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Carlson AP, Mayer AR, Cole C, van der Horn HJ, Marquez J, Stevenson TC, Shuttleworth CW. Cerebral autoregulation, spreading depolarization, and implications for targeted therapy in brain injury and ischemia. Rev Neurosci 2024; 35:651-678. [PMID: 38581271 PMCID: PMC11297425 DOI: 10.1515/revneuro-2024-0028] [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: 02/22/2024] [Accepted: 03/25/2024] [Indexed: 04/08/2024]
Abstract
Cerebral autoregulation is an intrinsic myogenic response of cerebral vasculature that allows for preservation of stable cerebral blood flow levels in response to changing systemic blood pressure. It is effective across a broad range of blood pressure levels through precapillary vasoconstriction and dilation. Autoregulation is difficult to directly measure and methods to indirectly ascertain cerebral autoregulation status inherently require certain assumptions. Patients with impaired cerebral autoregulation may be at risk of brain ischemia. One of the central mechanisms of ischemia in patients with metabolically compromised states is likely the triggering of spreading depolarization (SD) events and ultimately, terminal (or anoxic) depolarization. Cerebral autoregulation and SD are therefore linked when considering the risk of ischemia. In this scoping review, we will discuss the range of methods to measure cerebral autoregulation, their theoretical strengths and weaknesses, and the available clinical evidence to support their utility. We will then discuss the emerging link between impaired cerebral autoregulation and the occurrence of SD events. Such an approach offers the opportunity to better understand an individual patient's physiology and provide targeted treatments.
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Affiliation(s)
- Andrew P. Carlson
- Department of Neurosurgery, University of New Mexico School of Medicine, MSC10 5615, 1 UNM, Albuquerque, NM, 87131, USA
- Department of Neurosciences, University of New Mexico School of Medicine, 915 Camino de Salud NE, Albuquerque, NM, 87106, USA
| | - Andrew R. Mayer
- Mind Research Network, 1101 Yale, Blvd, NE, Albuquerque, NM, 87106, USA
| | - Chad Cole
- Department of Neurosurgery, University of New Mexico School of Medicine, MSC10 5615, 1 UNM, Albuquerque, NM, 87131, USA
| | | | - Joshua Marquez
- University of New Mexico School of Medicine, 915 Camino de Salud NE, Albuquerque, NM, 87106, USA
| | - Taylor C. Stevenson
- Department of Neurosurgery, University of New Mexico School of Medicine, MSC10 5615, 1 UNM, Albuquerque, NM, 87131, USA
| | - C. William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine, 915 Camino de Salud NE, Albuquerque, NM, 87106, USA
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Chinda B, Tran KH, Doesburg S, Siu W, Medvedev G, Liang SS, Brooks-Wilson A, Song X. Functional MRI evaluation of cognitive effects of carotid stenosis revascularization. Brain Behav 2022; 12:e2512. [PMID: 35233977 PMCID: PMC9014987 DOI: 10.1002/brb3.2512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 12/10/2021] [Accepted: 01/07/2022] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION Severe internal carotid stenosis, if left untreated, can pose serious risks for ischemic stroke and cognitive impairments. The effects of revascularization on any aspects of cognition, however, are not well understood, as conflicting results are reported, which have mainly been centered on paper-based cognitive analyses. Here, we summarized and evaluated the publications to date of functional MRI (fMRI) studies that examined the mechanisms of functional brain activation and connectivity as a way to reflect cognitive effects of revascularization on patients with carotid stenosis. METHODS A PubMed and Google Scholar (covering the relevant literature until November 1, 2021) search yielded eight original studies of the research line, including seven resting-state and one task-based fMRI reports. RESULTS Findings demonstrated treatment-related alterations in fMRI signal intensity and symmetry level, regional fMRI activation pattern, and functional brain network connectivity. The functional brain changes were associated largely with improvement in cognitive function assessed using standard cognitive test scores. CONCLUSIONS These findings support the contribution of fMRI to the understanding of brain functional activation and connectivity changes revealing cognitive effects of revascularization in the management of severe carotid stenosis. The review also highlighted the importance of reproducibility through enhancing experimental designs and cognitive task applications with future research for potential clinical translation.
