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Olsen MH, Riberholt CG, Berg RMG, Møller K. Myths and methodologies: Assessment of dynamic cerebral autoregulation by the mean flow index. Exp Physiol 2024; 109:614-623. [PMID: 38376110 PMCID: PMC10988760 DOI: 10.1113/ep091327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 01/17/2024] [Indexed: 02/21/2024]
Abstract
The mean flow index-usually referred to as Mx-has been used for assessing dynamic cerebral autoregulation (dCA) for almost 30 years. However, concerns have arisen regarding methodological consistency, construct and criterion validity, and test-retest reliability. Methodological nuances, such as choice of input (cerebral perfusion pressure, invasive or non-invasive arterial pressure), pre-processing approach and artefact handling, significantly influence mean flow index values, and previous studies correlating mean flow index with other established dCA metrics are confounded by inherent methodological flaws like heteroscedasticity, while the mean flow index also fails to discriminate individuals with presumed intact versus impaired dCA (discriminatory validity), and its prognostic performance (predictive validity) across various conditions remains inconsistent. The test-retest reliability, both within and between days, is generally poor. At present, no single approach for data collection or pre-processing has proven superior for obtaining the mean flow index, and caution is advised in the further use of mean flow index-based measures for assessing dCA, as current evidence does not support their clinical application.
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Affiliation(s)
- Markus Harboe Olsen
- Department of Neuroanaesthesiology, The Neuroscience CentreCopenhagen University Hospital − RigshospitaletCopenhagenDenmark
| | - Christian Gunge Riberholt
- Department of Neuroanaesthesiology, The Neuroscience CentreCopenhagen University Hospital − RigshospitaletCopenhagenDenmark
- Department of Brain and Spinal Cord Injury, The Neuroscience CentreCopenhagen University Hospital − RigshospitaletCopenhagenDenmark
| | - Ronan M. G. Berg
- Department of Clinical Physiology and Nuclear MedicineCopenhagen University Hospital − RigshospitaletCopenhagenDenmark
- Centre for Physical Activity ResearchCopenhagen University Hospital − RigshospitaletCopenhagenDenmark
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
| | - Kirsten Møller
- Department of Neuroanaesthesiology, The Neuroscience CentreCopenhagen University Hospital − RigshospitaletCopenhagenDenmark
- Department of Clinical Medicine, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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2
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Sheriff FG, Ahmad A, Inam ME, Khatri R, Maud A, Rodriguez GJ. A systematic review on the assessment of cerebral autoregulation in patients with Large Vessel Occlusion. Front Neurol 2023; 14:1287873. [PMID: 38046584 PMCID: PMC10693431 DOI: 10.3389/fneur.2023.1287873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 11/02/2023] [Indexed: 12/05/2023] Open
Abstract
As the majority of large vessel occlusion (LVO) patients are not treated with revascularization therapies or efficiently revascularized, complementary management strategies are needed. In this article we explore the importance of cerebral autoregulation (CA) assessment in the prediction and/or modification of infarct growth and hemorrhagic transformation. In patients with LVO, these are important factors that affect prognosis. A systematic search of the PubMed, EMBASE databases and a targeted Google search was conducted, resulting in the inclusion of 34 relevant articles. There is an agreement that CA is impaired in patients with LVO; several factors have been identified such as time course, revascularization status, laterality, disease subtype and location, some of which may be potentially modifiable and affect outcomes. The personalized CA assessment of these patients suggests potential for better understanding of the inter-individual variability. Further research is needed for the development of more accurate, noninvasive techniques for continuous monitoring and personalized thresholds for CA.
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Affiliation(s)
- Faheem G. Sheriff
- Department of Neurology, Section of Interventional Neurology, Texas Tech University Health Sciences Center El Paso, El Paso, TX, United States
| | | | - Mehmet E. Inam
- University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Rakesh Khatri
- Department of Neurology, Section of Interventional Neurology, Texas Tech University Health Sciences Center El Paso, El Paso, TX, United States
| | - Alberto Maud
- Department of Neurology, Section of Interventional Neurology, Texas Tech University Health Sciences Center El Paso, El Paso, TX, United States
| | - Gustavo J. Rodriguez
- Department of Neurology, Section of Interventional Neurology, Texas Tech University Health Sciences Center El Paso, El Paso, TX, United States
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3
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Sainbhi AS, Marquez I, Gomez A, Stein KY, Amenta F, Vakitbilir N, Froese L, Zeiler FA. Regional disparity in continuously measured time-domain cerebrovascular reactivity indices: a scoping review of human literature. Physiol Meas 2023; 44:07TR02. [PMID: 37336236 DOI: 10.1088/1361-6579/acdfb6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/19/2023] [Indexed: 06/21/2023]
Abstract
Objective: Cerebral blood vessels maintaining relatively constant cerebral blood flow (CBF) over wide range of systemic arterial blood pressure (ABP) is referred to as cerebral autoregulation (CA). Impairments in CA expose the brain to pressure-passive flow states leading to hypoperfusion and hyperperfusion. Cerebrovascular reactivity (CVR) metrics refer to surrogate metrics of pressure-based CA that evaluate the relationship between slow vasogenic fluctuations in cerebral perfusion pressure/ABP and a surrogate for pulsatile CBF/cerebral blood volume.Approach: We performed a systematically conducted scoping review of all available human literature examining the association between continuous CVR between more than one brain region/channel using the same CVR index.Main Results: In all the included 22 articles, only handful of transcranial doppler (TCD) and near-infrared spectroscopy (NIRS) based metrics were calculated for only two brain regions/channels. These metrics found no difference between left and right sides in healthy volunteer, cardiac surgery, and intracranial hemorrhage patient studies. In contrast, significant differences were reported in endarterectomy, and subarachnoid hemorrhage studies, while varying results were found regarding regional disparity in stroke, traumatic brain injury, and multiple population studies.Significance: Further research is required to evaluate regional disparity using NIRS-based indices and to understand if NIRS-based indices provide better regional disparity information than TCD-based indices.
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Affiliation(s)
- Amanjyot Singh Sainbhi
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Izabella Marquez
- Undergraduate Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Alwyn Gomez
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Kevin Y Stein
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Fiorella Amenta
- Undergraduate Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Nuray Vakitbilir
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Logan Froese
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Frederick A Zeiler
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, Canada
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
- Centre on Aging, University of Manitoba, Winnipeg, Canada
- Division of Anaesthesia, Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, Karolinksa Institutet, Stockholm, Sweden
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Daher A, Payne S. A network-based model of dynamic cerebral autoregulation. Microvasc Res 2023; 147:104503. [PMID: 36773930 DOI: 10.1016/j.mvr.2023.104503] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/21/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023]
Abstract
Cerebrovascular diseases continue to be one of the leading causes of morbidity and mortality in humans. Abnormalities in dynamic cerebral autoregulation (dCA) have been implicated in many of these disease conditions. Accurate models are therefore needed to better understand the complex pathophysiology behind impaired dCA. We thus present here a simple framework for modelling a vessel-driven network model of dCA in the microvasculature, as opposed to the conventional compartmental modelling approach. Network models incorporate the actual connectivity and anatomy of the vasculature, thereby allowing us to include and trace changes in the calibre and morphology of individual vessels, investigate the spatial specificity and heterogeneity of the various control mechanisms to help disentangle their contributions, and link the model parameters to the actual network physiology. The proposed control feedback mechanisms are incorporated at the level of the individual vessel, and the dynamic pressure and flow fields are solved for here within a simple vessel network. In response to an upstream pressure drop, the network is found to be able to recover cerebral blood flow (CBF) while exhibiting the characteristic autoregulatory behaviour in terms of changes in vessel calibre and the biphasic flow response. We assess the feasibility of our formulation in larger networks by comparing the simulation results to those obtained using a one-dimensional (1D) model of CBF applied to the same microvasculature network and find that our model results are in very good agreement with the 1D solution, while significantly reducing the computational cost, thus enabling more detailed models of network behaviour to be adopted in the future. Accurate and computationally feasible models of dCA that are more representative of the vasculature can help increase the translatability of haemodynamic models into the clinical environment, which would help develop more informed treatment guidelines for patients with cerebrovascular diseases.
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Affiliation(s)
- Ali Daher
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom.
| | - Stephen Payne
- Institute of Applied Mechanics, National Taiwan University, Taiwan
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D'Andrea A, Fabiani D, Cante L, Caputo A, Sabatella F, Riegler L, Alfano G, Russo V. Transcranial Doppler ultrasound: Clinical applications from neurological to cardiological setting. JOURNAL OF CLINICAL ULTRASOUND : JCU 2022; 50:1212-1223. [PMID: 36218211 DOI: 10.1002/jcu.23344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Transcranial Doppler (TCD) ultrasonography is a rapid, noninvasive, real-time, and low-cost imaging technique. It is performed with a low-frequency (2 MHz) probe in order to evaluate the cerebral blood flow (CBF) and its pathological alterations, through specific acoustic windows. In the recent years, TCD use has been expanded across many clinical settings. Actually, the most widespread indication for TCD exam is represented by the diagnosis of paradoxical embolism, due to patent foramen ovale, in young patients with cryptogenic stroke. In addition, TCD has also found useful applications in neurological care setting, including the following: cerebral vasospasm following acute subarachnoid hemorrhage, brain trauma, cerebrovascular atherosclerosis, and evaluation of CBF and cerebral autoregulation after an ischemic stroke event. The present review aimed to describe the most recent evidences of TCD utilization from neurological to cardiological setting.
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Affiliation(s)
- Antonello D'Andrea
- Cardiology Unit, Umberto I Hospital, University of Campania "Luigi Vanvitelli", Nocera Inferiore, Italy
| | - Dario Fabiani
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli"-Monaldi Hospital, Naples, Italy
| | - Luigi Cante
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli"-Monaldi Hospital, Naples, Italy
| | - Adriano Caputo
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli"-Monaldi Hospital, Naples, Italy
| | - Francesco Sabatella
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli"-Monaldi Hospital, Naples, Italy
| | - Lucia Riegler
- Cardiology Unit, Umberto I Hospital, University of Campania "Luigi Vanvitelli", Nocera Inferiore, Italy
| | - Gabriele Alfano
- Cardiology Unit, Umberto I Hospital, University of Campania "Luigi Vanvitelli", Nocera Inferiore, Italy
| | - Vincenzo Russo
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania "Luigi Vanvitelli"-Monaldi Hospital, Naples, Italy
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Al-Kawaz M, Cho SM, Gottesman RF, Suarez JI, Rivera-Lara L. Impact of Cerebral Autoregulation Monitoring in Cerebrovascular Disease: A Systematic Review. Neurocrit Care 2022; 36:1053-1070. [PMID: 35378665 DOI: 10.1007/s12028-022-01484-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 03/01/2022] [Indexed: 12/16/2022]
Abstract
Cerebral autoregulation (CA) prevents brain injury by maintaining a relatively constant cerebral blood flow despite fluctuations in cerebral perfusion pressure. This process is disrupted consequent to various neurologic pathologic processes, which may result in worsening neurologic outcomes. Herein, we aim to highlight evidence describing CA changes and the impact of CA monitoring in patients with cerebrovascular disease, including ischemic stroke, intracerebral hemorrhage (ICH), and aneurysmal subarachnoid hemorrhage (aSAH). The study was preformed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. English language publications were identified through a systematic literature conducted in Ovid Medline, PubMed, and Embase databases. The search spanned the dates of each database's inception through January 2021. We selected case-control studies, cohort observational studies, and randomized clinical trials for adult patients (≥ 18 years) who were monitored with continuous metrics using transcranial Doppler, near-infrared spectroscopy, and intracranial pressure monitors. Of 2799 records screened, 48 studies met the inclusion criteria. There were 23 studies on ischemic stroke, 18 studies on aSAH, 5 studies on ICH, and 2 studies on systemic hypertension. CA impairment was reported after ischemic stroke but generally improved after tissue plasminogen activator administration and successful mechanical thrombectomy. Persistent impairment in CA was associated with hemorrhagic transformation, malignant cerebral edema, and need for hemicraniectomy. Studies that investigated large ICHs described bilateral CA impairment up to 12 days from the ictus, especially in the presence of small vessel disease. In aSAH, impairment of CA was associated with angiographic vasospasm, delayed cerebral ischemia, and poor functional outcomes at 6 months. This systematic review highlights the available evidence for CA disruption during cerebrovascular diseases and its possible association with long-term neurological outcome. CA may be disrupted even before acute stroke in patients with untreated chronic hypertension. Monitoring CA may help in establishing individualized management targets in patients with cerebrovascular disease.
