1
|
Harmon JN, Chandran P, Chandrasekaran A, Hyde JE, Hernandez GJ, Reed MJ, Bruce MF, Khaing ZZ. Contrast-enhanced ultrasound imaging detects anatomical and functional changes in rat cervical spine microvasculature with normal aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584672. [PMID: 38559128 PMCID: PMC10980054 DOI: 10.1101/2024.03.12.584672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Normal aging is associated with significant deleterious cerebrovascular changes; these have been implicated in disease pathogenesis and increased susceptibility to ischemic injury. While these changes are well documented in the brain, few studies have been conducted in the spinal cord. Here, we utilize specialized contrast-enhanced ultrasound (CEUS) imaging to investigate age-related changes in cervical spinal vascular anatomy and hemodynamics in male Fisher 344 rats, a common strain in aging research. Aged rats (24-26 mo., N=6) exhibited significant tortuosity in the anterior spinal artery and elevated vascular resistance compared to adults (4-6 mo., N=6; tortuosity index 2.20±0.15 vs 4.74±0.45, p<0.05). Baseline blood volume was lower in both larger vessels and the microcirculation in the aged cohort, specifically in white matter (4.44e14±1.37e13 vs 3.66e14±2.64e13 CEUS bolus AUC, p<0.05). To elucidate functional differences, animals were exposed to a hypoxia challenge; whereas adult rats exhibited significant functional hyperemia in both gray and white matter (GM: 1.13±0.10-fold change from normoxia, p<0.05; WM: 1.16±0.13, p<0.05), aged rats showed no response. Immunohistochemistry revealed reduced pericyte coverage and activated microglia behavior in aged rats, which may partially explain the lack of vascular response. This study provides the first in vivo description of age-related hemodynamic differences in the cervical spinal cord.
Collapse
Affiliation(s)
- Jennifer N. Harmon
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA
| | - Preeja Chandran
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA
| | | | - Jeffrey E. Hyde
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA
| | - Gustavo J. Hernandez
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA
| | - May J. Reed
- Department of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
| | - Matthew F. Bruce
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Zin Z. Khaing
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA
| |
Collapse
|
2
|
Sayin ES, Duffin J, Stumpo V, Bellomo J, Piccirelli M, Poublanc J, Wijeya V, Para A, Pangalu A, Bink A, Nemeth B, Kulcsar Z, Mikulis DJ, Fisher JA, Sobczyk O, Fierstra J. Assessing Perfusion in Steno-Occlusive Cerebrovascular Disease Using Transient Hypoxia-Induced Deoxyhemoglobin as a Dynamic Susceptibility Contrast Agent. AJNR Am J Neuroradiol 2023; 45:37-43. [PMID: 38164571 PMCID: PMC10756578 DOI: 10.3174/ajnr.a8068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 11/01/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND AND PURPOSE Resting brain tissue perfusion in cerebral steno-occlusive vascular disease can be assessed by MR imaging using gadolinium-based susceptibility contrast agents. Recently, transient hypoxia-induced deoxyhemoglobin has been investigated as a noninvasive MR imaging contrast agent. Here we present a comparison of resting perfusion metrics using transient hypoxia-induced deoxyhemoglobin and gadolinium-based contrast agents in patients with known cerebrovascular steno-occlusive disease. MATERIALS AND METHODS Twelve patients with steno-occlusive disease underwent DSC MR imaging using a standard bolus of gadolinium-based contrast agent compared with transient hypoxia-induced deoxyhemoglobin generated in the lungs using an automated gas blender. A conventional multi-slice 2D gradient echo sequence was used to acquire the perfusion data and analyzed using a standard tracer kinetic model. MTT, relative CBF, and relative CBV maps were generated and compared between contrast agents. RESULTS The spatial distributions of the perfusion metrics generated with both contrast agents were consistent. Perfusion metrics in GM and WM were not statistically different except for WM MTT. CONCLUSIONS Cerebral perfusion metrics generated with noninvasive transient hypoxia-induced changes in deoxyhemoglobin are very similar to those generated using a gadolinium-based contrast agent in patients with cerebrovascular steno-occlusive disease.