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Affiliation(s)
- Betty Chinda
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.,Clinical Research and Evaluation, Surrey Memorial Hospital, Fraser Health Authority, Surrey, British Columbia, Canada
| | - Kim H Tran
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.,Clinical Research and Evaluation, Surrey Memorial Hospital, Fraser Health Authority, Surrey, British Columbia, Canada
| | - Sam Doesburg
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - William Siu
- Department of Radiology, Fraser Health Authority, Royal Columbian Hospital, New Westminster, British Columbia, Canada
| | - George Medvedev
- Department of Neurology, Fraser Health Authority, Royal Columbian Hospital, New Westminster, British Columbia, Canada
| | - S Simon Liang
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Angela Brooks-Wilson
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.,Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, British Columbia, Canada
| | - Xiaowei Song
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.,Clinical Research and Evaluation, Surrey Memorial Hospital, Fraser Health Authority, Surrey, British Columbia, Canada
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Sebök M, van Niftrik CHB, Winklhofer S, Wegener S, Esposito G, Stippich C, Luft A, Regli L, Fierstra J. Mapping Cerebrovascular Reactivity Impairment in Patients With Symptomatic Unilateral Carotid Artery Disease. J Am Heart Assoc 2021; 10:e020792. [PMID: 34102856 PMCID: PMC8477889 DOI: 10.1161/jaha.121.020792] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Background Comprehensive hemodynamic impairment mapping using blood oxygenation‐level dependent (BOLD) cerebrovascular reactivity (CVR) can be used to identify hemodynamically relevant symptomatic unilateral carotid artery disease. Methods and Results This prospective cohort study was conducted between February 2015 and July 2020 at the Clinical Neuroscience Center of the University Hospital Zurich, Zurich, Switzerland. One hundred two patients with newly diagnosed symptomatic unilateral internal carotid artery (ICA) occlusion or with 70% to 99% ICA stenosis were included. An age‐matched healthy cohort of 12 subjects underwent an identical BOLD functional magnetic resonance imaging examination. Using BOLD functional magnetic resonance imaging with a standardized CO2 stimulus, CVR impairment was evaluated. Moreover, embolic versus hemodynamic ischemic patterns were evaluated on diffusion‐weighted imaging. Sixty‐seven patients had unilateral ICA occlusion and 35 patients unilateral 70% to 99% ICA stenosis. Patients with ICA occlusion exhibited lower whole‐brain and ipsilateral hemisphere mean BOLD‐CVR values as compared with healthy subjects (0.12±0.08 versus 0.19±0.04, P=0.004 and 0.09±0.09 versus 0.18±0.04, P<0.001) and ICA stenosis cohort (0.12±0.08 versus 0.16±0.05, P=0.01 and 0.09±0.09 versus 0.15±0.05, P=0.01); however, only 40 (58%) patients of the cohort showed significant BOLD‐CVR impairment. Conversely, there was no difference in mean BOLD‐CVR values between healthy patients and patients with ICA stenosis, although 5 (14%) patients with ICA stenosis showed a significant BOLD‐CVR impairment. No significant BOLD‐CVR difference was discernible between patients with hemodynamic ischemic infarcts versus those with embolic infarct distribution (0.11±0.08 versus 0.13±0.06, P=0.12). Conclusions Comprehensive BOLD‐CVR mapping allows for identification of hemodynamically relevant symptomatic unilateral carotid artery stenosis or occlusion.
