside the CB with one having arterial venous anastomoses. Both sympathetic and parasympathetic nerves are present with postganglionic neurons located within the CB or close to it in the form of paraganglia. Their role in arterial vascular resistance control is described as is how CB blood flow relates to carotid sinus afferent activity. We discuss non-vascular targets of autonomic nerves, their possible role in controlling glomus cell activity, and how certain transmitters may relate to function. We propose that the autonomic nerves sub-serving the CB provide a rapid mechanism to tune the gain of peripheral chemoreflex sensitivity based on alterations in blood flow and oxygen delivery, and might provide future therapeutic targets. However, there remain a number of unknowns regarding these mechanisms that require further research that is discussed.
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Affiliation(s)
- Fernanda Brognara
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand.,Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Igor S A Felippe
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand
| | - Helio C Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand
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Wang F, Li D, Wang L, Zhu J, Zhao M, Lei P. Mild hypertension protects the elderly from cognitive impairment: a 7-year retrospective cohort study. Psychogeriatrics 2020; 20:412-418. [PMID: 31972899 DOI: 10.1111/psyg.12519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 01/04/2020] [Indexed: 01/10/2023]
Abstract
AIM People with mild cognitive impairment have a high risk of converting to dementia. Previous studies have suggested that hypertension is implicated in the development of mild cognitive impairment, but such effect in people much older than 70 years may be quite different. The aim of the study was to reveal the relationship between hypertension and mild cognitive impairment risk in this age group. METHODS A total of 985 subjects were retrospectively enrolled from Tianjin Medical University General Hospital, and all of them were cognitively normal 7 years earlier. During these years, 134 subjects were diagnosed with mild cognitive impairment according to the Mini-Mental State Examination. Research data of all the subjects were collected from medical records. RESULTS Multivariate Cox regression analysis revealed that compared with the subjects without hypertension, the subjects with grade 1 hypertension or duration <10 years showed a decreased risk of mild cognitive impairment (hazards ratio (HR): 0.54, 95%CI: 0.32-0.87; HR: 0.65, 95%CI: 0.40-0.99), and the subjects with grade 2-3 hypertension or duration ≥10 years had an increased risk of the disease (HR: 1.75, 95%CI: 1.25-2.42; HR: 1.52, 95%CI: 1.08-2.15). In addition, compared with the patients without hypertension, the patients taking angiotensin II receptor antagonists / angiotensin converting enzyme inhibitors had an increased risk of the disease (HR: 1.91, 95%CI: 1.29-2.83). CONCLUSION In subjects over 70 years old, short-term and mild hypertension might be a protective factor for mild cognitive impairment and prevent them from such a disease.
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Affiliation(s)
- Feng Wang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
| | - Dai Li
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
| | - Lu Wang
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
| | - Jialin Zhu
- Department of Ultrasound Diagnosis and Treatment, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China
| | - Minghui Zhao
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
| | - Ping Lei
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, 300052, China
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26
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Jennings JR, Muldoon MF, Sved AF. Is the Brain an Early or Late Component of Essential Hypertension? Am J Hypertens 2020; 33:482-490. [PMID: 32170317 DOI: 10.1093/ajh/hpaa038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/17/2020] [Accepted: 03/11/2020] [Indexed: 11/13/2022] Open
Abstract
The brain's relationship to essential hypertension is primarily understood to be that of an end-organ, damaged late in life by stroke or dementia. Emerging evidence, however, shows that heightened blood pressure (BP) early in life and prior to traditionally defined hypertension, relates to altered brain structure, cerebrovascular function, and cognitive processing. Deficits in cognitive function, cerebral blood flow responsivity, volumes of brain areas, and white matter integrity all relate to increased but prehypertensive levels of BP. Such relationships may be observed as early as childhood. In this review, we consider the basis of these relationships by examining the emergence of putative causative factors for hypertension that would impact or involve brain function/structure, e.g., sympathetic nervous system activation and related endocrine and inflammatory activation. Currently, however, available evidence is not sufficient to fully explain the specific pattern of brain deficits related to heightened BP. Despite this uncertainty, the evidence reviewed suggests the value that early intervention may have, not only for reducing BP, but also for maintaining brain function.
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Affiliation(s)
- John Richard Jennings
- Department of Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Matthew F Muldoon
- Division of Cardiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Heart and Vascular Institute, Hypertension Center, UPMC Medical Center, Pittsburgh, Pennsylvania, USA
| | - Alan F Sved
- Center for Neuroscience, University of Pittsburgh, Pennsylvania, USA
- Department of Neuroscience, University of Pittsburgh, Pennsylvania, USA
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27
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Nandi M, Aston PJ. Extracting new information from old waveforms: Symmetric projection attractor reconstruction: Where maths meets medicine. Exp Physiol 2020; 105:1444-1451. [PMID: 32347611 DOI: 10.1113/ep087873] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 04/23/2020] [Indexed: 01/05/2023]
Abstract
NEW FINDINGS What is the topic of this review? Symmetric Projection Attractor Reconstruction (SPAR) is a relatively new mathematical method that can extract additional information pertaining to the morphology and variability of physiological waveforms, such as arterial pulse pressure. Herein, we describe the potential utility of the method for more sensitive quantification of cardiovascular changes. What advances does it highlight? We use a simple example of a human tilt table to illustrate these concepts. SPAR can be used on any approximately periodic waveform and may add value to experimental and clinical settings, where such signals are collected routinely. ABSTRACT Periodic physiological waveform data, such as blood pressure, pulse oximetry and ECG, are routinely sampled between 100 and 1000 Hz in preclinical research and in the clinical setting from a wide variety of implantable, bedside and wearable monitoring devices. Despite the underlying numerical waveform data being captured at such high fidelity, conventional analysis tends to reside in reporting only averages of minimum, maximum, amplitude and rate, as single point averages. Although these averages are undoubtedly of value, simplification of the data in this way means that most of the available numerical data are discarded. In turn, this may lead to subtle physiological changes being missed when investigating the cardiovascular system over time. We have developed a mathematical method (symmetric projection attractor reconstruction) that uses all the numerical data, replotting and revisualizing them in a manner that allows unique quantification of multiple changes in waveform morphology and variability. We propose that the additional quantification of these features will allow the complex behaviour of the cardiovascular system to be mapped more sensitively in different physiological and pathophysiological settings.
