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Labrecque L, Roy MA, Soleimani Dehnavi S, Taghizadeh M, Smirl JD, Brassard P. Directional sensitivity of the cerebral pressure-flow relationship during forced oscillations induced by oscillatory lower body negative pressure. J Cereb Blood Flow Metab 2024:271678X241247633. [PMID: 38613236 DOI: 10.1177/0271678x241247633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
A directional sensitivity of the cerebral pressure-flow relationship has been described using repeated squat-stands. Oscillatory lower body negative pressure (OLBNP) is a reproducible method to characterize dynamic cerebral autoregulation (dCA). It could represent a safer method to examine the directional sensitivity of the cerebral pressure-flow relationship within clinical populations and/or during pharmaceutical administration. Therefore, examining the cerebral pressure-flow directional sensitivity during an OLBNP-induced cyclic physiological stress is crucial. We calculated changes in middle cerebral artery mean blood velocity (MCAv) per alterations to mean arterial pressure (MAP) to compute ratios adjusted for time intervals (ΔMCAvT/ΔMAPT) with respect to the minimum-to-maximum MCAv and MAP, for each OLBNP transition (0 to -90 Torr), during 0.05 Hz and 0.10 Hz OLBNP. We then compared averaged ΔMCAvT/ΔMAPT during OLBNP-induced MAP increases (INC) (ΔMCAvT/Δ MAP T INC ) and decreases (DEC) (ΔMCAvT/Δ MAP T DEC ). Nineteen healthy participants [9 females; 30 ± 6 years] were included. There were no differences in ΔMCAvT/ΔMAPT between INC and DEC at 0.05 Hz. ΔMCAvT/Δ MAP T INC (1.06 ± 0.35 vs. 1.33 ± 0.60 cm⋅s-1/mmHg; p = 0.0076) was lower than ΔMCAvT/Δ MAP T DEC at 0.10 Hz. These results support OLBNP as a model to evaluate the directional sensitivity of the cerebral pressure-flow relationship.
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Affiliation(s)
- Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Marc-Antoine Roy
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Shahrzad Soleimani Dehnavi
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Mahmoudreza Taghizadeh
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Jonathan D Smirl
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Canada
- Concussion Research Laboratory, Faculty of Health and Exercise Science, University of British Columbia, Kelowna, BC, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Canada
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
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Bari V, Gelpi F, Cairo B, Anguissola M, Pugliese S, De Maria B, Ranucci M, Porta A. Link Between Cardiovascular and Cerebrovascular Controls in Patients Undergoing Surgical Aortic Valve Replacement. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082726 DOI: 10.1109/embc40787.2023.10340133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Although the autonomic influence on cardiovascular (CV) and cerebrovascular (CBV) regulations has been widely recognized, their relationship is poorly explored especially in pathological situations. This study investigates the correlation between CV and CBV markers in 73 patients (48 males, age 63.6±13.1 yrs) undergoing surgical aortic valve replacement (SAVR) evaluated before the intervention (PRE), within 1-week post-surgery (POST) and after a 3-month follow-up (POST3). Patients were acquired before and after an orthostatic challenge. Frequency domain analysis assessing transfer function gain (TFG), phase (Ph), and squared coherence (K2) between heart period and systolic arterial pressure was exploited to evaluate CV control. The same frequency domain functions were derived to assess CBV regulation from mean cerebral blood velocity and mean arterial pressure. A correlation analysis between indexes of CV and CBV controls was carried out. Results showed that CV control was impaired in PRE, worsened in POST, and recovered in POST3, while CBV markers were almost unchanged. A significant positive relationship between CV and CBV markers was observed, especially in POST and POST3, thus suggesting that the compensation of a baroreflex impairment with a more efficient CBV control and vice versa. The maintenance of this relationship between CV and CBV controls in patients undergoing SAVR could be fundamental to prevent risky situations.Clinical Relevance- After surgical aortic valve replacement an impaired baroreflex control could be compensated by a more efficient cerebral autoregulation.
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Dumančić D, Stupin A, Kožul M, Šerić V, Kibel A, Goswami N, Brix B, Debeljak Ž, Scitovski R, Drenjančević I. Increased cerebral vascular resistance underlies preserved cerebral blood flow in response to orthostasis in humans on a high-salt diet. Eur J Appl Physiol 2023; 123:923-933. [PMID: 36598577 DOI: 10.1007/s00421-022-05124-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/20/2022] [Indexed: 01/05/2023]
Abstract
Cerebral blood flow autoregulation protects brain tissue from blood pressure variations and maintains cerebral perfusion pressure by changes in vascular resistance. High salt (HS) diet impairs endothelium-dependent vasodilation in many vascular beds, including cerebral microcirculation, and may affect vascular resistance. The aim of present study was to determine if 7-day HS diet affected the reactivity of middle cerebral artery (MCA) to orthostatic challenge in healthy human individuals, and if autoregulatory mechanisms and sympathetic neural regulation were involved in this phenomenon.Twenty-seven persons participated in study (F:21, M:6, age range 19-24). Participants consumed 7-day low-salt (LS) diet (< 2.3 g kitchen salt/day) and afterwards 7-day HS diet (> 11.2 g kitchen salt/day). Blood and urine analysis and anthropometric measurements were performed after each diet. Arterial blood pressure, heart rate and heart rate variability, and cerebral and systemic hemodynamic parameters were recorded simultaneously with transcranial Doppler ultrasound and The Task Force® Monitor in response to orthostatic test.Participants remained normotensive during HS diet. Following both, the LS and HS dietary protocols, mean cerebral blood flow (CBF), as well as the velocity time integral and diastolic blood pressure decreased, and cerebral pulsatility index increased after rising up. Importantly, cerebrovascular resistance significantly increased in response to orthostasis only after HS diet. Urine concentration of noradrenaline and vanillylmandelic acid, baroreflex sensitivity (BRS), and sympathetic neural control was significantly decreased in HS diet.Results suggest that CBF in response to orthostatic test was preserved in HS condition due to altered vascular reactivity of MCA, with increased cerebrovascular resistance and blunted BRS and sympathetic activity.
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Affiliation(s)
- Dijana Dumančić
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
- Department of Diagnostic and Interventional Radiology, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Ana Stupin
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Maja Kožul
- Department of Dermatology and Venereology, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Vatroslav Šerić
- Department of Clinical Laboratory Diagnostics, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Aleksandar Kibel
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
- Department of Heart and Vascular Diseases, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Nandu Goswami
- Physiology Division, Otto Loewi Research Center, Medical University of Graz, Auenbruggerplatz 2, 8036, Graz, Austria
| | - Bianca Brix
- Physiology Division, Otto Loewi Research Center, Medical University of Graz, Auenbruggerplatz 2, 8036, Graz, Austria
| | - Željko Debeljak
- Department of Clinical Laboratory Diagnostics, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
- Department of Pharmacology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Rudolf Scitovski
- Department of Mathematics, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Ines Drenjančević
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia.
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Cerebral blood flow response to cardiorespiratory oscillations in healthy humans. Auton Neurosci 2023; 245:103069. [PMID: 36584666 DOI: 10.1016/j.autneu.2022.103069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Dynamic cerebral autoregulation (CA) characterizes the cerebral blood flow (CBF) response to abrupt changes in arterial blood pressure (ABP). CA operates at frequencies below 0.15 Hz. ABP regulation and probably CA are modified by autonomic nervous activity. We investigated the CBF response and CA dynamics to mild increase in sympathetic activity. Twelve healthy volunteers underwent oscillatory lower body negative pressure (oLBNP), which induced respiratory-related ABP oscillations at an average of 0.22 Hz. We recorded blood velocity in the internal carotid artery (ICA) by Doppler ultrasound and ABP. We quantified variability and peak wavelet power of ABP and ICA blood velocity by wavelet analysis at low frequency (LF, 0.05-0.15 Hz) and Mayer waves (0.08-0.12 Hz), respectively. CA was quantified by calculation of the wavelet synchronization gamma index for the pair ABP-ICA blood velocity in the LF and Mayer wave band. oLBNP increased ABP peak wavelet power at the Mayer wave frequency. At the Mayer wave, ABP peak wavelet power increased by >70 % from rest to oLBNP (p < 0.05), while ICA blood flow velocity peak wavelet power was unchanged, and gamma index increased (from 0.49 to 0.69, p < 0.05). At LF, variability in both ABP and ICA blood velocity and gamma index were unchanged from rest to oLBNP. Despite an increased gamma index at Mayer wave, ICA blood flow variability was unchanged during increased ABP variability. The increased synchronization during oLBNP did not cause less stable CBF or less active CA. Sympathetic activation seems to improve the mechanisms of CA.
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Mankoo A, Roy S, Davies A, Panerai RB, Robinson TG, Brassard P, Beishon LC, Minhas JS. The role of the autonomic nervous system in cerebral blood flow regulation in stroke: A review. Auton Neurosci 2023; 246:103082. [PMID: 36870192 DOI: 10.1016/j.autneu.2023.103082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 11/22/2022] [Accepted: 02/22/2023] [Indexed: 03/02/2023]
Abstract
Stroke is a pathophysiological condition which results in alterations in cerebral blood flow (CBF). The mechanism by which the brain maintains adequate CBF in presence of fluctuating cerebral perfusion pressure (CPP) is known as cerebral autoregulation (CA). Disturbances in CA may be influenced by a number of physiological pathways including the autonomic nervous system (ANS). The cerebrovascular system is innervated by adrenergic and cholinergic nerve fibers. The role of the ANS in regulating CBF is widely disputed owing to several factors including the complexity of the ANS and cerebrovascular interactions, limitations to measurements, variation in methods to assess the ANS in relation to CBF as well as experimental approaches that can or cannot provide insight into the sympathetic control of CBF. CA is known to be impaired in stroke however the number of studies investigating the mechanisms by which this occurs are limited. This literature review will focus on highlighting the assessment of the ANS and CBF via indices derived from the analyses of heart rate variability (HRV), and baroreflex sensitivity (BRS), and providing a summary of both clinical and animal model studies investigating the role of the ANS in influencing CA in stroke. Understanding the mechanisms by which the ANS influences CBF in stroke patients may provide the foundation for novel therapeutic approaches to improve functional outcomes in stroke patients.
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Affiliation(s)
- Alex Mankoo
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom
| | - Sankanika Roy
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom.
| | - Aaron Davies
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom
| | - Ronney B Panerai
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Thompson G Robinson
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, QC, Canada; Research center of the Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval, Québec, QC, Canada
| | - Lucy C Beishon
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom
| | - Jatinder S Minhas
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
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Rosenberg AJ, Kay VL, Anderson GK, Luu ML, Barnes HJ, Sprick JD, Alvarado HB, Rickards CA. The reciprocal relationship between cardiac baroreceptor sensitivity and cerebral autoregulation during simulated hemorrhage in humans. Auton Neurosci 2022; 241:103007. [PMID: 35716525 PMCID: PMC10424721 DOI: 10.1016/j.autneu.2022.103007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 04/07/2022] [Accepted: 06/09/2022] [Indexed: 11/16/2022]
Abstract
A reciprocal relationship between the baroreflex and cerebral autoregulation (CA) has been demonstrated at rest and in response to acute hypotension. We hypothesized that the reciprocal relationship between cardiac baroreflex sensitivity (BRS) and CA would be maintained during sustained central hypovolemia induced by lower body negative pressure (LBNP), and that the strength of this relationship would be greater in subjects with higher tolerance to this stress. Healthy young adults (n = 51; 23F/28M) completed a LBNP protocol to presyncope. Subjects were classified as high tolerant (HT; completion of -60 mmHg LBNP stage, ≥20-min) or low tolerant (LT; did not complete -60 mmHg LBNP stage, <20-min). R-R intervals (RRI), systolic arterial pressure (SAP), mean arterial pressure (MAP), and middle cerebral artery velocity (MCAv) were measured continuously. Cardiac BRS was calculated in the time domain (ΔHR/ΔSAP) and frequency domain (RRI-SAP low frequency (LF) transfer function gain), and CA was calculated in the time domain (ΔMCAv/ΔMAP) and frequency domain (MAP-mean MCAv LF transfer function gain). There was a moderate relationship between cardiac BRS and CA for the group of 51 subjects in both the time (R = -0.54, P < 0.0001) and frequency (R = 0.61, P < 0.001) domains; there was a stronger relationship in the HT group (R = 0.73) compared to the LT group (R = 0.31) in the frequency domain (P = 0.08), but no difference between groups in the time domain (HT: R = -0.73 vs. LT: R = -0.63; P = 0.27). These findings suggest that an interaction between BRS and CA may be an important compensatory mechanism that contributes to tolerance to simulated hemorrhage in young healthy adults.
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Affiliation(s)
- Alexander J Rosenberg
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA; Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, IL, USA; Physiology Department, Midwestern University, IL, USA
| | - Victoria L Kay
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Garen K Anderson
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - My-Loan Luu
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Haley J Barnes
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Justin D Sprick
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA; Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Hannah B Alvarado
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA; Department of Family Medicine, Mayo Clinic, Jacksonville, FL, USA
| | - Caroline A Rickards
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA.