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Affiliation(s)
- Martina Sebök
- Department of Neurosurgery University Hospital ZurichUniversity of Zurich Switzerland.,Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland
| | - Christiaan Hendrik Bas van Niftrik
- Department of Neurosurgery University Hospital ZurichUniversity of Zurich Switzerland.,Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland
| | - Sebastian Winklhofer
- Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland.,Department of Neuroradiology University Hospital ZurichUniversity of Zurich Switzerland
| | - Susanne Wegener
- Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland.,Department of Neurology University Hospital ZurichUniversity of Zurich Switzerland
| | - Giuseppe Esposito
- Department of Neurosurgery University Hospital ZurichUniversity of Zurich Switzerland.,Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland
| | - Christoph Stippich
- Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland.,Neuroradiology and Radiology Schmieder Clinic Allensbach Germany
| | - Andreas Luft
- Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland.,Department of Neurology University Hospital ZurichUniversity of Zurich Switzerland.,Cereneo Center for Neurology and Rehabilitation Vitznau Switzerland
| | - Luca Regli
- Department of Neurosurgery University Hospital ZurichUniversity of Zurich Switzerland.,Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland
| | - Jorn Fierstra
- Department of Neurosurgery University Hospital ZurichUniversity of Zurich Switzerland.,Clinical Neuroscience Center University Hospital ZurichUniversity of Zurich Switzerland
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Schaafsma M, Glade GJ, Keller PJ, Schaafsma A. Age corrected changes in intracranial hemodynamics after carotid endarterectomy. THE JOURNAL OF CARDIOVASCULAR SURGERY 2021; 62:354-363. [PMID: 33829743 DOI: 10.23736/s0021-9509.21.11705-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Transcranial Doppler ultrasound (TCD) is a frequently used method to monitor brain perfusion during and following carotid endarterectomy (CEA). Our aim was to define the normally occurring changes of intracranial hemodynamics in patients undergoing CEA measuring recently developed TCD parameters. METHODS A retrospective, single-center cohort study was performed. Patients undergoing CEA were evaluated pre- and postoperatively from day 0 to day 3 measuring middle cerebral artery flow velocity (MCAFV). The following parameters were analyzed: the first systolic peak (Sys1), the second systolic peak (Sys2) and diastolic flow velocity at a fixed time after heartbeat onset (Dias@560). These parameters linearly decrease with age and were, therefore, transformed to Z-scores. RESULTS Three hundred eighteen patients were included with a mean age of 70.8 years. Most patients were male (71%). Compared to preoperatively, the Z-scores of Sys1 and Sys2 were larger on postoperative day 3: +1.12 standard deviation (SD) or 16.0 cm/s (CI: 0.93 to 1.32; P<0.001) and +0.55 SD or 7.8 cm/s (CI: 0.35 to 0.74; P<0.001), respectively. The Z-score for Dias@560 was smaller than preoperatively: -0.23 SD or -1.9 cm/s (CI: -0.41 to -0.05, P=0.015). CONCLUSIONS Under normal circumstances Sys1 profits more from CEA than Sys2, whilst diastolic flow velocity decreases. This indicates a return to normal arteriolar vascular resistance. Carefully describing normal changes in MCAFV, may in future enable discrimination of abnormalities, such as hyperperfusion syndrome.
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Affiliation(s)
- Mirte Schaafsma
- Amsterdam University Medical Center, Amsterdam, the Netherlands -
| | - Gerard J Glade
- Department of Vascular Surgery and Clinical Neurophysiology, Martini Ziekenhuis Groningen, Groningen, the Netherlands
| | - Paul J Keller
- Department of Vascular Surgery and Clinical Neurophysiology, Martini Ziekenhuis Groningen, Groningen, the Netherlands
| | - Arjen Schaafsma
- Department of Vascular Surgery and Clinical Neurophysiology, Martini Ziekenhuis Groningen, Groningen, the Netherlands
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Sleight E, Stringer MS, Marshall I, Wardlaw JM, Thrippleton MJ. Cerebrovascular Reactivity Measurement Using Magnetic Resonance Imaging: A Systematic Review. Front Physiol 2021; 12:643468. [PMID: 33716793 PMCID: PMC7947694 DOI: 10.3389/fphys.2021.643468] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 12/27/2022] Open
Abstract
Cerebrovascular reactivity (CVR) magnetic resonance imaging (MRI) probes cerebral haemodynamic changes in response to a vasodilatory stimulus. CVR closely relates to the health of the vasculature and is therefore a key parameter for studying cerebrovascular diseases such as stroke, small vessel disease and dementias. MRI allows in vivo measurement of CVR but several different methods have been presented in the literature, differing in pulse sequence, hardware requirements, stimulus and image processing technique. We systematically reviewed publications measuring CVR using MRI up to June 2020, identifying 235 relevant papers. We summarised the acquisition methods, experimental parameters, hardware and CVR quantification approaches used, clinical populations investigated, and corresponding summary CVR measures. CVR was investigated in many pathologies such as steno-occlusive diseases, dementia and small vessel disease and is generally lower in patients than in healthy controls. Blood oxygen level dependent (BOLD) acquisitions with fixed inspired CO2 gas or end-tidal CO2 forcing stimulus are the most commonly used methods. General linear modelling of the MRI signal with end-tidal CO2 as the regressor is the most frequently used method to compute CVR. Our survey of CVR measurement approaches and applications will help researchers to identify good practice and provide objective information to inform the development of future consensus recommendations.