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Affiliation(s)
- Manasi Nandi
- School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Philip J Aston
- Department of Mathematics, University of Surrey, Guildford, UK
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28
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Warnert EAH, Steketee RME, Vernooij MW, Ikram MA, Vogel M, Hernandez Tamames JA, Kotek G. Implementation and validation of ASL perfusion measurements for population imaging. Magn Reson Med 2020; 84:2048-2054. [PMID: 32239745 PMCID: PMC7383568 DOI: 10.1002/mrm.28271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 01/10/2023]
Abstract
Purpose Pseudocontinuous arterial spin labeling (pCASL) allows for noninvasive measurement of regional cerebral blood flow (CBF), which has the potential to serve as biomarker for neurodegenerative and cardiovascular diseases. This work aimed to implement and validate pCASL on the dedicated MRI system within the population‐based Rotterdam Study, which was installed in 2005 and for which software and hardware configurations have remained fixed. Methods Imaging was performed on two 1.5T MRI systems (General Electric); (I) the Rotterdam Study system, and (II) a hospital‐based system with a product pCASL sequence. An in‐house implementation of pCASL was created on scanner I. A flow phantom and three healthy volunteers (<27 years) were scanned on both systems for validation purposes. The data of the first 30 participants (86 ± 4 years) of the Rotterdam Study undergoing pCASL scans on scanner I only were analyzed with and without partial volume correction for gray matter. Results The validation study showed a difference in blood flow velocity, sensitivity, and spatial coefficient of variation of the perfusion‐weighted signal between the two scanners, which was accounted for during post‐processing. Gray matter CBF for the Rotterdam Study participants was 52.4 ± 8.2 ml/100 g/min, uncorrected for partial volume effects of gray matter. In this elderly cohort, partial volume correction for gray matter had a variable effect on measured CBF in a range of cortical and sub‐cortical regions of interest. Conclusion Regional CBF measurements are now included to investigate novel biomarkers in the Rotterdam Study. This work highlights that when it is not feasible to purchase a novel ASL sequence, an in‐house implementation is valuable.
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Affiliation(s)
- Esther A H Warnert
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Rebecca M E Steketee
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Meike W Vernooij
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands.,Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands
| | | | | | - Gyula Kotek
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, the Netherlands
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29
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Rodrigues JCL, Strelko G, Warnert EAH, Burchell AE, Neumann S, Ratcliffe LEK, Harris AD, Chant B, Bowles R, Nightingale AK, Wise RG, Paton JFR, Hart EC. Retrograde blood flow in the internal jugular veins of humans with hypertension may have implications for cerebral arterial blood flow. Eur Radiol 2020; 30:3890-3899. [PMID: 32157411 DOI: 10.1007/s00330-020-06752-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/10/2019] [Accepted: 02/14/2020] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To use multi-parametric magnetic resonance imaging (MRI) to test the hypothesis that hypertensives would have higher retrograde venous blood flow (RVBF) in the internal jugular veins (IJV) vs. normotensives, and that this would inversely correlate with arterial inflow and gray matter, white matter, and cerebrospinal fluid volumes. METHODS Following local institutional review board approval and written consent, a prospective observational 3-T MRI study of 42 hypertensive patients (53 ± 2 years, BMI 28.2 ± 0.6 kg/m2, ambulatory daytime systolic BP 148 ± 2 mmHg, ambulatory daytime diastolic BP 101 ± 2 mmHg) and 35 normotensive patients (48 ± 2 years, BMI 25.2 ± 0.8 kg/m2, ambulatory daytime systolic BP 119 ± 3 mmHg, ambulatory daytime diastolic BP 90 ± 2 mmHg) was performed. Phase contrast imaging calculated percentage retrograde venous blood flow (%RVBF), brain segmentation estimated regional brain volumes from 3D T1-weighted images, and pseudo-continuous arterial spin labeling measured regional cerebral blood perfusion. Statistical analysis included two-sample equal variance Student's T tests, two-way analysis of variance with Tukey's post hoc correction, and permutation-based two-group general linear modeling (p < 0.05). RESULTS In the left IJV, %RVBF was higher in hypertensives (6.1 ± 1.5%) vs. normotensives (1.1 ± 0.3%, p = 0.003). In hypertensives, there was an inverse relationship of %RVBF (permutation-based general linear modeling) to cerebral blood flow in several brain regions, including the left occipital pole and the cerebellar vermis (p < 0.01). Percentage retrograde flow in the left IJV correlated inversely with the total matter volume (gray plus white matter volume) in hypertensives (r = - 0.49, p = 0.004). CONCLUSION RVBF in the left IJV is greater in hypertensives vs. normotensives and is linked to regional hypoperfusion and brain total matter volume. KEY POINTS • Hypertensive humans have higher retrograde cerebral venous blood flow, associated with regional brain hypoperfusion and lower tissue volume, compared with controls. • Cerebral retrograde venous blood flow may add further stress to already hypoperfused tissue in hypertensive patients. • The amount of retrograde venous blood flow in hypertensive patients may predict which patients might be at higher risk of developing cerebral pathologies.
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Affiliation(s)
- Jonathan C L Rodrigues
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Bath, Avon, BA1 3NG, UK
| | - Galina Strelko
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Esther A H Warnert
- Department of Radiology and Nuclear Medicine, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Amy E Burchell
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Clinical Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Sandra Neumann
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Laura E K Ratcliffe
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Ashley D Harris
- Department of Radiology, CAIR Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Benjamin Chant
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Ruth Bowles
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Angus K Nightingale
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Clinical Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Richard G Wise
- School of Psychology, Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, CF10 3AT, UK
| | - Julian F R Paton
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Emma C Hart
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK.
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30
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Thakkar PC, McGregor AL, Barber PA, Paton JFR, Barrett CJ, McBryde FD. Therapeutic Relevance of Elevated Blood Pressure After Ischemic Stroke in the Hypertensive Rats. Hypertension 2020; 75:740-747. [PMID: 31957520 DOI: 10.1161/hypertensionaha.119.14219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Over 80% of patients exhibit an acute increase in blood pressure (BP) following stroke. Current clinical guidelines make no distinction in BP management between patients with or without prior hypertension. Spontaneously hypertensive (SH) rats were preinstrumented with telemeters to record BP, intracranial pressure, and brain tissue oxygen in the predicted ischemic penumbra for 3 days before and 10 days after transient middle cerebral artery occlusion (n=8 per group) or sham (n=5). Before stroke, BP was either left untreated or chronically treated to a normotensive level (enalapril 10 mg/kg per day). Poststroke elevations in BP were either left uncontrolled, controlled (to the prestroke baseline level), or overcontrolled (to a normotensive level) via subcutaneous infusion of labetalol. Baseline values of intracranial pressure and brain tissue oxygen were similar between all groups, whereas BP was lower in treated SH rats (144±3 versus 115±5 mm Hg; P<0.001). Following middle cerebral artery occlusion, a similar rise in BP was observed in untreated (+16±2 mm Hg; P=0.005) and treated SH rats (+13±5 mm Hg; P=0.021). Intervening to prevent BP from increasing after stroke did not worsen outcome. However, reducing BP below prestroke baseline levels was associated with higher intracranial pressure (days 1-3; P<0.001), reduced cerebral perfusion pressure (days 2-4; P<0.001), higher mortality, slower functional recovery and larger infarct volumes. Although treating to maintain BP at the prestroke baseline level was not detrimental, our results suggest that when setting BP targets after stroke, consideration must be given to the potential negative impact of inadvertent excessive BP lowering in subjects with undiagnosed or poorly controlled hypertension.