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Sirant LW, Singh J, Martin S, Gaul CA, Stuart-Hill L, Candow DG, Mang C, Neary JP. Long-term effects of multiple concussions on prefrontal cortex oxygenation during repeated squat-stands in retired contact sport athletes. Brain Inj 2022; 36:931-938. [PMID: 35968581 DOI: 10.1080/02699052.2022.2109737] [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: 11/02/2022]
Abstract
BACKGROUND This study investigated the long-term effects of multiple concussions on prefrontal cortex oxygenation using near-infrared spectroscopy (NIRS) during a squat-stand maneuver that activated dynamic cerebral autoregulation. METHODS Active male retired contact sport athletes with a history of 3+ concussions (mTBI; n = 55), and active retired athletes with no concussion history (CTRL; n = 29) were recruited. Participants completed a 5-min squat-stand maneuve (10-s squat, 10-s stand, 0.05 Hz; 15 times). Oxygenated (O2Hb), deoxygenated (HHb), total (tHb) hemoglobin, and hemoglobin difference (HbDiff) were analyzed through the change in maximal and minimal values during the test (∆MAX), Z-scores, and standard deviations. RESULTS mTBI group showed left prefrontal cortex O2Hb ∆MAX (p = 0.046) and HbDiff ∆MAX (p = 0.018) were significantly higher. Within-group analyses showed significantly higher left HHb ∆MAX (p = 0.003) and lower left HbDiff Z-scores (p = 0.010) only in the mTBI group. The CTRL group demonstrated significantly lower left HbDiff SD (p = 0.039), tHb Z-scores (p = 0.030), and HbDiff ∆MAX (p = 0.037) compared to right prefrontal cortex response. CONCLUSION These preliminary results suggest changes in prefrontal cortex oxygenation potentially affecting the brain's ability to adapt to changing cerebral perfusion pressure after multiple previous concussions.
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Affiliation(s)
- Luke W Sirant
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada
| | - Jyotpal Singh
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada
| | - Steve Martin
- School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
| | - Catherine A Gaul
- School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
| | - Lynneth Stuart-Hill
- School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
| | - Darren G Candow
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada
| | - Cameron Mang
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada
| | - J Patrick Neary
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada
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Pereira TJ, Wasef S, Ivry I, Assadpour E, Adeyinka B, Edgell H. Menstrual cycle and oral contraceptives influence cerebrovascular dynamics during hypercapnia. Physiol Rep 2022; 10:e15373. [PMID: 35822289 PMCID: PMC9277257 DOI: 10.14814/phy2.15373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023] Open
Abstract
Women experience fluctuating orthostatic intolerance during the menstrual cycle, suggesting sex hormones may influence cerebral blood flow. Young (aged 18-30) healthy women, either taking oral contraceptives (OC; n = 14) or not taking OC (NOC; n = 12), were administered hypercapnic gas (5%) for 5 min in the low hormone (LH; placebo pill) and high hormone (HH; active pill) menstrual phases. Hemodynamic and cerebrovascular variables were continuously measured. Cerebral blood velocity changes were monitored using transcranial doppler ultrasound of the middle cerebral artery to determine cerebrovascular reactivity. Cerebral autoregulation was assessed using steady-state analysis (static cerebral autoregulation) and transfer function analysis (dynamic cerebral autoregulation; dCA). In response to hypercapnia, menstrual phase did not influence static cardiovascular or cerebrovascular responses (all p > 0.07); however, OC users had a greater increase of mean middle cerebral artery blood velocity compared to NOC (NOC-LH 12 ± 6 cm/s vs. NOC-HH 16 ± 9 cm/s; OC-LH 18 ± 5 cm/s vs. OC-HH 17 ± 11 cm/s; p = 0.048). In all women, hypercapnia improved high frequency (HF) and very low frequency (VLF) cerebral autoregulation (decreased nGain; p = 0.002 and <0.001, respectively), whereas low frequency (LF) Phase decreased in NOC-HH (p = 0.001) and OC-LH (p = 0.004). Therefore, endogenous sex hormones reduce LF dCA during hypercapnia in the HH menstrual phase. In contrast, pharmaceutical sex hormones (OC use) have no acute influence (HH menstrual phase) yet elicit a chronic attenuation of LF dCA (LH menstrual phase) during hypercapnia.
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Affiliation(s)
- Tania J. Pereira
- School of Kinesiology and Health ScienceYork UniversityTorontoOntarioCanada
| | - Sara Wasef
- School of Kinesiology and Health ScienceYork UniversityTorontoOntarioCanada
| | - Ilana Ivry
- School of Kinesiology and Health ScienceYork UniversityTorontoOntarioCanada
| | - Elnaz Assadpour
- School of Kinesiology and Health ScienceYork UniversityTorontoOntarioCanada
| | | | - Heather Edgell
- School of Kinesiology and Health ScienceYork UniversityTorontoOntarioCanada
- Muscle Health Research CentreYork UniversityTorontoOntarioCanada
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Sympathovagal imbalance in early ischemic stroke is linked to impaired cerebral autoregulation and increased infarct volumes. Auton Neurosci 2022; 241:102986. [DOI: 10.1016/j.autneu.2022.102986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 03/23/2022] [Accepted: 04/28/2022] [Indexed: 11/24/2022]
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Maxwell JD, Bannell DJ, Brislane A, Carter SE, Miller GD, Roberts KA, Hopkins ND, Low DA, Carter HH, Thompson A, Claassen JAHR, Thijssen DHJ, Jones H. The impact of age, sex, cardio-respiratory fitness, and cardiovascular disease risk on dynamic cerebral autoregulation and baroreflex sensitivity. Eur J Appl Physiol 2022; 122:1531-1541. [PMID: 35429292 PMCID: PMC9132800 DOI: 10.1007/s00421-022-04933-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/08/2022] [Indexed: 11/10/2022]
Abstract
Background Humans display an age-related decline in cerebral blood flow and increase in blood pressure (BP), but changes in the underlying control mechanisms across the lifespan are less well understood. We aimed to; (1) examine the impact of age, sex, cardiovascular disease (CVD) risk, and cardio-respiratory fitness on dynamic cerebral autoregulation and cardiac baroreflex sensitivity, and (2) explore the relationships between dynamic cerebral autoregulation (dCA) and cardiac baroreflex sensitivity (cBRS). Methods 206 participants aged 18–70 years were stratified into age categories. Cerebral blood flow velocity was measured using transcranial Doppler ultrasound. Repeated squat-stand manoeuvres were performed (0.10 Hz), and transfer function analysis was used to assess dCA and cBRS. Multivariable linear regression was used to examine the influence of age, sex, CVD risk, and cardio-respiratory fitness on dCA and cBRS. Linear models determined the relationship between dCA and cBRS. Results Age, sex, CVD risk, and cardio-respiratory fitness did not impact dCA normalised gain, phase, or coherence with minimal change in all models (P > 0.05). cBRS gain was attenuated with age when adjusted for sex and CVD risk (young–older; β = − 2.86 P < 0.001) along with cBRS phase (young–older; β = − 0.44, P < 0.001). There was no correlation between dCA normalised gain and phase with either parameter of cBRS. Conclusion Ageing was associated with a decreased cBRS, but dCA appears to remain unchanged. Additionally, our data suggest that sex, CVD risk, and cardio-respiratory fitness have little effect.
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Mol A, Claassen JAHR, Maier AB, van Wezel RJA, Meskers CGM. Determinants of orthostatic cerebral oxygenation assessed using near-infrared spectroscopy. Auton Neurosci 2022; 238:102942. [PMID: 35124323 DOI: 10.1016/j.autneu.2022.102942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/18/2021] [Accepted: 01/16/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND To understand the relationship between blood pressure changes during standing up and clinical outcome, cerebral oxygenation needs to be measured, which may be performed using near-infrared spectroscopy (NIRS). However, the role of potential determinants of NIRS-derived orthostatic cerebral oxygenation, i.e., age, sex, type of postural change (i.e., standing up from sitting versus supine position), blood pressure (BP) and baroreflex sensitivity (BRS) is still unknown and needed to better interpret findings from studies using orthostatic NIRS measurements. METHODS 34 younger (median age 25 years, inter quartile range (IQR) 22-45) and 31 older adults (median age 77 years, IQR 72-81) underwent BP, BRS and NIRS measurements during standing up from sitting and supine position. Linear regression models were used to assess the potential determinant role of age, sex, type of postural change, BP and BRS in orthostatic cerebral oxygenation drop and recovery. Orthostatic cerebral oxygenation test-retest reliability was assessed using intra class correlations. RESULTS Younger age, male sex and standing up from supine compared to sitting position were positively associated with cerebral oxygenation drop; older age and standing up from sitting compared to supine position were associated with higher cerebral oxygenation recovery. Test-retest reliability was highest (ICC > 0.83) during standing up from supine position. CONCLUSION Based on the findings of this study, age, sex and type of postural change are significant determinants of NIRS-derived orthostatic cerebral oxygenation and should be taken into account in the interpretation of NIRS measurements. In the design of new studies, standing up from supine position is preferable (higher reliability) over standing up from sitting position.
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Affiliation(s)
- Arjen Mol
- Department of Human Movement Sciences, @AgeAmsterdam, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorstraat 9, 1081 BT Amsterdam, the Netherlands; Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
| | - Jurgen A H R Claassen
- Department of Geriatric Medicine, Radboud University Medical Center, Reinier Postlaan 4, 6525 GC Nijmegen, the Netherlands
| | - Andrea B Maier
- Department of Human Movement Sciences, @AgeAmsterdam, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorstraat 9, 1081 BT Amsterdam, the Netherlands; Department of Medicine and Aged Care, @AgeMelbourne, The University of Melbourne, The Royal Melbourne Hospital, City Campus, Level 6 North, 300 Grattan Street, Parkville, Victoria 3050, Australia; Yong Loo Lin School of Medicine, National University of Singapore, Centre for Healthy Longevity, National University Health System, 10 Medical Dr, Singapore 117597, Singapore
| | - Richard J A van Wezel
- Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen, the Netherlands; Department of Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Zuidhorst Building, P.O. Box 217, 7500 AE Enschede, the Netherlands
| | - Carel G M Meskers
- Department of Rehabilitation Medicine, Amsterdam UMC, Vrije Universiteit, Amsterdam Movement Sciences, P.O. Box 7057, 1007 MB Amsterdam, the Netherlands
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12
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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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13
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Llwyd O, Fan JL, Müller M. Effect of drug interventions on cerebral hemodynamics in ischemic stroke patients. J Cereb Blood Flow Metab 2022; 42:471-485. [PMID: 34738511 PMCID: PMC8985436 DOI: 10.1177/0271678x211058261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The ischemic penumbra is sensitive to alterations in cerebral perfusion. A myriad of drugs are used in acute ischemic stroke (AIS) management, yet their impact on cerebral hemodynamics is poorly understood. As part of the Cerebral Autoregulation Network led INFOMATAS project (Identifying New Targets for Management and Therapy in Acute Stroke), this paper reviews some of the most common drugs a patient with AIS will come across and their potential influence on cerebral hemodynamics with a particular focus being on cerebral autoregulation (CA). We first discuss how compounds that promote clot lysis and prevent clot formation could potentially impact cerebral hemodynamics, before focusing on how the different classes of antihypertensive drugs can influence cerebral hemodynamics. We discuss the different properties of each drug and their potential impact on cerebral perfusion and CA. With emerging interest in CA status of AIS patients, either during or soon after treatment when timely reperfusion and salvageable tissue is at its most critical, the properties of these pharmacological agents may be relevant for modelling cerebral perfusion accuracy and for setting individualised treatment strategies.
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Affiliation(s)
- Osian Llwyd
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, UK
| | - Jui-Lin Fan
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - Martin Müller
- Neurozentrum, Klinik für Neurologie und Neurorehabilitation, Luzerner Kantonsspital, Spitalstrasse, Luzern, Switzerland
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14
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Uryga A, Nasr N, Kasprowicz M, Budohoski K, Sykora M, Smielewski P, Burzyńska M, Czosnyka M. Relationship Between Baroreflex and Cerebral Autoregulation in Patients With Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage. Front Neurol 2022; 12:740338. [PMID: 35095711 PMCID: PMC8790510 DOI: 10.3389/fneur.2021.740338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 12/02/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Common consequences following aneurysmal subarachnoid hemorrhage (aSAH) are cerebral vasospasm (CV), impaired cerebral autoregulation (CA), and disturbance in the autonomic nervous system, as indicated by lower baroreflex sensitivity (BRS). The compensatory interaction between BRS and CA has been shown in healthy volunteers and stable pathological conditions such as carotid atherosclerosis. The aim of this study was to investigate whether the inverse correlation between BRS and CA would be lost in patients after aSAH during vasospasm. A secondary objective was to analyze the time-trend of BRS after aSAH. Materials and Methods: Retrospective analysis of prospectively collected data was performed at the Neuro-Critical Care Unit of Addenbrooke's Hospital (Cambridge, UK) between June 2010 and January 2012. The cerebral blood flow velocity (CBFV) was measured in the middle cerebral artery using transcranial Doppler ultrasonography (TCD). The arterial blood pressure (ABP) was monitored invasively through an arterial line. CA was quantified by the correlation coefficient (Mxa) between slow oscillations in ABP and CBFV. BRS was calculated using the sequential cross-correlation method using the ABP signal. Results: A total of 73 patients with aSAH were included. The age [median (lower-upper quartile)] was 58 (50–67). WFNS scale was 2 (1–4) and the modified Fisher scale was 3 (1–3). In the total group, 31 patients (42%) had a CV and 42 (58%) had no CV. ABP and CBFV were higher in patients with CV during vasospasm compared to patients without CV (p = 0.001 and p < 0.001). There was no significant correlation between Mxa and BRS in patients with CV, neither during nor before vasospasm. In patients without CV, a significant, although moderate correlation was found between BRS and Mxa (rS = 0.31; p = 0.040), with higher BRS being associated with worse CA. Multiple linear regression analysis showed a significant worsening of BRS after aSAH in patients with CV (Rp = −0.42; p < 0.001). Conclusions: Inverse compensatory correlation between BRS and CA was lost in patients who developed CV after aSAH, both before and during vasospasm. The impact of these findings on the prognosis of aSAH should be investigated in larger studies.
