1
|
Roy S, Lam MY, Panerai RB, Robinson TG, Minhas JS. Blood pressure variability at rest and during pressor challenges in patients with acute ischemic stroke. Blood Press Monit 2024:00126097-990000000-00111. [PMID: 38841869 DOI: 10.1097/mbp.0000000000000710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
INTRODUCTION Patients with acute ischemic stroke (AIS) have elevated blood pressure (BP) variability (BPV) and reduced baroreflex sensitivity (BRS) at rest for several days after initial stroke symptoms. We aimed to assess BPV and BRS in AIS patients during pressor challenge maneuvers in the acute and subacute phases of stroke. Pressor challenge maneuvers simulate day-to-day activities and can predict the quality of life. METHODS Continuous beat-to-beat BP and ECG in 15 AIS patients (mean age 69 ± 7.5 years) and 15 healthy controls (57 ± 16 years) were recorded at rest and during a 5-min rapid head positioning (RHP) paradigm. Patients were assessed within 24 h (acute phase) and 7 days (subacute phase) of stroke onset. Low frequency (LF) SBP power (measure of BPV), LF-α, and combined α-index (measure of BRS) were calculated from the recordings. RESULTS In the acute phase, at rest, LF-SBP power was higher (P = 0.024) and α-index was lower (P = 0.006) in AIS patients than in healthy controls. There was no change in LF-SBP during RHP in the patients but in healthy controls, it increased significantly (P = 0.018). In the subacute phase, at rest, the alpha-index increased (P = 0.037) and LF-SBP decreased (P = 0.029) significantly in the AIS patients, however, there was still no rise in the LF-SBP power during RHP (P = 0.240). CONCLUSION AIS patients have a high resting BPV. High resting BPV may be responsible for blunted BPV responses during pressor challenge maneuvers such as RHP, suggesting ongoing autonomic dysfunction and compromised quality of life.
Collapse
Affiliation(s)
- Sankanika Roy
- Department of Cardiovascular Sciences, University of Leicester
| | - Man Y Lam
- Department of Cardiovascular Sciences, University of Leicester
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Jatinder S Minhas
- Department of Cardiovascular Sciences, University of Leicester
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| |
Collapse
|
2
|
Lengyel B, Magyar-Stang R, Pál H, Debreczeni R, Sándor ÁD, Székely A, Gyürki D, Csippa B, István L, Kovács I, Sótonyi P, Mihály Z. Non-Invasive Tools in Perioperative Stroke Risk Assessment for Asymptomatic Carotid Artery Stenosis with a Focus on the Circle of Willis. J Clin Med 2024; 13:2487. [PMID: 38731014 PMCID: PMC11084304 DOI: 10.3390/jcm13092487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/17/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
This review aims to explore advancements in perioperative ischemic stroke risk estimation for asymptomatic patients with significant carotid artery stenosis, focusing on Circle of Willis (CoW) morphology based on the CTA or MR diagnostic imaging in the current preoperative diagnostic algorithm. Functional transcranial Doppler (fTCD), near-infrared spectroscopy (NIRS), and optical coherence tomography angiography (OCTA) are discussed in the context of evaluating cerebrovascular reserve capacity and collateral vascular systems, particularly the CoW. These non-invasive diagnostic tools provide additional valuable insights into the cerebral perfusion status. They support biomedical modeling as the gold standard for the prediction of the potential impact of carotid artery stenosis on the hemodynamic changes of cerebral perfusion. Intraoperative risk assessment strategies, including selective shunting, are explored with a focus on CoW variations and their implications for perioperative ischemic stroke and cognitive function decline. By synthesizing these insights, this review underscores the potential of non-invasive diagnostic methods to support clinical decision making and improve asymptomatic patient outcomes by reducing the risk of perioperative ischemic neurological events and preventing further cognitive decline.
Collapse
Affiliation(s)
- Balázs Lengyel
- Department of Vascular and Endovascular Surgery, Heart and Vascular Center, Semmelweis University, 1122 Budapest, Hungary; (B.L.); (P.S.J.)
| | - Rita Magyar-Stang
- Department of Neurology, Semmelweis University, 1085 Budapest, Hungary; (R.M.-S.); (H.P.); (R.D.)
- Szentágothai Doctoral School of Neurosciences, Semmelweis University, 1085 Budapest, Hungary
| | - Hanga Pál
- Department of Neurology, Semmelweis University, 1085 Budapest, Hungary; (R.M.-S.); (H.P.); (R.D.)
- Szentágothai Doctoral School of Neurosciences, Semmelweis University, 1085 Budapest, Hungary
| | - Róbert Debreczeni
- Department of Neurology, Semmelweis University, 1085 Budapest, Hungary; (R.M.-S.); (H.P.); (R.D.)
- Szentágothai Doctoral School of Neurosciences, Semmelweis University, 1085 Budapest, Hungary
| | - Ágnes Dóra Sándor
- Department of Anesthesiology and Intensive Therapy, Semmelweis University, 1085 Budapest, Hungary; (Á.D.S.); (A.S.)
| | - Andrea Székely
- Department of Anesthesiology and Intensive Therapy, Semmelweis University, 1085 Budapest, Hungary; (Á.D.S.); (A.S.)
| | - Dániel Gyürki
- Department of Hydrodynamic Systems, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, 1085 Budapest, Hungary; (D.G.); (B.C.)
| | - Benjamin Csippa
- Department of Hydrodynamic Systems, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, 1085 Budapest, Hungary; (D.G.); (B.C.)
| | - Lilla István
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary; (L.I.); (I.K.)
| | - Illés Kovács
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary; (L.I.); (I.K.)
- Department of Ophthalmology, Weill Cornell Medical College, New York, NY 10065, USA
- Department of Clinical Ophthalmology, Faculty of Health Sciences, Semmelweis University, 1085 Budapest, Hungary
| | - Péter Sótonyi
- Department of Vascular and Endovascular Surgery, Heart and Vascular Center, Semmelweis University, 1122 Budapest, Hungary; (B.L.); (P.S.J.)
| | - Zsuzsanna Mihály
- Department of Vascular and Endovascular Surgery, Heart and Vascular Center, Semmelweis University, 1122 Budapest, Hungary; (B.L.); (P.S.J.)
| |
Collapse
|
3
|
Lakatos LB, Shin DC, Müller M, Österreich M, Marmarelis V, Bolognese M. Impaired dynamic cerebral autoregulation measured in the middle cerebral artery in patients with vertebrobasilar ischemia is associated with autonomic failure. J Stroke Cerebrovasc Dis 2024; 33:107454. [PMID: 37931481 PMCID: PMC10841591 DOI: 10.1016/j.jstrokecerebrovasdis.2023.107454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/21/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023] Open
Abstract
OBJECTIVES To assess whether vertebrobasilar artery ischemia (VBI) affects cortical cerebral blood flow (CBF) regulation. MATERIAL AND METHODS 107 consecutive patients (mean age 65 ± 15 years; women 21) with VBI underwent structured stroke care with assessment of dynamic cerebral autoregulation (dCA) in both middle cerebral arteries (MCAs) by transfer function analysis using spontaneous oscillations of blood pressure (BP) and CBF velocity that yields by extraction of phase and gain information in the very low (0.02-0.07 Hz), low (0.07-0.15 Hz) and high frequency (0.15-0.5 Hz) ranges. Additionally, power spectrum analysis of BP and heart rate variability (HRV) was performed. The control group consists of 29 age- and sex-matched healthy persons. RESULTS Compared to controls, phase in the VBI patients was significantly reduced and gain increased in the very low frequencies (VLF), in the low (LF), phase was significantly reduced only ipsilaterally. In the high frequencies (HF), phase reduction was only marginally significant. BP power spectral density (PSD) was much higher in the patients than in the controls across all frequencies. In the PSD of heart rate variability the controls but not the patients exhibited a strong peak around 0.11Hz, while the patients, but not the controls, exhibit a strong peak around 0.36 Hz. In regression analysis, patient's phase and gain results were not related to age, sex, arterial hypertension, diabetes mellitus, renal dysfunction, heart failure as indicated by left ventricular ejection fraction, stroke subtype, presence or absence of cerebral small vessel disease. CONCLUSION Patients with VBI exhibit bilateral cortical autoregulation impairment in association with an autonomic nervous system disbalance. CLINICALTRIALS GOV IDENTIFIER NCT04611672.