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Affiliation(s)
- Pratik C Thakkar
- From the Department of Physiology, School of Medical Sciences (P.C.T., J.F.R.P., C.J.B., F.D.M.), University of Auckland, Auckland, New Zealand
| | - Ailsa L McGregor
- School of Pharmacy, University of Otago, Dunedin, New Zealand (A.L.M.)
| | - P Alan Barber
- Department of Medicine, Centre for Brain Research, School of Medical Sciences (P.A.B.), University of Auckland, Auckland, New Zealand
| | - Julian F R Paton
- From the Department of Physiology, School of Medical Sciences (P.C.T., J.F.R.P., C.J.B., F.D.M.), University of Auckland, Auckland, New Zealand
| | - Carolyn J Barrett
- From the Department of Physiology, School of Medical Sciences (P.C.T., J.F.R.P., C.J.B., F.D.M.), University of Auckland, Auckland, New Zealand
| | - Fiona D McBryde
- From the Department of Physiology, School of Medical Sciences (P.C.T., J.F.R.P., C.J.B., F.D.M.), University of Auckland, Auckland, New Zealand
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Kandil H, Soliman A, Taher F, Ghazal M, Khalil A, Giridharan G, Keynton R, Jennings JR, El-Baz A. A novel computer-aided diagnosis system for the early detection of hypertension based on cerebrovascular alterations. NEUROIMAGE-CLINICAL 2019; 25:102107. [PMID: 31830715 PMCID: PMC6926373 DOI: 10.1016/j.nicl.2019.102107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/31/2019] [Accepted: 11/19/2019] [Indexed: 01/21/2023]
Abstract
3-D CNN segmentation succeeded in delineating cerebrovasculature accurately. Segmentation approach is automatic and applicable on healthy/pathological vessels. Blood flow variability challenge was addressed by processing MRA scans locally. Proposed vascular features were efficient to quantify cerebral changes. Proposed CAD system could help clinicians predict hypertension before its onset.
Hypertension is a leading cause of mortality in the USA. While simple tools such as the sphygmomanometer are widely used to diagnose hypertension, they could not predict the disease before its onset. Clinical studies suggest that alterations in the structure of human brains’ cerebrovasculature start to develop years before the onset of hypertension. In this research, we present a novel computer-aided diagnosis (CAD) system for the early detection of hypertension. The proposed CAD system analyzes magnetic resonance angiography (MRA) data of human brains to detect and track the cerebral vascular alterations and this is achieved using the following steps: i) MRA data are preprocessed to eliminate noise effects, correct the bias field effect, reduce the contrast inhomogeneity using the generalized Gauss-Markov random field (GGMRF) model, and normalize the MRA data, ii) the cerebral vascular tree of each MRA volume is segmented using a 3-D convolutional neural network (3D-CNN), iii) cerebral features in terms of diameters and tortuosity of blood vessels are estimated and used to construct feature vectors, iv) feature vectors are then used to train and test various artificial neural networks to classify data into two classes; normal and hypertensive. A balanced data set of 66 subjects were used to test the CAD system. Experimental results reported a classification accuracy of 90.9% which supports the efficacy of the CAD system components to accurately model and discriminate between normal and hypertensive subjects. Clinicians would benefit from the proposed CAD system to detect and track cerebral vascular alterations over time for people with high potential of developing hypertension and to prepare appropriate treatment plans to mitigate adverse events.
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Affiliation(s)
- Heba Kandil
- Bioimaging Laboratory, J.B Speed School of Engineering, University of Louisville, KY, USA; Information Technology Department, Faculty of Computer Science and Information, Mansoura University, Egypt
| | - Ahmed Soliman
- Bioimaging Laboratory, J.B Speed School of Engineering, University of Louisville, KY, USA
| | | | - Mohammed Ghazal
- Electrical and Computer Engineering Department, Abu Dhabi University, UAE
| | - Ashraf Khalil
- Electrical and Computer Engineering Department, Abu Dhabi University, UAE
| | - Guruprasad Giridharan
- Bioimaging Laboratory, J.B Speed School of Engineering, University of Louisville, KY, USA
| | - Robert Keynton
- Bioimaging Laboratory, J.B Speed School of Engineering, University of Louisville, KY, USA
| | - J Richard Jennings
- Department of Psychiatry and Psychology, University of Pittsburgh, PA, USA
| | - Ayman El-Baz
- Bioimaging Laboratory, J.B Speed School of Engineering, University of Louisville, KY, USA.
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Kobuch S, Macefield VG, Henderson LA. Resting regional brain activity and connectivity vary with resting blood pressure but not muscle sympathetic nerve activity in normotensive humans: An exploratory study. J Cereb Blood Flow Metab 2019; 39:2433-2444. [PMID: 30182800 PMCID: PMC6893974 DOI: 10.1177/0271678x18798442] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Blood pressure is tightly controlled by the central nervous system, particularly the brainstem. The aim of this study was to investigate the relationship between mean blood pressure (MBP), muscle sympathetic nerve activity (MSNA) and resting regional brain activity in healthy human subjects. Pseudocontinuous arterial spin labeling and functional magnetic resonance imaging of the brain were performed immediately following a laboratory microneurography recording of MSNA and BP measurement in 31 young, healthy normotensive subjects. Regional cerebral blood flow (CBF) correlated significantly with resting MBP levels in the region encompassing the rostroventrolateral medulla (RVLM), dorsolateral pons, and insular, prefrontal and cingulate cortices. Functional connectivity analysis revealed that the ventrolateral prefrontal cortex displayed greater resting connectivity strength within the RVLM in the lower compared with the higher MBP group. No significant differences in CBF were found when subjects were divided based on their MSNA levels. These results suggest that even subtle differences in resting MBP are associated with significant differences in resting activity in brain regions, which are well known to play a role in cardiovascular function. These data raise the question of the potential long-term consequences of differences in regional brain activity levels and their relationship with systemic blood pressure.
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Affiliation(s)
- Sophie Kobuch
- School of Medicine, Western Sydney University, Sydney, Australia
| | - Vaughan G Macefield
- School of Medicine, Western Sydney University, Sydney, Australia.,Neuroscience Research Australia, Sydney, Australia.,Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Luke A Henderson
- Department of Anatomy and Histology, University of Sydney, Sydney, Australia
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Lee J, Kim SK, Kang HG, Ha IS, Wang KC, Lee JY, Phi JH. High prevalence of systemic hypertension in pediatric patients with moyamoya disease years after surgical treatment. J Neurosurg Pediatr 2019; 25:131-137. [PMID: 31703203 DOI: 10.3171/2019.9.peds1986] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 09/10/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Although an association between moyamoya disease (MMD) and renovascular hypertension has been acknowledged, the literature on systemic hypertension without renal artery stenosis among patients with MMD is scarce. The authors aimed to evaluate the prevalence and risk factors of hypertension using data from MMD patients who visited an outpatient clinic of a pediatric neurosurgical department in 2016. METHODS The authors evaluated the blood pressure (BP) of pediatric MMD patients at their postsurgical appointment following the American Academy of Pediatrics clinical practice guideline on high BP, in which hypertension was defined as BP measurements higher than the value of age-, sex-, and height-specific 95th percentile of the general population from at least 3 separate visits. Growth of patients was determined using 2017 Korean National Growth Charts for children and adolescents. The cutoff value of the 95th percentile of BP was determined by referring to normative BP tables of Korean children and adolescents. A logistic regression model was used to assess the associations between patients' clinical characteristics and prevalent hypertension. RESULTS In total, 131 surgically treated pediatric MMD patients were included, of whom 38.9% were male and the median age at diagnosis was 8.0 years (range 1.2-15.0 years). The definition of hypertension was met in 38 patients, with a prevalence of 29.0% (95% CI 21.2%-36.8%). A tendency was observed for a higher prevalence of hypertension in male patients (31.4%), in patients with posterior cerebral artery (PCA) involvement (47.8%), and in cases in which infarction was shown on initial MRI (37.3%). Age at diagnosis (adjusted OR [aOR] 0.82, 95% CI 0.70-0.97), PCA involvement (aOR 3.81, 95% CI 1.29-11.23), body mass index (aOR 1.30, 95% CI 1.13-1.51), and years of follow-up since surgery (aOR 0.80, 95% CI 0.68-0.94) were related to systemic hypertension. CONCLUSIONS A high prevalence of hypertension was demonstrated in pediatric MMD patients. Therefore, adequate attention should be paid to reduce BP and prevent subsequent events.