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Affiliation(s)
- Agnieszka Uryga
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wrocław, Poland
| | - Nathalie Nasr
- INSERM UMR 1297, Institute of Cardiovascular and Metabolic Diseases (I2MC), Toulouse, France.,Department of Neurology, Toulouse University Hospital, Toulouse, France
| | - Magdalena Kasprowicz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wrocław, Poland
| | - Karol Budohoski
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Marek Sykora
- Department of Neurology, St. John's Hospital, Vienna, Austria.,Medical Faculty, Sigmund Freud University, Vienna, Austria
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Małgorzata Burzyńska
- Department of Anaesthesiology and Intensive Care, Wroclaw Medical University, Wrocław, Poland
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
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15
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Tomoto T, Repshas J, Zhang R, Tarumi T. Midlife aerobic exercise and dynamic cerebral autoregulation: associations with baroreflex sensitivity and central arterial stiffness. J Appl Physiol (1985) 2021; 131:1599-1612. [PMID: 34647828 PMCID: PMC8616602 DOI: 10.1152/japplphysiol.00243.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 10/04/2021] [Accepted: 10/11/2021] [Indexed: 12/20/2022] Open
Abstract
Midlife aerobic exercise may significantly impact age-related changes in the cerebro- and cardiovascular regulations. This study investigated the associations of midlife aerobic exercise with dynamic cerebral autoregulation (dCA), cardiovagal baroreflex sensitivity (BRS), and central arterial stiffness. Twenty middle-aged athletes (MA) who had aerobic training for >10 yr were compared with 20 young (YS) and 20 middle-aged sedentary (MS) adults. Beat-to-beat cerebral blood flow velocity, blood pressure (BP), and heart rate were measured at rest and during forced BP oscillations induced by repeated sit-stand maneuvers at 0.05 Hz. Transfer function analysis was used to calculate dCA and BRS parameters. Carotid distensibility was measured by ultrasonography. MA had the highest peak oxygen uptake (V̇o2peak) among all groups. During forced BP oscillations, MS showed lower BRS gain than YS, but this age-related reduction was absent in MA. Conversely, dCA was similar among all groups. At rest, BRS and dCA gains at low frequency (∼0.1 Hz) were higher in the MA than in MS and YS groups. Carotid distensibility was similar between MA and YS groups, but it was lower in the MS. Across all subjects, V̇o2peak was positively associated with BRS gains at rest and during forced BP oscillations (r = 0.257∼0.382, P = 0.003∼0.050) and carotid distensibility (r = 0.428∼0.490, P = 0.001). Furthermore, dCA gain at rest and carotid distensibility were positively correlated with BRS gain at rest in YS and MA groups (all P < 0.05). These findings suggest that midlife aerobic exercise improves central arterial elasticity and BRS, which may contribute to cerebral blood flow (CBF) regulation through dCA.NEW & NOTEWORTHY Middle-aged athletes (MA) showed intact dynamic cerebral autoregulation (dCA) during sit-stand maneuvers when compared with young (YS) and middle-aged sedentary (MS) adults. Conversely, MA showed the significant attenuation of age-related carotid distensibility and baroreflex sensitivity (BRS) impairments. In MA and YS groups, BRS was positively associated with dCA gain at rest and carotid distensibility. Our findings suggest that midlife aerobic exercise improves BRS by reducing central arterial stiffness, which contributes to CBF regulation through dCA.
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Affiliation(s)
- Tsubasa Tomoto
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Justin Repshas
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Takashi Tarumi
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
- Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
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16
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Claassen JAHR, Thijssen DHJ, Panerai RB, Faraci FM. Regulation of cerebral blood flow in humans: physiology and clinical implications of autoregulation. Physiol Rev 2021; 101:1487-1559. [PMID: 33769101 PMCID: PMC8576366 DOI: 10.1152/physrev.00022.2020] [Citation(s) in RCA: 295] [Impact Index Per Article: 98.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Brain function critically depends on a close matching between metabolic demands, appropriate delivery of oxygen and nutrients, and removal of cellular waste. This matching requires continuous regulation of cerebral blood flow (CBF), which can be categorized into four broad topics: 1) autoregulation, which describes the response of the cerebrovasculature to changes in perfusion pressure; 2) vascular reactivity to vasoactive stimuli [including carbon dioxide (CO2)]; 3) neurovascular coupling (NVC), i.e., the CBF response to local changes in neural activity (often standardized cognitive stimuli in humans); and 4) endothelium-dependent responses. This review focuses primarily on autoregulation and its clinical implications. To place autoregulation in a more precise context, and to better understand integrated approaches in the cerebral circulation, we also briefly address reactivity to CO2 and NVC. In addition to our focus on effects of perfusion pressure (or blood pressure), we describe the impact of select stimuli on regulation of CBF (i.e., arterial blood gases, cerebral metabolism, neural mechanisms, and specific vascular cells), the interrelationships between these stimuli, and implications for regulation of CBF at the level of large arteries and the microcirculation. We review clinical implications of autoregulation in aging, hypertension, stroke, mild cognitive impairment, anesthesia, and dementias. Finally, we discuss autoregulation in the context of common daily physiological challenges, including changes in posture (e.g., orthostatic hypotension, syncope) and physical activity.
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Affiliation(s)
- Jurgen A H R Claassen
- Department of Geriatrics, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, The Netherlands
| | - Dick H J Thijssen
- Department of Physiology, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- >National Institute for Health Research Leicester Biomedical Research Centre, University of Leicester, Leicester, United Kingdom
| | - Frank M Faraci
- Departments of Internal Medicine, Neuroscience, and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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17
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Abstract
BACKGROUND Circulatory shock is a life-threatening disorder that is associated with high mortality, with a state of systemic and tissue hypoperfusion that can lead to organ failure, including the brain, where altered mental state is often observed. We hypothesized that cerebral autoregulation (CA) is impaired in patients with circulatory shock. METHODS Adult patients with circulatory shock and healthy controls were included. Cerebral blood flow velocity (CBFV, transcranial Doppler ultrasound) and arterial blood pressure (BP, Finometer or intra-arterial line) were continuously recorded during 5 min in both groups. Autoregulation Index (ARI) was estimated from the CBFV response to a step change in BP, derived by transfer function analysis; ARI ≤ 4 was considered impaired CA. The relationship between organ dysfunction, assessed with the Sequential Organ Failure Assessment (SOFA) score and the ARI, was assessed with linear regression. RESULTS Twenty-five shock patients and 28 age-matched healthy volunteers were studied. The mean ± SD SOFA score was 10.8 ± 4.3. Shock patients compared with control subjects had lower ARI values (4.0 ± 2.1 vs. 5.9 ± 1.5, P = 0.001). Impaired CA was more common in shock patients (44.4% vs. 7.1%, P = 0.003). There was a significant inverse relationship between the ARI and the SOFA score (R = -0.63, P = 0.0008). CONCLUSIONS These results suggest that circulatory shock is often associated with impaired CA and that the severity of CA alterations is correlated with the degree of multiple organ failure, reinforcing the need to monitor cerebral hemodynamics in patients with circulatory shock.
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18
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Rosenberg AJ, Kay VL, Anderson GK, Luu ML, Barnes HJ, Sprick JD, Rickards CA. The impact of acute central hypovolemia on cerebral hemodynamics: does sex matter? J Appl Physiol (1985) 2021; 130:1786-1797. [PMID: 33914663 DOI: 10.1152/japplphysiol.00499.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Trauma-induced hemorrhage is a leading cause of disability and death due, in part, to impaired perfusion and oxygenation of the brain. It is unknown if cerebrovascular responses to blood loss are differentiated based on sex. We hypothesized that compared to males, females would have reduced tolerance to simulated hemorrhage induced by maximal lower body negative pressure (LBNP), and this would be associated with an earlier reduction in cerebral blood flow and cerebral oxygenation. Healthy young males (n = 29, 26 ± 4 yr) and females (n = 23, 27 ± 5 yr) completed a step-wise LBNP protocol to presyncope. Mean arterial pressure (MAP), stroke volume (SV), middle cerebral artery velocity (MCAv), end-tidal CO2 (etCO2), and cerebral oxygen saturation (ScO2) were measured continuously. Unexpectedly, tolerance to LBNP was similar between the sexes (males, 1,604 ± 68 s vs. females, 1,453 ± 78 s; P = 0.15). Accordingly, decreases (%Δ) in MAP, SV, MCAv, and ScO2 were similar between males and females throughout LBNP and at presyncope (P ≥ 0.20). Interestingly, although decreases in etCO2 were similar between the sexes throughout LBNP (P = 0.16), at presyncope, the %Δ etCO2 from baseline was greater in males compared to females (-30.8 ± 2.6% vs. -21.3 ± 3.0%; P = 0.02). Contrary to our hypothesis, sex does not influence tolerance, or the central or cerebral hemodynamic responses to simulated hemorrhage. However, the etCO2 responses at presyncope do suggest potential sex differences in cerebral vascular sensitivity to CO2 during central hypovolemia.NEW & NOTEWORTHY Tolerance and cerebral blood velocity responses to simulated hemorrhage (elicited by lower body negative pressure) were similar between male and female subjects. Interestingly, the change in etCO2 from baseline was greater in males compared to females at presyncope, suggesting potential sex differences in cerebral vascular sensitivity to CO2 during simulated hemorrhage. These findings may facilitate development of individualized therapeutic interventions to improve survival from hemorrhagic injuries in both men and women.
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Affiliation(s)
- Alexander J Rosenberg
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas.,Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Illinois
| | - Victoria L Kay
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Garen K Anderson
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - My-Loan Luu
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Haley J Barnes
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Justin D Sprick
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas.,Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Caroline A Rickards
- Cerebral and Cardiovascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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19
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Cerritelli F, Chiacchiaretta P, Gambi F, Saggini R, Perrucci MG, Ferretti A. Osteopathy modulates brain-heart interaction in chronic pain patients: an ASL study. Sci Rep 2021; 11:4556. [PMID: 33633195 PMCID: PMC7907192 DOI: 10.1038/s41598-021-83893-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 02/09/2021] [Indexed: 01/31/2023] Open
Abstract
In this study we used a combination of measures including regional cerebral blood flow (rCBF) and heart rate variability (HRV) to investigate brain-heart correlates of longitudinal baseline changes of chronic low back pain (cLBP) after osteopathic manipulative treatment (OMT). Thirty-two right-handed patients were randomised and divided into 4 weekly session of OMT (N = 16) or Sham (N = 16). Participants aged 42.3 ± 7.3 (M/F: 20/12) with cLBP (duration: 14.6 ± 8.0 m). At the end of the study, patients receiving OMT showed decreased baseline rCBF within several regions belonging to the pain matrix (left posterior insula, left anterior cingulate cortex, left thalamus), sensory regions (left superior parietal lobe), middle frontal lobe and left cuneus. Conversely, rCBF was increased in right anterior insula, bilateral striatum, left posterior cingulate cortex, right prefrontal cortex, left cerebellum and right ventroposterior lateral thalamus in the OMT group as compared with Sham. OMT showed a statistically significant negative correlation between baseline High Frequency HRV changes and rCBF changes at T2 in the left posterior insula and bilateral lentiform nucleus. The same brain regions showed a positive correlation between rCBF changes and Low Frequency HRV baseline changes at T2. These findings suggest that OMT can play a significant role in regulating brain-heart interaction mechanisms.