Collapse
Affiliation(s)
- Ece Su Sayin
- From the Department of Physiology (E.S.S., J.D., J.A.F.), University of Toronto, Toronto, Ontario, Canada
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab (E.S.S., J.P., V.W., A. Para, D.J.M., O.S.), University Health Network, Toronto, Ontario, Canada
| | - James Duffin
- From the Department of Physiology (E.S.S., J.D., J.A.F.), University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesia and Pain Management (J.D., J.A.F.), University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Vittorio Stumpo
- Department of Neurosurgery (V.S., J.B. J.F.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Jacopo Bellomo
- Department of Neurosurgery (V.S., J.B. J.F.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology and Clinical Neuroscience Center (M.P., A. Pangalu, A.B., B.N., Z.K.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab (E.S.S., J.P., V.W., A. Para, D.J.M., O.S.), University Health Network, Toronto, Ontario, Canada
| | - Vepeson Wijeya
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab (E.S.S., J.P., V.W., A. Para, D.J.M., O.S.), University Health Network, Toronto, Ontario, Canada
| | - Andrea Para
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab (E.S.S., J.P., V.W., A. Para, D.J.M., O.S.), University Health Network, Toronto, Ontario, Canada
| | - Athina Pangalu
- Department of Neuroradiology and Clinical Neuroscience Center (M.P., A. Pangalu, A.B., B.N., Z.K.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Andrea Bink
- Department of Neuroradiology and Clinical Neuroscience Center (M.P., A. Pangalu, A.B., B.N., Z.K.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Bence Nemeth
- Department of Neuroradiology and Clinical Neuroscience Center (M.P., A. Pangalu, A.B., B.N., Z.K.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Zsolt Kulcsar
- Department of Neuroradiology and Clinical Neuroscience Center (M.P., A. Pangalu, A.B., B.N., Z.K.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - David J Mikulis
- Department of Medical Biophysics (D.J.M.), University of Toronto, Toronto, Ontario, Canada
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab (E.S.S., J.P., V.W., A. Para, D.J.M., O.S.), University Health Network, Toronto, Ontario, Canada
| | - Joseph A Fisher
- From the Department of Physiology (E.S.S., J.D., J.A.F.), University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesia and Pain Management (J.D., J.A.F.), University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Olivia Sobczyk
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab (E.S.S., J.P., V.W., A. Para, D.J.M., O.S.), University Health Network, Toronto, Ontario, Canada
| | - Jorn Fierstra
- Department of Neurosurgery (V.S., J.B. J.F.), University Hospital Zurich, University of Zurich, Zurich, Switzerland
| |
Collapse
|
3
|
Liu Y, Yuan F, Peng Z, Zhan Y, Lin J, Zhang R, Zhang J. Decrease in Cerebral Blood Flow after Reoxygenation Is Associated with Neurological Syndrome Sequelae and Blood Pressure. Brain Sci 2023; 13:1600. [PMID: 38002559 PMCID: PMC10669967 DOI: 10.3390/brainsci13111600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/30/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Changes in cerebral blood flow (CBF) and regulation of cerebral circulation occur at high altitude (HA). However, the changes in CBF and their associations with neurological syndrome sequelae and blood pressure after subjects return to the lowlands remain unclear. In this study, the subjects were 23 college students who were teaching at an altitude of 4300 m for 30 days. These subjects were studied before reaching the HA (Test 1), one week after returning to the lowlands (Test 2), and three months after returning to the lowlands (Test 3). Symptom scores for de-acclimatization syndrome were evaluated. Changes in CBF were measured using the magnetic resonance imaging arterial spin labeling (ASL) technique. Additionally, the velocity of CBF in the cerebral arteries was measured using a transcranial doppler (TCD). In Test 2 vs. Test 1, the peak systolic velocity and mean velocity in the basilar artery were significantly decreased. CBF exhibited significant decreases in the left putamen/cerebellum crus1/vermis and right thalamus/inferior temporal gyrus, while significant increases were observed in the left postcentral gyrus/precuneus and right middle cingulate gyrus/superior frontal gyrus. In Test 3 vs. Test 1, the basilar artery velocity returned to the baseline level, while CBF continued to decrease. The mean global CBF showed a decreasing trend from Test 1 to Test 3. Furthermore, the mean global CBF had a negative correlation with the systolic pressure, pulse pressure, and mean arterial pressure. The decrease in CBF after reoxygenation may underlie the neurological symptoms in subjects returning to the lowlands. Increased blood pressure could serve as a predictor of a decrease in CBF.
Collapse
Affiliation(s)
- Yanqiu Liu
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Fengjuan Yuan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Zhongwei Peng
- Department of Neurology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Yadong Zhan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Jianzhong Lin
- Department of Radiology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Ran Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| |
Collapse
|
4
|
Chen X, Zhang J, Lin Y, Li Y, Wang H, Wang Z, Liu H, Hu Y, Liu L. Mechanism, prevention and treatment of cognitive impairment caused by high altitude exposure. Front Physiol 2023; 14:1191058. [PMID: 37731540 PMCID: PMC10507266 DOI: 10.3389/fphys.2023.1191058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/05/2023] [Indexed: 09/22/2023] Open
Abstract
Hypobaric hypoxia (HH) characteristics induce impaired cognitive function, reduced concentration, and memory. In recent years, an increasing number of people have migrated to high-altitude areas for work and study. Headache, sleep disturbance, and cognitive impairment from HH, severely challenges the physical and mental health and affects their quality of life and work efficiency. This review summarizes the manifestations, mechanisms, and preventive and therapeutic methods of HH environment affecting cognitive function and provides theoretical references for exploring and treating high altitude-induced cognitive impairment.