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Affiliation(s)
- Emilie Sleight
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Michael S. Stringer
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom,*Correspondence: Michael S. Stringer
| | - Ian Marshall
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Joanna M. Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
| | - Michael J. Thrippleton
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom,UK Dementia Research Institute, Edinburgh, United Kingdom
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Chen DW, Zheng J, Shi J, Yin YW, Song C, Yang F, Zhang YQ, Ma LN. Assessment of the Cerebral Hemodynamic Benefits of Carotid Artery Stenting for Patients with Preoperative Hemodynamic Impairment Using Cerebral Single Photon Emission Computed Tomography (SPECT) and Carbon Dioxide Inhalation. Med Sci Monit 2018; 24:5398-5404. [PMID: 30074982 PMCID: PMC6087634 DOI: 10.12659/msm.909401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The aim of this study was to evaluate the effects of carotid artery angioplasty and carotid artery stenting (CAS) on cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in patients with preoperative cerebrovascular hemodynamic impairment. MATERIAL AND METHODS Seventeen patients with unilateral severe internal carotid artery (ICA) stenosis and ipsilateral CVR impairment underwent CAS. CBF and CVR were measured by single photon emission computed tomography (SPECT) with inhalation of carbon dioxide (CO2) one week before and three months after CAS. Sixty-eight ROIs in the middle cerebral artery (MCA) territory were analyzed in 17 patients. RESULTS Before CAS, CVR was impaired in all ROIs. CBF was impaired in 16 ROIs (23.5%). The percentage of ROIs with impaired CBF was significantly increased in patients with ≥90% carotid artery stenosis (p=0.047) without collateral flow through the circle of Willis (p=0.005). CAS significantly increased CVR in ROIs with a normal preoperative CBF and impaired CVR, indicating mild hemodynamic impairment (0.9±6.7% vs. 4.9±8.6%) (p=0.014). CAS significantly increased CBF in ROIs with preoperative impaired CBF and impaired CVR, indicating severe hemodynamic impairment (79.1±7.5% vs. 86.7±10.0%) (p<0.001). Following CAS, ROIs with normal CBF and impaired CVR had a significantly increased percentage of improved CVR (p=0.047); ROIs with impaired CBF and impaired CVR had a significantly increased percentage of improved CBF (p=0.027). CONCLUSIONS The severity of preoperative hemodynamic impairment, which is related to the degree of carotid artery stenosis and cerebral collateral flow, may influence hemodynamic benefits by CAS.