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Affiliation(s)
- Francesco Cerritelli
- grid.412451.70000 0001 2181 4941Department of Neuroscience, Imaging and Clinical Sciences, “G. D’Annunzio” University of Chieti-Pescara, Via dei Vestini, 33, Chieti Scalo, Italy ,Clinical-Based Human Research Department, Foundation C.O.ME. Collaboration, Pescara, Italy
| | - Piero Chiacchiaretta
- grid.412451.70000 0001 2181 4941Department of Neuroscience, Imaging and Clinical Sciences, “G. D’Annunzio” University of Chieti-Pescara, Via dei Vestini, 33, Chieti Scalo, Italy ,grid.412451.70000 0001 2181 4941ITAB-Institute for Advanced Biomedical Technologies, “G. D’Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Francesco Gambi
- grid.412451.70000 0001 2181 4941Department of Neuroscience, Imaging and Clinical Sciences, “G. D’Annunzio” University of Chieti-Pescara, Via dei Vestini, 33, Chieti Scalo, Italy ,grid.412451.70000 0001 2181 4941ITAB-Institute for Advanced Biomedical Technologies, “G. D’Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Raoul Saggini
- grid.412451.70000 0001 2181 4941School of Specialty in Physical and Rehabilitation Medicine, “G. D’Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Mauro Gianni Perrucci
- grid.412451.70000 0001 2181 4941Department of Neuroscience, Imaging and Clinical Sciences, “G. D’Annunzio” University of Chieti-Pescara, Via dei Vestini, 33, Chieti Scalo, Italy ,grid.412451.70000 0001 2181 4941ITAB-Institute for Advanced Biomedical Technologies, “G. D’Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Antonio Ferretti
- grid.412451.70000 0001 2181 4941Department of Neuroscience, Imaging and Clinical Sciences, “G. D’Annunzio” University of Chieti-Pescara, Via dei Vestini, 33, Chieti Scalo, Italy ,grid.412451.70000 0001 2181 4941ITAB-Institute for Advanced Biomedical Technologies, “G. D’Annunzio” University of Chieti-Pescara, Chieti, Italy
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20
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Robertson AD, Papadhima I, Edgell H. Sex differences in the autonomic and cerebrovascular responses to upright tilt. Auton Neurosci 2020; 229:102742. [PMID: 33197693 DOI: 10.1016/j.autneu.2020.102742] [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] [Received: 07/15/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 01/11/2023]
Abstract
Sex differences in the regulation of autonomic and cerebrovascular responses to orthostatic stress remain unclear. The objectives of this study were to concurrently investigate autonomic control and cerebrovascular resistance indices, including critical closing pressure (CrCP) and resistance area product (RAP), during upright tilt in men and women. In 13 women and 14 men (18-29 years), ECG, non-invasive blood pressure, middle cerebral artery blood velocity, and end-tidal CO2 (ETCO2) were continuously measured during supine rest and 70° tilt. Heart rate variability (HRV), cardiovagal baroreflex sensitivity (cBRS), and transfer function parameters of dynamic cerebral autoregulation were calculated. Compared to supine, upright tilt increased the low frequency-to-high frequency ratio of HRV in men only (P = 0.044), and decreased cBRS more in women (P = 0.001). Cerebrovascular resistance index (CVRi) increased during tilt only in men (sex-by-time interaction: P = 0.004). RAP was lower in women throughout tilt (main effect of sex: P = 0.022). CrCP decreased during tilt in both sexes (main effect of time: P < 0.001). Normalizing to ETCO2 did not alter the effect of tilt on cerebrovascular resistance. Men displayed a greater increase of sympathetic indices and CVRi during tilt while women had greater parasympathetic withdrawal. We hypothesize that increased sympathetic activity in men may drive sex differences in the cerebrovascular response to upright posture.
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Affiliation(s)
- Andrew D Robertson
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada; Schlegel-UW Research Institute for Aging, University of Waterloo, Waterloo, Ontario, Canada
| | - Ismina Papadhima
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada
| | - Heather Edgell
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada; Muscle Health Research Centre, York University, Toronto, Ontario, Canada.
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21
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Burma JS, Copeland PV, Macaulay A, Khatra O, Smirl JD. Effects of high-intensity intervals and moderate-intensity exercise on baroreceptor sensitivity and heart rate variability during recovery. Appl Physiol Nutr Metab 2020; 45:1156-1164. [DOI: 10.1139/apnm-2019-0810] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Numerous studies have examined heart rate variability (HRV) and cardiac baroreceptor sensitivity (BRS) variables during recovery both acutely (under 3 h) and long-term (24, 48, and 72 h) postexercise. However, there is little literature examining HRV and BRS measures between these timepoints. Spontaneous short-term HRV and cardiac BRS measures were collected in 9 participants before and at zero, 1, 2, 4, 6, and 8 h after 3 separate conditions: moderate-intensity continuous exercise (MICE; 45 min at 50% heart rate reserve), high-intensity interval exercise (HIIE; 25 min including ten 1-min intervals at 85% heart rate reserve), and control (30 min quiet rest). HRV measures in the time domain were only affected immediately following HIIE and MICE at hour zero (all p < 0.043), whereas frequency-domain metrics were unaltered (all p > 0.102). These measures were highly consistent across the control day (all p > 0.420). Cardiac BRS was assessed via low-frequency (LF) gain, and revealed reductions following HIIE at hour zero (p < 0.012). Cardiac BRS LF gain remained consistent following MICE and control interventions (all p > 0.280). The common practice of waiting 12 to 24 h is overly conservative as the current findings demonstrate measures return to baseline at ∼60 min after exercise. Moreover, these metrics demonstrated high levels of within- and between-day reliability. Novelty Previously a 12-h minimum restriction from exercise was required before participation in HRV/BRS studies. Recovery from moderate-intensity exercise for HRV and BRS metrics was <60 min; whereas, high-intensity intervals led to alterations for approximately 60 min. Spontaneous HRV and cardiac BRS demonstrated high levels of within-day reproducibility.
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Affiliation(s)
- Joel S. Burma
- Concussion Research Laboratory, Faculty of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Paige V. Copeland
- Concussion Research Laboratory, Faculty of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
| | - Alannah Macaulay
- Concussion Research Laboratory, Faculty of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
- School of Health Sciences, Nuclear Medicine, British Columbia Institute of Technology, Burnaby, BC V6T 1Z4, Canada
| | - Omeet Khatra
- Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jonathan D. Smirl
- Concussion Research Laboratory, Faculty of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 1N4, Canada
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB T2N 1N4, Canada
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22
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Sprick JD, Nocera JR, Hajjar I, O'Neill WC, Bailey J, Park J. Cerebral blood flow regulation in end-stage kidney disease. Am J Physiol Renal Physiol 2020; 319:F782-F791. [PMID: 32985235 DOI: 10.1152/ajprenal.00438.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD) experience an increased risk of cerebrovascular disease and cognitive dysfunction. Hemodialysis (HD), a major modality of renal replacement therapy in ESKD, can cause rapid changes in blood pressure, osmolality, and acid-base balance that collectively present a unique stress to the cerebral vasculature. This review presents an update regarding cerebral blood flow (CBF) regulation in CKD and ESKD and how the maintenance of cerebral oxygenation may be compromised during HD. Patients with ESKD exhibit decreased cerebral oxygen delivery due to anemia, despite cerebral hyperperfusion at rest. Cerebral oxygenation further declines during HD due to reductions in CBF, and this may induce cerebral ischemia or "stunning." Intradialytic reductions in CBF are driven by decreases in cerebral perfusion pressure that may be partially opposed by bicarbonate shifts during dialysis. Intradialytic reductions in CBF have been related to several variables that are routinely measured in clinical practice including ultrafiltration rate and blood pressure. However, the role of compensatory cerebrovascular regulatory mechanisms during HD remains relatively unexplored. In particular, cerebral autoregulation can oppose reductions in CBF driven by reductions in systemic blood pressure, while cerebrovascular reactivity to CO2 may attenuate intradialytic reductions in CBF through promoting cerebral vasodilation. However, whether these mechanisms are effective in ESKD and during HD remain relatively unexplored. Important areas for future work include investigating potential alterations in cerebrovascular regulation in CKD and ESKD and how key regulatory mechanisms are engaged and integrated during HD to modulate intradialytic declines in CBF.
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Affiliation(s)
- Justin D Sprick
- Division of Renal Medicine, Department of Medicine, Emory University Department of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Joe R Nocera
- Department of Veterans Affairs Health Care System, Decatur, Georgia.,Center for Visual and Neurocognitive Rehabilitation, Department of Veterans Affairs Health Care System, Decatur, Georgia.,Departments of Neurology and Rehabilitation Medicine, Emory University Department of Medicine, Atlanta, Georgia
| | - Ihab Hajjar
- Department of Neurology, Emory University Department of Medicine, Atlanta, Georgia
| | - W Charles O'Neill
- Division of Renal Medicine, Department of Medicine, Emory University Department of Medicine, Atlanta, Georgia
| | - James Bailey
- Division of Renal Medicine, Department of Medicine, Emory University Department of Medicine, Atlanta, Georgia
| | - Jeanie Park
- Division of Renal Medicine, Department of Medicine, Emory University Department of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia.,Center for Visual and Neurocognitive Rehabilitation, Department of Veterans Affairs Health Care System, Decatur, Georgia
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23
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Presa JL, Saravia F, Bagi Z, Filosa JA. Vasculo-Neuronal Coupling and Neurovascular Coupling at the Neurovascular Unit: Impact of Hypertension. Front Physiol 2020; 11:584135. [PMID: 33101063 PMCID: PMC7546852 DOI: 10.3389/fphys.2020.584135] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/04/2020] [Indexed: 12/18/2022] Open
Abstract
Components of the neurovascular unit (NVU) establish dynamic crosstalk that regulates cerebral blood flow and maintain brain homeostasis. Here, we describe accumulating evidence for cellular elements of the NVU contributing to critical physiological processes such as cerebral autoregulation, neurovascular coupling, and vasculo-neuronal coupling. We discuss how alterations in the cellular mechanisms governing NVU homeostasis can lead to pathological changes in which vascular endothelial and smooth muscle cell, pericyte and astrocyte function may play a key role. Because hypertension is a modifiable risk factor for stroke and accelerated cognitive decline in aging, we focus on hypertension-associated changes on cerebral arteriole function and structure, and the molecular mechanisms through which these may contribute to cognitive decline. We gather recent emerging evidence concerning cognitive loss in hypertension and the link with vascular dementia and Alzheimer’s disease. Collectively, we summarize how vascular dysfunction, chronic hypoperfusion, oxidative stress, and inflammatory processes can uncouple communication at the NVU impairing cerebral perfusion and contributing to neurodegeneration.
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Affiliation(s)
- Jessica L Presa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Flavia Saravia
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Zsolt Bagi
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jessica A Filosa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
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24
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Impaired cerebral blood flow regulation in chronic traumatic brain injury. Brain Res 2020; 1743:146924. [DOI: 10.1016/j.brainres.2020.146924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 05/28/2020] [Accepted: 06/01/2020] [Indexed: 01/26/2023]
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25
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Hissen SL, Taylor CE. Sex differences in vascular transduction of sympathetic nerve activity. Clin Auton Res 2020; 30:381-392. [PMID: 32865664 DOI: 10.1007/s10286-020-00722-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/18/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE Sympathetic vasoconstriction plays a major role in the beat-to-beat control of blood pressure. To be effective and thus avoid dangerously high or low blood pressures, this mechanism relies upon transduction of sympathetic nerve activity at the level of the vasculature. However, recent evidence suggests that considerable variability exists in beat-to-beat vascular transduction, particularly between the sexes. METHODS We reviewed the methods available for quantifying beat-to-beat transduction of muscle sympathetic nerve activity (MSNA) and explored the recent evidence for sex differences in vascular transduction. We paid specific attention to relationships between vascular transduction and factors such as resting levels of sympathetic nerve activity and baroreflex sensitivity. RESULTS There are two dominant methods now available for the quantification of beat-to-beat transduction of muscle sympathetic nerve activity at rest. Whilst there is some evidence to suggest that young females exhibit lower levels of vascular transduction, results vary depending on the method used and the direction of change in MSNA. Evidence suggests that compensatory relationships may exist between key components of neurovascular control, such as vascular transduction and resting levels of MSNA. Also consistent is the presence of such relationships in young males but not young females. CONCLUSION The lack of significant relationships in young females may reflect the influence of vasodilator mechanisms that counteract sympathetic vasoconstriction. The assessment of vascular transduction following MSNA bursts and non-bursts in males and females, both young and older, may help to gain a mechanistic understanding of the prevalence of hypotensive and hypertensive disorders across the lifespan.
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Affiliation(s)
- Sarah L Hissen
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Chloe E Taylor
- School of Health Sciences, Western Sydney University, Campbelltown Campus, Locked Bag 1797, Penrith, Sydney, NSW, 2751, Australia.
- School of Medicine, Western Sydney University, Sydney, Australia.
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26
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Maasakkers CM, Melis RJF, Kessels RPC, Gardiner PA, Olde Rikkert MGM, Thijssen DHJ, Claassen JAHR. The short-term effects of sedentary behaviour on cerebral hemodynamics and cognitive performance in older adults: a cross-over design on the potential impact of mental and/or physical activity. ALZHEIMERS RESEARCH & THERAPY 2020; 12:76. [PMID: 32571399 PMCID: PMC7310280 DOI: 10.1186/s13195-020-00644-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/15/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND Sedentary behaviour might be a potential risk factor for cognitive decline. However, the short-term effects of sedentary behaviour on (cerebro) vascular and cognitive performance in older people are unknown. METHODS We used a cross-over design with 22 older adults (78 years, 9 females) to assess the short-term hemodynamic and cognitive effects of three hours uninterrupted sitting and explored if these effects can be counteracted with regular (every 30 min) two-minute walking breaks. In addition, we investigated if low versus high mental activity during the three hours of sitting modified these effects. Before and after each condition, alertness, executive functioning, and working memory were assessed with the Test of Attentional Performance battery. Additionally, cerebral blood flow velocity (Transcranial Doppler) and blood pressure (Finapres) were measured in rest, and during sit-to-stand and CO2 challenges to assess baroreflex sensitivity, cerebral autoregulation, and cerebral vasomotor reactivity. RESULTS No short-term differences were observed in cognitive performance, cerebral blood flow velocity, baroreflex sensitivity, cerebral autoregulation, or cerebral vasomotor reactivity across time, or between conditions. Blood pressure and cerebrovascular resistance increased over time (8.6 mmHg (5.0;12.1), p < 0.001), and 0.23 in resistance (0.01;0.45), p = 0.04). However, these effects were not mitigated by mental activity or by short walking breaks to interrupt sitting. CONCLUSIONS In older individuals, three hours of sitting did not influence cognitive performance or cerebral perfusion. However, the sitting period increased blood pressure and cerebrovascular resistance, which are known to negatively impact brain health in the long-term. Importantly, we found that these effects in older individuals cannot be mitigated by higher mental activity and/or regular walking breaks. TRIAL REGISTRATION Clinical trial registration URL: https://www.toetsingonline.nl/. Unique identifier: NL64309.091.17. Date of registration: 06-02-2018.