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Affiliation(s)
- Joongyub Lee
- 1Department of Prevention and Management, Inha University Hospital, School of Medicine, Inha University
- 2Incheon Regional Cardiocerebrovascular Disease Center, Incheon
| | | | - Hee Gyung Kang
- 4Department of Pediatrics, Seoul National University Children's Hospital; and
| | - Il-Soo Ha
- 4Department of Pediatrics, Seoul National University Children's Hospital; and
| | | | - Ji Yeoun Lee
- 3Division of Pediatric Neurosurgery and
- 5Department of Anatomy, Seoul National University College of Medicine, Seoul, Korea
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Rodrigues JCL, Jaring MFR, Werndle MC, Mitrousi K, Lyen SM, Nightingale AK, Hamilton MCK, Curtis SL, Manghat NE, Paton JFR, Hart EC. Repaired coarctation of the aorta, persistent arterial hypertension and the selfish brain. J Cardiovasc Magn Reson 2019; 21:68. [PMID: 31703697 PMCID: PMC6839237 DOI: 10.1186/s12968-019-0578-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/21/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND It has been estimated that 20-30% of repaired aortic coarctation (CoA) patients develop hypertension, with significant cardiovascular morbidity and mortality. Vertebral artery hypoplasia (VAH) with an incomplete posterior circle of Willis (ipCoW; VAH + ipCoW) is associated with increased cerebrovascular resistance before the onset of increased sympathetic nerve activity in borderline hypertensive humans, suggesting brainstem hypoperfusion may evoke hypertension to maintain cerebral blood flow: the "selfish brain" hypothesis. We now assess the "selfish brain" in hypertension post-CoA repair. METHODS Time-of-flight cardiovascular magnetic resonance angiography from 127 repaired CoA patients (34 ± 14 years, 61% male, systolic blood pressure (SBP) 138 ± 19 mmHg, diastolic blood pressure (DBP) 76 ± 11 mmHg) was compared with 33 normotensive controls (42 ± 14 years, 48% male, SBP 124 ± 10 mmHg, DBP 76 ± 8 mmHg). VAH was defined as < 2 mm and ipCoW as hypoplasia of one or both posterior communicating arteries. RESULTS VAH + ipCoW was more prevalent in repaired CoA than controls (odds ratio: 5.8 [1.6-20.8], p = 0.007), after controlling for age, sex and body mass index (BMI). VAH + ipCoW was an independent predictor of hypertension (odds ratio: 2.5 [1.2-5.2], p = 0.017), after controlling for age, gender and BMI. Repaired CoA subjects with VAH + ipCoW were more likely to have difficult to treat hypertension (odds ratio: 3.3 [1.01-10.7], p = 0.049). Neither age at time of CoA repair nor any specific repair type were significant predictors of VAH + ipCoW in univariate regression analysis. CONCLUSIONS VAH + ipCoW predicts arterial hypertension and difficult to treat hypertension in repaired CoA. It is unrelated to age at time of repair or repair type. CoA appears to be a marker of wider congenital cerebrovascular problems. Understanding the "selfish brain" in post-CoA repair may help guide management. JOURNAL SUBJECT CODES High Blood Pressure; Hypertension; Magnetic Resonance Imaging (MRI); Cardiovascular Surgery; Cerebrovascular Malformations.
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Affiliation(s)
- Jonathan C. L. Rodrigues
- Department of Cardiovascular Magnetic Resonance, Bristol Cardiovascular Biomedical Research Unit, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
- School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Science, University of Bristol, Bristol, UK
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Bath, UK
| | - Matthew F. R. Jaring
- Department of Radiology, Bristol Royal Infirmary, University Bristol NHS Foundation Trust, Bristol, UK
| | - Melissa C. Werndle
- Department of Radiology, Bristol Royal Infirmary, University Bristol NHS Foundation Trust, Bristol, UK
| | - Konstantina Mitrousi
- School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Science, University of Bristol, Bristol, UK
| | - Stephen M. Lyen
- Department of Radiology, Bristol Royal Infirmary, University Bristol NHS Foundation Trust, Bristol, UK
| | - Angus K. Nightingale
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, University of Bristol, Bristol, UK
| | - Mark C. K. Hamilton
- Department of Radiology, Bristol Royal Infirmary, University Bristol NHS Foundation Trust, Bristol, UK
| | - Stephanie L. Curtis
- Adult Congenital Heart Disease Unit, Bristol Heart Institute, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Upper Maudlin Street, Bristol, UK
| | - Nathan E. Manghat
- Department of Radiology, Bristol Royal Infirmary, University Bristol NHS Foundation Trust, Bristol, UK
| | - Julian F. R. Paton
- School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Science, University of Bristol, Bristol, UK
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, University of Bristol, Bristol, UK
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Park Road, Grafton, Auckland, New Zealand
| | - Emma C. Hart
- School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Science, University of Bristol, Bristol, UK
- BHI CardioNomics Research Group, Clinical Research and Imaging Centre-Bristol, University of Bristol, Bristol, UK
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Ogoh S, Tarumi T. Cerebral blood flow regulation and cognitive function: a role of arterial baroreflex function. J Physiol Sci 2019; 69:813-823. [PMID: 31444691 PMCID: PMC10717347 DOI: 10.1007/s12576-019-00704-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/13/2019] [Indexed: 10/26/2022]
Abstract
A strict adequate perfusion pressure via arterial baroreflex for the delivery of oxygen to the tissues of the body is well established; however, the importance of baroreflex for cerebral blood flow (CBF) is unclear. On the other hand, there is convincing evidence for arterial baroreflex function playing an important role in maintaining brain homeostasis, e.g., cerebral metabolism, cerebral hemodynamics, and cognitive function. For example, mild cognitive impairment attenuates the sensitivity of baroreflex, and Alzheimer's disease further decreases it. These clinical findings suggest that CBF and cerebral function are affected by systemic blood pressure regulation via the arterial baroreflex. However, dysfunction of arterial baroreflex is likely to affect CBF regulation as well as the underlying neuronal function, but identifying how this is achieved is arduous since neurological diseases affect systemic as well as cerebral circulation independently. Recent insights into the influence of blood pressure regulation via the arterial baroreflex on cerebral function and blood flow regulation may help elucidate this important question. This review summarizes some update findings regarding direct (autonomic regulation) and indirect (systemic blood pressure regulation) contributions of the arterial baroreflex to the maintenance of cerebral vasculature regulation.