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Affiliation(s)
- Da-Wei Chen
- Department of Neurology, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
| | - Jin Zheng
- Department of Neurology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China (mainland)
| | - Jin Shi
- Department of Neurology, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
| | - Yang-Wei Yin
- Department of Neurology, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
| | - Chen Song
- Department of Neurology, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
| | - Fen Yang
- Department of Neurology, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
| | - Ying-Qian Zhang
- Department of Neurology, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
| | - Lu-Na Ma
- Positron Emission Tomography (PET) Center, Air Force General Hospital of the Chinese Peoples' Liberation Army, Beijing, China (mainland)
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7
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Bain AR, Nybo L, Ainslie PN. Cerebral Vascular Control and Metabolism in Heat Stress. Compr Physiol 2016; 5:1345-80. [PMID: 26140721 DOI: 10.1002/cphy.c140066] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review provides an in-depth update on the impact of heat stress on cerebrovascular functioning. The regulation of cerebral temperature, blood flow, and metabolism are discussed. We further provide an overview of vascular permeability, the neurocognitive changes, and the key clinical implications and pathologies known to confound cerebral functioning during hyperthermia. A reduction in cerebral blood flow (CBF), derived primarily from a respiratory-induced alkalosis, underscores the cerebrovascular changes to hyperthermia. Arterial pressures may also become compromised because of reduced peripheral resistance secondary to skin vasodilatation. Therefore, when hyperthermia is combined with conditions that increase cardiovascular strain, for example, orthostasis or dehydration, the inability to preserve cerebral perfusion pressure further reduces CBF. A reduced cerebral perfusion pressure is in turn the primary mechanism for impaired tolerance to orthostatic challenges. Any reduction in CBF attenuates the brain's convective heat loss, while the hyperthermic-induced increase in metabolic rate increases the cerebral heat gain. This paradoxical uncoupling of CBF to metabolism increases brain temperature, and potentiates a condition whereby cerebral oxygenation may be compromised. With levels of experimentally viable passive hyperthermia (up to 39.5-40.0 °C core temperature), the associated reduction in CBF (∼ 30%) and increase in cerebral metabolic demand (∼ 10%) is likely compensated by increases in cerebral oxygen extraction. However, severe increases in whole-body and brain temperature may increase blood-brain barrier permeability, potentially leading to cerebral vasogenic edema. The cerebrovascular challenges associated with hyperthermia are of paramount importance for populations with compromised thermoregulatory control--for example, spinal cord injury, elderly, and those with preexisting cardiovascular diseases.
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Affiliation(s)
- Anthony R Bain
- Centre for Heart Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan Campus, Kelowna, Canada
| | - Lars Nybo
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Philip N Ainslie
- Centre for Heart Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan Campus, Kelowna, Canada
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Goode SD, Altaf N, Munshi S, MacSweeney STR, Auer DP. Impaired Cerebrovascular Reactivity Predicts Recurrent Symptoms in Patients with Carotid Artery Occlusion: A Hypercapnia BOLD fMRI Study. AJNR Am J Neuroradiol 2016; 37:904-9. [PMID: 27012300 DOI: 10.3174/ajnr.a4739] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 09/01/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE A key factor in predicting recurrent ischemic episodes in patients with carotid artery occlusion is the presence of hemodynamic impairment. There is, however, no consensus on how to best assess this risk in terms of imaging modalities or thresholds used. Here we investigated whether a predefined threshold of hemispheric asymmetry in hypercapnia fMRI predicts recurrent symptoms in patients with carotid artery occlusion. MATERIALS AND METHODS We studied 23 patients (2 women) with a mean age of 67.5 ± 9 years. Patients were assessed for recurrent ischemic events until lost to follow-up, study end, death, or recurrent ischemic event. Hypercapnia fMRI was used to assess the cerebrovascular reserve and quantify the percentage signal change in GM in the MCA territory and the hemispheric asymmetry index. Kaplan-Meier survival analysis and log-rank tests were performed to assess differences between patients with normal or abnormal hemispheric indices. RESULTS The median follow-up was 20 months. During this period, 8 patients experienced recurrent events, and 15 did not. The percentage signal change in GM in the MCA territory was significantly decreased in those patients with recurrent events compared with those without (2.39 ± 0.22 versus 2.70 ± 0.42, P = .032). The normal hemispheric index predicted event-free survival during follow-up (median, 20 months) for both the combined outcome (recurrent events and/or death, log-rank, P = .034) and recurrent retinal or ipsilateral ischemic events only (log-rank, P = .012). CONCLUSIONS The hemispheric asymmetry index derived from hypercapnia fMRI showed hemodynamic impairment in more than half of the studied patients with carotid occlusion, and those patients showed a higher risk of recurrent ischemic symptoms.