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Affiliation(s)
- Carlijn M Maasakkers
- Department of Geriatrics/Radboud Alzheimer Center, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J F Melis
- Department of Geriatrics/Radboud Alzheimer Center, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Roy P C Kessels
- Department of Medical Psychology/Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.,Center for Cognition, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Paul A Gardiner
- Centre for Health Services Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Marcel G M Olde Rikkert
- Department of Geriatrics/Radboud Alzheimer Center, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dick H J Thijssen
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
| | - Jurgen A H R Claassen
- Department of Geriatrics/Radboud Alzheimer Center, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.
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27
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Favre ME, Serrador JM. Reply to "On the need of considering cardiorespiratory fitness when examining the influence of sex on dynamic cerebral autoregulation". Am J Physiol Heart Circ Physiol 2020; 316:H1230-H1231. [PMID: 31070462 DOI: 10.1152/ajpheart.00199.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Michelle E Favre
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Jorge M Serrador
- Department of Pharmacology, Physiology, and Neuroscience, Rutgers Biomedical and Health Sciences, Newark, New Jersey.,War Related Illness and Injury Study Center, Department of Veterans Affairs , East Orange, New Jersey.,Department of Cardiovascular Electronics, National University of Ireland Galway , Galway , Ireland
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28
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Perry BG, Cotter JD, Korad S, Lark S, Labrecque L, Brassard P, Paquette M, Le Blanc O, Lucas SJE. Implications of habitual endurance and resistance exercise for dynamic cerebral autoregulation. Exp Physiol 2019; 104:1780-1789. [DOI: 10.1113/ep087675] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 09/23/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Blake G. Perry
- School of Health SciencesMassey University Wellington New Zealand
- School of Sport, Exercise and NutritionMassey University Wellington New Zealand
| | - James D. Cotter
- School of Physical EducationSport and Exercise SciencesUniversity of Otago Dunedin New Zealand
| | - Stephanie Korad
- School of Sport, Exercise and NutritionMassey University Wellington New Zealand
| | - Sally Lark
- School of Sport, Exercise and NutritionMassey University Wellington New Zealand
| | - Lawrence Labrecque
- Department of KinesiologyFaculty of MedicineLaval University Quebec Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec Quebec Canada
| | - Patrice Brassard
- Department of KinesiologyFaculty of MedicineLaval University Quebec Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec Quebec Canada
| | - Myriam Paquette
- Department of KinesiologyFaculty of MedicineLaval University Quebec Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec Quebec Canada
| | - Olivier Le Blanc
- Department of KinesiologyFaculty of MedicineLaval University Quebec Canada
- Research center of the Institut universitaire de cardiologie et de pneumologie de Québec Quebec Canada
| | - Samuel J. E. Lucas
- Department of PhysiologyUniversity of Otago Dunedin New Zealand
- School of Sport, Exercise and Rehabilitation Sciences & Centre for Human Brain HealthUniversity of Birmingham Birmingham UK
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29
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Sarafis ZK, Monga AK, Phillips AA, Krassioukov AV. Is Technology for Orthostatic Hypotension Ready for Primetime? PM R 2019; 10:S249-S263. [PMID: 30269810 DOI: 10.1016/j.pmrj.2018.04.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/04/2018] [Accepted: 04/12/2018] [Indexed: 01/29/2023]
Abstract
Spinal cord injury (SCI) often results in the devastating loss of motor, sensory, and autonomic function. After SCI, the interruption of descending sympathoexcitatory pathways disrupts supraspinal control of blood pressure (BP). A common clinical consequence of cardiovascular dysfunction after SCI is orthostatic hypotension (OH), a debilitating condition characterized by rapid profound decreases in BP when assuming an upright posture. OH can result in a diverse array of insidious and pernicious health consequences. Acute effects of OH include decreased cardiac filling, cerebral hypoperfusion, and associated presyncopal symptoms such as lightheadedness and dizziness. Over the long term, repetitive exposure to OH is associated with a drastically increased prevalence of heart attack and stroke, which are leading causes of death in those with SCI. Current recommendations for managing BP after SCI primarily include pharmacologic interventions with prolonged time to effect. Because most episodes of OH occur in less than 3 minutes, this delay in action often renders most pharmacologic interventions ineffective. New innovative technologies such as epidural and transcutaneous spinal cord stimulation are being explored to solve this problem. It might be possible to electrically stimulate sympathetic circuitry caudal to the injury and elicit rapid modulation of BP to manage OH. This review describes autonomic control of the cardiovascular system before injury, resulting cardiovascular consequences after SCI such as OH, and the clinical assessment tools for evaluating autonomic dysfunction after SCI. In addition, current approaches for clinically managing OH are outlined, and new promising interventions are described for managing this condition.
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Affiliation(s)
- Zoe K Sarafis
- ICORD-BSCC, University of British Columbia, Vancouver, BC, Canada(∗)
| | - Aaron K Monga
- ICORD-BSCC, University of British Columbia, Vancouver, BC, Canada(†)
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, Libin Cardiovascular Institute of Alberta, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada(‡)
| | - Andrei V Krassioukov
- ICORD-BSCC; Experimental Medicine Program; Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia; GF Strong Rehabilitation Center, Vancouver Coastal Health; 818 West 10th Avenue, Vancouver, BC, Canada, V5Z1M9(§).
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30
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Vesoulis ZA, Liao SM, Mathur AM. Delayed cord clamping is associated with improved dynamic cerebral autoregulation and decreased incidence of intraventricular hemorrhage in preterm infants. J Appl Physiol (1985) 2019; 127:103-110. [PMID: 31046516 DOI: 10.1152/japplphysiol.00049.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Delayed cord clamping (DCC) improves neurologic outcomes in preterm infants through a reduction in intraventricular hemorrhage (IVH) incidence. The mechanism behind this neuroprotective effect is not known. Infants born <28 wk gestation were recruited for longitudinal monitoring. All infants underwent 72 h of synchronized near-infrared spectroscopy (NIRS) and mean arterial blood pressure (MABP) recording within 24 h of birth. Infants with DCC were compared with control infants with immediate cord clamping (ICC), controlling for severity of illness [clinical risk index for babies (CRIB-II) score], chorioamnionitis, antenatal steroids, sedation, inotropes, and delivery mode. Autoregulatory dampening was calculated as the transfer function gain coefficient between the MABP and NIRS signals. Forty-five infants were included (DCC; n = 15, paired 2:1 with ICC controls n = 30). ICC and DCC groups were similar including gestational age (25.5 vs. 25.2 wk, P = 0.48), birth weight (852.3 vs. 816.6 g, P = 0.73), percent female (40 vs. 40%, P = 0.75), and dopamine usage (27 vs. 23%, P = 1.00). There was a significant difference in IVH incidence between the DCC and ICC groups (20 vs. 50%, P = 0.04). Mean MABP was not different (35.9 vs. 35.1 mmHg, P = 0.44). Compared with the DCC group, the ICC group had diminished autoregulatory dampening capacity (-12.96 vs. -15.06 dB, P = 0.01), which remained significant when controlling for confounders. Dampening capacity was, in turn, strongly associated with decreased risk of IVH (odds ratio = 0.14, P < 0.01). The results of this pilot study demonstrate that DCC is associated with improved dynamic cerebral autoregulatory function and may be the mechanism behind the decreased incidence of IVH. NEW & NOTEWORTHY The neuroprotective mechanism of delayed cord clamping in premature infants is unclear. Delayed cord clamping was associated with improved cerebral autoregulatory function and a marked decrease in intraventricular hemorrhage (IVH). Improved dynamic cerebral autoregulation may decrease arterial baroreceptor sensitivity, thereby reducing the risk of IVH.
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Affiliation(s)
- Zachary A Vesoulis
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine , St. Louis, Missouri
| | - Steve M Liao
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine , St. Louis, Missouri
| | - Amit M Mathur
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine , St. Louis, Missouri
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31
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Favre ME, Serrador JM. Sex differences in cerebral autoregulation are unaffected by menstrual cycle phase in young, healthy women. Am J Physiol Heart Circ Physiol 2019; 316:H920-H933. [DOI: 10.1152/ajpheart.00474.2018] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sex is known to affect the prevalence of conditions such as stroke. However, effects of sex on cerebral blood flow regulation are still not well understood. Critical to this understanding is how fluctuations in hormones across the menstrual cycle affect cerebral autoregulation. We measured autoregulation in the early follicular, late follicular, and midluteal phases during spontaneous and induced blood pressure oscillations in 26 young, healthy individuals (13 women and 13 men, age: 26 ± 4 yr). Men participated three times, ~1–3 wk apart. Beat-by-beat blood pressure, heart rate, end-tidal CO2, and transcranial Doppler ultrasonography of the middle (MCA) and anterior (ACA) cerebral arteries were obtained. We did not find a difference in cerebral autoregulation across the menstrual cycle in women but found significantly improved autoregulation in the MCA and ACA of women compared with men. Women demonstrated significantly lower MCA gain (0.97 ± 0.13 vs. 1.17 ± 0.14%/mmHg, P = 0.001), higher MCA phase (46.1 ± 12.6 vs. 35.8 ± 7.9°, P = 0.019), and higher ACA phase (40.5 ± 10.8 vs 31.5 ± 8.5°, P = 0.040) during repeated squat-to-stand maneuvers. Women also had lower MCA gain (1.50 ± 0.11 vs. 1.72 ± 0.30%/mmHg, P = 0.029) during spontaneous fluctuations in pressure while standing and less of a decrease in MCA flow velocity (−18.7 ± 2.7 vs. −23.2 ± 6.0%, P = 0.014) during sit-to-stand maneuvers. Our results suggest that young women have improved cerebral autoregulation compared with young men regardless of menstrual cycle phase and that autoregulation is relatively robust to acute fluctuations in female sex hormones. NEW & NOTEWORTHY This is the first study to investigate thoroughly the effects of menstrual cycle phase and sex differences in cerebral autoregulation in young, healthy individuals. Cerebral autoregulation was unaffected by menstrual cycle phase during both repeated squat-to-stand and sit-to-stand maneuvers. However, women demonstrated significantly improved cerebral autoregulation in the middle and anterior cerebral arteries, suggesting women were able to maintain cerebral blood flow during changes in blood pressure more efficiently than men.
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Affiliation(s)
- Michelle E. Favre
- Department of Pharmacology, Physiology and Neuroscience; Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Jorge M. Serrador
- Department of Pharmacology, Physiology and Neuroscience; Rutgers Biomedical and Health Sciences, Newark, New Jersey
- War-Related Illness and Injury Study Center, Department of Veterans Affairs, East Orange, New Jersey
- Department of Cardiovascular Electronics, National University of Ireland Galway, Galway, Ireland
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32
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Teixeira SC, Madureira JB, Azevedo EI, Castro PM. Ageing affects the balance between central and peripheral mechanisms of cerebrovascular regulation with increasing influence of systolic blood pressure levels. Eur J Appl Physiol 2018; 119:519-529. [PMID: 30467594 DOI: 10.1007/s00421-018-4036-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 11/15/2018] [Indexed: 01/02/2023]
Abstract
BACKGROUND Arterial baroreflex (BR) and cerebral autoregulation (CA) are two major regulatory mechanisms that maintain constant cerebral perfusion. Little is known about the interplay between these mechanisms, particularly when considering the effects of ageing or sex. PURPOSE We studied the relationship between dynamic CA and BR sensitivity (BRS) in healthy subjects by sex and in different age strata. METHODS 95 healthy adults (52% female), 20-80 years-old, were recruited. Arterial blood pressure (Finometer), 3-lead electrocardiogram and cerebral blood flow velocity in middle cerebral arteries (transcranial Doppler) were monitored. We assessed CA by transfer function analysis and BRS in frequency and time domain. RESULTS With increasing age, BRS diminished (ANCOVA R2 = 0.281, p < 0.001) but CA parameters did not change significantly (p > 0.05). Overall, there was an inverse relationship between the efficacy of BRS and CA low-frequency gain [multivariate linear regression β = 0.41 (0.31; 0.61), p < 0.001]. However, this association suffers changes with ageing: in older subjects BRS and CA were not correlated [β = 0.10 (- 0.41; 0.62), p = 0.369]. Instead, decreasing systolic blood pressure correlated with less efficient CA [lower CA low-frequency gain β = - 0.02 (- 0.03; - 0.02), p = 0.003]. Sex did not affect BRS and CA relationship. CONCLUSIONS Cerebral blood supply is governed by a tuned balance between BR and CA which is lost with age as BRS decreases dramatically. Low systolic blood pressure values might be harmful to older subjects as they might reduce the ability to keep cerebral blood flow tightly controlled.