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Affiliation(s)
- Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan.
| | - Takashi Tarumi
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
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Neumann S, Burchell AE, Rodrigues JC, Lawton CB, Burden D, Underhill M, Kobetić MD, Adams ZH, Brooks JC, Nightingale AK, Paton JFR, Hamilton MC, Hart EC. Cerebral Blood Flow Response to Simulated Hypovolemia in Essential Hypertension: A Magnetic Resonance Imaging Study. Hypertension 2019; 74:1391-1398. [PMID: 31656098 PMCID: PMC7069391 DOI: 10.1161/hypertensionaha.119.13229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Supplemental Digital Content is available in the text. Hypertension is associated with raised cerebral vascular resistance and cerebrovascular remodeling. It is currently unclear whether the cerebral circulation can maintain cerebral blood flow (CBF) during reductions in cardiac output (CO) in hypertensive patients thereby avoiding hypoperfusion of the brain. We hypothesized that hypertension would impair the ability to effectively regulate CBF during simulated hypovolemia. In the present study, 39 participants (13 normotensive, 13 controlled, and 13 uncontrolled hypertensives; mean age±SD, 55±10 years) underwent lower body negative pressure (LBNP) at −20, −40, and −50 mmHg to decrease central blood volume. Phase-contrast MR angiography was used to measure flow in the basilar and internal carotid arteries, as well as the ascending aorta. CBF and CO decreased during LBNP (P<0.0001). Heart rate increased during LBNP, reaching significance at −50 mmHg (P<0.0001). There was no change in mean arterial pressure during LBNP (P=0.3). All participants showed similar reductions in CBF (P=0.3, between groups) and CO (P=0.7, between groups) during LBNP. There was no difference in resting CBF between the groups (P=0.36). In summary, during reductions in CO induced by hypovolemic stress, mean arterial pressure is maintained but CBF declines indicating that CBF is dependent on CO in middle-aged normotensive and hypertensive volunteers. Hypertension is not associated with impairments in the CBF response to reduced CO.
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Affiliation(s)
- Sandra Neumann
- From the Faculty of Life Sciences, School of Physiology, Pharmacology and Neuroscience (S.N., Z.H.A., J.B., A.K.N., J.P., E.C.H.), University of Bristol, United Kingdom
- Faculty of Health Sciences, Bristol Medical School (S.N., M.K.), University of Bristol, United Kingdom
| | - Amy E. Burchell
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
| | - Jonathan C.L. Rodrigues
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, United Kingdom (J.R.)
| | - Christopher B. Lawton
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
| | - Daniel Burden
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
| | - Melissa Underhill
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
| | - Matthew D. Kobetić
- Faculty of Health Sciences, Bristol Medical School (S.N., M.K.), University of Bristol, United Kingdom
| | - Zoe H. Adams
- From the Faculty of Life Sciences, School of Physiology, Pharmacology and Neuroscience (S.N., Z.H.A., J.B., A.K.N., J.P., E.C.H.), University of Bristol, United Kingdom
| | - Jonathan C.W. Brooks
- From the Faculty of Life Sciences, School of Physiology, Pharmacology and Neuroscience (S.N., Z.H.A., J.B., A.K.N., J.P., E.C.H.), University of Bristol, United Kingdom
| | - Angus K. Nightingale
- From the Faculty of Life Sciences, School of Physiology, Pharmacology and Neuroscience (S.N., Z.H.A., J.B., A.K.N., J.P., E.C.H.), University of Bristol, United Kingdom
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
| | - Julian F. R. Paton
- From the Faculty of Life Sciences, School of Physiology, Pharmacology and Neuroscience (S.N., Z.H.A., J.B., A.K.N., J.P., E.C.H.), University of Bristol, United Kingdom
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand (J.P.)
| | - Mark C.K. Hamilton
- University Hospitals Bristol NHS Foundation Trust, United Kingdom (A.E.B., J.R., C.B.L., D.B., M.U., A.K.N., M.H.)
| | - Emma C. Hart
- From the Faculty of Life Sciences, School of Physiology, Pharmacology and Neuroscience (S.N., Z.H.A., J.B., A.K.N., J.P., E.C.H.), University of Bristol, United Kingdom
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Walas D, Nowicki-Osuch K, Alibhai D, von Linstow Roloff E, Coghill J, Waterfall C, Paton JF. Inflammatory pathways are central to posterior cerebrovascular artery remodelling prior to the onset of congenital hypertension. J Cereb Blood Flow Metab 2019; 39:1803-1817. [PMID: 29651914 PMCID: PMC6724458 DOI: 10.1177/0271678x18769180] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cerebral artery hypoperfusion may provide the basis for linking ischemic stroke with hypertension. Brain hypoperfusion may induce hypertension that may serve as an auto-protective mechanism to prevent ischemic stroke. We hypothesised that hypertension is caused by remodelling of the cerebral arteries, which is triggered by inflammation. We used a congenital rat model of hypertension and examined age-related changes in gene expression of the cerebral arteries using RNA sequencing. Prior to hypertension, we found changes in signalling pathways associated with the immune system and fibrosis. Validation studies using second harmonics generation microscopy revealed upregulation of collagen type I and IV in both tunica externa and media. These changes in the extracellular matrix of cerebral arteries pre-empted hypertension accounting for their increased stiffness and resistance, both potentially conducive to stroke. These data indicate that inflammatory driven cerebral artery remodelling occurs prior to the onset of hypertension and may be a trigger elevating systemic blood pressure in genetically programmed hypertension.