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Affiliation(s)
- Mais Al-Kawaz
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Sung-Min Cho
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rebecca F Gottesman
- Stroke Branch, National Institute of Neurological Disorders and Stroke Intramural Program, National Institutes of Health, Bethesda, MD, USA
| | - Jose I Suarez
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lucia Rivera-Lara
- Division of Stroke and Neurocritical Care, Stanford University, Palo Alto, CA, USA
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7
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Porta A, Gelpi F, Bari V, Cairo B, De Maria B, Tonon D, Rossato G, Ranucci M, Faes L. Categorizing the Role of Respiration in Cardiovascular and Cerebrovascular Variability Interactions. IEEE Trans Biomed Eng 2021; 69:2065-2076. [PMID: 34905489 DOI: 10.1109/tbme.2021.3135313] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Respiration disturbs cardiovascular and cerebrovascular controls but its role is not fully elucidated. METHODS Respiration can be classified as a confounder if its observation reduces the strength of the causal relationship from source to target. Respiration is a suppressor if the opposite situation holds. We prove that a confounding/suppression (C/S) test can be accomplished by evaluating the sign of net redundancy/synergy balance in the predictability framework based on multivariate autoregressive modelling. In addition, we suggest that, under the hypothesis of Gaussian processes, the C/S test can be given in the transfer entropy decomposition framework as well. Experimental protocols: We applied the C/S test to variability series of respiratory movements, heart period, systolic arterial pressure, mean arterial pressure, and mean cerebral blood flow recorded in 17 pathological individuals (age: 648 yrs; 17 males) before and after induction of propofol-based general anesthesia prior to coronary artery bypass grafting, and in 13 healthy subjects (age: 278 yrs; 5 males) at rest in supine position and during head-up tilt with a table inclination of 60. RESULTS Respiration behaved systematically as a confounder for cardiovascular and cerebrovascular controls. In addition, its role was affected by propofol-based general anesthesia but not by a postural stimulus of limited intensity. CONCLUSION The C/S test can be fruitfully exploited to categorize the role of respiration over causal variability interactions. SIGNIFICANCE The application of the C/S test could favor the comprehension of the role of respiration in cardiovascular and cerebrovascular regulations.
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Nogueira RC, Beishon L, Bor-Seng-Shu E, Panerai RB, Robinson TG. Cerebral Autoregulation in Ischemic Stroke: From Pathophysiology to Clinical Concepts. Brain Sci 2021; 11:511. [PMID: 33923721 PMCID: PMC8073938 DOI: 10.3390/brainsci11040511] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/02/2021] [Accepted: 04/09/2021] [Indexed: 11/17/2022] Open
Abstract
Ischemic stroke (IS) is one of the most impacting diseases in the world. In the last decades, new therapies have been introduced to improve outcomes after IS, most of them aiming for recanalization of the occluded vessel. However, despite this advance, there are still a large number of patients that remain disabled. One interesting possible therapeutic approach would be interventions guided by cerebral hemodynamic parameters such as dynamic cerebral autoregulation (dCA). Supportive hemodynamic therapies aiming to optimize perfusion in the ischemic area could protect the brain and may even extend the therapeutic window for reperfusion therapies. However, the knowledge of how to implement these therapies in the complex pathophysiology of brain ischemia is challenging and still not fully understood. This comprehensive review will focus on the state of the art in this promising area with emphasis on the following aspects: (1) pathophysiology of CA in the ischemic process; (2) methodology used to evaluate CA in IS; (3) CA studies in IS patients; (4) potential non-reperfusion therapies for IS patients based on the CA concept; and (5) the impact of common IS-associated comorbidities and phenotype on CA status. The review also points to the gaps existing in the current research to be further explored in future trials.
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Affiliation(s)
- Ricardo C. Nogueira
- Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, São Paulo 01246-904, Brazil;
- Department of Neurology, Hospital Nove de Julho, São Paulo 01409-002, Brazil
| | - Lucy Beishon
- Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE2 7LX, UK; (L.B.); (R.B.P.); (T.G.R.)
| | - Edson Bor-Seng-Shu
- Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, São Paulo 01246-904, Brazil;
| | - Ronney B. Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE2 7LX, UK; (L.B.); (R.B.P.); (T.G.R.)
- National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, University of Leicester, Leicester LE5 4PW, UK
| | - Thompson G. Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE2 7LX, UK; (L.B.); (R.B.P.); (T.G.R.)
- National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, University of Leicester, Leicester LE5 4PW, UK
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Riberholt CG, Olsen MH, Skovgaard LT, Berg RMG, Møller K, Mehlsen J. Reliability of the transcranial Doppler ultrasound-derived mean flow index for assessing dynamic cerebral autoregulation in healthy volunteers. Med Eng Phys 2021; 89:1-6. [PMID: 33608119 DOI: 10.1016/j.medengphy.2021.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/06/2021] [Accepted: 01/17/2021] [Indexed: 11/27/2022]
Abstract
The transcranial Doppler ultrasound-derived mean flow index (Mxa) is widely used for assessing dynamic cerebral autoregulation (dCA) in different clinical populations. This study aimed at estimating the relative and absolute reliability of Mxa in healthy participants in the supine position and during head-up tilt (HUT). Fourteen healthy participants were examined on two separate occasions during which, mean middle cerebral artery blood flow velocity (MCAv), non-invasive blood pressure, and heart rate were continuously recorded in the supine position and during HUT. Mxa was calculated as the correlation coefficient between mean arterial blood pressure and MCAv using either 3-, 5-, or 10-second averages collected over a 300 second period. Intraclass correlation coefficient (ICC1.1) was calculated to assess relative reliability, while the standard error of measurement (SEM), and limits of agreement (LOA) were used to assess absolute reliability. Mxa-based 3-second averages yielded a similar relative and absolute reliability in both positions. When Mxa was calculated from 5-second averages, the most reliable values were obtained during HUT. The poorest reliability was achieved using 10-second averages, regardless of posture. The Mxa shows fair reliability with acceptable LOA in healthy volunteers when based on 3-second averages, both in the supine position and during HUT.
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Affiliation(s)
- Christian Gunge Riberholt
- Department of Neurorehabilitation / TBI-unit, Rigshospitalet, University of Copenhagen, Kette Gaard Alle 30, 2650 Hvidovre, Denmark; Department of Clinical Medicine, Faculty of Healthcare Sciences, University of Copenhagen, Denmark.
| | - Markus Harboe Olsen
- Department of Clinical Medicine, Faculty of Healthcare Sciences, University of Copenhagen, Denmark; Department of Neuroanaesthesiology, Rigshospitalet, University of Copenhagen, Denmark
| | | | - Ronan M G Berg
- Department of Biomedical Sciences, University of Copenhagen, Denmark; Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University of Copenhagen, Denmark
| | - Kirsten Møller
- Department of Clinical Medicine, Faculty of Healthcare Sciences, University of Copenhagen, Denmark; Department of Neuroanaesthesiology, Rigshospitalet, University of Copenhagen, Denmark
| | - Jesper Mehlsen
- Section for Surgical Pathophysiology, Rigshospitalet, University of Copenhagen, Denmark
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Zevallos CB, Dai B, Dandapat S, Quispe-Orozco D, Holcombe A, Ansari S, Farooqui M, Derdeyn CP, Samaniego EA, Ortega-Gutierrez S. Greater intraprocedural systolic blood pressure and blood pressure variability are associated with contrast-induced neurotoxicity after neurointerventional procedures. J Neurol Sci 2020; 420:117209. [PMID: 33187680 DOI: 10.1016/j.jns.2020.117209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Contrast-induced neurotoxicity (CIN) is a rare complication of neurointerventional procedures and its understanding remains limited. We evaluated the association of CIN with systemic hemodynamics in patients undergoing neuroendovascular interventions. METHODS We conducted a 1:2 matched case-control study from a prospectively collected database of 2510 neurointerventional patients. We defined CIN as new neurological deficits presented ≤24 h post-operation after excluding other possible etiologies. We obtained demographic, clinical and imaging data, and baseline and intraprocedural blood pressures (BP) from medical records. The area between baseline and intraprocedural BP was used to measure sustained variability of BP over time. A generalized linear mixed model and generalized estimating equation were used to analyze the BP difference between groups over time. RESULTS We evaluated 11 CIN cases and 22 controls. 2746 and 5837 min of continued BP data were analyzed for cases and controls, respectively. CIN cases had higher measurements and greater variability for: Systolic BP (SBP) [median 125 (IQR:121-147) vs. 114 (IQR:107-124) mmHg], median area above baseline [median 350 (IQR:25-1328) vs. 52 (IQR:0-293) mmHg*minutes] and mean arterial pressure (MAP) [median 85 (IQR:79-98) vs. 80 (IQR:74-89) mmHg]. CIN cases demonstrated a significant mean increase in SBP and MAP of 23.41 mmHg (p < 0.01) and 13.79 mmHg (p < 0.01) when compared to controls, respectively, over the perioperative time. CONCLUSION Sustained hypertension and high BP variability may contribute to the pathophysiology of CIN. Acute hypertension can increase blood-brain barrier permeability and potentially allow contrast to leak into the brain parenchyma causing direct toxicity and CIN symptoms.
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Affiliation(s)
- Cynthia B Zevallos
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Biyue Dai
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Sudeepta Dandapat
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Darko Quispe-Orozco
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Andrea Holcombe
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Sameer Ansari
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Mudassir Farooqui
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Colin P Derdeyn
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Edgar A Samaniego
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Santiago Ortega-Gutierrez
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA; Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
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11
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Han B, Sun X, Tong X, Raynald, Jia B, Mo D, Li X, Luo G, Miao Z. Early blood pressure management for endovascular therapy in acute ischemic stroke: A review of the literature. Interv Neuroradiol 2020; 26:785-792. [PMID: 32524863 DOI: 10.1177/1591019920931651] [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: 11/17/2022] Open
Abstract
The perioperative optimal blood pressure targets during mechanical thrombectomy for acute ischemic stroke are uncertain, and randomized controlled trials addressing this issue are lacking. There is still no consensus on the optimal target for perioperative blood pressure in acute ischemic stroke patients with large vessel occlusion. In addition, there are many confounding factors that can influence the outcome including the patient's clinical history and stroke characteristics. We review the factors that have an impact on perioperative blood pressure change and discuss the influence of perioperative blood pressure on functional outcome after mechanical thrombectomy. In conclusion, we suggest that blood pressure should be carefully and flexibly managed perioperatively in patient-received mechanical thrombectomy. Blood pressure changes during mechanical thrombectomy were independently correlated with poor prognosis, and blood pressure should be maintained in a normal range perioperatively. Postoperative blood pressure control is associated with recanalization status in which successful recanalization requires normal range blood pressure (systolic blood pressure 120-140 mmHg), while non-recanalization requires higher blood pressure (systolic blood pressure 160-180 mmHg). The preoperative blood pressure targets for mechanical thrombectomy should be tailored based on the patient's clinical history (systolic blood pressure ≤185 mmHg). Blood pressure should be carefully and flexibly managed intraoperatively (systolic blood pressure 140-180 mmHg) in patient-received endovascular therapy.