Collapse
Affiliation(s)
- Lehel Barna Lakatos
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland
| | - Dae C Shin
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, United States
| | - Martin Müller
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland.
| | - Mareike Österreich
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland
| | - Vasilis Marmarelis
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, United States
| | - Manuel Bolognese
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland
| |
Collapse
|
4
|
Brassard P, Roy MA, Burma JS, Labrecque L, Smirl JD. Quantification of dynamic cerebral autoregulation: welcome to the jungle! Clin Auton Res 2023; 33:791-810. [PMID: 37758907 DOI: 10.1007/s10286-023-00986-2] [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: 08/01/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
PURPOSE Patients with dysautonomia often experience symptoms such as dizziness, syncope, blurred vision and brain fog. Dynamic cerebral autoregulation, or the ability of the cerebrovasculature to react to transient changes in arterial blood pressure, could be associated with these symptoms. METHODS In this narrative review, we go beyond the classical view of cerebral autoregulation to discuss dynamic cerebral autoregulation, focusing on recent advances pitfalls and future directions. RESULTS Following some historical background, this narrative review provides a brief overview of the concept of cerebral autoregulation, with a focus on the quantification of dynamic cerebral autoregulation. We then discuss the main protocols and analytical approaches to assess dynamic cerebral autoregulation, including recent advances and important issues which need to be tackled. CONCLUSION The researcher or clinician new to this field needs an adequate comprehension of the toolbox they have to adequately assess, and interpret, the complex relationship between arterial blood pressure and cerebral blood flow in healthy individuals and clinical populations, including patients with autonomic disorders.
Collapse
Affiliation(s)
- 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.
| | - 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
| | - Joel S Burma
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - 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
| | - Jonathan D Smirl
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
5
|
Ince J, Minhas JS, Panerai RB. Point/counterpoint: Cerebrovascular resistance is a flawed concept. J Cereb Blood Flow Metab 2023; 43:1216-1218. [PMID: 37113067 PMCID: PMC10291456 DOI: 10.1177/0271678x231172854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 03/18/2023] [Accepted: 03/27/2023] [Indexed: 04/29/2023]
Abstract
The relationship between cerebral blood flow and blood pressure is a critical part of investigation of cerebral autoregulation. Conventionally, cerebrovascular resistance (CVR) has been used to describe this relationship, but the underlying principles used for this method is flawed in real-world application for several reasons. Despite this, the use of CVR remains entrenched within current literature. This 'Point/Counterpoint' review provides a summary of the flaws in using CVR and explains the benefits of calculating the more accurate critical closing pressure (CrCP) and resistance-area product (RAP) parameters, with support of real-world data.
Collapse
Affiliation(s)
- Jonathan Ince
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, Leicester, UK
| | - Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, Leicester, UK
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Panerai RB, Brassard P, Burma JS, Castro P, Claassen JA, van Lieshout JJ, Liu J, Lucas SJ, Minhas JS, Mitsis GD, Nogueira RC, Ogoh S, Payne SJ, Rickards CA, Robertson AD, Rodrigues GD, Smirl JD, Simpson DM. Transfer function analysis of dynamic cerebral autoregulation: A CARNet white paper 2022 update. J Cereb Blood Flow Metab 2023; 43:3-25. [PMID: 35962478 PMCID: PMC9875346 DOI: 10.1177/0271678x221119760] [Citation(s) in RCA: 47] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cerebral autoregulation (CA) refers to the control of cerebral tissue blood flow (CBF) in response to changes in perfusion pressure. Due to the challenges of measuring intracranial pressure, CA is often described as the relationship between mean arterial pressure (MAP) and CBF. Dynamic CA (dCA) can be assessed using multiple techniques, with transfer function analysis (TFA) being the most common. A 2016 white paper by members of an international Cerebrovascular Research Network (CARNet) that is focused on CA strove to improve TFA standardization by way of introducing data acquisition, analysis, and reporting guidelines. Since then, additional evidence has allowed for the improvement and refinement of the original recommendations, as well as for the inclusion of new guidelines to reflect recent advances in the field. This second edition of the white paper contains more robust, evidence-based recommendations, which have been expanded to address current streams of inquiry, including optimizing MAP variability, acquiring CBF estimates from alternative methods, estimating alternative dCA metrics, and incorporating dCA quantification into clinical trials. Implementation of these new and revised recommendations is important to improve the reliability and reproducibility of dCA studies, and to facilitate inter-institutional collaboration and the comparison of results between studies.
Collapse
Affiliation(s)
- Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester and NIHR Biomedical Research Centre, Leicester, UK
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, and Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Joel S Burma
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Pedro Castro
- Department of Neurology, Centro Hospitalar Universitário de São João, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Jurgen Ahr Claassen
- Department of Geriatric Medicine and Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Johannes J van Lieshout
- Department of Internal Medicine, Amsterdam, UMC, The Netherlands and Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, UK
| | - Jia Liu
- Institute of Advanced Computing and Digital Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen University Town, Shenzhen, China
| | - Samuel Je Lucas
- School of Sport, Exercise and Rehabilitation Sciences and Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Jatinder S Minhas
- Department of Cardiovascular Sciences, University of Leicester and NIHR Biomedical Research Centre, Leicester, UK
| | - Georgios D Mitsis
- Department of Bioengineering, McGill University, Montreal, Québec, QC, Canada
| | - Ricardo C Nogueira
- Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil
| | - Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan
| | - Stephen J Payne
- Institute of Applied Mechanics, National Taiwan University, Taipei
| | - Caroline A Rickards
- Department of Physiology & Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Andrew D Robertson
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, Canada
| | - Gabriel D Rodrigues
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Jonathan D Smirl
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - David M Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | | |
Collapse
|
8
|
Quispe-Cornejo AA, Crippa IA, Bakos P, Dominguez-Faure A, Creteur J, Taccone FS. Correlation between heart rate variability and cerebral autoregulation in septic patients. Auton Neurosci 2023; 244:103051. [PMID: 36493585 DOI: 10.1016/j.autneu.2022.103051] [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: 11/28/2021] [Revised: 10/20/2022] [Accepted: 11/09/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND Heart rate variability (HRV) may provide an estimation of the autonomous nervous system (ANS) integrity in critically ill patients. Disturbances of cerebral autoregulation (CAR) may share common pathways of ANS dysfunction. AIM To explore whether changes in HRV and CAR index correlate in critically ill septic patients. METHODS Prospectively collected data on septic adult (> 18 years) patients admitted into a mixed Intensive Care between February 2016 and August 2019 with a recorded transcranial doppler CAR assessment. CAR was assessed calculating the Pearson's correlation coefficient (i.e. mean flow index, Mxa) between the left middle cerebral artery flow velocity (FV), insonated with a 2-MHz probe, and invasive blood pressure (BP) signal, both recorded simultaneously through a Doppler Box (DWL, Germany). MATLAB software was used for CAR assessment using a validated script; a Mxa >0.3 was considered as impaired CAR. HRV was assessed during the same time period using a specific software (Kubios HRV 3.2.0) and analyzed in both time-domain and frequency domain methods. Correlation between HRV-derived variables and Mxa were assessed using the Spearman's coefficient. RESULTS A total of 141 septic patients was studied; median Mxa was 0.35 [0.13-0.60], with 77 (54.6 %) patients having an impaired CAR. Mxa had a significant although weak correlation with HRV time domain (SDNN, r = 0.17, p = 0.04; RMSSD, r = 0.18, p = 0.03; NN50, r = 0.23, p = 0.006; pNN50, r = 0.23, p = 0.007), frequency domain (FFT-HF, r = 0.21; p = 0.01; AR-HF, r = 0.19; p = 0.02), and non-linear domain (SD1, r = 0.18, p = 0.03) parameters. Impaired CAR patients had also all of these HRV-derived parameters higher than those with intact CAR. CONCLUSIONS In this exploratory study, a potential association of ANS dysfunction and impaired CAR during sepsis was observed.
Collapse
Affiliation(s)
- Armin Alvaro Quispe-Cornejo
- Department of Intensive Care, Erasme University Hospital, Brussels, Belgium; Instituto Académico Científico Quispe-Cornejo, INAAQC, La Paz, Bolivia.
| | | | - Péter Bakos
- Department of Intensive Care, Erasme University Hospital, Brussels, Belgium; Instituto Académico Científico Quispe-Cornejo, INAAQC, La Paz, Bolivia
| | | | - Jacques Creteur
- Department of Intensive Care, Erasme University Hospital, Brussels, Belgium
| | | |
Collapse
|
9
|
Lee E, Anselmo M, Tahsin CT, Vanden Noven M, Stokes W, Carter JR, Keller-Ross ML. Vasomotor symptoms of menopause, autonomic dysfunction, and cardiovascular disease. Am J Physiol Heart Circ Physiol 2022; 323:H1270-H1280. [PMID: 36367692 PMCID: PMC9744645 DOI: 10.1152/ajpheart.00477.2022] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/18/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022]
Abstract
Cardiovascular disease (CVD), the leading cause of death among US adults, is more prevalent in menopausal females compared with age-matched males. Vasomotor symptoms of menopause (VMS; hot flashes/flushes and night sweats) are common among females undergoing menopausal transition and have been associated with elevated blood pressure (BP) and increased CVD risk. Autonomic dysregulation of BP has been posited as a contributing factor to the elevated CVD risk in menopausal females with VMS. This review includes 1) a brief overview of the relationship between VMS and CVD, 2) mechanisms of hot flushes and their potential impact on short- and long-term BP regulation, and 3) how the disruption of autonomic function associated with VMS might provide a mechanistic pathway to CVD development. Finally, this review will highlight knowledge gaps and future directions toward better understanding of hot flush physiology and VMS contributions to CVD.