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Affiliation(s)
- Dawid Walas
- 1 School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | | | - Dominic Alibhai
- 3 Wolfson Bioimaging Facility, School of Biochemistry, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Eva von Linstow Roloff
- 1 School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Jane Coghill
- 4 Genomics Facility, School of Biological Sciences, Bristol, UK
| | | | - Julian Fr Paton
- 1 School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK.,5 Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Grafton, New Zealand
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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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Williams R. Circulation Research "In This Issue" Anthology. Circ Res 2019; 120:e58-e84. [PMID: 28596178 DOI: 10.1161/res.0000000000000152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Genetic and Environmental Contributions to Variation in the Posterior Communicating Collaterals of the Circle of Willis. Transl Stroke Res 2019; 10:189-203. [PMID: 29589286 DOI: 10.1007/s12975-018-0626-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/14/2018] [Accepted: 03/16/2018] [Indexed: 02/07/2023]
Abstract
Variation in blood flow mediated by the posterior communicating collateral arteries (PComs) contributes to variation in the severity of tissue injury in obstructive disease. Evidence in animals and humans indicates that differences in the extent of PComs, i.e., their anatomic lumen diameter and whether they are present bilaterally, unilaterally, or absent, are a major factor. These differences arise during development since they are present at birth. However, the causal mechanisms are unknown. We used angiography after maximal dilation to examine involvement of genetic, environmental, and stochastic factors. The extent of PComs varied widely among seven genetically diverse strains of mice. Like pial collaterals in the microcirculation, aging and hypertension reduced PCom diameter, while in contrast, obesity, hyperlipidemia, metabolic syndrome, and diabetes mellitus had no effect. Naturally occurring intrauterine growth restriction had no effect on extent of PCom or pial collaterals in the adult. The number and diameter of PComs evidenced much larger apparent stochastic-dependent variation than pial collaterals. In addition, both PComs underwent flow-mediated outward remodeling after unilateral permanent MCA occlusion that varied with genetic background and was greater on the ipsilesional side. These findings indicate that variation in the number and diameter of PCom collateral arteries arises from stochastic factors and naturally occurring genetic variants that differ from those that cause variation in pial collateral arterioles. Environmental factors also contribute: aging and hypertension reduce PCom diameter. Our results suggest possible sources of variation of PComs in humans and provide information relevant when studying mouse models of occlusive cerebrovascular disease.
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Glodzik L, Rusinek H, Tsui W, Pirraglia E, Kim HJ, Deshpande A, Li Y, Storey P, Randall C, Chen J, Osorio RS, Butler T, Tanzi E, McQuillan M, Harvey P, Williams SK, Ogedegbe OG, Babb JS, de Leon MJ. Different Relationship Between Systolic Blood Pressure and Cerebral Perfusion in Subjects With and Without Hypertension. Hypertension 2019; 73:197-205. [PMID: 30571554 PMCID: PMC7986962 DOI: 10.1161/hypertensionaha.118.11233] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although there is an increasing agreement that hypertension is associated with cerebrovascular compromise, relationships between blood pressure (BP) and cerebral blood flow are not fully understood. It is not known what BP level, and consequently what therapeutic goal, is optimal for brain perfusion. Moreover, there is limited data on how BP affects hippocampal perfusion, a structure critically involved in memory. We conducted a cross-sectional (n=445) and longitudinal (n=185) study of adults and elderly without dementia or clinically apparent stroke, who underwent clinical examination and brain perfusion assessment (age 69.2±7.5 years, 62% women, 45% hypertensive). Linear models were used to test baseline BP-blood flow relationship and to examine how changes in BP influence changes in perfusion. In the entire group, systolic BP (SBP) was negatively related to cortical (β=-0.13, P=0.005) and hippocampal blood flow (β=-0.12, P=0.01). Notably, this negative relationship was apparent already in subjects without hypertension. Hypertensive subjects showed a quadratic relationship between SBP and hippocampal blood flow (β=-1.55, P=0.03): Perfusion was the highest in subjects with mid-range SBP around 125 mm Hg. Longitudinally, in hypertensive subjects perfusion increased with increased SBP at low baseline SBP but increased with decreased SBP at high baseline SBP. Cortical and hippocampal perfusion decrease with increasing SBP across the entire BP spectrum. However, in hypertension, there seems to be a window of mid-range SBP which maximizes perfusion.
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Affiliation(s)
- Lidia Glodzik
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York,Department of Radiology, NYU School of Medicine, New York,Corresponding author: Lidia Glodzik, Center for Brain Health, Department of Psychiatry, NYU School of Medicine, 145 East 32 Street, New York, NY, 10016. Tel: 212-263-5698, Fax: 212-263-3270;
| | - Henry Rusinek
- Department of Radiology, NYU School of Medicine, New York
| | - Wai Tsui
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Elizabeth Pirraglia
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Hee-Jin Kim
- Department of Neurology, Konkuk University College of Medicine, Seoul, South Korea
| | - Anup Deshpande
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Yi Li
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Pippa Storey
- Department of Radiology, NYU School of Medicine, New York
| | - Catherine Randall
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Jingyun Chen
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Ricardo S. Osorio
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Tracy Butler
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Emily Tanzi
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Molly McQuillan
- The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - Patrick Harvey
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | | | | | - James S. Babb
- Department of Radiology, NYU School of Medicine, New York
| | - Mony J. de Leon
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
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42
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Moriconi S, Zuluaga MA, Jager HR, Nachev P, Ourselin S, Cardoso MJ. Inference of Cerebrovascular Topology With Geodesic Minimum Spanning Trees. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:225-239. [PMID: 30059296 PMCID: PMC6319031 DOI: 10.1109/tmi.2018.2860239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
A vectorial representation of the vascular network that embodies quantitative features-location, direction, scale, and bifurcations-has many potential cardio- and neuro-vascular applications. We present VTrails, an end-to-end approach to extract geodesic vascular minimum spanning trees from angiographic data by solving a connectivity-optimized anisotropic level-set over a voxel-wise tensor field representing the orientation of the underlying vasculature. Evaluating real and synthetic vascular images, we compare VTrails against the state-of-the-art ridge detectors for tubular structures by assessing the connectedness of the vesselness map and inspecting the synthesized tensor field. The inferred geodesic trees are then quantitatively evaluated within a topologically aware framework, by comparing the proposed method against popular vascular segmentation tool kits on clinical angiographies. VTrails potentials are discussed towards integrating groupwise vascular image analyses. The performance of VTrails demonstrates its versatility and usefulness also for patient-specific applications in interventional neuroradiology and vascular surgery.
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43
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Tayler HM, Palmer JC, Thomas TL, Kehoe PG, Paton JF, Love S. Cerebral Aβ 40 and systemic hypertension. J Cereb Blood Flow Metab 2018; 38:1993-2005. [PMID: 28782443 PMCID: PMC6259324 DOI: 10.1177/0271678x17724930] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mid-life hypertension and cerebral hypoperfusion may be preclinical abnormalities in people who later develop Alzheimer's disease. Although accumulation of amyloid-beta (Aβ) is characteristic of Alzheimer's disease and is associated with upregulation of the vasoconstrictor peptide endothelin-1 within the brain, it is unclear how this affects systemic arterial pressure. We have investigated whether infusion of Aβ40 into ventricular cerebrospinal fluid modulates blood pressure in the Dahl salt-sensitive rat. The Dahl salt-sensitive rat develops hypertension if given a high-salt diet. Intracerebroventricular infusion of Aβ induced a progressive rise in blood pressure in rats with pre-existing hypertension produced by a high-salt diet ( p < 0.0001), but no change in blood pressure in normotensive rats. The elevation in arterial pressure in high-salt rats was associated with an increase in low frequency spectral density in systolic blood pressure, suggesting autonomic imbalance, and reduced cardiac baroreflex gain. Our results demonstrate the potential for intracerebral Aβ to exacerbate hypertension, through modulation of autonomic activity. Present findings raise the possibility that mid-life hypertension in people who subsequently develop Alzheimer's disease may in some cases be a physiological response to reduced cerebral perfusion complicating the accumulation of Aβ within the brain.