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Affiliation(s)
- Bin Han
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Department of Neurology, Shanxi Provincial People's Hospital, Taiyuan, China
| | - Xuan Sun
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xu Tong
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Raynald
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Baixue Jia
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Dapeng Mo
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiaoqing Li
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Gang Luo
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhongrong Miao
- NeuroIntervention Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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12
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Meyer M, Juenemann M, Braun T, Schirotzek I, Tanislav C, Engelhard K, Schramm P. Impaired Cerebrovascular Autoregulation in Large Vessel Occlusive Stroke after Successful Mechanical Thrombectomy: A Prospective Cohort Study. J Stroke Cerebrovasc Dis 2020; 29:104596. [PMID: 31902644 DOI: 10.1016/j.jstrokecerebrovasdis.2019.104596] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/27/2019] [Accepted: 12/05/2019] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION Successful thrombectomy improves morbidity and mortality after stroke. The present prospective, observational cohort study investigated a potential correlation between the successful restoration of tissue perfusion by mechanical thrombectomy and intact cerebrovascular autoregulation (CA). OBJECTIVE Status of CA in patients with large vessel occlusive stroke after thrombectomy. METHODS After thrombectomy CA was measured using transcranial Doppler ultrasound. For this purpose a moving correlation index (Mxa) based on spontaneous arterial blood pressure fluctuations and corresponding cerebral blood flow velocity changes was calculated. CA impairment was defined by Mxa values more than .3. RESULTS Twenty patients with an acute occlusion of the middle cerebral artery or distal internal carotid artery were included. A successful recanalization of the occluded vessel via interventional thrombectomy was achieved in 10 of these patients (successful recanalization group), while in 10 patients mechanical recanalization failed or could not be applied (no recanalization group). Mean Mxa at stroke side was .58 ± .21 Table 2a in patients with successful intervention. At the unaffected hemisphere Mxa was .50 ± .20 Table 2a in successful recanalization group and .45 ± .24 Table 2b in no recanalization group without statistically significant differences. Based on the previously defined Mxa cut off more than .3, CA impairment was observable in all successful recanalized patients and in 8 of 10 patients with unsuccessful interventional treatment. CONCLUSIONS These results suggest that brain perfusion may be affected due to impaired CA even after successful mechanical thrombectomy. Therefore, a tight blood pressure management is of great importance in post-thrombectomy stroke treatment to avoid cerebral hypo- and hyperperfusion.
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Affiliation(s)
- Marco Meyer
- Department of Geriatrics, Jung-Stilling Hospital Siegen, Siegen, Germany.
| | - Martin Juenemann
- Department of Neurology, University hospital Giessen and Marburg location Giessen, Giessen, Germany
| | - Tobias Braun
- Department of Neurology, University hospital Giessen and Marburg location Giessen, Giessen, Germany
| | - Ingo Schirotzek
- Department of Neurology, University hospital Giessen and Marburg location Giessen, Giessen, Germany
| | - Christian Tanislav
- Department of Geriatrics, Jung-Stilling Hospital Siegen, Siegen, Germany
| | - Kristin Engelhard
- Department of Anesthesiology, Johannes Gutenberg-University, University medical hospital Mainz, Mainz, Germany
| | - Patrick Schramm
- Department of Anesthesiology, Johannes Gutenberg-University, University medical hospital Mainz, Mainz, Germany
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13
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Llwyd O, Haunton V, Salinet ASM, Nath M, Lam MY, Saeed NP, Brodie F, Robinson TG, Panerai RB. Can we assess dynamic cerebral autoregulation in stroke patients with high rates of cardiac ectopicity? Med Biol Eng Comput 2019; 57:2731-2739. [PMID: 31734767 DOI: 10.1007/s11517-019-02064-0] [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: 03/18/2019] [Accepted: 11/02/2019] [Indexed: 10/25/2022]
Abstract
It is unclear whether physiological recordings containing high numbers of ectopic heartbeats can be used to measure the cerebral autoregulation (CA) of blood flow. This study evaluated the utility of such data for assessing dynamic CA capacity. Physiological recordings of cerebral blood flow velocity, heart rate, end-tidal CO2 and beat-to-beat blood pressure from acute ischaemic stroke (AIS) patients (n = 46) containing ectopic heartbeats of varying number (0.2 to 25 occurrences per minute) were analysed. Dynamic CA was determined using the autoregulation index (ARI) and the normalised mean square error (NMSE) was used to evaluate the fitting of the step response between BP and CBFV to Tiecks' model. We fitted linear mixed models on the CA variables incorporating ectopic burden, age, sex and hemisphere as predictor variables. Ectopic activity demonstrated an association with mean coherence (p = 0.006) but not with ARI (p = 0.162), impaired CA based on dichotomised ARI (p = 0.859) or NMSE (p = 0.671). Dynamic CA could be reliably assessed in AIS patients using physiological recordings with high rates of cardiac ectopic activity. This provides supportive data for future studies evaluating CA capability in AIS patients, with the potential to develop more individualised treatment strategies. Graphical Abstract.
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Affiliation(s)
- Osian Llwyd
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK
| | - Victoria Haunton
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Angela S M Salinet
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK
| | - Mintu Nath
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Man Y Lam
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK
| | - Nazia P Saeed
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK
| | - Fiona Brodie
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Room 225, Level 2, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX, UK. .,NIHR Leicester Biomedical Research Centre, University of Leicester, Leicester, UK.
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14
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Schumacher FK, Steinborn C, Weiller C, Schelter BO, Reinhard M, Kaller CP. The impact of physiological noise on hemodynamic-derived estimates of directed functional connectivity. Brain Struct Funct 2019; 224:3145-3157. [DOI: 10.1007/s00429-019-01954-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 08/31/2019] [Indexed: 11/29/2022]
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15
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16
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Sperna Weiland NH, Hermanides J, Hollmann MW, Preckel B, Stok WJ, van Lieshout JJ, Immink RV. Novel method for intraoperative assessment of cerebral autoregulation by paced breathing. Br J Anaesth 2019; 119:1141-1149. [PMID: 29028933 DOI: 10.1093/bja/aex333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2017] [Indexed: 11/14/2022] Open
Abstract
Background Cerebral autoregulation (CA) is the mechanism that maintains constancy of cerebral blood flow (CBF) despite variations in blood pressure (BP). Patients with attenuated CA have been shown to have an increased incidence of peri-operative stroke. Studies of CA in anaesthetized subjects are rare, because a simple and non-invasive method to quantify the integrity of CA is not available. In this study, we set out to improve non-invasive quantification of CA during surgery. For this purpose, we introduce a novel method to amplify spontaneous BP fluctuations during surgery by imposing mechanical positive pressure ventilation at three different frequencies and quantify CA from the resulting BP oscillations. Methods Fourteen patients undergoing sevoflurane anaesthesia were included in the study. Continuous non-invasive BP and transcranial Doppler-derived CBF velocity (CBF V ) were obtained before surgery during 3 min of paced breathing at 6, 10, and 15 bpm and during surgery from mechanical positive pressure ventilation at identical frequencies. Data were analysed using frequency domain analysis to obtain CBF V -to-BP phase lead as a continuous measure of CA efficacy. Group averages were calculated. Values are means ( sd ), and P <0.05 was used to indicate statistical significance. Results Preoperative vs intraoperative CBF V -to-BP phase lead was 43 (9) vs 45 (8)°, 25 (8) vs 24 (10)°, and 4 (6) vs -2 (12)° during 6, 10, and 15 bpm, respectively (all P =NS). Conclusions During surgery, cerebral autoregulation indices were similar to values determined before surgery. This indicates that CA can be quantified reliably and non-invasively using this novel method and confirms earlier evidence that CA is unaffected by sevoflurane anaesthesia. Clinical trial registration NCT03071432.
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Affiliation(s)
- N H Sperna Weiland
- Department of Anaesthesiology.,Department of Medical Biology, Laboratory for Clinical Cardiovascular Physiology
| | | | | | | | - W J Stok
- Department of Medical Biology, Laboratory for Clinical Cardiovascular Physiology
| | - J J van Lieshout
- Department of Medical Biology, Laboratory for Clinical Cardiovascular Physiology.,Department of Internal Medicine, Academic Medical Centre AMC Amsterdam, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands.,MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - R V Immink
- Department of Anaesthesiology.,Department of Medical Biology, Laboratory for Clinical Cardiovascular Physiology
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17
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Lan Y, Lyu J, Ma X, Ma L, Lou X. Longitudinal assessment of cerebral blood flow changes following carotid artery stenting and endarterectomy. Radiol Med 2019; 124:636-642. [PMID: 30771219 DOI: 10.1007/s11547-018-00986-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/20/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Carotid artery stenting (CAS) and endarterectomy (CEA) are major treatment strategies for patients with internal carotid artery (ICA) stenosis; however, the dynamic cerebral blood flow (CBF) changes after CAS and CEA remain unclear. PURPOSE This study aimed to monitor consecutive CBF changes at 24-h intervals in patients who underwent CAS and CEA to explore the potential pattern of CBF alternation and compare the effect on CBF changes of different surgical methods. METHODS Thirty-two patients (28 males and 4 females; age = 63.0 ± 7.3 years) with 70-99% ipsilateral stenosis in the ICA were enrolled, of which 19 underwent CAS and 13 underwent CEA by prospective cross-sectional study. Routine head MRI and three-dimensional pseudo-continuous arterial spin labeling were performed using a 3.0-T system within 7 days prior to operations, and at 4 consecutive time-points (24, 48, 72, and 96 h) after operations. Comparisons within groups were made using paired t test, and comparisons between groups were made using independent-sample t test. RESULTS The CBF values markedly increased at 24 h after CAS and CEA (P < 0.05) compared with baseline. Most patients showed peak CBF values on the ipsilateral side at 72 h (13/19, 68%) after CAS and at 48 h (10/13, 77%) after CEA, which then declined. The CBF values for the ipsilateral ICA territory of CEA group were higher than those of CAS group at 24, 48, 72, and 96 h (P < 0.05). CONCLUSIONS The pattern of dynamic CBF changes is different after CAS and CEA, which may be helpful for the improvement of the patient's postoperative management.