Collapse
Affiliation(s)
- Emma Lee
- Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Miguel Anselmo
- Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Chowdhury Tasnova Tahsin
- Division of Rehabilitation Science, Medical School, University of Minnesota, Minneapolis, Minnesota
| | | | - William Stokes
- Division of Rehabilitation Science, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Jason R Carter
- Department of Health and Human Development, Montana State University, Bozeman, Montana
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas
| | - Manda L Keller-Ross
- Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota
- Division of Rehabilitation Science, Medical School, University of Minnesota, Minneapolis, Minnesota
| |
Collapse
|
10
|
Castro P, Freitas J, Azevedo E, Tan CO. Cerebrovascular regulation in patients with vasovagal syncope and autonomic failure due to familial amyloidotic polyneuropathy. Auton Neurosci 2022; 242:103010. [PMID: 35907336 DOI: 10.1016/j.autneu.2022.103010] [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: 08/27/2021] [Revised: 05/10/2022] [Accepted: 07/03/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION While there is strong evidence for autonomic involvement in cerebrovascular function acutely, long-term role of autonomic nervous system in cerebrovascular function has been controversial. We assessed autoregulation in 10 healthy individuals, nine patients with vasovagal syncope (VVS), and nine with Familial Amyloidotic Polyneuropathy (FAP), in response to head-up tilt test (HUTT). METHODS Arterial blood pressure heart rate, cardiac output, and bilateral cerebral blood flow velocity (CBFV) at the M1 segment of middle cerebral artery (transcranial Doppler ultrasound) were recorded during supine rest and 70° HUTT. Autoregulation was quantified using a validated nonlinear and nonparametric approach based on projection pursuit regression. Plasma adrenaline and noradrenaline were also measured at rest and during HUTT. RESULTS During supine rest and HUTT, plasma noradrenaline content was lower in FAP patients. During HUTT, VVS patients had a hyperadrenergic status; CBFV decreased in all groups, which was greater in FAP patients (p < 0.01). Healthy controls responded to HUTT with a reduction in CBFV responses to increases (p = 0.01) and decreases (p < 0.01) in arterial pressure without any change in the range or effectiveness of autoregulation. VVS patients responded to HUTT with a reduction in falling (p = 0.02), but not rising slope (p = 0.40). Autoregulatory range (p < 0.01) and effectiveness increased (p = 0.09), consistent with the rapid increase in levels of catecholamines. In FAP patients, the level of increase in range of autoregulation was significantly related to the magnitude of increase in plasma noradrenaline in response to HUTT (R2 = 0.26, p = 0.05). CONCLUSION Autonomic dysfunction affects the cerebral autoregulatory response orthostatic to challenge.
Collapse
Affiliation(s)
- Pedro Castro
- Department of Neurology, Centro Hospitalar Universitário São João, Cardiovascular R&D Unit, Faculty of Medicine of University of Porto, Porto, Portugal.
| | - João Freitas
- Autonomic Unit, São João Hospital Center, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Elsa Azevedo
- Department of Neurology, Centro Hospitalar Universitário São João, Cardiovascular R&D Unit, Faculty of Medicine of University of Porto, Porto, Portugal.
| | - Can Ozan Tan
- Cerebrovascular Research Laboratory and Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Boston, MA, US.
| |
Collapse
|
11
|
Exploring metrics for the characterization of the cerebral autoregulation during head-up tilt and propofol general anesthesia. Auton Neurosci 2022; 242:103011. [PMID: 35834916 DOI: 10.1016/j.autneu.2022.103011] [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: 10/26/2021] [Revised: 05/30/2022] [Accepted: 07/03/2022] [Indexed: 11/22/2022]
Abstract
Techniques grounded on the simultaneous utilization of Tiecks' second order differential equations and spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV), recorded from middle cerebral arteries through a transcranial Doppler device, provide a characterization of cerebral autoregulation (CA) via the autoregulation index (ARI). These methods exploit two metrics for comparing the measured MCBFV series with the version predicted by Tiecks' model: normalized mean square prediction error (NMSPE) and normalized correlation ρ. The aim of this study is to assess the two metrics for ARI computation in 13 healthy subjects (age: 27 ± 8 yrs., 5 males) at rest in supine position (REST) and during 60° head-up tilt (HUT) and in 19 patients (age: 64 ± 8 yrs., all males), scheduled for coronary artery bypass grafting, before (PRE) and after (POST) propofol general anesthesia induction. Analyses were carried out over the original MAP and MCBFV pairs and surrogate unmatched couples built individually via time-shifting procedure. We found that: i) NMSPE and ρ metrics exhibited similar performances in passing individual surrogate test; ii) the two metrics could lead to different ARI estimates; iii) CA was not different during HUT or POST compared to baseline and this conclusion held regardless of the technique and metric for ARI estimation. Results suggest a limited impact of the sympathetic control on CA.
Collapse
|
12
|
Clough RH, Minhas JS, Haunton VJ, Hanby MF, Robinson TG, Panerai RB. Dynamics of the cerebral autoregulatory response to paced hyperventilation assessed using sub-component and time-varying analyses. J Appl Physiol (1985) 2022; 133:311-319. [PMID: 35736950 DOI: 10.1152/japplphysiol.00100.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral blood flow (CBF) can be altered by a change in partial pressure of arterial CO2 (pCO2), being reduced during hyperventilation (HPV). Critical closing pressure (CrCP) and resistance area product (RAP) are parameters which can be studied to understand this change, but their dynamic response has not been investigated during paced HPV (PHPV). Seventy five participants had recordings at rest and during PHPV. Blood pressure (BP) (Finometer), bilateral CBF velocity (CBFV) (transcranial Doppler), end-tidal CO2 (capnography) and heart rate (HR) were recorded continuously. Subcomponent analysis (SCA) and time-varying CrCP, RAP and dynamic cerebral autoregulation (Autoregulation Index, ARI) were estimated comparing PHPV to poikilocapnia. PHPV caused a change in CBFV (p<0.01), EtCO2, (p<0.01), HR (p<0.001) and RAP (p<0.01). SCA demonstrated RAP was the main parameter explaining the changes in CBFV due to PHPV. The time-varying step responses for CBFV and RAP during PHPV demonstrated considerable non-stationarity compared to poikilocapnia (p<0.00001). Although time-varying ARI was temporarily depressed, after 60 s of PHPV it was significantly higher (6.81 ± 1.88) (p<0.0001) than in poikilocapnia (5.08 ± 1.86). The mean plateau of the RAP step response was -98.3 ± 58.8 % 60 s after the onset of PHPV but -71.7 ± 45.0 % for poikilocapnia (p=0.0026), with no corresponding changes in CrCP (p=0.6). Further work is needed to assess the role of sex and aging in our findings, and the potential for using RAP and CrCP to improve the sensitivity and specificity of CO2 reactivity studies in cerebrovascular conditions.
Collapse
Affiliation(s)
- Rebecca H Clough
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Victoria J Haunton
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Martha Frances Hanby
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Thompson G Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| |
Collapse
|
13
|
The role of the autonomic nervous system in cerebral blood flow regulation in dementia: A review. Auton Neurosci 2022; 240:102985. [DOI: 10.1016/j.autneu.2022.102985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/28/2022] [Accepted: 04/28/2022] [Indexed: 11/19/2022]
|
14
|
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]
|
15
|
Hamarat Y, Deimantavicius M, Dambrauskas V, Labunskas V, Putnynaite V, Lucinskas P, Siaudvytyte L, Simiene E, Stoskuviene A, Januleviciene I, Petkus V, Ragauskas A. Prospective Pilot Clinical Study of Noninvasive Cerebrovascular Autoregulation Monitoring in Open-Angle Glaucoma Patients and Healthy Subjects. Transl Vis Sci Technol 2022; 11:17. [PMID: 35138342 PMCID: PMC8842541 DOI: 10.1167/tvst.11.2.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To analyze the cerebrovascular autoregulation (CA) dynamics in patients with normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) as well as healthy subjects using noninvasive ultrasound technologies for the first time. Methods The CA status of 10 patients with NTG, 8 patients with HTG, and 10 healthy subjects was assessed, using an innovative noninvasive ultrasonic technique, based on intracranial blood volume slow-wave measurements. Identified in each participant were intraocular pressure, ocular perfusion pressure, and CA-related parameter volumetric reactivity index (VRx), as well as the duration and doses of the longest cerebral autoregulation impairment (LCAI). In addition, we calculated the associations of these parameters with patients' diagnoses. Results The VRx value, the LCAI dose, and duration in healthy subjects were significantly lower than in patients with NTG (P < 0.05). However, no significant differences were noted in these parameters between healthy subjects and HTG and between NTG and HTG groups. Conclusions NTG is associated with the disturbed cerebral blood flow and could be diagnosed by performing noninvasive CA assessments. Translational Relevance The VRx monitoring method can be applied to a wider range of patient groups, especially patients with normal-tension glaucoma.