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Affiliation(s)
- Hannah M Tayler
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
| | | | - Taya L Thomas
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Patrick G Kehoe
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Julian Fr Paton
- 2 School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Seth Love
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
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Neumann S, Sophocleous F, Kobetic MD, Hart EC, Nightingale AK, Parker KH, Hamilton MK, Biglino G. Wave intensity analysis in the internal carotid artery of hypertensive subjects using phase-contrast MR angiography and preliminary assessment of the effect of vessel morphology on wave dynamics. Physiol Meas 2018; 39:104003. [PMID: 30192235 PMCID: PMC6372132 DOI: 10.1088/1361-6579/aadfc5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Objective: Hypertension is associated with reduced cerebral blood flow, but it is not known how this impacts on wave dynamics or potentially relates to arterial morphology. Given the location of the internal carotid artery (ICA) and risks associated with invasive measurements, wave dynamics in this artery have not been extensively assessed in vivo. This study explores the feasibility of studying wave dynamics in the internal carotid artery non-invasively. Approach: Normotensive, uncontrolled and controlled hypertensive participants were recruited (daytime ambulatory blood pressure <135/85 mmHg and >135/85 mmHg, respectively; n = 38). Wave intensity, reservoir pressure and statistical shape analyses were performed on the right ICA and ascending aorta high-resolution phase-contrast magnetic resonance angiography data. Main results: Wave speed in the aorta was significantly lower in normotensive compared to hypertensive participants (6.7 ± 1.8 versus 11.2 ± 6.2 m s−1 for uncontrolled and 11.8 ± 4.6 m s−1 for controlled hypertensives, p = 0.02), whilst there were no differences in wave speed in the ICA. There were no significant differences between the groups for the wave intensity or reservoir pressure. Interestingly, a significant association between the anatomy of the ICA and wave energy (FCW and size, r2 = 0.12, p = 0.04) was found. Significance: This study shows it is feasible to study wave dynamics in the ICA non-invasively. Whilst changes in aortic wave speed confirmed an expected increase in arterial stiffness, this was not observed in the ICA. This might suggest a protective mechanism in the cerebral circulation, in conjunction with the effect of vessel tortuosity. Furthermore, it was observed that ICA shape correlated with wave energy but not wave speed.
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Affiliation(s)
- S Neumann
- University of Bristol, Bristol, United Kingdom
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Vianna LC, Fernandes IA, Barbosa TC, Amaral TG, Rocha NG, Secher NH, Nóbrega AC. Absent increase in vertebral artery blood flow during l-arginine infusion in hypertensive men. Am J Physiol Regul Integr Comp Physiol 2018; 315:R820-R824. [DOI: 10.1152/ajpregu.00088.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelial dysfunction is observed in the peripheral vasculature of hypertensive patients, but it is unclear how the cerebral circulation is affected. More specifically, little is known about the impact of human hypertension on vertebral artery (VA) endothelial function. This study evaluated whether the endothelial function of the VA is impaired in hypertensive men. For 13 male hypertensive subjects (46 ± 3 yr) and eight age-matched male controls (46 ± 4 yr), blood pressure (BP; photoplethysmography), VA, and common carotid (CC) blood flow (duplex ultrasound) were determined at rest and during 30 min of intravenous l-arginine (30 g; a precursor of nitric oxide) or isotonic saline infusion. Controls and hypertensive subjects demonstrated a similar resting CC (601 ± 30 vs. controls 570 ± 43 ml/min; P = 0.529) and VA blood flow (119 ± 11 vs. controls 112 ± 9 ml/min; P = 0.878). During administration of l-arginine, CC blood flow increased similarly between groups (hypertensive 12 ± 3%, controls 13 ± 2%; P = 0.920). In contrast, the increase in VA blood flow was nonexistent in the hypertensive subjects (0.8 ± 3% vs. controls: 16 ± 4%; P = 0.015) with no significant change in BP. Both CC and VA flow returned to near-resting values within 30 min after the infusion, and for four hypertensive subjects and three controls, time-control experiments using 0.9% saline did not affect VA or CC blood flow significantly. The results demonstrate endothelial dysfunction in the posterior cerebral circulation of middle-aged hypertensive men.
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Affiliation(s)
- Lauro C. Vianna
- NeuroVASQ Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Federal District, Brazil
- Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Igor A. Fernandes
- Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Thales C. Barbosa
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - Tatiana G. Amaral
- Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Natalia G. Rocha
- Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Niels H. Secher
- Department of Anaesthesiology, The Copenhagen Muscle Research Center, University of Copenhagen, Copenhagen, Denmark
| | - Antonio C. Nóbrega
- Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
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46
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Guild SJ, Saxena UA, McBryde FD, Malpas SC, Ramchandra R. Intracranial pressure influences the level of sympathetic tone. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1049-R1053. [PMID: 30207755 DOI: 10.1152/ajpregu.00183.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sympathetic overdrive is associated with many diseases, but its origin remains an enigma. An emerging hypothesis in the development of cardiovascular disease is that the brain puts the utmost priority on maintaining its own blood supply; even if this comes at the "cost" of high blood pressure to the rest of the body. A critical step in making a causative link between reduced brain blood flow and cardiovascular disease is how changes in cerebral perfusion affect the sympathetic nervous system. A direct link between decreases in cerebral perfusion pressure and sympathetic tone generation in a conscious large animal has not been shown. We hypothesized that there is a novel control pathway between physiological levels of intracranial pressure (ICP) and blood pressure via the sympathetic nervous system. Intracerebroventricular infusion of saline produced a ramped increase in ICP of up to 20 mmHg over a 30-min infusion period (baseline 4.0 ± 1.1 mmHg). The ICP increase was matched by an increase in mean arterial pressure such that cerebral perfusion pressure remained constant. Direct recordings of renal sympathetic nerve activity indicated that sympathetic drive increased with increasing ICP. Ganglionic blockade, by hexamethonium, preventing sympathetic transmission, abolished the increase in arterial pressure in response to increased ICP and was associated with a significant decrease in cerebral perfusion pressure. This is the first study to show that physiological elevations in ICP regulate renal sympathetic activity in conscious animals. We have demonstrated a novel physiological mechanism linking ICP levels with sympathetic discharge via a possible novel intracranial baroreflex.