Collapse
Affiliation(s)
- Xin Chen
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Jiexin Zhang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
- Faculty of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, Hubei, China
| | - Yuan Lin
- Sichuan Xincheng Biological Co., LTD., Chengdu, Sichuan, China
| | - Yan Li
- Department of General Surgery, The 77th Army Hospital, Leshan, Sichuan, China
| | - Han Wang
- Department of Cardiology, Affiliated Hospital of Southwest Jiaotong University, The Third People’s Hospital of Chengdu, Chengdu, Sichuan, China
| | - Zhanhao Wang
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Huawei Liu
- Department of Clinical Laboratory Medicine, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Yonghe Hu
- Faculty of Medicine, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Lei Liu
- Medical Research Center, The Third People’s Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu, Sichuan, China
| |
Collapse
|
5
|
Ardellier FD, Baloglu S, Sokolska M, Noblet V, Lersy F, Collange O, Ferré JC, Maamar A, Carsin-Nicol B, Helms J, Schenck M, Khalil A, Gaudemer A, Caillard S, Pottecher J, Lefèbvre N, Zorn PE, Matthieu M, Brisset JC, Boulay C, Mutschler V, Hansmann Y, Mertes PM, Schneider F, Fafi-Kremer S, Ohana M, Meziani F, Meyer N, Yousry T, Anheim M, Cotton F, Jäger HR, Kremer S. Cerebral perfusion using ASL in patients with COVID-19 and neurological manifestations: A retrospective multicenter observational study. J Neuroradiol 2023; 50:470-481. [PMID: 36657613 PMCID: PMC9842391 DOI: 10.1016/j.neurad.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 01/15/2023] [Accepted: 01/15/2023] [Indexed: 01/18/2023]
Abstract
BACKGROUND AND PURPOSE Cerebral hypoperfusion has been reported in patients with COVID-19 and neurological manifestations in small cohorts. We aimed to systematically assess changes in cerebral perfusion in a cohort of 59 of these patients, with or without abnormalities on morphological MRI sequences. METHODS Patients with biologically-confirmed COVID-19 and neurological manifestations undergoing a brain MRI with technically adequate arterial spin labeling (ASL) perfusion were included in this retrospective multicenter study. ASL maps were jointly reviewed by two readers blinded to clinical data. They assessed abnormal perfusion in four regions of interest in each brain hemisphere: frontal lobe, parietal lobe, posterior temporal lobe, and temporal pole extended to the amygdalo-hippocampal complex. RESULTS Fifty-nine patients (44 men (75%), mean age 61.2 years) were included. Most patients had a severe COVID-19, 57 (97%) needed oxygen therapy and 43 (73%) were hospitalized in intensive care unit at the time of MRI. Morphological brain MRI was abnormal in 44 (75%) patients. ASL perfusion was abnormal in 53 (90%) patients, and particularly in all patients with normal morphological MRI. Hypoperfusion occurred in 48 (81%) patients, mostly in temporal poles (52 (44%)) and frontal lobes (40 (34%)). Hyperperfusion occurred in 9 (15%) patients and was closely associated with post-contrast FLAIR leptomeningeal enhancement (100% [66.4%-100%] of hyperperfusion with enhancement versus 28.6% [16.6%-43.2%] without, p = 0.002). Studied clinical parameters (especially sedation) and other morphological MRI anomalies had no significant impact on perfusion anomalies. CONCLUSION Brain ASL perfusion showed hypoperfusion in more than 80% of patients with severe COVID-19, with or without visible lesion on conventional MRI abnormalities.
Collapse
Affiliation(s)
- François-Daniel Ardellier
- Service D'imagerie 2, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; Engineering science, computer science and imaging laboratory (ICube), Integrative Multimodal Imaging in Healthcare, UMR 7357, University of Strasbourg-CNRS, Strasbourg, France.