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Affiliation(s)
- Sofia Cunha Teixeira
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319, Porto, Portugal.
| | - João Brandão Madureira
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319, Porto, Portugal
| | - Elsa Irene Azevedo
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319, Porto, Portugal.,Cardiovascular Research and Development Centre, Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Neurology, São João Hospital Centre, Porto, Portugal
| | - Pedro Miguel Castro
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319, Porto, Portugal.,Cardiovascular Research and Development Centre, Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Neurology, São João Hospital Centre, Porto, Portugal
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33
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Falvo MJ, Lindheimer JB, Serrador JM. Dynamic cerebral autoregulation is impaired in Veterans with Gulf War Illness: A case-control study. PLoS One 2018; 13:e0205393. [PMID: 30321200 PMCID: PMC6188758 DOI: 10.1371/journal.pone.0205393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 09/25/2018] [Indexed: 02/03/2023] Open
Abstract
Neurological dysfunction has been reported in Gulf War Illness (GWI), including abnormal cerebral blood flow (CBF) responses to physostigmine challenge. However, it is unclear whether the CBF response to normal physiological challenges and regulation is similarly dysfunctional. The goal of the present study was to evaluate the CBF velocity response to orthostatic stress (i.e., sit-to-stand maneuver) and increased fractional concentration of carbon dioxide. 23 cases of GWI (GWI+) and 9 controls (GWI) volunteered for this study. Primary variables of interest included an index of dynamic autoregulation and cerebrovascular reactivity. Dynamic autoregulation was significantly lower in GWI+ than GWI- both for autoregulatory index (2.99±1.5 vs 4.50±1.5, p = 0.017). In addition, we observed greater decreases in CBF velocity both at the nadir after standing (-18.5±6.0 vs -9.8±4.9%, p = 0.001) and during steady state standing (-5.7±7.1 vs -1.8±3.2%, p = 0.042). In contrast, cerebrovascular reactivity was not different between groups. In our sample of Veterans with GWI, dynamic autoregulation was impaired and consistent with greater cerebral hypoperfusion when standing. This reduced CBF may contribute to cognitive difficulties in these Veterans when upright.
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Affiliation(s)
- Michael J. Falvo
- War Related Illness and Injury Study Center, Department of Veterans Affairs, East Orange, New Jersey, United States of America
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- Department of Physical Medicine and Rehabilitation, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
| | - Jacob B. Lindheimer
- William S. Middleton Memorial Veterans Hospital, Department of Veterans Affairs, Madison, Wisconsin, United States of America
- Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jorge M. Serrador
- War Related Illness and Injury Study Center, Department of Veterans Affairs, East Orange, New Jersey, United States of America
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- Department of Cardiovascular Electronics, National University of Ireland Galway, Galway, Connacht, IRE
- * E-mail:
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Uryga A, Burzyńska M, Tabakow P, Kasprowicz M, Budohoski KP, Kazimierska A, Smielewski P, Czosnyka M, Goździk W. Baroreflex sensitivity and heart rate variability are predictors of mortality in patients with aneurysmal subarachnoid haemorrhage. J Neurol Sci 2018; 394:112-119. [PMID: 30245190 DOI: 10.1016/j.jns.2018.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/24/2018] [Accepted: 09/11/2018] [Indexed: 01/09/2023]
Abstract
OBJECT We aimed to investigate the link between the autonomic nervous system (ANS) impairment, assessed using baroreflex sensitivity (BRS) and heart rate variability (HRV) indices, and mortality after aneurysmal subarachnoid haemorrhage (aSAH). METHODS A total of 57 patients (56 ± 18 years) diagnosed with aSAH were retrospectively enrolled in the study, where 25% of patients died in the hospital. BRS was calculated using a modified cross-correlation method. Time- and frequency-domain HRV indices were calculated from a time-series of systolic peak intervals of arterial blood pressure signals. Additionally, cerebral autoregulation (CA) was assessed using the mean velocity index (Mxa), where Mxa > 0 indicates impaired CA. RESULTS Both BRS and HRV indices were lower in non-survivors than in survivors. The patients with disturbed BRS and HRV had more extensive haemorrhage in the H-H scale (p = .040) and were more likely to die (p = .013) when compared to patients with the intact ANS. The logistic regression model for mortality included: the APACHE II score (p = .002; OR 0.794) and the normalised high frequency power of the HRV (p < <.001; OR 0.636). A positive relationship was found between the Mxa and BRS (R = 0.48, p = .003), which suggests that increasing BRS is moderately strongly associated with worsening CA. CONCLUSION Our results indicated that lower values of HRV indices and BRS correlate with mortality and that there is a link between cerebral dysautoregulation and the analysed estimates of the ANS in aSAH patients.
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Affiliation(s)
- Agnieszka Uryga
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland.
| | - Małgorzata Burzyńska
- Department of Anesthesiology and Intensive Care, Wroclaw Medical University, Wroclaw, Poland
| | - Paweł Tabakow
- Department of Neurosurgery, Wroclaw Medical University, Wroclaw, Poland
| | - Magdalena Kasprowicz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Karol P Budohoski
- Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Agnieszka Kazimierska
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Peter Smielewski
- Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Marek Czosnyka
- Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Cambridge, UK; Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - Waldemar Goździk
- Department of Anesthesiology and Intensive Care, Wroclaw Medical University, Wroclaw, Poland
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Llwyd O, Salinet ASM, Panerai RB, Lam MY, Saeed NP, Brodie F, Bor-Seng-Shu E, Robinson TG, Nogueira RC. Cerebral Haemodynamics following Acute Ischaemic Stroke: Effects of Stroke Severity and Stroke Subtype. Cerebrovasc Dis Extra 2018; 8:80-89. [PMID: 29996123 PMCID: PMC6489023 DOI: 10.1159/000487514] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/07/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Acute ischaemic stroke (AIS) patients often show impaired cerebral autoregulation (CA). We tested the hypothesis that CA impairment and other alterations in cerebral haemodynamics are associated with stroke subtype and severity. METHODS AIS patients (n = 143) were amalgamated from similar studies. Data from baseline (< 48 h stroke onset) physiological recordings (beat-to-beat blood pressure [BP], cerebral blood flow velocity (CBFV) from bilateral insonation of the middle cerebral arteries) were calculated for mean values and autoregulation index (ARI). Differences were assessed between stroke subtype (Oxfordshire Community Stroke Project [OCSP] classification) and severity (National Institutes of Health Stroke Scale [NIHSS] score < 5 and 5-25). Correlation coefficients assessed associations between NIHSS and physiological measurements. RESULTS Thirty-two percent of AIS patients had impaired CA (ARI < 4) in affected hemisphere (AH) that was similar between stroke subtypes and severity. CBFV in AH was comparable between stroke subtype and severity. In unaffected hemisphere (UH), differences existed in mean CBFV between lacunar and total anterior circulation OCSP subtypes (42 vs. 56 cm•s-1, p < 0.01), and mild and moderate-to-severe stroke severity (45 vs. 51 cm•s-1, p = 0.04). NIHSS was associated with peripheral (diastolic and mean arterial BP) and cerebral haemodynamic parameters (CBFV and ARI) in the UH. CONCLUSIONS AIS patients with different OCSP subtypes and severity have homogeneity in CA capability. Cerebral haemodynamic measurements in the UH were distinguishable between stroke subtype and severity, including the association between deteriorating ARI in UH with stroke severity. More studies are needed to determine their clinical significance and to understand the determinants of CA impairment in AIS patients.
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Affiliation(s)
- Osian Llwyd
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom
| | - Angela S M Salinet
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom.,Neurology Department, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Ronney B Panerai
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom
| | - Man Y Lam
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom
| | - Nazia P Saeed
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom
| | - Fiona Brodie
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom
| | - Edson Bor-Seng-Shu
- Neurology Department, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Thompson G Robinson
- Department of Cardiovascular Sciences Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, United Kingdom
| | - Ricardo C Nogueira
- Neurology Department, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
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36
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de Heus RA, de Jong DL, Sanders ML, van Spijker GJ, Oudegeest-Sander MH, Hopman MT, Lawlor BA, Olde Rikkert MG, Claassen JA. Dynamic Regulation of Cerebral Blood Flow in Patients With Alzheimer Disease. Hypertension 2018; 72:139-150. [DOI: 10.1161/hypertensionaha.118.10900] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 02/09/2018] [Accepted: 04/05/2018] [Indexed: 01/18/2023]
Abstract
Cerebral autoregulation and baroreflex sensitivity are key mechanisms that maintain cerebral blood flow. This study assessed whether these control mechanisms are affected in patients with dementia and mild cognitive impairment due to Alzheimer disease, as this would increase the risks of antihypertensive treatment. We studied 53 patients with dementia (73.1 years [95% confidence interval (CI), 71.4–74.8]), 37 patients with mild cognitive impairment (69.2 years [95% CI, 66.4–72.0]), and 47 controls (69.4 years [95% CI, 68.3–70.5]). Beat-to-beat blood pressure (photoplethysmography), heart rate, and cerebral blood flow velocity (transcranial Doppler) were measured during 5-minute rest (sitting) and 5 minutes of orthostatic challenges, using repeated sit-to-stand maneuvers. Cerebral autoregulation was assessed using transfer function analysis and the autoregulatory index. Baroreflex sensitivity was estimated with transfer function analysis and by calculating the heart rate response to blood pressure changes during the orthostatic challenges. Dementia patients had the lowest cerebral blood flow velocity (
P
=0.004). During rest, neither transfer function analysis nor the autoregulatory index indicated impairments in cerebral autoregulation. During the orthostatic challenges, higher autoregulatory index (
P
=0.011) and lower transfer function gain (
P
=0.017), indicating better cerebral autoregulation, were found in dementia (4.56 arb. unit [95% CI, 4.14–4.97]; 0.59 cm/s per mm Hg [95% CI, 0.51–0.66]) and mild cognitive impairment (4.59 arb. unit [95% CI, 4.04–5.13]; 0.51 cm/s per mm Hg [95% CI, 0.44–0.59]) compared with controls (3.71 arb. unit [95% CI, 3.35–4.07]; 0.67 cm/s per mm Hg [95% CI, 0.59–0.74]). Baroreflex sensitivity measures did not differ between groups. In conclusion, the key mechanisms to control blood pressure and cerebral blood flow are not reduced in 2 stages of Alzheimer disease compared with controls, both in rest and during orthostatic changes that reflect daily life challenges.
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Affiliation(s)
- Rianne A.A. de Heus
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
| | - Daan L.K. de Jong
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
| | - Marit L. Sanders
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
| | - Gerrita J. van Spijker
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
| | - Madelijn H. Oudegeest-Sander
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Department of Physiology (M.H.O.-S., M.T.H.), Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
| | - Maria T. Hopman
- Department of Physiology (M.H.O.-S., M.T.H.), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Brian A. Lawlor
- Mercer's Institute for Research on Ageing, St. James's Hospital and Global Brain Health Institute, Trinity College Dublin, Ireland (B.A.L.)
| | - Marcel G.M. Olde Rikkert
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
| | - Jurgen A.H.R. Claassen
- From the Department of Geriatric Medicine, Radboud Alzheimer Centre (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
- Donders Institute for Brain Cognition and Behaviour, Nijmegen, The Netherlands (R.A.A.d.H., D.L.K.d.J., M.L.S., G.J.v.S., M.H.O.-S., M.G.M.O.R., J.A.H.R.C.)
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Tarumi T, Zhang R. Cerebral blood flow in normal aging adults: cardiovascular determinants, clinical implications, and aerobic fitness. J Neurochem 2018; 144:595-608. [PMID: 28986925 PMCID: PMC5874160 DOI: 10.1111/jnc.14234] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 09/05/2017] [Accepted: 10/02/2017] [Indexed: 12/13/2022]
Abstract
Senescence is a leading cause of mortality, disability, and non-communicable chronic diseases in older adults. Mounting evidence indicates that the presence of cardiovascular disease and risk factors elevates the incidence of both vascular cognitive impairment and Alzheimer's disease (AD). Age-related declines in cardiovascular function may impair cerebral blood flow (CBF) regulation, leading to the disruption of neuronal micro-environmental homeostasis. The brain is the most metabolically active organ with limited intracellular energy storage and critically depends on CBF to sustain neuronal metabolism. In patients with AD, cerebral hypoperfusion, increased CBF pulsatility, and impaired blood pressure control during orthostatic stress have been reported, indicating exaggerated, age-related decline in both cerebro- and cardiovascular function. Currently, AD lacks effective treatments; therefore, the development of preventive strategy is urgently needed. Regular aerobic exercise improves cardiovascular function, which in turn may lead to a better CBF regulation, thus reducing the dementia risk. In this review, we discuss the effects of aging on cardiovascular regulation of CBF and provide new insights into the vascular mechanisms of cognitive impairment and potential effects of aerobic exercise training on CBF regulation. This article is part of the Special Issue "Vascular Dementia".