Collapse
Affiliation(s)
- Yasin Hamarat
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania.,0000-0002-1343-5068
| | - Mantas Deimantavicius
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Vilius Dambrauskas
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Vaidas Labunskas
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Vilma Putnynaite
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Paulius Lucinskas
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Lina Siaudvytyte
- Eye Clinic, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Evelina Simiene
- Eye Clinic, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | | | | | - Vytautas Petkus
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Arminas Ragauskas
- Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| |
Collapse
|
16
|
Gelpi F, Bari V, Cairo B, De Maria B, Tonon D, Rossato G, Faes L, Porta A. Dynamic cerebrovascular autoregulation in patients prone to postural syncope: Comparison of techniques assessing the autoregulation index from spontaneous variability series. Auton Neurosci 2021; 237:102920. [PMID: 34808528 DOI: 10.1016/j.autneu.2021.102920] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 10/20/2021] [Accepted: 11/15/2021] [Indexed: 10/19/2022]
Abstract
Three approaches to the assessment of cerebrovascular autoregulation (CA) via the computation of the autoregulation index (ARI) from spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV) were applied: 1) a time domain method (TDM); 2) a nonparametric method (nonPM); 3) a parametric method (PM). Performances were tested over matched and surrogate unmatched pairs. Data were analyzed at supine resting (REST) and during the early phase of 60° head-up tilt (TILT) in 13 subjects with previous history of postural syncope (SYNC, age: 28 ± 9 yrs.; 5 males) and 13 control individuals (noSYNC, age: 27 ± 8 yrs.; 5 males). Analysis was completed by computing autonomic markers from heart period (HP) and systolic arterial pressure (SAP) variability series via spectral approach. HP and SAP spectral indexes suggested that noSYNC and SYNC groups exhibited different autonomic responses to TILT. ARI analysis indicated that: i) all methods have a sufficient statistical power to separate matched from unmatched pairs with the exception of nonPM applied to impulse response; ii) ARI estimates derived from different methods might be uncorrelated and, even when correlated, might exhibit a significant bias; iii) orthostatic stressor did not induce any evident ARI change in either noSYNC or SYNC individuals; iv) this conclusion held regardless of the method. Methods for the ARI estimation from spontaneous variability provide different ARIs but none indicate that noSYNC and SYNC subjects have different dynamic component of CA.
Collapse
Affiliation(s)
- Francesca Gelpi
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Vlasta Bari
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Beatrice Cairo
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | | | - Davide Tonon
- Department of Neurology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy
| | - Gianluca Rossato
- Department of Neurology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy
| | - Luca Faes
- Department of Engineering, University of Palermo, Palermo, Italy
| | - Alberto Porta
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
| |
Collapse
|
17
|
Panerai RB, Haunton VJ, Llwyd O, Minhas JS, Katsogridakis E, Salinet ASM, Maggio P, Robinson TG. Cerebral critical closing pressure and resistance-area product: the influence of dynamic cerebral autoregulation, age and sex. J Cereb Blood Flow Metab 2021; 41:2456-2469. [PMID: 33818187 PMCID: PMC8392773 DOI: 10.1177/0271678x211004131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 01/19/2021] [Accepted: 02/16/2021] [Indexed: 11/21/2022]
Abstract
Instantaneous arterial pressure-flow (or velocity) relationships indicate the existence of a cerebral critical closing pressure (CrCP), with the slope of the relationship expressed by the resistance-area product (RAP). In 194 healthy subjects (20-82 years, 90 female), cerebral blood flow velocity (CBFV, transcranial Doppler), arterial blood pressure (BP, Finapres) and end-tidal CO2 (EtCO2, capnography) were measured continuously for five minutes during spontaneous fluctuations of BP at rest. The dynamic cerebral autoregulation (CA) index (ARI) was extracted with transfer function analysis from the CBFV step response to the BP input and step responses were also obtained for the BP-CrCP and BP-RAP relationships. ARI was shown to decrease with age at a rate of -0.025 units/year in men (p = 0.022), but not in women (p = 0.40). The temporal patterns of the BP-CBFV, BP-CrCP and BP-RAP step responses were strongly influenced by the ARI (p < 0.0001), but not by sex. Age was also a significant determinant of the peak of the CBFV step response and the tail of the RAP response. Whilst the RAP step response pattern is consistent with a myogenic mechanism controlling dynamic CA, further work is needed to explore the potential association of the CrCP step response with the flow-mediated component of autoregulation.
Collapse
Affiliation(s)
- Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Victoria J Haunton
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Osian Llwyd
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Emmanuel Katsogridakis
- Department of Vascular Surgery, Wythenshawe Hospital, Manchester Foundation Trust, Manchester, UK
| | - Angela SM Salinet
- Neurology Department, Hospital das Clinicas, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Paola Maggio
- Neurology Department, ASST Bergamo EST (BG), Italy
| | - Thompson G Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| |
Collapse
|
18
|
Castro P, Serrador J, Rocha I, Chaves PC, Sorond F, Azevedo E. Heart failure patients have enhanced cerebral autoregulation response in acute ischemic stroke. J Thromb Thrombolysis 2021; 50:753-761. [PMID: 32488831 DOI: 10.1007/s11239-020-02166-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The cerebrovascular effects of a failing heart-pump are largely unknown. Chronic heart failure (HF) might cause pre-conditioning effect on cerebral hemodynamics but not study so far in acute stroke. We aimed to investigate if HF induces effects in dynamic cerebral autoregulation (CA), within 6 h of symptom-onset through chronic stage of ischemic stroke. We enrolled 50 patients with acute ischemic stroke. Groups with (N = 8) and without HF and 20 heathy controls were compared. Arterial blood pressure (Finometer) and cerebral blood flow velocity (transcranial Doppler) were monitored within 6 and at 24 h from symptom-onset and at 3 months. We assessed dynamic CA by transfer function analysis and cardiac disease markers. HF associated with higher phase (better dynamic CA) at ischemic hemisphere within 6 (p = 0.042) and at 24 h (p = 0.006) but this effect was not evident at 3 months (p > 0.05). Gain and coherence trends were similar between groups. We found a positive correlation between phase and admission troponin I levels (Spearman's r = 0.348, p = 0.044). Our findings advances on the knowledge of how brain and heart interact in acute ischemic stroke by showing a sustained dynamic cerebral autoregulation response in HF patients mainly with severe aortic valve disease. Understanding the physiological mechanisms that govern this complex interplay can be useful to find novel therapeutic targets which can improve outcome in ischemic stroke.
Collapse
Affiliation(s)
- Pedro Castro
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200-319, Porto, Portugal. .,Department of Neurology, Centro Hospitalar Universitário de São João, Porto, Portugal.
| | - Jorge Serrador
- Veterans Biomedical Institute and War Related Illness and Injury Study Center, Department of Veterans Affairs, New Jersey Healthcare System, East Orange, USA.,New Jersey Medical School, Newark, NJ, USA
| | - Isabel Rocha
- Cardiovascular Autonomic Function Lab, Institute of Physiology, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Paulo Castro Chaves
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200-319, Porto, Portugal
| | - Farzaneh Sorond
- Division of Stroke and Neurocritical, Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Elsa Azevedo
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200-319, Porto, Portugal.,Department of Neurology, Centro Hospitalar Universitário de São João, Porto, Portugal
| |
Collapse
|
19
|
Robles FAB, Panerai RB, Katsogridakis E, Chacon M. Superior fitting of arterial resistance and compliance parameters with genetic algorithms in models of dynamic cerebral autoregulation. IEEE Trans Biomed Eng 2021; 69:503-512. [PMID: 34314353 DOI: 10.1109/tbme.2021.3100288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The capacity of discriminating between normal and impaired dynamic cerebral autoregulation (dCA), based on spontaneous fluctuations in arterial blood pressure (ABP) and cerebral blood flow (CBF), has considerable clinical relevance. This study aimed to quantify the separate contributions of vascular resistance and compliance as parameters that could reflect myogenic and metabolic mechanisms to dCA. METHODS Forty-five subjects were studied under normo and hypercapnic conditions induced by breathing a mixture of 5% carbon dioxide in air. Dynamic cerebrovascular resistance and compliance models with ABP as input and CBFV as output were fitted using Genetic Algorithms to identify parameter values for each subject, and respiratory condition. RESULTS The efficiency of dCA was assessed from the models generated CBFV response to an ABP step change, corresponding to an autoregulation index of 5.561.57 in normocapnia and 2.381.73 in hypercapnia, with an area under the ROC curve (AUC) of 0.9 between both conditions. Vascular compliance increased from 0.750.7 ml/mmHg in normocapnia to 5.8212.0 ml/mmHg during hypercapnia, with an AUC of 0.88. CONCLUSION we demonstrated that Genetic Algorithms are a powerful tool to provide accurate identification of model parameters expressing the performance of human CA Significance: Further work is needed to validate this approach in clinical applications where individualised model parameters could provide relevant diagnostic and prognostic information about dCA impairment Index Terms arterial compliance, autoregulation impairment, cerebral blood flow, Genetic Algorithms, hypercapnia.