| | - Seyyid Baloglu
- Service D'imagerie 2, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Magdalena Sokolska
- Department of Medical Physics and Biomedical Engineering, University College London Hospitals NHS Foundation Trust, 235 Euston Road, London NW1 2BU, United Kingdom; Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Vincent Noblet
- Engineering science, computer science and imaging laboratory (ICube), Integrative Multimodal Imaging in Healthcare, UMR 7357, University of Strasbourg-CNRS, Strasbourg, France
| | - François Lersy
- Service D'imagerie 2, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Olivier Collange
- Service d'Anesthésie-Réanimation, Nouvel Hôpital Civil, Hôpitaux universitaires de Strasbourg, Strasbourg, France
| | | | - Adel Maamar
- Medical Intensive Care Unit, CHU Rennes, Rennes, France
| | | | - Julie Helms
- Service de Médecine Intensive Réanimation, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; Immuno-Rhumatologie Moléculaire, INSERM UMR S1109, LabEx TRANSPLANTEX, Centre de Recherche d'Immunologie et d'Hématologie, Faculté de Médecine, Fédération Hospitalo-Universitaire (FHU) OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg (UNISTRA), Strasbourg, France
| | - Maleka Schenck
- Service de Médecine Intensive Réanimation, Hôpitaux universitaires de Strasbourg, Hautepierre, Strasbourg, France
| | - Antoine Khalil
- Department of Radiology, Assistance Publique-Hôpitaux de Paris (APHP), Denis Diderot University and Medical School, Bichat University Hospital, Paris, France
| | - Augustin Gaudemer
- Neuroradiology Unit, Department of Radiology, Assistance Publique-Hôpitaux de Paris (APHP), Bichat University Hospital, Paris, France
| | - Sophie Caillard
- Immuno-Rhumatologie Moléculaire, INSERM UMR S1109, LabEx TRANSPLANTEX, Centre de Recherche d'Immunologie et d'Hématologie, Faculté de Médecine, Fédération Hospitalo-Universitaire (FHU) OMICARE, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg (UNISTRA), Strasbourg, France; Nephrology and Transplantation department, Hôpitaux Universitaires de Strasbourg. Inserm UMR S1109, LabEx Transplantex, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Julien Pottecher
- Hôpital de Hautepierre, Service d'Anesthésie, Réanimation & Médecine Péri-Opératoire - Université de Strasbourg, Faculté de Médecine, FMTS, EA3072, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Nicolas Lefèbvre
- Service de Maladies Infectieuses, NHC, CHU de Strasbourg, Strasbourg, France
| | - Pierre-Emmanuel Zorn
- Hôpitaux Universitaires de Strasbourg, UCIEC, Pôle d'Imagerie, Strasbourg, France
| | - Muriel Matthieu
- Hôpitaux Universitaires de Strasbourg, UCIEC, Pôle d'Imagerie, Strasbourg, France
| | | | - Clotilde Boulay
- Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Véronique Mutschler
- Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Yves Hansmann
- Service de Maladies Infectieuses, NHC, CHU de Strasbourg, Strasbourg, France
| | - Paul-Michel Mertes
- Service d'Anesthésie-Réanimation, Nouvel Hôpital Civil, Hôpitaux universitaires de Strasbourg, Strasbourg, France
| | - Francis Schneider
- Service de Médecine Intensive Réanimation, Hôpitaux universitaires de Strasbourg, Hautepierre, Strasbourg, France
| | - Samira Fafi-Kremer
- Laboratoire de Virologie Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Mickael Ohana
- Radiology Department, Nouvel Hôpital Civil, Strasbourg University Hospital, Strasbourg, France
| | - Ferhat Meziani
- Service de Médecine Intensive Réanimation, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; UMR 1260, Regenerative Nanomedicine (RNM), FMTS, INSERM (French National Institute of Health and Medical Research), Strasbourg, France
| | - Nicolas Meyer
- Service de Santé Publique, GMRC, CHU de Strasbourg, Strasbourg F-67091 , France
| | - Tarek Yousry
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Mathieu Anheim
- Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
| | - François Cotton
- MRI center, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, Lyon, France; CREATIS-LRMN, CNRS/UMR/5220-INSERM U630, Université Lyon 1, Villeurbanne, France
| | - Hans Rolf Jäger
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Stéphane Kremer
- Service D'imagerie 2, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; Engineering science, computer science and imaging laboratory (ICube), Integrative Multimodal Imaging in Healthcare, UMR 7357, University of Strasbourg-CNRS, Strasbourg, France
| |
Collapse
|
6
|
Bakker ME, Djerourou I, Belanger S, Lesage F, Vanni MP. Alteration of functional connectivity despite preserved cerebral oxygenation during acute hypoxia. Sci Rep 2023; 13:13269. [PMID: 37582847 PMCID: PMC10427674 DOI: 10.1038/s41598-023-40321-3] [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: 04/06/2023] [Accepted: 08/08/2023] [Indexed: 08/17/2023] Open
Abstract
Resting state networks (RSN), which show the connectivity in the brain in the absence of any stimuli, are increasingly important to assess brain function. Here, we investigate the changes in RSN as well as the hemodynamic changes during acute, global hypoxia. Mice were imaged at different levels of oxygen (21, 12, 10 and 8%) over the course of 10 weeks, with hypoxia and normoxia acquisitions interspersed. Simultaneous GCaMP and intrinsic optical imaging allowed tracking of both neuronal and hemodynamic changes. During hypoxic conditions, we found a global increase of both HbO and HbR in the brain. The saturation levels of blood dropped after the onset of hypoxia, but surprisingly climbed back to levels similar to baseline within the 10-min hypoxia period. Neuronal activity also showed a peak at the onset of hypoxia, but dropped back to baseline as well. Despite regaining baseline sO2 levels, changes in neuronal RSN were observed. In particular, the connectivity as measured with GCaMP between anterior and posterior parts of the brain decreased. In contrast, when looking at these same connections with HbO measurements, an increase in connectivity in anterior-posterior brain areas was observed suggesting a potential neurovascular decoupling.