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Affiliation(s)
- Takashi Tarumi
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (8200 Walnut Hill Ln, Dallas, TX, USA 75231)
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center (5323 Harry Hines Blvd, TX, USA 75390)
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (8200 Walnut Hill Ln, Dallas, TX, USA 75231)
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center (5323 Harry Hines Blvd, TX, USA 75390)
- Department of Internal Medicine, University of Texas Southwestern Medical Center (5323 Harry Hines Blvd, TX, USA 75390)
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Ferreira D, Castro P, Videira G, Filipe JP, Santos R, Sá MJ, Azevedo E, Abreu P. Cerebral autoregulation is preserved in multiple sclerosis patients. J Neurol Sci 2017; 381:298-304. [PMID: 28991702 DOI: 10.1016/j.jns.2017.09.009] [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: 07/02/2017] [Revised: 08/23/2017] [Accepted: 09/06/2017] [Indexed: 11/16/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory disease that may also be associated with vascular dysfunction. One master component of vascular regulation is cerebral autoregulation (CA). We aimed to investigate the integrity of CA in MS patients and study its relationship with autonomic dysfunction (AD), magnetic-resonance-imaging (MRI) lesion load and hemodynamic parameters. We enrolled 20 relapsing-remitting MS and 20 healthy subjects. CA was assessed by transfer function analysis parameters (coherence, gain and phase), as obtained in the very low, low and high-frequency domains (VLF, LF, HF, respectively). We evaluated the autonomic parameters heart rate variability and spontaneous baroreflex sensitivity (BRS). There were no significant differences in CA parameters between MS and controls (p>0.05). Lesion load was not correlated with any CA parameter. LF gain was positively correlated with BRS in both groups (MS: p=0.017; controls: p=0.025). Brainstem lesion load in MS was associated with higher systolic blood pressure (SBP; p=0.009). Our findings suggest that CA is preserved in our MS cohort. On the other hand, AD in MS patients with brainstem lesions could contribute to the increase of supine SBP. Whether this systemic deregulation could contribute to disease burden remains to be investigated.
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Affiliation(s)
- Daniel Ferreira
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal.
| | - Pedro Castro
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal; Department of Neurology, São João Hospital Center, 4200-319 Porto, Portugal
| | - Gonçalo Videira
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal
| | - João Pedro Filipe
- Department of Neuroradiology, Hospital Center São João, 4200-319 Porto, Portugal
| | - Rosa Santos
- Department of Neurology, São João Hospital Center, 4200-319 Porto, Portugal
| | - Maria José Sá
- Department of Neurology, São João Hospital Center, 4200-319 Porto, Portugal; Faculty of Health Sciences, University Fernando Pessoa, 4249-004 Porto, Portugal
| | - Elsa Azevedo
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal; Department of Neurology, São João Hospital Center, 4200-319 Porto, Portugal
| | - Pedro Abreu
- Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, 4200-319 Porto, Portugal; Department of Neurology, São João Hospital Center, 4200-319 Porto, Portugal
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Witter T, Tzeng YC, O'Donnell T, Kusel J, Walker B, Berry M, Taylor CE. Inter-individual Relationships between Sympathetic Arterial Baroreflex Function and Cerebral Perfusion Control in Healthy Males. Front Neurosci 2017; 11:457. [PMID: 28860964 PMCID: PMC5559461 DOI: 10.3389/fnins.2017.00457] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/28/2017] [Indexed: 12/29/2022] Open
Abstract
Maintenance of adequate cerebral perfusion during normal physiological challenges requires integration between cerebral blood flow (CBF) and systemic blood pressure control mechanisms. Previous studies have shown that cardiac baroreflex sensitivity (BRS) is inversely related to some measures of cerebral autoregulation. However, interactions between the sympathetic arterial baroreflex and cerebral perfusion control mechanisms have not been explored. To determine the nature and magnitude of these interactions we measured R–R interval, blood pressure, CBF velocity, and muscle sympathetic nerve activity (MSNA) in 11 healthy young males. Sympathetic BRS was estimated using modified Oxford method as the relationship between beat-to-beat diastolic blood pressure (DBP) and MSNA. Integrated control of CBF was quantified using transfer function analysis (TFA) metrics derived during rest and Tieck's autoregulatory index following bilateral thigh cuff deflation. Sympathetic BRS during modified Oxford trials was significantly related to autoregulatory index (r = 0.64, p = 0.03). Sympathetic BRS during spontaneous baseline was significantly related to transfer function gain (r = −0.74, p = 0.01). A more negative value for sympathetic BRS indicates more effective arterial baroreflex regulation, and a lower transfer function gain reflects greater cerebral autoregulation. Therefore, these findings indicate that males with attenuated CBF regulation have greater sympathetic BRS (and vice versa), consistent with compensatory interactions between blood pressure and cerebral perfusion control mechanisms.
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Affiliation(s)
- Trevor Witter
- Wellington Medical Technology Group, Centre for Translational Physiology, University of OtagoWellington, New Zealand
| | - Yu-Chieh Tzeng
- Wellington Medical Technology Group, Centre for Translational Physiology, University of OtagoWellington, New Zealand
| | - Terry O'Donnell
- Wellington Medical Technology Group, Centre for Translational Physiology, University of OtagoWellington, New Zealand
| | - Jessica Kusel
- Wellington Medical Technology Group, Centre for Translational Physiology, University of OtagoWellington, New Zealand
| | - Bridget Walker
- Wellington Medical Technology Group, Centre for Translational Physiology, University of OtagoWellington, New Zealand
| | - Mary Berry
- Wellington Medical Technology Group, Centre for Translational Physiology, University of OtagoWellington, New Zealand
| | - Chloe E Taylor
- School of Science and Health, Western Sydney UniversitySydney, NSW, Australia.,School of Medicine, Western Sydney UniversitySydney, NSW, Australia
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40
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Alterations in autonomic cerebrovascular control after spinal cord injury. Auton Neurosci 2017; 209:43-50. [PMID: 28416148 PMCID: PMC6432623 DOI: 10.1016/j.autneu.2017.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 04/02/2017] [Accepted: 04/03/2017] [Indexed: 11/24/2022]
Abstract
Among chronic cardiovascular and metabolic sequelae of spinal cord injury (SCI) is an up-to four-fold increase in the risk of ischemic and hemorrhagic stroke, suggesting that individuals with SCI cannot maintain stable cerebral perfusion. In able-bodied individuals, the cerebral vasculature is able to regulate cerebral perfusion in response to swings in arterial pressure (cerebral autoregulation), blood gases (cerebral vasoreactivity), and neural metabolic demand (neurovascular coupling). This ability depends, at least partly, on intact autonomic function, but high thoracic and cervical spinal cord injuries result in disruption of sympathetic and parasympathetic cerebrovascular control. In addition, alterations in autonomic and/or vascular function secondary to paralysis and physical inactivity can impact cerebrovascular function independent of the disruption of autonomic control due to injury. Thus, it is conceivable that SCI results in cerebrovascular dysfunction that may underlie an elevated risk of stroke in this population, and that rehabilitation strategies targeting this dysfunction may alleviate the long-term risk of adverse cerebrovascular events. However, despite this potential direct link between SCI and the risk of stroke, studies exploring this relationship are surprisingly scarce, and the few available studies provide equivocal results. The focus of this review is to provide an integrated overview of the available data on alterations in cerebral vascular function after SCI in humans, and to provide suggestions for future research.
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41
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Xing CY, Tarumi T, Meijers RL, Turner M, Repshas J, Xiong L, Ding K, Vongpatanasin W, Yuan LJ, Zhang R. Arterial Pressure, Heart Rate, and Cerebral Hemodynamics Across the Adult Life Span. Hypertension 2017; 69:712-720. [PMID: 28193707 DOI: 10.1161/hypertensionaha.116.08986] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 01/08/2017] [Accepted: 01/19/2017] [Indexed: 01/15/2023]
Abstract
Age-related alterations in systemic and cerebral hemodynamics are not well understood. The purpose of this study is to characterize age-related alterations in beat-to-beat oscillations in arterial blood pressure (BP), heart rate (HR), cerebral blood flow (CBF), cardiac baroreflex sensitivity, and dynamic cerebral autoregulation across the adult life span. We studied 136 healthy adults aged 21 to 80 years (60% women). Beat-to-beat BP, HR, and CBF velocity were measured at rest and during sit-stand maneuvers to mimic effects of postural changes on BP and CBF. Transfer function analysis was used to assess baroreflex sensitivity and dynamic cerebral autoregulation. Carotid-femoral pulse wave velocity was measured to assess central arterial stiffness. Advanced aging was associated with elevated carotid-femoral pulse wave velocity, systolic and pulse BP, cerebrovascular resistance, and CBF pulsatility, but reduced mean CBF velocity. Compared with the young and middle-aged, older adults had lower beat-to-beat BP, HR, and CBF variability in the low-frequency ranges at rest, but higher BP and CBF variability during sit-stand maneuvers. Baroreflex sensitivity was reduced, whereas dynamic cerebral autoregulation gain was elevated at rest in older adults. Multiple linear regression analysis indicated that systolic BP variability is correlated positively with carotid-femoral pulse wave velocity independent of HR variability. In conclusion, advanced aging is associated with elevated pulsatility in BP and CBF; reduced beat-to-beat low-frequency oscillations in BP, HR, and CBF; and impaired baroreflex sensitivity and dynamic cerebral autoregulation at rest. The augmented BP and CBF variability in older adults during sit-stand maneuvers indicate diminished cardiovascular regulatory capability and increased hemodynamic stress on the cerebral circulation with aging.
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Affiliation(s)
- Chang-Yang Xing
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Takashi Tarumi
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Rutger L Meijers
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Marcel Turner
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Justin Repshas
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Li Xiong
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Kan Ding
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Wanpen Vongpatanasin
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Li-Jun Yuan
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.)
| | - Rong Zhang
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (C.-Y.X., T.T., R.L.M., M.T., J.R., R.Z.); Department of Internal Medicine (C.-Y.X., W.V., R.Z.) and Department of Neurology and Neurotherapeutics (T.T., K.D., R.Z.), University of Texas Southwestern Medical Center, Dallas; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China (C.-Y.X., L.-J.Y.); Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, The Netherlands (R.L.M.); and Department of Medicine and Therapeutics, Chinese University of Hong Kong, China (L.X.).
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Smith R, Thayer JF, Khalsa SS, Lane RD. The hierarchical basis of neurovisceral integration. Neurosci Biobehav Rev 2017; 75:274-296. [PMID: 28188890 DOI: 10.1016/j.neubiorev.2017.02.003] [Citation(s) in RCA: 262] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 02/07/2023]
Abstract
The neurovisceral integration (NVI) model was originally proposed to account for observed relationships between peripheral physiology, cognitive performance, and emotional/physical health. This model has also garnered a considerable amount of empirical support, largely from studies examining cardiac vagal control. However, recent advances in functional neuroanatomy, and in computational neuroscience, have yet to be incorporated into the NVI model. Here we present an updated/expanded version of the NVI model that incorporates these advances. Based on a review of studies of structural/functional anatomy, we first describe an eight-level hierarchy of nervous system structures, and the contribution that each level plausibly makes to vagal control. Second, we review recent work on a class of computational models of brain function known as "predictive coding" models. We illustrate how the computational dynamics of these models, when implemented within our proposed vagal control hierarchy, can increase understanding of the relationship between vagal control and both cognitive performance and emotional/physical health. We conclude by discussing novel implications of this updated NVI model for future research.
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Affiliation(s)
- Ryan Smith
- Department of Psychiatry, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724-5002, United States.
| | - Julian F Thayer
- Department of Psychology, Ohio State University, Columbus, OH, United States
| | - Sahib S Khalsa
- Laureate Institute for Brain Research, Tulsa, OK, United States; University of Tulsa, Oxley College of Health Sciences, Tulsa, OK, United States
| | - Richard D Lane
- Department of Psychiatry, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724-5002, United States
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43
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Bishop S, Dech R, Baker T, Butz M, Aravinthan K, Neary JP. Parasympathetic baroreflexes and heart rate variability during acute stage of sport concussion recovery. Brain Inj 2017; 31:247-259. [DOI: 10.1080/02699052.2016.1226385] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Scott Bishop
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
| | - Ryan Dech
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
| | - Taylor Baker
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
| | - Matthew Butz
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Kaishan Aravinthan
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
| | - J. Patrick Neary
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada
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Viski S, Orosz M, Czuriga-Kovacs KR, Magyar MT, Csiba L, Olah L. The acute effects of alcohol on cerebral hemodynamic changes induced by the head-up tilt test in healthy subjects. J Neurol Sci 2016; 368:113-20. [PMID: 27538612 DOI: 10.1016/j.jns.2016.06.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/07/2016] [Accepted: 06/27/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Alcohol is a known triggering factor for orthostatic dysfunction, increasing the risk of neurally-mediated syncope. Since orthostatic tolerance may be affected by both systemic and cerebral hemodynamic changes, our aim was to investigate the acute effects of alcohol on cerebral vasoreactivity measured during the head-up tilt (HUT) test in 20 healthy subjects. METHODS Mean arterial blood pressure (mBP), heart rate, and flow parameters in both middle cerebral arteries (MCAs) were continuously recorded in the supine and during a 10-minute HUT positions before and after alcohol intake. RESULTS The HUT test resulted in a more prominent decline of adjusted mBP at the level of MCAs (mBPMCA) and a significantly larger decrease of MCA mean flow velocities (MFVMCA) in the post-alcohol period than before alcohol intake. During the HUT phase, the relative decrease in MFVMCA was significantly smaller than the reduction in mBPMCA before drinking alcohol, while these changes were similar after alcohol ingestion. The cerebrovascular resistance index (CVRi) decreased during the HUT phase in the control period, however, it increased after alcohol intake. CONCLUSION The similar decrease in mBPMCA and MFVMCA during orthostatic stress after alcohol ingestion together with the increased CVRi indicated the impairment of the compensatory vasodilation of cerebral resistance vessels, i.e. impaired cerebral autoregulation. These findings suggest that alcohol may contribute to impaired orthostatic tolerance not only by a hypotensive response but also by the alteration of cerebral blood flow regulation.