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Affiliation(s)
- S D Goode
- From the Sheffield Vascular Institute (S.D.G.), Northern General Hospital, Sheffield, UK Department of Vascular Surgery (S.D.G., N.A., S.T.R.M.), Queens Medical Centre, Nottingham, UK Department of Radiological Sciences (S.D.G., N.A., D.P.A.), Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK.
| | - N Altaf
- Department of Vascular Surgery (S.D.G., N.A., S.T.R.M.), Queens Medical Centre, Nottingham, UK Department of Radiological Sciences (S.D.G., N.A., D.P.A.), Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK
| | - S Munshi
- Department of Stroke Medicine (S.M.), Nottingham City Hospital, Nottingham, UK
| | - S T R MacSweeney
- Department of Vascular Surgery (S.D.G., N.A., S.T.R.M.), Queens Medical Centre, Nottingham, UK
| | - D P Auer
- Department of Radiological Sciences (S.D.G., N.A., D.P.A.), Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK.
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Transcranial Doppler Examination. Neuroophthalmology 2016. [DOI: 10.1007/978-3-319-28956-4_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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10
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Krainik A, Villien M, Troprès I, Attyé A, Lamalle L, Bouvier J, Pietras J, Grand S, Le Bas JF, Warnking J. Functional imaging of cerebral perfusion. Diagn Interv Imaging 2013; 94:1259-78. [PMID: 24011870 DOI: 10.1016/j.diii.2013.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The functional imaging of perfusion enables the study of its properties such as the vasoreactivity to circulating gases, the autoregulation and the neurovascular coupling. Downstream from arterial stenosis, this imaging can estimate the vascular reserve and the risk of ischemia in order to adapt the therapeutic strategy. This method reveals the hemodynamic disorders in patients suffering from Alzheimer's disease or with arteriovenous malformations revealed by epilepsy. Functional MRI of the vasoreactivity also helps to better interpret the functional MRI activation in practice and in clinical research.
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Affiliation(s)
- A Krainik
- Clinique universitaire de neuroradiologie et IRM, CHU de Grenoble, CS 10217, 38043 Grenoble cedex, France; Inserm U836, université Joseph-Fourier, site santé, chemin Fortuné-Ferrini, 38706 La Tronche cedex, France; UMS IRMaGe, unité IRM 3T recherche, CHU de Grenoble, CS 10217, 38043 Grenoble cedex 9, France.
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11
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Impaired hemodynamic response in the ischemic brain assessed with BOLD fMRI. Neuroimage 2012; 61:579-90. [DOI: 10.1016/j.neuroimage.2012.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 03/29/2012] [Accepted: 04/01/2012] [Indexed: 11/21/2022] Open
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Assessing Cerebrovascular Reactivity in Carotid Steno-Occlusive Disease Using MRI BOLD and ASL Techniques. Radiol Res Pract 2012; 2012:268483. [PMID: 22919485 PMCID: PMC3388310 DOI: 10.1155/2012/268483] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 04/17/2012] [Accepted: 04/17/2012] [Indexed: 12/13/2022] Open
Abstract
Impaired cerebrovascular reactivity (CVR), a predictive factor of imminent stroke, has been shown to be associated with carotid steno-occlusive disease. Magnetic resonance imaging (MRI) techniques, such as blood oxygenation level-dependent (BOLD) and arterial spin labeling (ASL), have emerged as promising noninvasive tools to evaluate altered CVR with whole-brain coverage, when combined with a vasoactive stimulus, such as respiratory task or injection of acetazolamide. Under normal cerebrovascular conditions, CVR has been shown to be globally and homogenously distributed between hemispheres, but with differences among cerebral regions. Such differences can be explained by anatomical specificities and different biochemical mechanisms responsible for vascular regulation. In patients with carotid steno-occlusive disease, studies have shown that MRI techniques can detect impaired CVR in brain tissue supplied by the affected artery. Moreover, resulting CVR estimations have been well correlated to those obtained with more established techniques, indicating that BOLD and ASL are robust and reliable methods to assess CVR in patients with cerebrovascular diseases. Therefore, the present paper aims to review recent studies which use BOLD and ASL to evaluate CVR, in healthy individuals and in patients with carotid steno-occlusive disease, providing a source of information regarding the obtained results and the methodological difficulties.