Collapse
|
20
|
Panerai RB, Minhas JS, Llwyd O, Salinet ASM, Katsogridakis E, Maggio P, Robinson TG. The critical closing pressure contribution to dynamic cerebral autoregulation in humans: influence of arterial partial pressure of CO 2. J Physiol 2020; 598:5673-5685. [PMID: 32975820 DOI: 10.1113/jp280439] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/16/2020] [Indexed: 03/07/2024] Open
Abstract
KEY POINTS Dynamic cerebral autoregulation (CA) is often expressed by the mean arterial blood pressure (MAP)-cerebral blood flow (CBF) relationship, with little attention given to the dynamic relationship between MAP and cerebrovascular resistance (CVR). In CBF velocity (CBFV) recordings with transcranial Doppler, evidence demonstrates that CVR should be replaced by a combination of a resistance-area product (RAP) with a critical closing pressure (CrCP) parameter, the blood pressure value where CBFV reaches zero due to vessels collapsing. Transfer function analysis of the MAP-CBFV relationship can be extended to the MAP-RAP and MAP-CrCP relationships, to assess their contribution to the dynamic CA response. During normocapnia, both RAP and CrCP make a significant contribution to explaining the MAP-CBFV relationship. Hypercapnia, a surrogate state of depressed CA, leads to marked changes in dynamic CA, that are entirely explained by the CrCP response, without further contribution from RAP in comparison with normocapnia. ABSTRACT Dynamic cerebral autoregulation (CA) is manifested by changes in the diameter of intra-cerebral vessels, which control cerebrovascular resistance (CVR). We investigated the contribution of critical closing pressure (CrCP), an important determinant of CVR, to explain the cerebral blood flow (CBF) response to a sudden change in mean arterial blood pressure (MAP). In 76 healthy subjects (age range 21-70 years, 36 women), recordings of MAP (Finometer), CBF velocity (CBFV; transcranial Doppler ultrasound), end-tidal CO2 (capnography) and heart rate (ECG) were performed for 5 min at rest (normocapnia) and during hypercapnia induced by breathing 5% CO2 in air. CrCP and the resistance-area product (RAP) were obtained for each cardiac cycle and their dynamic response to a step change in MAP was calculated by means of transfer function analysis. The recovery of the CBFV response, following a step change in MAP, was mainly due to the contribution of RAP during both breathing conditions. However, CrCP made a highly significant contribution during normocapnia (P < 0.0001) and was the sole determinant of changes in the CBFV response, resulting from hypercapnia, which led to a reduction in the autoregulation index from 5.70 ± 1.58 (normocapnia) to 4.14 ± 2.05 (hypercapnia; P < 0.0001). In conclusion, CrCP makes a very significant contribution to the dynamic CBFV response to changes in MAP and plays a major role in explaining the deterioration of dynamic CA induced by hypercapnia. Further studies are needed to assess the relevance of CrCP contribution in physiological and clinical studies.
Collapse
Affiliation(s)
- Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Osian Llwyd
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Angela S M Salinet
- Neurology Department, Hospital das Clinicas, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Emmanuel Katsogridakis
- Department of Vascular Surgery, Wythenshawe Hospital, Manchester Foundation Trust, Manchester, UK
| | - Paola Maggio
- Neurology Department, ASST Bergamo EST (BG), Italy
| | - Thompson G Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| |
Collapse
|
21
|
Dadar M, Fereshtehnejad S, Zeighami Y, Dagher A, Postuma RB, Collins DL. Reply To: Cerebral Vasomotor Reactivity in Parkinson's Disease: A Missing Link between Dysautonomia, White Matter Lesions, and Cognitive Decline? Mov Disord Clin Pract 2020; 7:996-998. [PMID: 33163575 PMCID: PMC7604642 DOI: 10.1002/mdc3.13073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 07/30/2020] [Indexed: 11/07/2022] Open
Affiliation(s)
- Mahsa Dadar
- NeuroImaging and Surgical Tools LaboratoryMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
- McConnell Brain Imaging CentreMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
- CERVO Brain Research Center, Centre intégré universitaire santé et services sociaux de la Capitale NationaleQuébecQCCanada
| | - Seyed‐Mohammad Fereshtehnejad
- McConnell Brain Imaging CentreMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
- Division of Neurology, Department of MedicineUniversity of Ottawa and Ottawa Hospital Research InstituteOttawaOntarioCanada
| | - Yashar Zeighami
- McConnell Brain Imaging CentreMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| | - Alain Dagher
- McConnell Brain Imaging CentreMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| | - Ronald B. Postuma
- McConnell Brain Imaging CentreMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| | - D. Louis Collins
- NeuroImaging and Surgical Tools LaboratoryMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
- McConnell Brain Imaging CentreMontreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| |
Collapse
|
22
|
Yang MT. Multimodal neurocritical monitoring. Biomed J 2020; 43:226-230. [PMID: 32651135 PMCID: PMC7424082 DOI: 10.1016/j.bj.2020.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 01/11/2023] Open
Abstract
Neurocritical monitoring is important in caring for patients in the neurological intensive care unit. Although clinical neurologic examination is standard for neurocritical monitoring, changes found during the examination are often late signs and insufficient to detect and prevent secondary brain injury. Therefore, various neuromonitoring tools have been developed to monitor different physiologic parameters, such as cerebral oxygenation, cerebral blood flow, cerebral pressure, cerebral autoregulation, cerebral electric activity, and cerebral metabolism. In this review, we have discussed current commonly used neurocritical monitoring tools. No single monitor is sufficient and perfect for neurocritical monitoring. Multimodal neurocritical monitoring is the current trend. However, the lack of common formatting standards and uncertainty of improvement in patients' outcomes warrant further studies of multimodal neurocritical monitoring. Nevertheless, multimodal neurocritical monitoring considers individual pathophysiological variations in patients or their injuries and allows clinicians to tailor individualized management decisions.
Collapse
Affiliation(s)
- Ming-Tao Yang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan, Taiwan.
| |
Collapse
|
23
|
Placek MM, Smielewski P, Wachel P, Budohoski KP, Czosnyka M, Kasprowicz M. Can interhemispheric desynchronization of cerebral blood flow anticipate upcoming vasospasm in aneurysmal subarachnoid haemorrhage patients? J Neurosci Methods 2019; 325:108358. [PMID: 31306719 DOI: 10.1016/j.jneumeth.2019.108358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 06/12/2019] [Accepted: 07/11/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Asymmetry of cerebral autoregulation (CA) was demonstrated in patients after aneurysmal subarachnoid haemorrhage (aSAH). A classical method for CA assessment requires simultaneous measurement of both arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV). In this study, we have proposed a cerebral blood flow asymmetry index based only on CBFV and analysed its association with the occurrence of vasospasm after aSAH. NEW METHOD The phase shifts (PS) between slow oscillations in left and right CBFV (side-to-side PS) and between ABP and CBFV (CBFV-ABP PS) were estimated using multichannel matching pursuit (MMP) and cross-spectral analysis. RESULTS We retrospectively analysed data collected from 45 aSAH patients (26 with vasospasm). Data were analysed up to 7th day after aSAH unless the vasospasm was detected earlier. A progressive asymmetry, manifested by a gradual increase in side-to-side PS on consecutive days after aSAH, was observed in patients who developed vasospasm (Radj2 = 0.14, p = 0.009). In these patients, early side-to-side PS was more positive than in patients without vasospasm (2.8° ± 5.6° vs -1.7° ± 5.7°, p = 0.011). No such a difference was found in CBFV-ABP PS. Patients with positive side-to-side PS were more likely to develop vasospasm than patients with negative side-to-side PS (21/7 vs 5/12, p = 0.0047). COMPARISON WITH EXISTING METHOD MMP, in contrast to the spectral approach, accounts for non-stationarity of analysed signals. MMP applied to the PS estimation reflects the cerebral blood flow asymmetry in aSAH better than the spectral analysis. CONCLUSIONS Changes in side-to-side PS might be helpful to identify patients who are at risk of vasospasm.