Collapse
Affiliation(s)
- Marleen E Bakker
- École d'Optométrie, Université de Montréal, 2500 Chem. De Polytechnique, Montréal, QC, H3T 1J4, Canada.
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada.
| | - Ismaël Djerourou
- École d'Optométrie, Université de Montréal, 2500 Chem. De Polytechnique, Montréal, QC, H3T 1J4, Canada
| | | | - Frédéric Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada
- Montréal Heart Institute, Montréal, Canada
| | - Matthieu P Vanni
- École d'Optométrie, Université de Montréal, 2500 Chem. De Polytechnique, Montréal, QC, H3T 1J4, Canada
| |
Collapse
|
7
|
Schulman JB, Sayin ES, Manalac A, Poublanc J, Sobczyk O, Duffin J, Fisher JA, Mikulis D, Uludağ K. DSC MRI in the human brain using deoxyhemoglobin and gadolinium-Simulations and validations at 3T. FRONTIERS IN NEUROIMAGING 2023; 2:1048652. [PMID: 37554650 PMCID: PMC10406263 DOI: 10.3389/fnimg.2023.1048652] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 02/01/2023] [Indexed: 08/10/2023]
Abstract
INTRODUCTION Dynamic susceptibility contrast (DSC) MRI allows clinicians to determine perfusion parameters in the brain, such as cerebral blood flow, cerebral blood volume, and mean transit time. To enable quantification, susceptibility changes can be induced using gadolinium (Gd) or deoxyhemoglobin (dOHb), the latter just recently introduced as a contrast agent in DSC. Previous investigations found that experimental parameters and analysis choices, such as the susceptibility amplitude and partial volume, affect perfusion quantification. However, the accuracy and precision of DSC MRI has not been systematically investigated, particularly in the lower susceptibility range. METHODS In this study, we compared perfusion values determined using Gd with values determined using a contrast agent with a lower susceptibility-dOHb-under different physiological conditions, such as varying the baseline blood oxygenation and/or magnitude of hypoxic bolus, by utilizing numerical simulations and conducting experiments on healthy subjects at 3T. The simulation framework we developed for DSC incorporates MRI signal contributions from intravascular and extravascular proton spins in arterial, venous, and cerebral tissue voxels. This framework allowed us to model the MRI signal in response to both Gd and dOHb. RESULTS AND DISCUSSION We found, both in the experimental results and simulations, that a reduced intravascular volume of the selected arterial voxel, reduced baseline oxygen saturation, greater susceptibility of applied contrast agent (Gd vs. dOHb), and/or larger magnitude of applied hypoxic bolus reduces the overestimation and increases precision of cerebral blood volume and flow. As well, we found that normalizing tissue to venous rather than arterial signal increases the accuracy of perfusion quantification across experimental paradigms. Furthermore, we found that shortening the bolus duration increases the accuracy and reduces the calculated values of mean transit time. In summary, we experimentally uncovered an array of perfusion quantification dependencies, which agreed with the simulation framework predictions, using a wider range of susceptibility values than previously investigated. We argue for caution when comparing absolute and relative perfusion values within and across subjects obtained from a standard DSC MRI analysis, particularly when employing different experimental paradigms and contrast agents.