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Affiliation(s)
- Sarah-Jane Guild
- Cardiovascular Autonomic Research Cluster, Department of Physiology, University of Auckland , Auckland , New Zealand.,Auckland Bioengineering Institute , Auckland , New Zealand
| | | | - Fiona D McBryde
- Cardiovascular Autonomic Research Cluster, Department of Physiology, University of Auckland , Auckland , New Zealand
| | - Simon C Malpas
- Cardiovascular Autonomic Research Cluster, Department of Physiology, University of Auckland , Auckland , New Zealand.,Auckland Bioengineering Institute , Auckland , New Zealand
| | - Rohit Ramchandra
- Cardiovascular Autonomic Research Cluster, Department of Physiology, University of Auckland , Auckland , New Zealand
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47
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Are the Variants of the Circle of Willis Determined by Genetic or Environmental Factors? Results of a Twin Study and Review of the Literature. Twin Res Hum Genet 2018; 21:384-393. [PMID: 30201058 DOI: 10.1017/thg.2018.50] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Anatomic variants of the circle of Willis (CW) are commonly observed in healthy subjects. Genetic and environmental factors influencing these variants remain unclear. Our aim was to assess the genetic and environmental background affecting variant CW phenotypes. METHODS A total of 122 adult healthy twins from the Hungarian Twin Registry (39 monozygotic (MZ) and 22 dizygotic (DZ) pairs, average age 49.7 ± 13.4 years) underwent Time-of-Flight magnetic resonance angiography and transcranial Doppler sonography. We investigated the anterior and posterior CW according to morphological categories. Prevalence and concordance rates of CW variants were calculated. MZ twins discordant for CW variants were analyzed for cardiovascular risk factors and altered blood flow. RESULTS Complete CW (45.0%) and bilaterally absent posterior communicating artery (PCoA) (22.5%) were the most prevalent variants in the anterior and posterior CW, respectively. There was no significant difference regarding the prevalence of variants across zygosity except for bilaterally hypoplastic PCoA (p = .02). DZ concordance was higher compared to MZ twins regarding morphological categories of the CW. Cardiovascular risk factors were not significantly associated with variant CW in MZ twins discordant to CW morphology. Flow parameters did not differ significantly among MZ twins discordant to CW variants. CONCLUSION CW variants may not be determined by substantial genetic effects and are not influenced by altered blood flow in healthy individuals. Further investigations are needed to identify potential environmental factors affecting these variants.
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48
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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: 19] [Impact Index Per Article: 3.2] [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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49
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Roloff EVL, Walas D, Moraes DJA, Kasparov S, Paton JFR. Differences in autonomic innervation to the vertebrobasilar arteries in spontaneously hypertensive and Wistar rats. J Physiol 2018; 596:3505-3529. [PMID: 29797726 PMCID: PMC6092310 DOI: 10.1113/jp275973] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/03/2018] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS Essential hypertension is associated with hyperactivity of the sympathetic nervous system and hypoperfusion of the brainstem area controlling arterial pressure. Sympathetic and parasympathetic innervation of vertebrobasilar arteries may regulate blood perfusion to the brainstem. We examined the autonomic innervation of these arteries in pre-hypertensive (PHSH) and hypertensive spontaneously hypertensive (SH) rats relative to age-matched Wistar rats. Our main findings were: (1) an unexpected decrease in noradrenergic sympathetic innervation in PHSH and SH compared to Wistar rats despite elevated sympathetic drive in PHSH rats; (2) a dramatic deficit in cholinergic and peptidergic parasympathetic innervation in PHSH and SH compared to Wistar rats; and (3) denervation of sympathetic fibres did not alter vertebrobasilar artery morphology or arterial pressure. Our results support a compromised vasodilatory capacity in PHSH and SH rats compared to Wistar rats, which may explain their hypoperfused brainstem. ABSTRACT Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the innervation density of noradrenergic sympathetic fibres in adult SH rats (P < 0.01) compared to Wistar rats. Unexpectedly, there was a 65% deficit in parasympathetic fibres, as assessed by both vesicular acetylcholine transporter (α-VAChT) and vasoactive intestinal peptide (α-VIP) immunofluorescence (P < 0.002) in PHSH rats compared to age-matched Wistar rats. Although the neural activity of the internal cervical sympathetic branch, which innervates the vertebrobasilar arteries, was higher in PHSH relative to Wistar rats, its denervation had no effect on the vertebrobasilar artery morphology or persistent effect on arterial pressure in SH rats. Our neuroanatomic and functional data do not support a role for sympathetic nerves in remodelling of the vertebrobasilar artery wall in PHSH or SH rats. The remodelling of vertebrobasilar arteries and the elevated activity in the internal cervical sympathetic nerve coupled with their reduced parasympathetic innervation suggests a compromised vasodilatory capacity in PHSH and SH rats that could explain their brainstem hypoperfusion.
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Affiliation(s)
- Eva v. L. Roloff
- School of PhysiologyPharmacology and NeuroscienceBiomedical SciencesUniversity of BristolBristol BS8 1TDUK
| | - Dawid Walas
- School of PhysiologyPharmacology and NeuroscienceBiomedical SciencesUniversity of BristolBristol BS8 1TDUK
| | - Davi J. A. Moraes
- Department of PhysiologySchool of Medicine of Ribeirão PretoUniversity of São PauloRibeirão PretoSP 14049–900Brazil
| | - Sergey Kasparov
- School of PhysiologyPharmacology and NeuroscienceBiomedical SciencesUniversity of BristolBristol BS8 1TDUK
| | - Julian F. R. Paton
- School of PhysiologyPharmacology and NeuroscienceBiomedical SciencesUniversity of BristolBristol BS8 1TDUK
- Department of PhysiologyFaculty of Medical and Health SciencesThe University of Auckland85 Park RoadGraftonAuckland1142New Zealand
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50
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Chant B, Bakali M, Hinton T, Burchell AE, Nightingale AK, Paton JF, Hart EC. Antihypertensive Treatment Fails to Control Blood Pressure During Exercise. Hypertension 2018; 72:102-109. [DOI: 10.1161/hypertensionaha.118.11076] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/03/2018] [Accepted: 04/06/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Benjamin Chant
- From the Bristol Heart Institute (BHI) CardioNomics Research Group, Clinical Research and Imaging Centre, School of Physiology, Pharmacology, Neuroscience (B.C., M.B., T.H., J.F.R.P., E.C.H.)
| | - Majda Bakali
- From the Bristol Heart Institute (BHI) CardioNomics Research Group, Clinical Research and Imaging Centre, School of Physiology, Pharmacology, Neuroscience (B.C., M.B., T.H., J.F.R.P., E.C.H.)
| | - Thomas Hinton
- From the Bristol Heart Institute (BHI) CardioNomics Research Group, Clinical Research and Imaging Centre, School of Physiology, Pharmacology, Neuroscience (B.C., M.B., T.H., J.F.R.P., E.C.H.)
| | - Amy E. Burchell
- Department of Cardiology, Bristol Heart Institute, University Hospitals Bristol National Health Service (NHS) Foundation Trust, United Kingdom (A.E.B., A.K.N.)
| | - Angus K. Nightingale
- Bristol Medical School, Translational Health Sciences (A.K.N.), University of Bristol, United Kingdom
- Department of Cardiology, Bristol Heart Institute, University Hospitals Bristol National Health Service (NHS) Foundation Trust, United Kingdom (A.E.B., A.K.N.)
| | - Julian F.R. Paton
- From the Bristol Heart Institute (BHI) CardioNomics Research Group, Clinical Research and Imaging Centre, School of Physiology, Pharmacology, Neuroscience (B.C., M.B., T.H., J.F.R.P., E.C.H.)
- Department of Physiology, University of Auckland, Grafton, New Zealand (J.F.R.P.)
| | - Emma C. Hart
- From the Bristol Heart Institute (BHI) CardioNomics Research Group, Clinical Research and Imaging Centre, School of Physiology, Pharmacology, Neuroscience (B.C., M.B., T.H., J.F.R.P., E.C.H.)
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