Collapse
Affiliation(s)
- Michał M Placek
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland; Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Hills Road, Cambridge CB2 0QQ, United Kingdom.
| | - Peter Smielewski
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Paweł Wachel
- Department of Control Systems and Mechatronics, Faculty of Electronics, Wrocław University of Science and Technology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Karol P Budohoski
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Marek Czosnyka
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Magdalena Kasprowicz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland
| |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Beishon L, Williams CAL, Robinson TG, Haunton VJ, Panerai RB. Neurovascular coupling response to cognitive examination in healthy controls: a multivariate analysis. Physiol Rep 2018; 6:e13803. [PMID: 30033685 PMCID: PMC6055030 DOI: 10.14814/phy2.13803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/24/2018] [Indexed: 12/21/2022] Open
Abstract
Cognitive testing with transcranial Doppler ultrasonography (TCD) has been used to assess neurovascular coupling (NVC), but few studies address its multiple contributions. Subcomponent analysis considers the relative myogenic (resistance area product, RAP) and metabolic (critical closing pressure (CrCP)) contributors. The aim of this study was to investigate the changes in subcomponents that occur with cognitive stimulation with the Addenbrooke's Cognitive Examination (ACE-III) in healthy controls. Healthy volunteers underwent continuous recording of bilateral TCD, heart rate (HR, three-lead ECG), end-tidal CO2 (ETCO2 , capnography), and mean arterial pressure (MAP, Finometer). The study comprised a 5-min baseline recording, followed by all 20 paradigms from the ACE-III. The cerebral blood flow velocity (CBFv) response was decomposed into the relative contributions (subcomponents); VBP (MAP), VCrCP (CrCP), and VRAP (RAP). Data are presented as peak population normalized mean changes from baseline, and median area under the curve (AUC). Forty bilateral datasets were obtained (27 female, 37 right hand dominant). VBP increased at task initiation in all paradigms but differed between tasks (range (SD): 4.06 (8.92)-16.04 (12.23) %, P < 0.05). HR, but not ETCO2 , also differed significantly (P < 0.05). Changes in VRAP reflected changes in MAP, but in some paradigms atypical responses were seen. VCrCP AUC varied significantly within paradigm sections (range [SD]: 18.4 [24.17] to 244.21 [243.21] %*s, P < 0.05). All paradigms demonstrated changes in subcomponents with cognitive stimulation, and can be ranked based on their relative presumed metabolic demand. The integrity of NVC requires further investigation in patient populations.
Collapse
Affiliation(s)
- Lucy Beishon
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
| | | | - Thompson G. Robinson
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
- NIHR Leicester Biomedical Research CentreUniversity of LeicesterLeicesterUnited Kingdom
| | - Victoria J. Haunton
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
- NIHR Leicester Biomedical Research CentreUniversity of LeicesterLeicesterUnited Kingdom
| | - Ronney B. Panerai
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
- NIHR Leicester Biomedical Research CentreUniversity of LeicesterLeicesterUnited Kingdom
| |
Collapse
|
26
|
Compromised Dynamic Cerebral Autoregulation in Patients with Epilepsy. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6958476. [PMID: 29568762 PMCID: PMC5820585 DOI: 10.1155/2018/6958476] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/18/2017] [Accepted: 12/26/2017] [Indexed: 12/17/2022]
Abstract
Objective The aim of this study is to analyze dynamic cerebral autoregulation (dCA) in patients with epilepsy. Methods One hundred patients with epilepsy and 100 age- and sex-matched healthy controls were recruited. Noninvasive continuous cerebral blood flow velocity of the bilateral middle artery and arterial blood pressure were recorded. Transfer function analyses were used to analyze the autoregulatory parameters (phase difference and gain). Results The overall phase difference of patients with epilepsy was significantly lower than that of the healthy control group (p = 0.046). Furthermore, patients with interictal slow wave had significant lower phase difference than the slow-wave-free patients (p = 0.012). There was no difference in overall phase between focal discharges and multifocal discharges in patients with epilepsy. Simultaneously, there was no difference in mean phase between the affected and unaffected hemispheres in patients with unilateral discharges. In particular, interictal slow wave was an independent factor that influenced phase difference in patients with epilepsy (p = 0.016). Conclusions Our study documented that dCA is impaired in patients with epilepsy, especially in those with interictal slow wave. The impairment of dCA occurs irrespective of the discharge location and type. Interictal slow wave is an independent factor to predict impaired dCA in patients with epilepsy. Clinical Trial Identifier This trial is registered with NCT02775682.
Collapse
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
Zong Y, Xu H, Yu J, Jiang C, Kong X, He Y, Sun X. Retinal Vascular Autoregulation during Phase IV of the Valsalva Maneuver: An Optical Coherence Tomography Angiography Study in Healthy Chinese Adults. Front Physiol 2017; 8:553. [PMID: 28804464 PMCID: PMC5532432 DOI: 10.3389/fphys.2017.00553] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/17/2017] [Indexed: 12/26/2022] Open
Abstract
The impairment of retinal vascular autoregulation can be an early manifestation of many systemic and ocular diseases. Therefore, quantifying retinal vascular autoregulation in a non-invasive manner is very important. This study evaluated the effects of a Valsalva maneuver (VM)-induced blood pressure increases on retinal vascular autoregulation. Parafoveal and peripapillary retinal vessel density were measured with optical coherence tomography angiography before (baseline) and 5 s after each subject completed a VM (Phase IV [VM-IV]). Hemodynamic parameters and intraocular pressure (IOP) were examined. Blood pressure (systolic, diastolic, and mean arterial) and ocular perfusion pressure significantly increased during VM-IV, but IOP and heart rate (HR) did not change. The VM-induced blood pressure overshoot significantly decreased parafoveal (8.43%) and peripapillary (1.57%) perfused retinal vessel density (both P < 0.001). The response in the parafoveal region was greater than that in the peripapillary region (P < 0.001), and was age-dependent (r = 0.201, P < 0.05). Foveal avascular zone area detectable with OCTA significantly increased from baseline by 6.63% during VM-IV (P < 0.05). Autoregulatory responses to a VM did not show gender-related differences in either retinal region. The autoregulation of retinal vessels may vary in different regions of the fundus. Optical coherence tomography angiography could be a useful method for evaluating the autoregulation of the retinal vascular system.
Collapse
Affiliation(s)
- Yuan Zong
- Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan UniversityShanghai, China.,Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai, China
| | - Huan Xu
- Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan UniversityShanghai, China.,Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai, China
| | - Jian Yu
- Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan UniversityShanghai, China.,Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai, China
| | - Chunhui Jiang
- Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan UniversityShanghai, China.,Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai, China.,Department of Ophthalmology, Fifth People's Hospital of ShanghaiShanghai, China
| | - Xiangmei Kong
- Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan UniversityShanghai, China.,Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai, China
| | - Yi He
- The Key Laboratory on Adaptive Optics, Chinese Academy of SciencesChengdu, China.,The Laboratory on Adaptive Optics, Institute of Optics and Electronics, Chinese Academy of SciencesChengdu, China
| | - Xinghuai Sun
- Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan UniversityShanghai, China.,Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai, China
| |
Collapse
|
29
|
Placek MM, Wachel P, Iskander DR, Smielewski P, Uryga A, Mielczarek A, Szczepański TA, Kasprowicz M. Applying time-frequency analysis to assess cerebral autoregulation during hypercapnia. PLoS One 2017; 12:e0181851. [PMID: 28750024 PMCID: PMC5531479 DOI: 10.1371/journal.pone.0181851] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 07/08/2017] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE Classic methods for assessing cerebral autoregulation involve a transfer function analysis performed using the Fourier transform to quantify relationship between fluctuations in arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV). This approach usually assumes the signals and the system to be stationary. Such an presumption is restrictive and may lead to unreliable results. The aim of this study is to present an alternative method that accounts for intrinsic non-stationarity of cerebral autoregulation and the signals used for its assessment. METHODS Continuous recording of CBFV, ABP, ECG, and end-tidal CO2 were performed in 50 young volunteers during normocapnia and hypercapnia. Hypercapnia served as a surrogate of the cerebral autoregulation impairment. Fluctuations in ABP, CBFV, and phase shift between them were tested for stationarity using sphericity based test. The Zhao-Atlas-Marks distribution was utilized to estimate the time-frequency coherence (TFCoh) and phase shift (TFPS) between ABP and CBFV in three frequency ranges: 0.02-0.07 Hz (VLF), 0.07-0.20 Hz (LF), and 0.20-0.35 Hz (HF). TFPS was estimated in regions locally validated by statistically justified value of TFCoh. The comparison of TFPS with spectral phase shift determined using transfer function approach was performed. RESULTS The hypothesis of stationarity for ABP and CBFV fluctuations and the phase shift was rejected. Reduced TFPS was associated with hypercapnia in the VLF and the LF but not in the HF. Spectral phase shift was also decreased during hypercapnia in the VLF and the LF but increased in the HF. Time-frequency method led to lower dispersion of phase estimates than the spectral method, mainly during normocapnia in the VLF and the LF. CONCLUSION The time-frequency method performed no worse than the classic one and yet may offer benefits from lower dispersion of phase shift as well as a more in-depth insight into the dynamic nature of cerebral autoregulation.