Collapse
Affiliation(s)
- Jacob Benjamin Schulman
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada
| | - Ece Su Sayin
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Angelica Manalac
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
| | - Olivia Sobczyk
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
| | - James Duffin
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Joseph A. Fisher
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
- Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, ON, Canada
| | - David Mikulis
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
- The Joint Department of Medical Imaging, The Toronto Western Hospital, Toronto, ON, Canada
| | - Kâmil Uludağ
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Center for Neuroscience Imaging Research, Institute for Basic Science & Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| |
Collapse
|
8
|
Sayin ES, Schulman J, Poublanc J, Levine HT, Raghavan LV, Uludag K, Duffin J, Fisher JA, Mikulis DJ, Sobczyk O. Investigations of hypoxia-induced deoxyhemoglobin as a contrast agent for cerebral perfusion imaging. Hum Brain Mapp 2022; 44:1019-1029. [PMID: 36308389 PMCID: PMC9875930 DOI: 10.1002/hbm.26131] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/01/2022] [Accepted: 10/09/2022] [Indexed: 01/28/2023] Open
Abstract
The assessment of resting perfusion measures (mean transit time, cerebral blood flow, and cerebral blood volume) with magnetic resonance imaging currently requires the presence of a susceptibility contrast agent such as gadolinium. Here, we present an initial comparison between perfusion measures obtained using hypoxia-induced deoxyhemoglobin and gadolinium in healthy study participants. We hypothesize that resting cerebral perfusion measures obtained using precise changes of deoxyhemoglobin concentration will generate images comparable to those obtained using a clinical standard, gadolinium. Eight healthy study participants were recruited (6F; age 23-60). The study was performed using a 3-Tesla scanner with an eight-channel head coil. The experimental protocol consisted of a high-resolution T1-weighted scan followed by two BOLD sequence scans in which each participant underwent a controlled bolus of transient pulmonary hypoxia, and subsequently received an intravenous bolus of gadolinium. The resting perfusion measures calculated using hypoxia-induced deoxyhemoglobin and gadolinium yielded maps that looked spatially comparable. There was no statistical difference between methods in the average voxel-wise measures of mean transit time, relative cerebral blood flow and relative cerebral blood volume, in the gray matter or white matter within each participant. We conclude that perfusion measures generated with hypoxia-induced deoxyhemoglobin are spatially and quantitatively comparable to those generated from a gadolinium injection in the same healthy participant.
Collapse
Affiliation(s)
- Ece Su Sayin
- Department of PhysiologyUniversity of TorontoTorontoOntarioCanada,Department of Anaesthesia and Pain ManagementUniversity Health Network, University of TorontoTorontoOntarioCanada
| | - Jacob Schulman
- Department of Medical BiophysicsUniversity of TorontoTorontoOntarioCanada,Techna Institute, University Health NetworkTorontoCanada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging LabUniversity Health NetworkTorontoOntarioCanada
| | - Harrison T. Levine
- Department of PhysiologyUniversity of TorontoTorontoOntarioCanada,Department of Anaesthesia and Pain ManagementUniversity Health Network, University of TorontoTorontoOntarioCanada
| | - Lakshmikumar Venkat Raghavan
- Department of Anaesthesia and Pain ManagementUniversity Health Network, University of TorontoTorontoOntarioCanada
| | - Kamil Uludag
- Techna Institute, University Health NetworkTorontoCanada,Joint Department of Medical Imaging and the Functional Neuroimaging LabUniversity Health NetworkTorontoOntarioCanada,Center for Neuroscience Imaging Research, Institute for Basic Science and Department of Biomedical EngineeringSungkyunkwan UniversitySuwonRepublic of Korea
| | - James Duffin
- Department of PhysiologyUniversity of TorontoTorontoOntarioCanada,Department of Anaesthesia and Pain ManagementUniversity Health Network, University of TorontoTorontoOntarioCanada
| | - Joseph A. Fisher
- Department of PhysiologyUniversity of TorontoTorontoOntarioCanada,Department of Anaesthesia and Pain ManagementUniversity Health Network, University of TorontoTorontoOntarioCanada
| | - David J. Mikulis
- Techna Institute, University Health NetworkTorontoCanada,Joint Department of Medical Imaging and the Functional Neuroimaging LabUniversity Health NetworkTorontoOntarioCanada
| | - Olivia Sobczyk
- Department of Anaesthesia and Pain ManagementUniversity Health Network, University of TorontoTorontoOntarioCanada,Joint Department of Medical Imaging and the Functional Neuroimaging LabUniversity Health NetworkTorontoOntarioCanada
| |
Collapse
|
9
|
Rogan M, Friend AT, Rossetti GM, Edden R, Mikkelsen M, Oliver SJ, Macdonald JH, Mullins PG. Hypoxia alters posterior cingulate cortex metabolism during a memory task: A 1H fMRS study. Neuroimage 2022; 260:119397. [PMID: 35752413 PMCID: PMC9513808 DOI: 10.1016/j.neuroimage.2022.119397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 06/16/2022] [Indexed: 11/16/2022] Open
Abstract
Environmental hypoxia (fraction of inspired oxygen (FIO2) ∼ 0.120) is known to trigger a global increase in cerebral blood flow (CBF). However, regionally, a heterogeneous response is reported, particularly within the posterior cingulate cortex (PCC) where decreased CBF is found after two hours of hypoxic exposure. Furthermore, hypoxia reverses task-evoked BOLD signals within the PCC, and other regions of the default mode network, suggesting a reversal of neurovascular coupling. An alternative explanation is that the neural architecture supporting cognitive tasks is reorganised. Therefore, to confirm if this previous result is neural or vascular in origin, a measure of neural activity that is not haemodynamic-dependant is required. To achieve this, we utilised functional magnetic resonance spectroscopy to probe the glutamate response to memory recall in the PCC during normoxia (FIO2 = 0.209) and after two hours of poikilocapnic hypoxia (FIO2 = 0.120). We also acquired ASL-based measures of CBF to confirm previous findings of reduced CBF within the PCC in hypoxia. Consistent with previous findings, hypoxia induced a reduction in CBF within the PCC and other regions of the default mode network. Under normoxic conditions, memory recall was associated with an 8% increase in PCC glutamate compared to rest (P = 0.019); a change which was not observed during hypoxia. However, exploratory analysis of other neurometabolites showed that PCC glucose was reduced during hypoxia compared to normoxia both at rest (P = 0.039) and during the task (P = 0.046). We conclude that hypoxia alters the activity-induced increase in glutamate, which may reflect a reduction in oxidative metabolism within the PCC. The reduction in glucose in hypoxia reflects continued metabolism, presumably by non-oxidative means, without replacement of glucose due to reduced CBF.