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Affiliation(s)
- Yina Lan
- Department of Radiology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Jinhao Lyu
- Department of Radiology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Xiaoxiao Ma
- Department of Radiology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Lin Ma
- Department of Radiology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Xin Lou
- Department of Radiology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
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18
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Sanders ML, Claassen JAHR, Aries M, Bor-Seng-Shu E, Caicedo A, Chacon M, Gommer ED, Van Huffel S, Jara JL, Kostoglou K, Mahdi A, Marmarelis VZ, Mitsis GD, Müller M, Nikolic D, Nogueira RC, Payne SJ, Puppo C, Shin DC, Simpson DM, Tarumi T, Yelicich B, Zhang R, Panerai RB, Elting JWJ. Reproducibility of dynamic cerebral autoregulation parameters: a multi-centre, multi-method study. Physiol Meas 2018; 39:125002. [PMID: 30523976 DOI: 10.1088/1361-6579/aae9fd] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Different methods to calculate dynamic cerebral autoregulation (dCA) parameters are available. However, most of these methods demonstrate poor reproducibility that limit their reliability for clinical use. Inter-centre differences in study protocols, modelling approaches and default parameter settings have all led to a lack of standardisation and comparability between studies. We evaluated reproducibility of dCA parameters by assessing systematic errors in surrogate data resulting from different modelling techniques. APPROACH Fourteen centres analysed 22 datasets consisting of two repeated physiological blood pressure measurements with surrogate cerebral blood flow velocity signals, generated using Tiecks curves (autoregulation index, ARI 0-9) and added noise. For reproducibility, dCA methods were grouped in three broad categories: 1. Transfer function analysis (TFA)-like output; 2. ARI-like output; 3. Correlation coefficient-like output. For all methods, reproducibility was determined by one-way intraclass correlation coefficient analysis (ICC). MAIN RESULTS For TFA-like methods the mean (SD; [range]) ICC gain was 0.71 (0.10; [0.49-0.86]) and 0.80 (0.17; [0.36-0.94]) for VLF and LF (p = 0.003) respectively. For phase, ICC values were 0.53 (0.21; [0.09-0.80]) for VLF, and 0.92 (0.13; [0.44-1.00]) for LF (p < 0.001). Finally, ICC for ARI-like methods was equal to 0.84 (0.19; [0.41-0.94]), and for correlation-like methods, ICC was 0.21 (0.21; [0.056-0.35]). SIGNIFICANCE When applied to realistic surrogate data, free from the additional exogenous influences of physiological variability on cerebral blood flow, most methods of dCA modelling showed ICC values considerably higher than what has been reported for physiological data. This finding suggests that the poor reproducibility reported by previous studies may be mainly due to the inherent physiological variability of cerebral blood flow regulatory mechanisms rather than related to (stationary) random noise and the signal analysis methods.
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Affiliation(s)
- Marit L Sanders
- Department of Geriatric Medicine, Radboudumc Alzheimer Centre and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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19
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Chi NF, Hu HH, Wang CY, Chan L, Peng CK, Novak V, Hu CJ. Dynamic Cerebral Autoregulation Is an Independent Functional Outcome Predictor of Mild Acute Ischemic Stroke. Stroke 2018; 49:2605-2611. [DOI: 10.1161/strokeaha.118.022481] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Nai-Fang Chi
- From the Graduate Institute of Clinical Medicine, College of Medicine (N.-F.C., C.-J.H.), Taipei Medical University, Taiwan
- Department of Neurology, School of Medicine, College of Medicine (N.-F.C., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Department of Neurology, Shuang Ho Hospital (N.-F.C., H.H.H., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Research Center of Cerebrovascular Disease Treatment, College of Medicine (N.-F.C., H.H.H., C.Y.W., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan (N.-F.C.)
| | - Han-Hwa Hu
- Department of Neurology, Shuang Ho Hospital (N.-F.C., H.H.H., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Research Center of Cerebrovascular Disease Treatment, College of Medicine (N.-F.C., H.H.H., C.Y.W., L.C., C.-J.H.), Taipei Medical University, Taiwan
| | - Cheng-Yen Wang
- Research Center of Cerebrovascular Disease Treatment, College of Medicine (N.-F.C., H.H.H., C.Y.W., L.C., C.-J.H.), Taipei Medical University, Taiwan
| | - Lung Chan
- Department of Neurology, School of Medicine, College of Medicine (N.-F.C., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Department of Neurology, Shuang Ho Hospital (N.-F.C., H.H.H., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Research Center of Cerebrovascular Disease Treatment, College of Medicine (N.-F.C., H.H.H., C.Y.W., L.C., C.-J.H.), Taipei Medical University, Taiwan
| | - Chung-Kang Peng
- Division of Interdisciplinary Medicine and Biotechnology (C.-K.P.), Beth Israel Deaconess Medical Center, Boston, MA
| | - Vera Novak
- Departments of Neurology (V.N.), Beth Israel Deaconess Medical Center, Boston, MA
| | - Chaur-Jong Hu
- From the Graduate Institute of Clinical Medicine, College of Medicine (N.-F.C., C.-J.H.), Taipei Medical University, Taiwan
- Department of Neurology, School of Medicine, College of Medicine (N.-F.C., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Department of Neurology, Shuang Ho Hospital (N.-F.C., H.H.H., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Research Center of Cerebrovascular Disease Treatment, College of Medicine (N.-F.C., H.H.H., C.Y.W., L.C., C.-J.H.), Taipei Medical University, Taiwan
- Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology (C.-J.H.), Taipei Medical University, Taiwan
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20
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Cardim D, Robba C, Matta B, Tytherleigh-Strong G, Kang N, Schmidt B, Donnelly J, Calviello L, Smielewski P, Czosnyka M. Cerebrovascular assessment of patients undergoing shoulder surgery in beach chair position using a multiparameter transcranial Doppler approach. J Clin Monit Comput 2018; 33:615-625. [PMID: 30328561 PMCID: PMC6602988 DOI: 10.1007/s10877-018-0211-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/10/2018] [Indexed: 01/25/2023]
Abstract
Although the beach-chair position (BCP) is widely used during shoulder surgery, it has been reported to associate with a reduction in cerebral blood flow, oxygenation, and risk of brain ischaemia. We assessed cerebral haemodynamics using a multiparameter transcranial Doppler-derived approach in patients undergoing shoulder surgery. 23 anaesthetised patients (propofol (2 mg/kg)) without history of neurologic pathology undergoing elective shoulder surgery were included. Arterial blood pressure (ABP, monitored with a finger-cuff plethysmograph calibrated at the auditory meatus level) and cerebral blood flow velocity (FV, monitored in the middle cerebral artery) were recorded in supine and in BCP. All subjects underwent interscalene block ipsilateral to the side of FV measurement. We evaluated non-invasive intracranial pressure (nICP) and cerebral perfusion pressure (nCPP) calculated with a black-box mathematical model; critical closing pressure (CrCP); diastolic closing margin (DCM—pressure reserve available to avoid diastolic flow cessation); cerebral autoregulation index (Mxa); pulsatility index (PI). Significant changes occured for DCM [mean decrease of 6.43 mm Hg (p = 0.01)] and PI [mean increase of 0.11 (p = 0.05)]. ABP, FV, nICP, nCPP and CrCP showed a decreasing trend. Cerebral autoregulation was dysfunctional (Mxa > 0.3) and PI deviated from normal ranges (PI > 0.8) in both phases. ABP and nCPP values were low (< 60 mm Hg) in both phases. Changes between phases did not result in CrCP reaching diastolic ABP, therefore DCM did not reach critical values (≤ 0 mm Hg). BCP resulted in significant cerebral haemodynamic changes. If left untreated, reduction in cerebral blood flow may result in brain ischaemia and post-operative neurologic deficit.
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Affiliation(s)
- Danilo Cardim
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Department of Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, Vancouver, Canada. .,Vancouver General Hospital, 899 W 12th Ave, Room 2469, Vancouver, V5Z 1M9, Canada.
| | - Chiara Robba
- Neurosciences Critical Care Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Department of Neuroscience, University of Genoa, Genoa, Italy.,Department of Anaesthesia and Intensive Care, San Martino Policlinico Hospital, Genoa, Italy
| | - Basil Matta
- Neurosciences Critical Care Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Department of Anaesthesia, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Graham Tytherleigh-Strong
- Department of Trauma and Orthopaedics, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Niel Kang
- Department of Trauma and Orthopaedics, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Bernhard Schmidt
- Department of Neurology, University Hospital Chemnitz, Chemnitz, Germany
| | - Joseph Donnelly
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Leanne Calviello
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
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21
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Gollion C, Nasr N, Fabre N, Barège M, Kermorgant M, Marquine L, Larrue V. Cerebral autoregulation in migraine with aura: A case control study. Cephalalgia 2018; 39:635-640. [PMID: 30296840 DOI: 10.1177/0333102418806861] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Migraine with aura is independently associated with increased risk of ischemic stroke, especially in younger subjects. This association might be related to an impairment of cerebral autoregulation, which normally maintains cerebral blood flow independent of arterial blood pressure variations. METHODS Patients aged 30-55, fulfilling ICHD-3 beta criteria for migraine with aura, were prospectively enrolled and compared with gender- and age-matched healthy controls without a history of migraine. Patients and controls with a history of stroke or any disease potentially impairing cerebral autoregulation were excluded. We assessed cerebral autoregulation with two different methods: Transfer function analysis, and the correlation coefficient index Mx. The transfer function phase and gain reflect responses of cerebral blood flow velocities to relatively fast fluctuations of arterial blood pressure, whereas Mx also reflects responses to slower arterial blood pressure fluctuations. RESULTS A total of 22 migraine with aura patients (median age [IQR]: 39.5 [12.5] years) and 22 controls (39 [9.75] years) were included. Transfer function parameters and Mx were not different between patients and controls. However, Mx was inversely correlated with age in patients (ρ = -0.567, p = 0.006) and not in controls (ρ = -0.084, p = 0.509). Mx was also inversely correlated with migraine with aura duration (ρ = -0.617, p = 0.002), suggesting improvement of cerebral autoregulation efficiency with disease duration. CONCLUSIONS Cerebral autoregulation did not differ between patients and controls aged 30-55. However, cerebral autoregulation efficiency was strongly correlated with migraine with aura duration. Further studies in younger patients are needed to determine whether cerebral autoregulation is impaired early in the course of disease. TRIAL REGISTRATION NCT02708797.
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Affiliation(s)
- Cédric Gollion
- 1 Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Nathalie Nasr
- 1 Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Nelly Fabre
- 1 Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Michèle Barège
- 1 Department of Neurology, University Hospital of Toulouse, Toulouse, France
| | - Marc Kermorgant
- 2 UMR Institut National de la Santé et de la Recherche Médicale 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France
| | - Laurent Marquine
- 3 Clinical Investigation Centre, University Hospital of Toulouse, Toulouse, France
| | - Vincent Larrue
- 1 Department of Neurology, University Hospital of Toulouse, Toulouse, France
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22
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Guo ZN, Lv S, Liu J, Wang Z, Jin H, Qiu Q, Sun X, Yang Y. Compromised dynamic cerebral autoregulation in patients with generalized anxiety disorder: a study using transfer function analysis. BMC Psychiatry 2018; 18:164. [PMID: 29859053 PMCID: PMC5984810 DOI: 10.1186/s12888-018-1713-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 05/02/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Patients with generalized anxiety disorder (GAD) usually present with various neurological symptoms, but the mechanisms remain unclear. We aimed to analyze the characteristics of dynamic cerebral autoregulation (dCA) in patients with GAD. METHODS Patients (aged ≥18 years) who were diagnosed with GAD were enrolled in this study. Medically and psychiatrically healthy volunteers were recruited as controls. Subjects received the Hamilton Rating Scale for Anxiety (HAMA) and 17-item Hamilton Depression Rating Scale (HAMD) evaluation. Noninvasive continuous arterial blood pressure and bilateral middle cerebral artery blood flow velocity were recorded simultaneously from each subject. Transfer function analysis was used to derive the autoregulatory parameters, including phase difference, gain, and coherence function. RESULTS A total of 57 patients with GAD and 40 healthy volunteers were enrolled. We found that the phase difference values were significantly compromised in patients with GAD. In the Spearman correlation analysis, the phase difference values were negatively correlated with the HAMA scores and the HAMD scores. In the multiple linear regression analysis, GAD is negatively correlated with the phase difference values, whereas age is positively correlated with the phase difference values. CONCLUSIONS Our results suggested that the dCA was compromised in patients with GAD and negatively correlated with the score of anxiety. Improving the dCA may be a potential therapeutic method for treating the neurological symptoms of GAD patients.