Collapse
Affiliation(s)
- Michał M. Placek
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
- * E-mail:
| | - Paweł Wachel
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
- Department of Control Systems and Mechatronics, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - D. Robert Iskander
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Peter Smielewski
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Agnieszka Uryga
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Arkadiusz Mielczarek
- Department of Cybernetics and Robotics, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland
| | | | - Magdalena Kasprowicz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| |
Collapse
|
30
|
Castro P, Freitas J, Santos R, Panerai R, Azevedo E. Indexes of cerebral autoregulation do not reflect impairment in syncope: insights from head-up tilt test of vasovagal and autonomic failure subjects. Eur J Appl Physiol 2017; 117:1817-1831. [PMID: 28681121 DOI: 10.1007/s00421-017-3674-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/26/2017] [Indexed: 12/27/2022]
Abstract
PURPOSE The study of dynamic cerebral autoregulation (CA), which adapts cerebral blood flow to arterial blood pressure (ABP) fluctuations, has been limited in orthostatic intolerance syndromes, mainly due to its stationary prerequisites hardly to meet during maneuvers to provoke syncope itself. New techniques of continuous estimates of CA could overcome this pitfall. We aimed to evaluate CA during head-up tilt test in common conditions causing syncope. METHODS We compared three groups: eight controls; eight patients with autonomic failure due to familial amyloidotic polyneuropathy; eight patients with vasovagal syncope (VVS). ABP and cerebral blood flow velocity (CBFV) were measured with Finometer® and transcranial Doppler. We calculated cerebrovascular resistance index (CVRi), critical closing pressure (CrCP) and resistance area product (RAP), and derived CA continuously from autoregulation index [ARI(t)]. RESULTS With HUTT, AF subjects showed a pronounced decrease in CBFV (-36 ± 17 versus -7 ± 6%, p < 0.0001), ABP (-29 ± 27 versus 7 ± 12%, p < 0.0001) and RAP (-17 ± 23 versus 3 ± 18%, p < 0.0001) but not CVRi (p = 0.110). VVS subjects showed progressive cerebral vasoconstriction prior to syncope, (reduced CBFV 19 ± 15 versus 1 ± 6, p < 0.000; increased RAP 12 ± 18 versus 2 ± 3%, p = 0.024 and CVRi 12 ± 18 versus 2 ± 3%, p = 0.005). ARI(t) increased significantly in AF patients (5.7 ± 1.2 versus 6.9 ± 1.2, p = 0.040) and VVS (5.8 ± 1.2 versus 7.3 ± 1.2, p = 0.015) in response to ABP fall during syncope. CONCLUSIONS Our data suggest that dynamic cerebral autoregulatory response to orthostatic challenge is neither affected by autonomic dysfunction nor in neutrally mediated syncope. This study also emphasizes that RAP + CrCP model is more informative than CVRi, mainly during cerebral vasodilatory response to orthostatic hypotension.
Collapse
Affiliation(s)
- Pedro Castro
- Department of Neurology, São João Hospital Center, Faculty of Medicine of University of Porto, Alameda Professor Hernani Monteiro, 4200-319, Porto, Portugal.
| | - João Freitas
- Autonomic Unit, São João Hospital Center, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Rosa Santos
- Department of Neurology, São João Hospital Center, Faculty of Medicine of University of Porto, Alameda Professor Hernani Monteiro, 4200-319, Porto, Portugal
| | - Ronney Panerai
- Department of Cardiovascular Sciences and NIH Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Elsa Azevedo
- Department of Neurology, São João Hospital Center, Faculty of Medicine of University of Porto, Alameda Professor Hernani Monteiro, 4200-319, Porto, Portugal
| |
Collapse
|
31
|
Madureira J, Castro P, Azevedo E. Demographic and Systemic Hemodynamic Influences in Mechanisms of Cerebrovascular Regulation in Healthy Adults. J Stroke Cerebrovasc Dis 2017; 26:500-508. [DOI: 10.1016/j.jstrokecerebrovasdis.2016.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/24/2016] [Accepted: 12/05/2016] [Indexed: 01/05/2023] Open
|
32
|
Hemorrhagic transformation and cerebral edema in acute ischemic stroke: Link to cerebral autoregulation. J Neurol Sci 2016; 372:256-261. [PMID: 28017224 DOI: 10.1016/j.jns.2016.11.065] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/01/2016] [Accepted: 11/28/2016] [Indexed: 01/19/2023]
Abstract
BACKGROUND Hemorrhagic transformation and cerebral edema are feared complications of acute ischemic stroke but mechanisms are poorly understood and reliable early markers are lacking. Early assessment of cerebrovascular hemodynamics may advance our knowledge in both areas. We examined the relationship between dynamic cerebral autoregulation (CA) in the early hours post ischemia, and the risk of developing hemorrhagic transformation and cerebral edema at 24h post stroke METHODS: We prospectively enrolled 46 patients from our center with acute ischemic stroke in the middle cerebral artery territory. Cerebrovascular resistance index was calculated. Dynamic CA was assessed by transfer function analysis (coherence, phase and gain) of the spontaneous blood flow velocity and blood pressure oscillations. Infarct volume, hemorrhagic transformation, cerebral edema, and white matter changes were collected from computed tomography performed at presentation and 24h. RESULTS At admission, phase was lower (worse CA) in patients with hemorrhagic transformation [6.6±30 versus 45±38°; adjusted odds ratio 0.95 (95% confidence internal 0.94-0.98), p=0.023] and with cerebral edema [6.6±30 versus 45±38°, adjusted odds ratio 0.96 (0.92-0.999), p=0.044]. Progression to edema was associated with lower cerebrovascular resistance (1.4±0.2 versus 2.3±1.5mmHg/cm/s, p=0.033) and increased cerebral blood flow velocity (51±25 versus 42±17cm/s, p=0.033) at presentation. All hemodynamic differences resolved at 3months CONCLUSIONS: Less effective CA in the early hour post ischemic stroke is associated with increased risk of hemorrhagic transformation and cerebral edema, possibly reflecting breakthrough hyperperfusion and microvascular injury. Early assessment of dynamic CA could be useful in identifying individuals at risk for these complications.
Collapse
|
33
|
Autonomic dysfunction in multiple sclerosis is better detected by heart rate variability and is not correlated with central autonomic network damage. J Neurol Sci 2016; 367:133-7. [PMID: 27423576 DOI: 10.1016/j.jns.2016.05.049] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 05/19/2016] [Accepted: 05/24/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND MS-associated autonomic dysfunction (AD) in multiple sclerosis (MS) is poorly understood and the best method for its detection unestablished. We compared classical Ewing battery and newer methods as heart rate variability (HRV) and spontaneous baroreflex sensibility (BRS) to detect AD in MS and related them to central autonomic network (CAN) lesions. METHODS We enrolled 20 relapsing-remitting MS patients, median age of 36 (interquartile range 32-46) years, disease duration of 5.5 (2.2-6.8) years, Expanded Disability Status Scale (EDSS) score of 1.0 (1.0-1.5) and 20 age- and gender-matched healthy controls. We assessed Ewing battery and spontaneous HRV and BRS. CAN involvement was evaluated by magnetic resonance imaging. RESULTS HRV showed both parasympathetic and sympathetic significant impairment in MS (p<0.05). From Ewing battery only isometric test was significantly decreased in MS (p=0.006). Disease duration and severity, lesion burden and CAN involvement were not correlated with laboratorial parameters. CONCLUSIONS Our MS cohort had both sympathetic and parasympathetic dysfunction independently from disease duration, neurological deficits and lesion burden or CAN involvement. HRV analysis maybe more useful than classical Ewing battery to screen AD.