Collapse
Affiliation(s)
- Matthew Rogan
- School of Human and Behavioural Sciences, Bangor University, Bangor, United Kingdom; The Bangor Imaging Unit, Bangor University, Bangor, United Kingdom; Institute for Applied Human Physiology, Bangor University, Bangor, United Kingdom
| | - Alexander T Friend
- School of Human and Behavioural Sciences, Bangor University, Bangor, United Kingdom; Institute for Applied Human Physiology, Bangor University, Bangor, United Kingdom
| | - Gabriella Mk Rossetti
- Centre for Integrative Neuroscience and Neurodynamics, University of Reading, Reading, United Kingdom
| | - Richard Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Mark Mikkelsen
- Department of Radiology, Weill Cornell Medicine, New York, NY, United States
| | - Samuel J Oliver
- School of Human and Behavioural Sciences, Bangor University, Bangor, United Kingdom; Institute for Applied Human Physiology, Bangor University, Bangor, United Kingdom
| | - Jamie H Macdonald
- School of Human and Behavioural Sciences, Bangor University, Bangor, United Kingdom; Institute for Applied Human Physiology, Bangor University, Bangor, United Kingdom
| | - Paul G Mullins
- School of Human and Behavioural Sciences, Bangor University, Bangor, United Kingdom; The Bangor Imaging Unit, Bangor University, Bangor, United Kingdom; Institute for Applied Human Physiology, Bangor University, Bangor, United Kingdom.
| |
Collapse
|
10
|
Zhang X, Zhang J. The human brain in a high altitude natural environment: A review. Front Hum Neurosci 2022; 16:915995. [PMID: 36188182 PMCID: PMC9520777 DOI: 10.3389/fnhum.2022.915995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
With the advancement of in vivo magnetic resonance imaging (MRI) technique, more detailed information about the human brain at high altitude (HA) has been revealed. The present review aimed to draw a conclusion regarding changes in the human brain in both unacclimatized and acclimatized states in a natural HA environment. Using multiple advanced analysis methods that based on MRI as well as electroencephalography, the modulations of brain gray and white matter morphology and the electrophysiological mechanisms underlying processing of cognitive activity have been explored in certain extent. The visual, motor and insular cortices are brain regions seen to be consistently affected in both HA immigrants and natives. Current findings regarding cortical electrophysiological and blood dynamic signals may be related to cardiovascular and respiratory regulations, and may clarify the mechanisms underlying some behaviors at HA. In general, in the past 10 years, researches on the brain at HA have gone beyond cognitive tests. Due to the sample size is not large enough, the current findings in HA brain are not very reliable, and thus much more researches are needed. Moreover, the histological and genetic bases of brain structures at HA are also needed to be elucidated.
Collapse
Affiliation(s)
- Xinjuan Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
- Department of Physiology, School of Medicine, Xiamen University, Xiamen, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
- Department of Physiology, School of Medicine, Xiamen University, Xiamen, China
- *Correspondence: Jiaxing Zhang,
| |
Collapse
|
11
|
Bhogal AA, Sayin ES, Poublanc J, Duffin J, Fisher JA, Sobcyzk O, Mikulis DJ. Quantifying cerebral blood arrival times using hypoxia-mediated arterial BOLD contrast. Neuroimage 2022; 261:119523. [PMID: 35907499 DOI: 10.1016/j.neuroimage.2022.119523] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/19/2022] Open
Abstract
Cerebral blood arrival and tissue transit times are sensitive measures of the efficiency of tissue perfusion and can provide clinically meaningful information on collateral blood flow status. We exploit the arterial blood oxygen level dependent (BOLD) signal contrast established by precisely decreasing, and then increasing, arterial hemoglobin saturation using respiratory re-oxygenation challenges to quantify arterial blood arrival times throughout the brain. We term this approach the Step Hemoglobin re-Oxygenation Contrast Stimulus (SHOCS). Carpet plot analysis yielded measures of signal onset (blood arrival), global transit time (gTT) and calculations of relative total blood volume. Onset times averaged across 12 healthy subjects were 1.1 ± 0.4 and 1.9 ± 0.6 for cortical gray and deep white matter, respectively. The average whole brain gTT was 4.5 ± 0.9 seconds. The SHOCS response was 1.7 fold higher in grey versus white matter; in line with known differences in tissue-specific blood volume fraction. SHOCS was also applied in a patient with unilateral carotid artery occlusion revealing ipsilateral prolonged signal onset with normal perfusion in the unaffected hemisphere. We anticipate that SHOCS will further inform on the extent of collateral blood flow in patients with upstream steno-occlusive vascular disease, including those already known to manifest reductions in vasodilatory reserve capacity or vascular steal.