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Affiliation(s)
- Zhen-Ni Guo
- grid.430605.4Department of Neurology, The First Hospital of Jilin University, Xinmin Street 71#, Chang Chun, 130021 China ,grid.430605.4Clinical Trail and Research Center for Stroke, Department of Neurology, The First Hospital of Jilin University, Chang Chun, China
| | - Shan Lv
- grid.430605.4Department of Neurology, The First Hospital of Jilin University, Xinmin Street 71#, Chang Chun, 130021 China
| | - Jia Liu
- 0000 0001 0483 7922grid.458489.cShenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Xueyuan Avenue, Shenzhen University Town, Shenzhen, China
| | - Zan Wang
- grid.430605.4Department of Neurology, The First Hospital of Jilin University, Xinmin Street 71#, Chang Chun, 130021 China
| | - Hang Jin
- grid.430605.4Department of Neurology, The First Hospital of Jilin University, Xinmin Street 71#, Chang Chun, 130021 China
| | - Quanli Qiu
- 0000 0001 0483 7922grid.458489.cShenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Xueyuan Avenue, Shenzhen University Town, Shenzhen, China
| | - Xin Sun
- Clinical Trail and Research Center for Stroke, Department of Neurology, The First Hospital of Jilin University, Chang Chun, China.
| | - Yi Yang
- Department of Neurology, The First Hospital of Jilin University, Xinmin Street 71#, Chang Chun, 130021, China. .,Clinical Trail and Research Center for Stroke, Department of Neurology, The First Hospital of Jilin University, Chang Chun, China.
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Abstract
PURPOSE OF REVIEW Cerebral autoregulation (CA) is a mechanism that maintains cerebral blood flow constant despite fluctuations in systemic arterial blood pressure. This review will focus on recent studies that measured CA non-invasively in acute cerebrovascular events, a feature unique to the transcranial Doppler ultrasound. We will summarize the rationale for CA assessment in acute cerebrovascular disorders and specifically evaluate the existing data on the value of CA measures in relation to clinical severity, guiding management decisions, and prognostication. RECENT FINDINGS Existing data suggest that CA is generally impaired in various cerebrovascular disorders. In patients with small vessel ischemic stroke, CA has been shown to be impaired in both hemispheres, whereas in large territorial strokes, CA impairment has been limited to the affected hemisphere. In these latter patients, impaired CA is also predictive of secondary complications such as hemorrhagic transformation and cerebral edema, hence worse functional outcome. In patients with carotid stenosis, impaired CA may also be associated with a higher ipsilateral hemispheric stroke risk. CA is also strongly linked to outcome in patients with intracranial hemorrhage. In patients with intraparenchymal hemorrhage, CA impairment correlated with clinical and imaging severity, whereas in those with subarachnoid hemorrhage, CA measures have a predictive value for development of delayed cerebral ischemia and radiographic vasospasm. Assessment of CA is increasingly more accessible in acute cerebrovascular disorders and promises to be a valuable measure in guiding hemodynamic management and predicting secondary complication, thus enhancing the care of these patients in the acute setting.
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Affiliation(s)
- Pedro Castro
- Department of Neurology, São João Hospital Center, Porto, Portugal.,Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Elsa Azevedo
- Department of Neurology, São João Hospital Center, Porto, Portugal.,Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, Porto, Portugal
| | - Farzaneh Sorond
- Department of Neurology, Division of Stroke and Neurocritical, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Ward 12-140, Chicago, IL, 60611, USA.
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24
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Comparing Different Recording Lengths of Dynamic Cerebral Autoregulation: 5 versus 10 Minutes. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7803426. [PMID: 29662898 PMCID: PMC5831790 DOI: 10.1155/2018/7803426] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 12/31/2017] [Indexed: 11/30/2022]
Abstract
We compared the dynamic cerebral autoregulation (dCA) indices between 5- and 10-minute data lengths by analyzing 37 patients with ischemic stroke and 51 controls in this study. Correlation coefficient (Mx) and transfer function analysis were applied for dCA analysis. Mx and phase shift in all frequency bands were not significantly different between 5- and 10-minute recordings [mean difference: Mx = 0.02; phase shift of very low frequency (0.02–0.07 Hz) = 0.3°, low frequency (0.07–0.20 Hz) = 0.6°, and high frequency (0.20–0.50 Hz) = 0.1°]. However, the gains in all frequency bands of a 5-minute recording were slightly but significantly higher than those of a 10-minute recording (mean difference of gain: very low frequency = 0.05 cm/s/mmHg, low frequency = 0.11 cm/s/mmHg, and high frequency = 0.14 cm/s/mmHg). The intraclass correlation coefficients between all dCA indices of 5- and 10-minute recordings were favorable, especially in Mx (0.93), phase shift in very low frequency (0.87), and gain in very low frequency (0.94). The areas under the receiver operating characteristic curve for stroke diagnosis between 5- and 10-minute recordings were not different. We concluded that dCA assessed by using a 5-minute recording is not significantly different from that using a 10-minute recording in the clinical application.
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25
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Smirl JD, Wright AD, Ainslie PN, Tzeng YC, van Donkelaar P. Differential Systolic and Diastolic Regulation of the Cerebral Pressure-Flow Relationship During Squat-Stand Manoeuvres. ACTA NEUROCHIRURGICA SUPPLEMENT 2018; 126:263-268. [DOI: 10.1007/978-3-319-65798-1_52] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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26
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Riberholt C, Olesen N, Hovind P, Mehlsen J, Petersen TH. Intravenous saline administration in patients with severe acquired brain injury and orthostatic intolerance for tilt-table mobilization. Brain Inj 2017; 32:252-256. [PMID: 29190150 DOI: 10.1080/02699052.2017.1408144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PRIMARY OBJECTIVE This study aimed to investigate the effect of intravenous saline administration on orthostatic hypotension (OH) during head up tilt (HUT) and the change in the renin-angiotensin-aldosterone system before and after HUT in patients with severe acquired brain injury (ABI). RESEARCH DESIGN The study is designed as an observational study. METHODS AND PROCEDURES Fourteen patients with ABI, low level of consciousness and OH were monitored before, during and after HUT with non-invasive beat-to-beat blood pressure measurement, and transcranial Doppler determination of middle cerebral artery blood flow velocity. Blood samples were collected before and after two HUT sessions separated by 1 hour and saline was administered in between. MAIN OUTCOMES AND RESULTS Patients' ability to stand upright did not change after saline administration due to OH. The patients showed signs of reduced cerebral autoregulation at both HUT sessions. The patients had a significant lower level of renin and angiotensin II but not aldosterone. CONCLUSIONS Patients with severe ABI and OH demonstrate no improvement in standing time with reduced plasma renin and angiotensin II after two HUT sessions and 1 hour fluid administration. Research focusing on the ability to retain fluid after bed rest is warranted.
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Affiliation(s)
- Christian Riberholt
- a Research Unit on Brain Injury Rehabilitation , Department of Neurorehabilitation/TBI Unit , Rigshospitalet, Copenhagen , Denmark
| | - Niels Olesen
- b Department of Anaesthesia , Rigshospitalet, Copenhagen , Denmark.,c Department of Neuroscience and Pharmacology , University of Copenhagen , Copenhagen , Denmark
| | - Peter Hovind
- d Department of Clinical Physiology , Nuclear Medicine and PET , Rigshospitalet, Copenhagen , Denmark
| | - Jesper Mehlsen
- e Coordinating Research Centre , Bispebjerg & Frederiksberg Hospital, Frederiksberg , Denmark
| | - Tue Hvass Petersen
- a Research Unit on Brain Injury Rehabilitation , Department of Neurorehabilitation/TBI Unit , Rigshospitalet, Copenhagen , Denmark
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27
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Semenyutin VB, Asaturyan GA, Nikiforova AA, Aliev VA, Panuntsev GK, Iblyaminov VB, Savello AV, Patzak A. Predictive Value of Dynamic Cerebral Autoregulation Assessment in Surgical Management of Patients with High-Grade Carotid Artery Stenosis. Front Physiol 2017; 8:872. [PMID: 29163214 PMCID: PMC5673646 DOI: 10.3389/fphys.2017.00872] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 10/17/2017] [Indexed: 01/20/2023] Open
Abstract
Dynamic cerebral autoregulation (DCA) capacity along with the degree of internal carotid artery (ICA) stenosis and characteristics of the plaque can also play an important role in selection of appropriate treatment strategy. This study aims to classify the patients with severe ICA stenosis according to preoperative state of DCA and to assess its dynamics after surgery. Thirty-five patients with severe ICA stenosis having different clinical type of disease underwent reconstructive surgery. DCA was assessed with transfer function analysis (TFA) by calculating phase shift (PS) between Mayer waves of blood flow velocity (BFV) and blood pressure (BP) before and after operation. In 18 cases, regardless of clinical type, preoperative PS on ipsilateral side was within the normal range and did not change considerably after surgery. In other 17 cases preoperative PS was reliably lower both in patients with symptomatic and asymptomatic stenosis. Surgical reconstruction led to restoration of impaired DCA evidenced by significant increase of PS in postoperative period. Our data suggest that regardless clinical type of disease various state of DCA may be present in patients with severe ICA stenosis. This finding can contribute to establishing the optimal treatment strategy, and first of all for asymptomatic patients. Patients with compromised DCA should be considered as ones with higher risk of stroke and first candidates for reconstructive surgery.
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Affiliation(s)
- Vladimir B Semenyutin
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia
| | - Gregory A Asaturyan
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia
| | - Anna A Nikiforova
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia
| | - Vugar A Aliev
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia.,Department of Neurosurgery, Municipal Hospital of Saint Martyr Elizabeth, Saint-Petersburg, Russia
| | - Grigory K Panuntsev
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia
| | - Vadim B Iblyaminov
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia
| | - Alexander V Savello
- Laboratory of Brain Circulation Pathology, Federal Almazov Medical Research Center, Saint-Petersburg, Russia
| | - Andreas Patzak
- Johannes-Mueller Institute of Physiology University Hospital Charite, Humboldt University of Berlin, Berlin, Germany
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28
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Ku HL, Wang JK, Lee HC, Lane TJ, Liu IC, Chen YC, Lee YT, Lin IC, Lin CP, Hu CJ, Chi NF. Cerebral blood flow autoregulation is impaired in schizophrenia: A pilot study. Schizophr Res 2017; 188:63-67. [PMID: 28108227 DOI: 10.1016/j.schres.2017.01.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/04/2017] [Accepted: 01/07/2017] [Indexed: 12/13/2022]
Abstract
Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of the participants had a history of cardiovascular diseases, hypertension, or diabetes. All participants underwent 10-min blood pressure and cerebral blood flow recording through finger plethysmography and Doppler ultrasonography, respectively. Cerebral autoregulation was assessed by analyzing two autoregulation indices: the mean blood pressure and cerebral blood flow correlation coefficient (Mx), and the phase shift between the waveforms of blood pressure and cerebral blood flow determined using transfer function analysis. Compared with the controls, the patients had a significantly higher Mx (0.257 vs. 0.399, p=0.036) and lower phase shift (44.3° vs. 38.7° in the 0.07-0.20Hz frequency band, p=0.019), which indicated impaired maintenance of constant cerebral blood flow and a delayed cerebrovascular autoregulatory response. Impaired cerebral autoregulation may be caused by schizophrenia and may not be an artifact of coexisting medical conditions. The mechanism underlying impaired cerebral autoregulation in schizophrenia and its probable role in the development of cerebrovascular diseases require further investigation.