Collapse
|
34
|
Bari V, Marchi A, De Maria B, Rossato G, Nollo G, Faes L, Porta A. Nonlinear effects of respiration on the crosstalk between cardiovascular and cerebrovascular control systems. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0179. [PMID: 27044988 DOI: 10.1098/rsta.2015.0179] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/27/2016] [Indexed: 05/03/2023]
Abstract
Cardiovascular and cerebrovascular regulatory systems are vital control mechanisms responsible for guaranteeing homeostasis and are affected by respiration. This work proposes the investigation of cardiovascular and cerebrovascular control systems and the nonlinear influences of respiration on both regulations through joint symbolic analysis (JSA), conditioned or unconditioned on respiration. Interactions between cardiovascular and cerebrovascular regulatory systems were evaluated as well by performing correlation analysis between JSA indexes describing the two control systems. Heart period, systolic and mean arterial pressure, mean cerebral blood flow velocity and respiration were acquired on a beat-to-beat basis in 13 subjects experiencing recurrent syncope episodes (SYNC) and 13 healthy individuals (non-SYNC) in supine resting condition and during head-up tilt test at 60° (TILT). Results showed that JSA distinguished conditions and groups, whereas time domain parameters detected only the effect of TILT. Respiration affected cardiovascular and cerebrovascular regulatory systems in a nonlinear way and was able to modulate the interactions between the two control systems with different outcome in non-SYNC and SYNC groups, thus suggesting that the analysis of the impact of respiration on cardiovascular and cerebrovascular regulatory systems might improve our understanding of the mechanisms underpinning the development of postural-related syncope.
Collapse
Affiliation(s)
- Vlasta Bari
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Andrea Marchi
- Department of Electronic Information and Bioengineering, Politecnico di Milano, Milan, Italy Department of Emergency and Intensive Care, San Gerardo Hospital, Monza, Italy
| | | | - Gianluca Rossato
- Department of Neurology, Sacro Cuore Hospital, Negrar, Verona, Italy
| | - Giandomenico Nollo
- Biotech, Department of Industrial Engineering, University of Trento, Trento, Italy IRCS Program, PAT-FBK, Trento, Italy
| | - Luca Faes
- Biotech, Department of Industrial Engineering, University of Trento, Trento, Italy IRCS Program, PAT-FBK, Trento, Italy
| | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| |
Collapse
|
35
|
Claassen JAHR, Meel-van den Abeelen ASS, Simpson DM, Panerai RB. Transfer function analysis of dynamic cerebral autoregulation: A white paper from the International Cerebral Autoregulation Research Network. J Cereb Blood Flow Metab 2016; 36:665-80. [PMID: 26782760 PMCID: PMC4821028 DOI: 10.1177/0271678x15626425] [Citation(s) in RCA: 342] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/15/2015] [Indexed: 01/07/2023]
Abstract
Cerebral autoregulation is the intrinsic ability of the brain to maintain adequate cerebral perfusion in the presence of blood pressure changes. A large number of methods to assess the quality of cerebral autoregulation have been proposed over the last 30 years. However, no single method has been universally accepted as a gold standard. Therefore, the choice of which method to employ to quantify cerebral autoregulation remains a matter of personal choice. Nevertheless, given the concept that cerebral autoregulation represents the dynamic relationship between blood pressure (stimulus or input) and cerebral blood flow (response or output), transfer function analysis became the most popular approach adopted in studies based on spontaneous fluctuations of blood pressure. Despite its sound theoretical background, the literature shows considerable variation in implementation of transfer function analysis in practice, which has limited comparisons between studies and hindered progress towards clinical application. Therefore, the purpose of the present white paper is to improve standardisation of parameters and settings adopted for application of transfer function analysis in studies of dynamic cerebral autoregulation. The development of these recommendations was initiated by (but not confined to) theCerebral Autoregulation Research Network(CARNet -www.car-net.org).
Collapse
Affiliation(s)
- Jurgen A H R Claassen
- Radboud University Medical Center, Department of Geriatric Medicine and Donders Institute for Brain, Cognition and Behaviour, The Netherlands
| | - Aisha S S Meel-van den Abeelen
- Radboud University Medical Center, Department of Geriatric Medicine and Donders Institute for Brain, Cognition and Behaviour, The Netherlands
| | - David M Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Ronney B Panerai
- Leicester NIHR Biomedical Research Unit in Cardiovascular Sciences, Glenfield Hospital, Leicester, UK
| | | |
Collapse
|
36
|
Ogoh S, Hirasawa A, Sugawara J, Nakahara H, Ueda S, Shoemaker JK, Miyamoto T. The effect of an acute increase in central blood volume on the response of cerebral blood flow to acute hypotension. J Appl Physiol (1985) 2015; 119:527-33. [DOI: 10.1152/japplphysiol.00277.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/07/2015] [Indexed: 11/22/2022] Open
Abstract
The purpose of the present study was to examine whether the response of cerebral blood flow to an acute change in perfusion pressure is modified by an acute increase in central blood volume. Nine young, healthy subjects voluntarily participated in this study. To measure dynamic cerebral autoregulation during normocapnic and hypercapnic (5%) conditions, the change in middle cerebral artery mean blood flow velocity was analyzed during acute hypotension caused by two methods: 1) thigh-cuff occlusion release (without change in central blood volume); and 2) during the recovery phase immediately following release of lower body negative pressure (LBNP; −50 mmHg) that initiated an acute increase in central blood volume. In the thigh-cuff occlusion release protocol, as expected, hypercapnia decreased the rate of regulation, as an index of dynamic cerebral autoregulation (0.236 ± 0.018 and 0.167 ± 0.025 s−1, P = 0.024). Compared with the cuff-occlusion release, the acute increase in central blood volume (relative to the LBNP condition) with LBNP release attenuated dynamic cerebral autoregulation ( P = 0.009). Therefore, the hypercapnia-induced attenuation of dynamic cerebral autoregulation was not observed in the LBNP release protocol ( P = 0.574). These findings suggest that an acute change in systemic blood distribution modifies dynamic cerebral autoregulation during acute hypotension.
Collapse
Affiliation(s)
| | | | - Jun Sugawara
- National Institute of Advanced Industrial Science and Technology, Ibaraki Japan
| | | | - Shinya Ueda
- Morinomiya University of Medical Sciences, Osaka, Japan; and
| | | | | |
Collapse
|
37
|
Panerai RB, Saeed NP, Robinson TG. Cerebrovascular effects of the thigh cuff maneuver. Am J Physiol Heart Circ Physiol 2015; 308:H688-96. [PMID: 25659488 PMCID: PMC4385993 DOI: 10.1152/ajpheart.00887.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/05/2015] [Indexed: 11/22/2022]
Abstract
Arterial hypotension can be induced by sudden release of inflated thigh cuffs (THC), but its effects on the cerebral circulation have not been fully described. In nine healthy subjects [aged 59 (9) yr], bilateral cerebral blood flow velocity (CBFV) was recorded in the middle cerebral artery (MCA), noninvasive arterial blood pressure (BP) in the finger, and end-tidal CO2 (ETCO2) with nasal capnography. Three THC maneuvers were performed in each subject with cuff inflation 20 mmHg above systolic BP for 3 min before release. Beat-to-beat values were extracted for mean CBFV, BP, ETCO2 , critical closing pressure (CrCP), resistance-area product (RAP), and heart rate (HR). Time-varying estimates of the autoregulation index [ARI(t)] were also obtained using an autoregressive-moving average model. Coherent averages synchronized by the instant of cuff release showed significant drops in mean BP, CBFV, and RAP with rapid return of CBFV to baseline. HR, ETCO2 , and ARI(t) were transiently increased, but CrCP remained relatively constant. Mean values of ARI(t) for the 30 s following cuff release were not significantly different from the classical ARI [right MCA 5.9 (1.1) vs. 5.1 (1.6); left MCA 5.5 (1.4) vs. 4.9 (1.7)]. HR was strongly correlated with the ARI(t) peak after THC release (in 17/22 and 21/24 recordings), and ETCO2 was correlated with the subsequent drop in ARI(t) (19/22 and 20/24 recordings). These results suggest a complex cerebral autoregulatory response to the THC maneuver, dominated by myogenic mechanisms and influenced by concurrent changes in ETCO2 and possible involvement of the autonomic nervous system and baroreflex.
Collapse
Affiliation(s)
- R B Panerai
- University of Leicester, Department of Cardiovascular Sciences, Leicester Royal Infirmary, Leicester, United Kingdom; and National Institutes for Health Research, Biomedical Research Unit in Cardiovascular Science, Glenfield Hospital, Leicester, United Kingdom
| | - N P Saeed
- University of Leicester, Department of Cardiovascular Sciences, Leicester Royal Infirmary, Leicester, United Kingdom; and
| | - T G Robinson
- University of Leicester, Department of Cardiovascular Sciences, Leicester Royal Infirmary, Leicester, United Kingdom; and National Institutes for Health Research, Biomedical Research Unit in Cardiovascular Science, Glenfield Hospital, Leicester, United Kingdom
| |
Collapse
|