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Nocuń A, Wilczyński M, Wroński J, Chrapko B. Usefulness of 99mTc-ECD brain SPECT with voxel-based analysis in evaluation of perfusion changes early after carotid endarterectomy. Med Sci Monit 2011; 17:CR297-303. [PMID: 21525813 PMCID: PMC3539580 DOI: 10.12659/msm.881771] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background Association between preoperative perfusion pattern and reperfusion after carotid endarterectomy (CEA) is an important yet unexplored topic. Therefore, the aim of our study was to determine whether 99mTc-ECD single-photon emission computed tomography (SPECT) performed before carotid endarterectomy in patients with internal carotid artery (ICA) stenosis may be helpful in predicting early perfusion changes after revascularization. Material/Methods The examined group consisted of 30 patients (mean age 67.4±9.6 years) with ICA stenosis who underwent CEA. Infarction was demonstrated on computed tomography (CT) in 12 cases. Brain perfusion SPECT was performed 1–3 days before CEA and 3–5 days after the surgery. Voxel-based analysis was carried out with Brain SPECT Quantification software. For evaluation of preoperative interhemispheric asymmetry of perfusion, the percentage asymmetry index (AI) was calculated. For comparison of perfusion before and after CEA, the percentage relative difference (RD) was computed. Results Before CEA, cerebral hypoperfusion was seen in 26 cases, including 15 participants with normal CT. After CEA, the following changes of perfusion were observed: perfusion increase n=18 (ipsilateral and bilateral), deterioration n=1, mixed patterns n=2, no change n=9. In patients with preoperative ipsilateral hypoperfusion and perfusion increase after CEA, AI correlated significantly with RD (r=0.48, p=0.04). Conclusions Our results suggest that perfusion increase 3–5 days after CEA is higher in patients with greater ipsilateral asymmetry index. Evaluation of preoperative AI may help to identify patients in whom rapid reperfusion is more likely.
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Affiliation(s)
- Anna Nocuń
- Department of Nuclear Medicine, Medical University of Lublin, Lublin, Poland. ampolak@o2
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Mandell DM, Han JS, Poublanc J, Crawley AP, Fierstra J, Tymianski M, Fisher JA, Mikulis DJ. Quantitative measurement of cerebrovascular reactivity by blood oxygen level-dependent MR imaging in patients with intracranial stenosis: preoperative cerebrovascular reactivity predicts the effect of extracranial-intracranial bypass surgery. AJNR Am J Neuroradiol 2011; 32:721-7. [PMID: 21436343 DOI: 10.3174/ajnr.a2365] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND PURPOSE CVR is a measure of cerebral hemodynamic impairment. A recently validated technique quantifies CVR by using a precise CO(2) vasodilatory stimulus and BOLD MR imaging. Our aim was to determine whether preoperative CO(2) BOLD CVR predicts the hemodynamic effect of ECIC bypass surgery in patients with intracranial steno-occlusive disease. MATERIALS AND METHODS Twenty-five patients undergoing ECIC bypass surgery for treatment of intracranial stenosis or occlusion were recruited. CVR was measured preoperatively and postoperatively and expressed as %ΔBOLD MR signal intensity per mm Hg ΔPetCO(2). Using normative data from healthy subjects, we stratified patients on the basis of preoperative CVR into 3 groups: normal CVR, reduced CVR, and negative (paradoxical) CVR. Wilcoxon 2-sample tests (2-sided, α = 0.05) were used to determine whether the 3 groups differed with respect to change in CVR following bypass surgery. RESULTS The group with normal preoperative CVR demonstrated no significant change in CVR following bypass surgery (mean, 0.22% ± 0.05% to 0.22% ± 0.01%; P = .881). The group with reduced preoperative CVR demonstrated a significant improvement following bypass surgery (mean, 0.08% ± 0.05% to 0.21 ± 0.08%; P < .001), and the group with paradoxical preoperative CVR demonstrated the greatest improvement (mean change, -0.04% ± 0.03% to 0.27% ± 0.03%; P = .028). CONCLUSIONS Preoperative measurement of CVR by using CO(2) BOLD MR imaging predicts the hemodynamic effect of ECIC bypass in patients with intracranial steno-occlusive disease. The technique is potentially useful for selecting patients for surgical revascularization.
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Affiliation(s)
- D M Mandell
- Division of Neuroradiology, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
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