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Affiliation(s)
- Hsiao-Lun Ku
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Brain and Consciousness Research Center, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - Jiunn-Kae Wang
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Brain and Consciousness Research Center, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - Hsin-Chien Lee
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Research Center of Sleep Medicine, College of Medicine, Taipei, Taiwan
| | - Timothy Joseph Lane
- Brain and Consciousness Research Center, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Graduate Institute of Humanities in Medicine, College of Humanities and Social Sciences, Taipei Medical University, Taipei, Taiwan; Institute of European and American Studies, Academia Sinica, Taipei, Taiwan; Research Center for Mind, Brain and Learning, National Chengchi University, Taipei, Taiwan
| | - I-Chao Liu
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yung-Chan Chen
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - Yao-Tung Lee
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - I-Cheng Lin
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - Chia-Pei Lin
- Department of Psychiatry, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan
| | - Chaur-Jong Hu
- Department of Neurology, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Cerebrovascular Research Center, Taipei Medical University, Taipei, Taiwan
| | - Nai-Fang Chi
- Department of Neurology, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan; Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Cerebrovascular Research Center, Taipei Medical University, Taipei, Taiwan.
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29
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Robba C, Cardim D, Sekhon M, Budohoski K, Czosnyka M. Transcranial Doppler: a stethoscope for the brain-neurocritical care use. J Neurosci Res 2017; 96:720-730. [PMID: 28880397 DOI: 10.1002/jnr.24148] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 06/12/2017] [Accepted: 08/10/2017] [Indexed: 02/03/2023]
Abstract
Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside monitoring technique that can evaluate cerebral blood flow hemodynamics in the intracranial arterial vasculature. TCD allows assessment of linear cerebral blood flow velocity, with a high temporal resolution and is inexpensive, reproducible, and portable. The aim of this review is to provide an overview of the most commonly used TCD derived signals and measurements used commonly in neurocritical care. We describe both basic (flow velocity, pulsatility index) and advanced concepts, including critical closing pressure, wall tension, autoregulation, noninvasive intracranial pressure, brain compliance, and cerebrovascular time constant; we also describe the clinical applications of TCD to highlight their utility in the diagnosis and monitoring of cerebrovascular diseases as the "stethoscope for the brain."
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Affiliation(s)
- Chiara Robba
- Neurocritical Care Unit, Addenbrooke's Hospital, Cambridge University, Box 1, Addenbrooke's Hospital, Cambridge University Hospitals Trust, Hills Road, Cambridge, CB2 0QQ.,Division of Neuroscience, University of Genoa, Genoa, Italy
| | - Danilo Cardim
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Mypinder Sekhon
- Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia
| | - Karol Budohoski
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Marek Czosnyka
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
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30
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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.
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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
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31
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Liu X, Czosnyka M, Pickard JD, Varsos GV, Nasr N, Smielewski P. Derangement of Cerebral Blood Flow Autoregulation During Intracranial Pressure Plateau Waves as Detected by Time and Frequency-Based Methods. ACTA NEUROCHIRURGICA. SUPPLEMENT 2017; 122:233-8. [PMID: 27165913 DOI: 10.1007/978-3-319-22533-3_47] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Plateau waves are sudden elevations of intracranial pressure (ICP) above 40 mmHg, lasting at least 5 min, and are associated with cerebral vasodilatation. We studied the performance of several parameters for cerebral autoregulation assessment during 30 plateau waves of 24 patients with traumatic brain injury. Continuous signals were collected for ICP, arterial blood pressure (ABP) and transcranial Doppler flow velocity (FV). Parameters both in the time domain (autoregulation index, ARI and mean flow index, Mx) and the frequency domain (transfer function gain, phase and coherence) were analysed. The role of different inputs, using either ABP or cerebral perfusion pressure (CPP) as input, was also tested.Autoregulation deteriorated from baseline to plateau, which could be demonstrated by a significant decrease in both ARI between ABP and FV (p = 0.013) and ARI between CPP and FV (p = 0.014). There was also a significant increase in Mx between CPP and FV (p = 0.004), but not in Mx between ABP and FV (p = 0.472). From the baseline to plateau, there was a significant increase in coherence between the ABP and FV at the very low frequency (p = 0.004). The transfer function phase and gain, on the other hand, revealed inconsistent performance.
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Affiliation(s)
- Xiuyun Liu
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.
| | - Marek Czosnyka
- Division of Neurosurgery , Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - John D Pickard
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Georgios V Varsos
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Nathalie Nasr
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Peter Smielewski
- Division of Neurosurgery , Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Mahdi A, Nikolic D, Birch AA, Olufsen MS, Panerai RB, Simpson DM, Payne SJ. Increased blood pressure variability upon standing up improves reproducibility of cerebral autoregulation indices. Med Eng Phys 2017; 47:151-158. [PMID: 28694108 DOI: 10.1016/j.medengphy.2017.06.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 04/19/2017] [Accepted: 06/01/2017] [Indexed: 11/16/2022]
Abstract
Dynamic cerebral autoregulation, that is the transient response of cerebral blood flow to changes in arterial blood pressure, is currently assessed using a variety of different time series methods and data collection protocols. In the continuing absence of a gold standard for the study of cerebral autoregulation it is unclear to what extent does the assessment depend on the choice of a computational method and protocol. We use continuous measurements of blood pressure and cerebral blood flow velocity in the middle cerebral artery from the cohorts of 18 normotensive subjects performing sit-to-stand manoeuvre. We estimate cerebral autoregulation using a wide variety of black-box approaches (including the following six autoregulation indices ARI, Mx, Sx, Dx, FIR and ARX) and compare them in the context of reproducibility and variability. For all autoregulation indices, considered here, the intra-class correlation was greater during the standing protocol, however, it was significantly greater (Fisher's Z-test) for Mx (p < 0.03), Sx (p < 0.003) and Dx (p < 0.03). In the specific case of the sit-to-stand manoeuvre, measurements taken immediately after standing up greatly improve the reproducibility of the autoregulation coefficients. This is generally coupled with an increase of the within-group spread of the estimates.
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Affiliation(s)
- Adam Mahdi
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK.
| | - Dragana Nikolic
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Anthony A Birch
- Department of Medical Physics and Bioengineering, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Mette S Olufsen
- Department of Mathematics, North Carolina State University, Raleigh, USA
| | - Ronney B Panerai
- Department of Cardiovascular Sciences and NIHR Cardiovascular Biomedical Research Unit, University of Leicester, Leicester, UK
| | - David M Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Stephen J Payne
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK
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Chi NF, Ku HL, Wang CY, Liu Y, Chan L, Lin YC, Peng CK, Novak V, Hu HH, Hu CJ. Dynamic Cerebral Autoregulation Assessment Using Extracranial Internal Carotid Artery Doppler Ultrasonography. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1307-1313. [PMID: 28411965 DOI: 10.1016/j.ultrasmedbio.2017.02.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/07/2017] [Accepted: 02/02/2017] [Indexed: 06/07/2023]
Abstract
Transcranial Doppler ultrasonography of the middle cerebral artery (MCA) is frequently used to assess dynamic cerebral autoregulation (dCA); however, this is difficult in patients with poor temporal bone windows. In the study described here, we investigated the agreement and sensitivity of dCA indices determined from the extracranial internal carotid artery (ICA) and those determined from the MCA. Measurements for 32 stroke patients and 59 controls were analyzed. Measurement of the mean flow correlation index (Mx) and transfer function analysis based on spontaneous blood pressure fluctuation were simultaneously performed for the extracranial ICA and MCA. The mean values of Mx and phase shift did not significantly differ between the ICA and MCA (mean difference: Mx = 0.01; phase shift of very low frequency [VLF] = 0.7°, low frequency [LF] = 3.3° and high frequency = 4.5°), but the gains in VLF and LF in the ICA were significantly lower than those in the MCA (mean difference: gain of VLF = -0.13, gain of LF = -0.10). The intra-class correlation coefficient between the dCA indices of the ICA and MCA was favorable in Mx (0.76) and the phase shift of VLF (0.72). The area under the receiver operating characteristic curve for stroke diagnosis did not differ among the dCA indices. We conclude that dCA assessed from the ICA is as effective as that from the MCA, but the results are not interchangeable.
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Affiliation(s)
- Nai-Fang Chi
- Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
| | - Hsiao-Lun Ku
- Department of Psychiatry, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chen-Yen Wang
- Research Center for Adaptive Data Analysis, National Central University, Taoyuan, Taiwan
| | - Yanhui Liu
- Fengsheng Yongkang Software Technology Corporation, Nanjing, China
| | - Lung Chan
- Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Ying-Chin Lin
- Health Management Center, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chung-Kang Peng
- Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Vera Novak
- Departments of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Han-Hwa Hu
- Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chaur-Jong Hu
- Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
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Mahdi A, Nikolic D, Birch AA, Payne SJ. At what data length do cerebral autoregulation measures stabilise? Physiol Meas 2017; 38:1396-1404. [DOI: 10.1088/1361-6579/aa76a9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Xiong L, Liu X, Shang T, Smielewski P, Donnelly J, Guo ZN, Yang Y, Leung T, Czosnyka M, Zhang R, Liu J, Wong KS. Impaired cerebral autoregulation: measurement and application to stroke. J Neurol Neurosurg Psychiatry 2017; 88:520-531. [PMID: 28536207 DOI: 10.1136/jnnp-2016-314385] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 11/04/2022]
Abstract
Cerebral autoregulation (CA) is a protective mechanism that maintains cerebral blood flow at a relatively constant level despite fluctuations of cerebral perfusion pressure or arterial blood pressure. It is a universal physiological mechanism that may involve myogenic, neural control as well as metabolic regulations of cerebral vasculature in response to changes in pressure or cerebral blood flow. Traditionally, CA has been represented by a sigmoid curve with a wide plateau between about 50 mm Hg and 170 mm Hg of steady-state changes in mean arterial pressure, defined as static CA. With the advent of transcranial Doppler, measurement of cerebral blood flow in response to transient changes in arterial pressure has been used to assess dynamic CA. However, a gold standard for measuring CA is not currently available. Stroke has been the leading cause of long-term adult disability throughout the world. A better understanding of CA and its response to pathological derangements can help assess the severity of stroke, guide management decisions, assess response to interventions and provide prognostic information. The objective of this review is to provide a comprehensive insight about physiology of autoregulation, measurement methodologies and clinical applications in stroke to help build a consensus for what should be included in an internationally agreed protocol for CA testing and monitoring, and to promote its translation into clinical bedside practice for stroke management.