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Affiliation(s)
- Sandor Viski
- Department of Neurology, University of Debrecen, Moricz Zs. krt. 22, H-4032 Debrecen, Hungary
| | - Miklos Orosz
- Bethesda Children's Hospital of Reformed Church in Hungary, Bethesda u. 3., H-1146 Budapest, Hungary
| | | | - Maria Tunde Magyar
- Department of Neurology, University of Debrecen, Moricz Zs. krt. 22, H-4032 Debrecen, Hungary
| | - Laszlo Csiba
- Department of Neurology, University of Debrecen, Moricz Zs. krt. 22, H-4032 Debrecen, Hungary
| | - Laszlo Olah
- Department of Neurology, University of Debrecen, Moricz Zs. krt. 22, H-4032 Debrecen, Hungary.
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Abstract
Regular aerobic exercise improves brain health; however, a potential dose-response relationship and the underling physiological mechanisms remain unclear. Existing data support the following hypotheses: 1) exercise-induced cardiovascular adaptation plays an important role in improving brain perfusion, structure, and function, and 2) a hormetic relation seems to exist between the intensity of exercise and brain health, which needs to be further elucidated.
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Affiliation(s)
- Takashi Tarumi
- 1Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas; and 2Departments of Internal Medicine and 3Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX
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46
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Abstract
BACKGROUND Little is known about intracranial pressure (ICP)-cerebral haemodynamic interplay during repetitive apnoea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. METHOD We tested the complex response of the pial artery and subarachnoid width to apnoea using this method. The pial artery and subarachnoid width response to consecutive apnoeas lasting 30, 60 s and maximal breath-hold (91.1 ± 23.1 s) were studied in 20 healthy volunteers. The cc-TQ and sas-TQ were measured using NIR-T/BSS; cerebral blood flow velocity (CBFV), pulsatility index and resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate (HR) and beat-to-beat SBP and DBP blood pressure were recorded using a Finometer; end-tidal CO2 (EtCO2) was measured using a medical gas analyser. RESULTS Apnoea evoked a multiphasic response in blood pressure, pial artery compliance and ICP. First, SBP declined, which was accompanied by an increase in cc-TQ and sas-TQ. Directly after these changes, SBP exceeded baseline values, which was followed by a decline in cc-TQ and the return of sas-TQ to baseline. During these initial changes, CBFV remained stable. Towards the end of the apnoea, BP, cc-TQ and CBFV increased, whereas pulsatility index, resistive index and sas-TQ declined. Changes in sas-TQ were linked to changes in EtCO2, HR and SBP. CONCLUSION Apnoea is associated with ICP swings, closely reflecting changes in EtCO2, HR and peripheral BP. The baroreflex influences the pial artery response.
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Demirel S, Celi de la Torre JA, Bruijnen H, Martin E, Popp E, Böckler D, Attigah N. Effect of Superficial Cervical Plexus Block on Baroreceptor Sensitivity in Patients Undergoing Carotid Endarterectomy. J Cardiothorac Vasc Anesth 2016; 30:309-16. [PMID: 26718664 DOI: 10.1053/j.jvca.2015.08.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Indexed: 11/11/2022]
Abstract
OBJECTIVES Regional anesthesia for patients undergoing carotid endarterectomy is associated with improved intraoperative hemodynamic stability compared with general anesthesia. The authors hypothesized that the reported advantages might be related to attenuated ipsilateral baroreflex control of blood pressure, caused by chemical denervation of the carotid bulb baroreceptor nerve fibers. DESIGN A prospective cohort study. SETTING Single-center university hospital. PARTICIPANTS The study included 46 patients undergoing carotid endarterectomy using superficial cervical block. INTERVENTIONS A noninvasive computational periprocedural measurement of baroreceptor sensitivity was performed in all patients. Two groups were formed, depending on the patients' subjective response to surgical stimulation regarding the necessity of additional intraoperative local anesthesia (LA) administration on the carotid bulb. Group A (block alone) included 23 patients who required no additional anesthesia, and group B (block + LA) consisted of 23 patients who required additional anesthesia. MEASUREMENTS AND MAIN RESULTS Baroreceptor sensitivity showed no significant change after application of the block in both groups (group A: median [IQR], 5.19 [3.07-8.54] v 4.96 [3.1-9.07]; p = 0.20) (group B: median [IQR], 4.47 [3.36-8.09] v 4.53 [3.29-8.01]; p = 0.55). There was a significant decrease in baroreceptor sensitivity in group B after intraoperative LA administration (median [IQR], 4.53 [3.29-8.01] v 3.31 [2.26-7.31]; p = 0.04). CONCLUSIONS Standard superficial cervical plexus block did not impair local baroreceptor function, and, therefore, it was not related to improved cerebral perfusion in awake patients undergoing carotid endarterectomy. However, direct infiltration of the carotid bulb was associated with the expected attenuation of baroreflex sensitivity.
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Affiliation(s)
- Serdar Demirel
- Department of Vascular and Endovascular Surgery, University Hospital of Heidelberg, Heidelberg, Germany;.
| | | | - Hans Bruijnen
- Department of Vascular and Thoracic Surgery, Augsburg City Hospital, University of Ludwig-Maximillians, Munich, Germany
| | - Eike Martin
- Department of Anesthesiology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Erik Popp
- Department of Anesthesiology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Dittmar Böckler
- Department of Vascular and Endovascular Surgery, University Hospital of Heidelberg, Heidelberg, Germany
| | - Nicolas Attigah
- Department of Vascular Surgery, City Hospital Triemli, Zurich, Switzerland
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Bleton H, Sejdić E. A cerebral blood flow evaluation during cognitive tasks following a cervical spinal cord injury: a case study using transcranial Doppler recordings. Cogn Neurodyn 2015; 9:615-26. [PMID: 26557931 DOI: 10.1007/s11571-015-9355-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 06/15/2015] [Accepted: 08/27/2015] [Indexed: 10/23/2022] Open
Abstract
A spinal cord injury (SCI) is one of the most common neurological disorders. In this paper, we examined the consequences of upper SCI in a male participant on the cerebral blood flow velocity. In particular, transcranial Doppler was used to study these effects through middle cerebral arteries (MCA) during resting-state periods and during cognitive challenges (non-verbal word-generation tasks and geometric-rotation tasks). Signal characteristics were analyzed from raw signals and envelope signals (maximum velocity) in the time domain, the frequency domain and the time-frequency domain. The frequency features highlighted an increase of the peak frequency in L-MCA and R-MCA raw signals, which revealed stronger cerebral blood flow during geometric/verbal processes respectively. This underlined a slight dominance of the right hemisphere during word-generation periods and a slight dominance of the left hemisphere during geometric processes. This finding was confirmed by cross-correlation in the time domain and by the entropy rate in information-theoretic domain. A comparison of our results to other neurological disorders (Alzheimer's disease, Parkinson's disease, autism, epilepsy, traumatic brain injury) showed that the SCI had similar effects such as general decreased cerebral blood flow and similar regular hemispheric dominance in a few cases.
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Affiliation(s)
- Héloïse Bleton
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA 15261 USA
| | - Ervin Sejdić
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA 15261 USA
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Winklewski PJ, Tkachenko Y, Mazur K, Kot J, Gruszecki M, Guminski W, Czuszynski K, Wtorek J, Frydrychowski AF. Sympathetic Activation Does Not Affect the Cardiac and Respiratory Contribution to the Relationship between Blood Pressure and Pial Artery Pulsation Oscillations in Healthy Subjects. PLoS One 2015; 10:e0135751. [PMID: 26284650 PMCID: PMC4540578 DOI: 10.1371/journal.pone.0135751] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/25/2015] [Indexed: 12/12/2022] Open
Abstract
Introduction Using a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) in humans, we assessed the influence of sympathetic activation on the cardiac and respiratory contribution to blood pressure (BP) cc-TQ oscillations in healthy subjects. Methods The pial artery and subarachnoid width response to handgrip (HGT) and cold test (CT) were studied in 20 healthy subjects. The cc-TQ and sas-TQ were measured using NIR-T/BSS; cerebral blood flow velocity (CBFV) was measured using Doppler ultrasound of the left internal carotid artery; heart rate (HR) and beat-to-beat mean BP were recorded using a continuous finger-pulse photoplethysmography; respiratory rate (RR), minute ventilation (MV), end-tidal CO2 (EtCO2) and end-tidal O2 (EtO2) were measured using a metabolic and spirometry module of the medical monitoring system. Wavelet transform analysis was used to assess the relationship between BP and cc-TQ oscillations. Results HGT evoked an increase in BP (+15.9%; P<0.001), HR (14.7; P<0.001), SaO2 (+0.5; P<0.001) EtO2 (+2.1; P<0.05) RR (+9.2%; P = 0.05) and MV (+15.5%; P<0.001), while sas-TQ was diminished (-8.12%; P<0.001), and a clear trend toward cc-TQ decline was observed (-11.0%; NS). CBFV (+2.9%; NS) and EtCO2 (-0.7; NS) did not change during HGT. CT evoked an increase in BP (+7.4%; P<0.001), sas-TQ (+3.5%; P<0.05) and SaO2(+0.3%; P<0.05). HR (+2.3%; NS), CBFV (+2.0%; NS), EtO2 (-0.7%; NS) and EtCO2 (+0.9%; NS) remained unchanged. A trend toward decreased cc-TQ was observed (-5.1%; NS). The sas-TQ response was biphasic with elevation during the first 40 seconds (+8.8% vs. baseline; P<0.001) and subsequent decline (+4.1% vs. baseline; P<0.05). No change with respect to wavelet coherence and wavelet phase coherence was found between the BP and cc-TQ oscillations. Conclusions Short sympathetic activation does not affect the cardiac and respiratory contribution to the relationship between BP—cc-TQ oscillations. HGT and CT display divergent effects on the width of the subarachnoid space, an indirect marker of changes in intracranial pressure.
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Affiliation(s)
- Pawel J. Winklewski
- Institute of Human Physiology, Medical University of Gdansk, Gdansk, Poland
- * E-mail:
| | - Yurii Tkachenko
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Gdynia, Poland
| | - Kamila Mazur
- Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Gdynia, Poland
| | - Marcin Gruszecki
- Department of Radiology Informatics and Statistics, Medical University of Gdansk, Gdansk, Poland
| | - Wojciech Guminski
- Department of Computer Communications, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | - Krzysztof Czuszynski
- Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | - Jerzy Wtorek
- Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
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50
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Berg RMG, Plovsing RR, Bailey DM, Holstein-Rathlou NH, Møller K. Dynamic cerebral autoregulation to induced blood pressure changes in human experimental and clinical sepsis. Clin Physiol Funct Imaging 2015; 36:490-496. [PMID: 26017052 DOI: 10.1111/cpf.12256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 03/24/2015] [Indexed: 12/25/2022]
Abstract
Previous studies have demonstrated that dynamic cerebral autoregulation to spontaneous fluctuations in blood pressure is enhanced following lipopolysaccharide (LPS) infusion, a human experimental model of early sepsis, whereas by contrast it is impaired in patients with severe sepsis or septic shock. In this study, we hypothesized that this pattern of response would be identical during induced changes in blood pressure. Dynamic cerebral autoregulation was assessed in nine healthy volunteers and six septic patients. The healthy volunteers underwent a 4-h intravenous infusion of LPS (total dose: 2 ng kg-1 ). Mean arterial blood pressure (MAP, arterial transducer) and middle cerebral artery blood flow velocity (MCAv, transcranial Doppler ultrasound) were recorded continuously during thigh-cuff deflation-induced changes in MAP for the determination of a modified rate of regulation (RoR). This was performed before and after LPS infusion in healthy volunteers, and within 72 h following clinical diagnosis of sepsis in patients. In healthy volunteers, thigh-cuff deflation caused a MAP reduction of 16 (13-20) % at baseline and 18 (16-20) % after LPS, while the MAP reduction was 12 (11-13) % in patients (P<0·05 versus volunteers at baseline; P<0·01 versus volunteers after LPS). The corresponding RoR values increased from 0·46 (0·31-0·49) s-1 at baseline to 0·58 (0·36-0·74) s-1 after LPS (P<0·05) in healthy volunteers, whereas they were similar to values observed in patients [0·43 (0·36-0·52) s-1 ; P = 0·91 versus baseline; P = 0·14 versus LPS]. While our findings support the concept that dynamic cerebral autoregulation is enhanced during the very early stages of sepsis, they remain inconclusive with regard to more advanced stages of disease, because thigh-cuff deflation failed to induce sufficient MAP reductions in patients.
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Affiliation(s)
- Ronan M G Berg
- Department of Clinical Physiology, Nuclear Medicine & PET, University Hospital Rigshospitalet, Copenhagen Ø, Denmark. .,Centre of Inflammation and Metabolism, Department of Infectious Diseases M7641, University Hospital Rigshospitalet, Copenhagen Ø, Denmark.
| | - Ronni R Plovsing
- Department of Intensive Care, University Hospital Rigshospitalet, Copenhagen Ø, Denmark.,Department of Anaesthesia, Køge Hospital, Køge, Denmark
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK
| | - Niels-Henrik Holstein-Rathlou
- Renal and Vascular Research Section, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen Ø, Denmark
| | - Kirsten Møller
- Centre of Inflammation and Metabolism, Department of Infectious Diseases M7641, University Hospital Rigshospitalet, Copenhagen Ø, Denmark.,Neurointensive Care Unit 2093, Department of Neuroanaesthesiology, University Hospital Rigshospitalet, Copenhagen Ø, Denmark
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