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Affiliation(s)
- Li Xiong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - Xiuyun Liu
- Department of Clinical Neurosciences, Brain Physics Laboratory, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Ty Shang
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Peter Smielewski
- Department of Clinical Neurosciences, Brain Physics Laboratory, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Joseph Donnelly
- Department of Clinical Neurosciences, Brain Physics Laboratory, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Zhen-Ni Guo
- Department of Neurology, Neuroscience Center, The First Norman Bethune Hospital of Jilin University, Changchun, China
| | - Yi Yang
- Chinese Academy of Sciences, Shenzhen Institutes of Advanced Technology, Shenzhen, China
| | - Thomas Leung
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - Marek Czosnyka
- Department of Clinical Neurosciences, Brain Physics Laboratory, Division of Neurosurgery, University of Cambridge, Cambridge, UK
| | - Rong Zhang
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jia Liu
- Chinese Academy of Sciences, Shenzhen Institutes of Advanced Technology, Shenzhen, China
| | - Ka Sing Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
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Uryga A, Placek MM, Wachel P, Szczepański T, Czosnyka M, Kasprowicz M. Phase shift between respiratory oscillations in cerebral blood flow velocity and arterial blood pressure. Physiol Meas 2017; 38:310-324. [PMID: 28099160 DOI: 10.1088/1361-6579/38/2/310] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Lee YK, Tang SC, Jeng JS, Shieh JS. Nonlinear analyses applied in cerebral autoregulation and blood flow changes in patients with acute intracerebral hemorrhage. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2016.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Patel N, Panerai RB, Haunton V, Katsogridakis E, Saeed NP, Salinet A, Brodie F, Syed N, D'Sa S, Robinson TG. The Leicester cerebral haemodynamics database: normative values and the influence of age and sex. Physiol Meas 2016; 37:1485-98. [PMID: 27511128 DOI: 10.1088/0967-3334/37/9/1485] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Normative values of physiological parameters hold significance in modern day clinical decision-making. Lack of such normative values has been a major hurdle in the translation of research into clinical practice. A large database containing uniform recordings was constructed to allow more robust estimates of normative ranges and also assess the influence of age and sex. Doppler recordings were performed on healthy volunteers in the same laboratory, using similar protocols and equipment. Beat-to-beat blood pressure, heart-rate, electrocardiogram, and end-tidal CO2 were measured continuously. Bilateral insonation of the middle cerebral arteries (MCAs) was performed using TCD following a 15 min stabilisation, and a 5 min baseline recording. Good quality Doppler recordings for both MCAs were obtained in 129 participants (57 female) with a median age of 57 years (range 20-82). Age was found to influence baseline haemodynamic and transfer function analysis parameters. Cerebral blood flow velocity and critical closing pressure were the only sex-related differences found, which was significantly higher in females than males. Normative values for cerebral haemodynamic parameters have been defined in a large, healthy population. Such age/sex-defined normal values can be used to reduce the burden of collecting additional control data in future studies, as well as to identify disease-associated changes.
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Affiliation(s)
- Nikil Patel
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, LE2 7LX, UK. NIHR Biomedical Research Unit for Cardiovascular Sciences, University of Leicester, Leicester, UK
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D’Andrea A, Conte M, Cavallaro M, Scarafile R, Riegler L, Cocchia R, Pezzullo E, Carbone A, Natale F, Santoro G, Caso P, Russo MG, Bossone E, Calabrò R. Transcranial Doppler ultrasonography: From methodology to major clinical applications. World J Cardiol 2016; 8:383-400. [PMID: 27468332 PMCID: PMC4958690 DOI: 10.4330/wjc.v8.i7.383] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/22/2016] [Accepted: 05/27/2016] [Indexed: 02/06/2023] Open
Abstract
Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler (TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency (≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called “paradoxical embolism”, most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called “microembolic signal grading score”. In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage (caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.
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Riberholt CG, Olesen ND, Thing M, Juhl CB, Mehlsen J, Petersen TH. Impaired Cerebral Autoregulation during Head Up Tilt in Patients with Severe Brain Injury. PLoS One 2016; 11:e0154831. [PMID: 27168188 PMCID: PMC4864314 DOI: 10.1371/journal.pone.0154831] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/19/2016] [Indexed: 12/12/2022] Open
Abstract
Early mobilization is of importance for improving long-term outcome for patients after severe acquired brain injury. A limiting factor for early mobilization by head-up tilt is orthostatic intolerance. The purpose of the present study was to examine cerebral autoregulation in patients with severe acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography, middle cerebral artery velocity was evaluated by transcranial Doppler, and near-infrared spectroscopy determined frontal lobe oxygenation in the supine position and during head-up tilt. Cerebral autoregulation was evaluated as the mean flow index calculated as the ratio between middle cerebral artery mean velocity and estimated cerebral perfusion pressure. Patients with acquired brain injury presented an increase in mean flow index during head-up tilt indicating impaired autoregulation (P < 0.001). Spectral analysis of heart rate variability in the frequency domain revealed lower magnitudes of ~0.1 Hz spectral power in patients compared to healthy controls suggesting baroreflex dysfunction. In conclusion, patients with severe acquired brain injury and orthostatic intolerance during head-up tilt have impaired cerebral autoregulation more than one month after brain injury.
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Affiliation(s)
- Christian Gunge Riberholt
- Research Unit on Brain Injury Neuro Rehabilitation Copenhagen, Department of Neurorehabilitation/ TBI Unit, Rigshospitalet, Copenhagen, Denmark
- * E-mail:
| | - Niels Damkjær Olesen
- Department of Anaesthesia, Rigshospitalet, Copenhagen, Denmark
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Mira Thing
- Department of Paediatrics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Carsten Bogh Juhl
- Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
- Department of Rehabilitation, Copenhagen University Hospital Herlev and Gentofte, Gentofte, Denmark
| | - Jesper Mehlsen
- Coordinating Research Centre, Bispebjerg & Frederiksberg Hospital, Frederiksberg, Denmark
| | - Tue Hvass Petersen
- Research Unit on Brain Injury Neuro Rehabilitation Copenhagen, Department of Neurorehabilitation/ TBI Unit, Rigshospitalet, Copenhagen, Denmark
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Marshall RS, Pavol MA, Cheung YK, Strom I, Slane K, Asllani I, Lazar RM. Dissociation among hemodynamic measures in asymptomatic high grade carotid artery stenosis. J Neurol Sci 2016; 367:143-7. [PMID: 27423579 DOI: 10.1016/j.jns.2016.05.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND Cerebral blood flow (CBF) regulation is a critical element in cerebrovascular pathophysiology, particularly in large vessel disease, but the best method to use for hemodynamic assessment is not clear. We examined 4 different blood-flow related measures in patients with unilateral high-grade carotid artery disease, assessing asymmetry between the occluded vs non-occluded side, and the correlations among the measures. METHODS Thirty-three patients (age 50-93, 19 M) with unilateral 80-100% ICA occlusion but no stroke underwent: 1) mean flow velocity (MFV) in both middle cerebral arteries by transcranial Doppler (TCD), 2) quantitative resting CBF using pseudo-continuous arterial spin labeling (pCASL) MRI, 3) vasomotor reactivity (VMR) in response to 5% CO2 inhalation, and 4) dynamic cerebral autoregulation (DCA) assessing the counter-regulation of blood flow to spontaneous changes in blood pressure using TCD monitoring and finger photoplethysmography. Paired t-tests and Pearson correlations assessed side-to-side differences within each measure, and correlations between measures. RESULTS CBF (p=0.001), MFV (p<0.001), VMR (p=0.008), and DCA (p=0.047) all showed significantly lower values on the occluded side. The 4 measures were independent of each other on correlation analysis, even when controlling for age and anterior circle of Willis collateral (all partial correlations <0.233 and p-values >0.468). CONCLUSIONS These 4 measures showed high sensitivity to the occluded carotid artery, but their dissociation suggests that any given measure only partially characterizes the hemodynamic state. Additional research is needed to explore the multifaceted biology of cerebral blood flow regulation.
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Affiliation(s)
| | - MaryKay A Pavol
- Columbia University, Department of Neurology, New York, United States
| | - Ying K Cheung
- Department of Biostatistics, Columbia University, New York, United States
| | - Isabelle Strom
- Columbia University, Department of Neurology, New York, United States
| | - Kevin Slane
- Columbia University, Department of Neurology, New York, United States
| | - Iris Asllani
- Rochester Institute of Neurology, Rochester, New York, United States
| | - Ronald M Lazar
- Columbia University, Department of Neurology, New York, United States
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D'Andrea A, Conte M, Scarafile R, Riegler L, Cocchia R, Pezzullo E, Cavallaro M, Carbone A, Natale F, Russo MG, Gregorio G, Calabrò R. Transcranial Doppler Ultrasound: Physical Principles and Principal Applications in Neurocritical Care Unit. J Cardiovasc Echogr 2016; 26:28-41. [PMID: 28465958 PMCID: PMC5224659 DOI: 10.4103/2211-4122.183746] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Transcranial Doppler (TCD) ultrasonography is a noninvasive ultrasound study, which has been extensively applied on both outpatient and inpatient settings. It involves the use of a low-frequency (≤2 MHz) transducer, placed on the scalp, to insonate the basal cerebral arteries through relatively thin bone windows and to measure the cerebral blood flow velocity and its alteration in many different conditions. In neurointensive care setting, TCD is useful for both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoid hemorrhage, traumatic brain injury, acute ischemic stroke, and brain stem death. It also allows to investigate the cerebrovascular autoregulation in setting of carotid disease and syncope. In this review, we will describe physical principles underlying TCD, flow indices most frequently used in clinical practice and critical care applications in Neurocritical Unit care.
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Affiliation(s)
- Antonello D'Andrea
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Marianna Conte
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Raffaella Scarafile
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Lucia Riegler
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Rosangela Cocchia
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Enrica Pezzullo
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Massimo Cavallaro
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Andreina Carbone
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Francesco Natale
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Maria Giovanna Russo
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
| | - Giovanni Gregorio
- Department of Cardiology, San Luca Hospital, Vallo della Lucania, Salerno, Italy
| | - Raffaele Calabrò
- Department of Cardiology, Integrated Diagnostic Cardiology, Second University of Neaples, Monaldi Hospital, Neaples, Italy
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Małowidzka-Serwińska M, Żabicka M, Witkowski A, Chmielak Z, Deptuch T. Brain perfusion evaluated by perfusion-weighted magnetic resonance imaging before and after stenting internal carotid artery stenosis in asymptomatic and symptomatic patients. Neurol Neurochir Pol 2015; 49:412-20. [PMID: 26652876 DOI: 10.1016/j.pjnns.2015.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 07/31/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
Abstract
PURPOSE To evaluate the brain perfusion with MRI perfusion weighted imaging (PWI) before and after ICA stenting in asymptomatic and symptomatic patients. MATERIALS AND METHODS PWI was performed 3-21 days before and 3 days after ICA stenting in 31 asymptomatic patients with ICA >70% stenosis - Group I, and in 14 symptomatic patients with ICA >50% stenosis - Group II. PWI was evaluated qualitatively and quantitatively in 5 cerebral territories with: mean transit time (MTT), cerebral blood volume (CBV) and cerebral blood flow (CBF). Mean values of perfusion parameters were measured before and after stenting ΔMTT, ΔCBV, ΔCBF were calculated as subtraction of after-treatment values from those before treatment. RESULTS In qualitative evaluation after ICA stenting perfusion was normalized in 21 patients (80.8%) in Group I and in 8 patients (80%) in Group II. In quantitative estimation MTT decreased significantly after CAS on stented side vs. non-stented side in all examined patients regardless of the group, p<0.05. MTT decreased more in Group II than in Group I in all territories (p<0.05) with the exception of temporal lobe. CBV and CBF have shown insignificant differences.
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Affiliation(s)
| | - Magdalena Żabicka
- Department of Radiology, Military Institute of Medicine, Warsaw, Poland
| | - Adam Witkowski
- Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw, Poland
| | - Zbigniew Chmielak
- Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw, Poland
| | - Tomasz Deptuch
- Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw, Poland
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Wang S, Guo ZN, Xing Y, Ma H, Jin H, Liu J, Yang Y. Dynamic Cerebral Autoregulation in Asymptomatic Patients With Unilateral Middle Cerebral Artery Stenosis. Medicine (Baltimore) 2015; 94:e2234. [PMID: 26717363 PMCID: PMC5291604 DOI: 10.1097/md.0000000000002234] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The aim of the study was to assess the capacity of dynamic cerebral autoregulation (dCA) in asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis.Fifty-seven patients with asymptomatic mild, moderate, and severe unilateral MCA stenosis and 8 patients with symptomatic severe unilateral MCA stenosis diagnosed by transcranial Doppler were enrolled. Twenty-four healthy volunteers served as controls. The noninvasive continuous cerebral blood flow velocity and arterial blood pressure were recorded simultaneously from each subject in the supine position. Transfer function analysis was applied to determine the autoregulatory parameters (phase difference [PD] and gain).The PD values in the severe stenosis groups were significantly lower than those of the control group (60.71 ± 18.63°), the asymptomatic severe stenosis group was impaired ipsilaterally (28.94 ± 27.43°, P < 0.001), and the symptomatic severe stenosis group was impaired bilaterally (13.74 ± 19.21°, P < 0.001; 19.68 ± 14.50°, P = 0.006, respectively). The PD values in the mild and moderate stenosis groups were not significantly different than the controls (44.49 ± 27.93°; 48.65 ± 25.49°, respectively). The gain values in the mild and moderate groups were higher than in the controls (1.00 ± 0.58 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, and 1.20 ± 0.59 cm/s/mm Hg vs 0.86 ± 0.34 cm/s/mm Hg, respectively). The gain values in the severe stenosis groups were significantly lower than that in the control group: the asymptomatic severe stenosis group was lower bilaterally (0.56 ± 0.32 cm/s/mm Hg, P = 0.003; 0.60 ± 0.32 cm/s/mm Hg, P < 0.05, respectively), whereas the symptomatic severe group was lower unilaterally (on the contralateral side) (0.53 ± 0.43 cm/s/mm Hg, P < 0.05).In asymptomatic patients with unilateral MCA stenosis, only the dCA of the severe stenosis was ipsilaterally impaired. Acute stroke may aggravate the impaired dCA and even spread contralaterally.
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Affiliation(s)
- Shuang Wang
- From the Stroke Center, Department of Neurology (SW, HM, HJ, YY); Neuroscience Center, Department of Neurology (Z-NG); Center for Neurovascular ultrasound (Y X), the First Hospital of Jilin Universit, Changchun, China and Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Xueyuan Avenue, Shenzhen University Town, Shenzhen, China (JL)
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Monitoring of cerebral blood flow autoregulation in adults undergoing sevoflurane anesthesia: a prospective cohort study of two age groups. J Clin Monit Comput 2015; 30:255-64. [PMID: 26285741 DOI: 10.1007/s10877-015-9754-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/10/2015] [Indexed: 10/23/2022]
Abstract
Autoregulation of blood flow is a key feature of the human cerebral vascular system to assure adequate oxygenation and metabolism of the brain under changing physiological conditions. The impact of advanced age and anesthesia on cerebral autoregulation remains unclear. The primary objective of this study was to determine the effect of sevoflurane anesthesia on cerebral autoregulation in two different age groups. This is a follow-up analysis of data acquired in a prospective observational cohort study. One hundred thirty-three patients aged 18-40 and ≥65 years scheduled for major noncardiac surgery under general anesthesia were included. Cerebral autoregulation indices, limits, and ranges were compared in young and elderly patient groups. Forty-nine patients (37 %) aged 18-40 years and 84 patients (63 %) aged ≥65 years were included in the study. Age-adjusted minimum alveolar concentrations of sevoflurane were 0.89 ± 0.07 in young and 0.99 ± 0.14 in older subjects (P < 0.001). Effective autoregulation was found in a blood pressure range of 13.8 ± 9.8 mmHg in young and 10.2 ± 8.6 mmHg in older patients (P = 0.079). The lower limit of autoregulation was 66 ± 12 mmHg and 73 ± 14 mmHg in young and older patients, respectively (P = 0.075). The association between sevoflurane concentrations and autoregulatory capacity was similar in both age groups. Our data suggests that the autoregulatory plateau is shortened in both young and older patients under sevoflurane anesthesia with approximately 1 MAC. Lower and upper limits of cerebral blood flow autoregulation, as well as the autoregulatory range, are not influenced by the age of anesthetized patients. Trial registration ClinicalTrials.gov (NCT00512200).
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Panunzi S, D’Orsi L, Iacoviello D, De Gaetano A. A stochastic delay differential model of cerebral autoregulation. PLoS One 2015; 10:e0118456. [PMID: 25830915 PMCID: PMC4382334 DOI: 10.1371/journal.pone.0118456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 01/16/2015] [Indexed: 01/09/2023] Open
Abstract
Mathematical models of the cardiovascular system and of cerebral autoregulation (CAR) have been employed for several years in order to describe the time course of pressures and flows changes subsequent to postural changes. The assessment of the degree of efficiency of cerebral auto regulation has indeed importance in the prognosis of such conditions as cerebro-vascular accidents or Alzheimer. In the quest for a simple but realistic mathematical description of cardiovascular control, which may be fitted onto non-invasive experimental observations after postural changes, the present work proposes a first version of an empirical Stochastic Delay Differential Equations (SDDEs) model. The model consists of a total of four SDDEs and two ancillary algebraic equations, incorporates four distinct delayed controls from the brain onto different components of the circulation, and is able to accurately capture the time course of mean arterial pressure and cerebral blood flow velocity signals, reproducing observed auto-correlated error around the expected drift.
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Affiliation(s)
- Simona Panunzi
- Consiglio Nazionale delle Ricerche, Istituto di Analisi dei Sistemi ed Informatica “Antonio Ruberti”, Rome, Italy
| | - Laura D’Orsi
- Consiglio Nazionale delle Ricerche, Istituto di Analisi dei Sistemi ed Informatica “Antonio Ruberti”, Rome, Italy
- * E-mail:
| | - Daniela Iacoviello
- Dipartimento di Ingegneria Informatica, Automatica e Gestionale “Antonio Ruberti”, Rome, Italy
| | - Andrea De Gaetano
- Consiglio Nazionale delle Ricerche, Istituto di Analisi dei Sistemi ed Informatica “Antonio Ruberti”, Rome, Italy
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Liu X, Czosnyka M, Donnelly J, Budohoski KP, Varsos GV, Nasr N, Brady KM, Reinhard M, Hutchinson PJ, Smielewski P. Comparison of frequency and time domain methods of assessment of cerebral autoregulation in traumatic brain injury. J Cereb Blood Flow Metab 2015; 35:248-56. [PMID: 25407266 PMCID: PMC4426741 DOI: 10.1038/jcbfm.2014.192] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/29/2014] [Accepted: 10/14/2014] [Indexed: 01/31/2023]
Abstract
The impulse response (IR)-based autoregulation index (ARI) allows for continuous monitoring of cerebral autoregulation using spontaneous fluctuations of arterial blood pressure (ABP) and cerebral flow velocity (FV). We compared three methods of autoregulation assessment in 288 traumatic brain injury (TBI) patients managed in the Neurocritical Care Unit: (1) IR-based ARI; (2) transfer function (TF) phase, gain, and coherence; and (3) mean flow index (Mx). Autoregulation index was calculated using the TF estimation (Welch method) and classified according to the original Tiecks' model. Mx was calculated as a correlation coefficient between 10-second averages of ABP and FV using a moving 300-second data window. Transfer function phase, gain, and coherence were extracted in the very low frequency (VLF, 0 to 0.05 Hz) and low frequency (LF, 0.05 to 0.15 Hz) bandwidths. We studied the relationship between these parameters and also compared them with patients' Glasgow outcome score. The calculations were performed using both cerebral perfusion pressure (CPP; suffix 'c') as input and ABP (suffix 'a'). The result showed a significant relationship between ARI and Mx when using either ABP (r=-0.38, P<0.001) or CPP (r=-0.404, P<0.001) as input. Transfer function phase and coherence_a were significantly correlated with ARI_a and ARI_c (P<0.05). Only ARI_a, ARI_c, Mx_a, Mx_c, and phase_c were significantly correlated with patients' outcome, with Mx_c showing the strongest association.
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Affiliation(s)
- Xiuyun Liu
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Marek Czosnyka
- 1] Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK [2] Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Joseph Donnelly
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Karol P Budohoski
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Georgios V Varsos
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Nathalie Nasr
- 1] Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK [2] Service de Neurologie Vasculaire, Hôpital Rangueil, INSERM U1048 - Team 11 (I2MC-Toulouse), Université de Toulouse III, Toulouse, France
| | - Ken M Brady
- Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA
| | - Matthias Reinhard
- Department of Neurology, University Hospital, University of Freiburg, Freiburg, Germany
| | - Peter J Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Peter Smielewski
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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Nasr N, Czosnyka M, Pavy-Le Traon A, Custaud MA, Liu X, Varsos GV, Larrue V. Baroreflex and cerebral autoregulation are inversely correlated. Circ J 2014; 78:2460-7. [PMID: 25187067 DOI: 10.1253/circj.cj-14-0445] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The relative stability of cerebral blood flow is maintained by the baroreflex and cerebral autoregulation (CA). We assessed the relationship between baroreflex sensitivity (BRS) and CA in patients with atherosclerotic carotid stenosis or occlusion. METHODS AND RESULTS Patients referred for assessment of atherosclerotic unilateral >50% carotid stenosis or occlusion were included. Ten healthy volunteers served as a reference group. BRS was measured using the sequence method. CA was quantified by the correlation coefficient (Mx) between slow oscillations in mean arterial blood pressure and mean cerebral blood flow velocities from transcranial Doppler. Forty-five patients (M/F: 36/9), with a median age of 68 years (IQR:17) were included. Thirty-four patients had carotid stenosis, and 11 patients had carotid occlusion (asymptomatic: 31 patients; symptomatic: 14 patients). The median degree of carotid steno-occlusive disease was 90% (IQR:18). Both CA (P=0.02) and BRS (P<0.001) were impaired in patients as compared with healthy volunteers. CA and BRS were inversely and strongly correlated with each other in patients (rho=0.58, P<0.001) and in healthy volunteers (rho=0.939; P<0.001). Increasing BRS remained strongly associated with impaired CA on multivariate analysis (P=0.004). CONCLUSIONS There was an inverse correlation between CA and BRS in healthy volunteers and in patients with carotid stenosis or occlusion. This might be due to a relative increase in sympathetic drive associated with weak baroreflex enhancing cerebral vasomotor tone and CA.
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Affiliation(s)
- Nathalie Nasr
- Department of Clinical Neurosciences, University of Cambridge, School of Clinical Medicine
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Bilateral Failure of Cerebral Autoregulation is Related to Unfavorable Outcome After Subarachnoid Hemorrhage. Neurocrit Care 2014; 22:65-73. [DOI: 10.1007/s12028-014-0032-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Transfer function analysis for the assessment of cerebral autoregulation using spontaneous oscillations in blood pressure and cerebral blood flow. Med Eng Phys 2014; 36:563-75. [DOI: 10.1016/j.medengphy.2014.02.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 01/31/2014] [Accepted: 02/03/2014] [Indexed: 12/21/2022]
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