Collapse
Affiliation(s)
- Alex A Bhogal
- Center of Imaging Sciences, High Field Department, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, CX 3584, the Netherlands.
| | - Ece Su Sayin
- Department of Physiology, University of Toronto, Toronto, Canada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
| | - James Duffin
- Department of Physiology, University of Toronto, Toronto, Canada; Toronto General Hospital Research Institute, Toronto, Canada
| | - Joseph A Fisher
- Department of Physiology, University of Toronto, Toronto, Canada; Department of Anesthesiology and Pain Medicine, University Health Network and University of Toronto, Toronto, Canada
| | - Olivia Sobcyzk
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada; Department of Anesthesiology and Pain Medicine, University Health Network and University of Toronto, Toronto, Canada
| | - David J Mikulis
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
| |
Collapse
|
12
|
Poublanc J, Sobczyk O, Shafi R, Sayin ES, Schulman J, Duffin J, Uludag K, Wood JC, Vu C, Dharmakumar R, Fisher JA, Mikulis DJ. Perfusion MRI using endogenous deoxyhemoglobin as a contrast agent: Preliminary data. Magn Reson Med 2021; 86:3012-3021. [PMID: 34687064 DOI: 10.1002/mrm.28974] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/22/2021] [Accepted: 07/27/2021] [Indexed: 11/12/2022]
Abstract
PURPOSE To demonstrate the feasibility of mapping cerebral perfusion metrics with BOLD MRI during modulation of pulmonary venous oxygen saturation. METHODS A gas blender with a sequential gas delivery breathing circuit was used to implement rapid isocapnic changes in the partial pressure of oxygen of the arterial blood. Partial pressure of oxygen was initially lowered to a baseline of 40 mmHg. It was then rapidly raised to 95 mmHg for 20 s before rapidly returning to baseline. The induced cerebral changes in deoxyhemoglobin concentration were tracked over time using BOLD MRI in 6 healthy subjects and 1 patient with cerebral steno-occlusive disease. BOLD signal change, contrast-to-noise ratio, and time delay metrics were calculated. Perfusion metrics such as mean transit time, relative cerebral blood volume, and relative cerebral blood flow were calculated using a parametrized method with a mono-exponential residue function. An arterial input function from within the middle cerebral artery was used to scale relative cerebral blood volume and calculate absolute cerebral blood volume and cerebral blood flow. RESULTS In normal subjects, average gray and white matter were: BOLD change = 6.3 ± 1.2% and 2.5 ± 0.6%, contrast-to-noise ratio = 4.3 ± 1.3 and 2.6 ± 0.7, time delay = 2.3 ± 0.6 s and 3.6 ± 0.7 s, mean transit time = 3.9 ± 0.6 s and 5.5 ± 0.6 s, relative cerebral blood volume = 3.7 ± 0.9 and 1.6 ± 0.4, relative cerebral blood flow = 70.1 ± 8.3 and 20.6 ± 4.0, cerebral blood flow volume = 4.1 ± 0.9 mL/100 g and 1.8 ± 0.5 mL/100 g, and cerebral blood flow = 97.2 ± 18.7 mL/100 g/min and 28.7 ± 5.9 mL/100 g/min. CONCLUSION This study demonstrates that induced abrupt changes in deoxyhemoglobin can function as a noninvasive vascular contrast agent that may be used for cerebral perfusion imaging.
Collapse
Affiliation(s)
- Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, Ontario, Canada
| | - Olivia Sobczyk
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, Ontario, Canada.,Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Reema Shafi
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, Ontario, Canada
| | - Ece Su Sayin
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jacob Schulman
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Techna Institute, University Health Network, Toronto, Ontario, Canada
| | - James Duffin
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Kamil Uludag
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Techna Institute & Koerner Scientist in MR Imaging, University Health Network, Toronto, Ontario, Canada.,Center for Neuroscience Imaging Research, Institute for Basic Science & Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - John C Wood
- Division of Cardiology, Department of Pediatrics and Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Chau Vu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Rohan Dharmakumar
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Joseph A Fisher
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - David J Mikulis
- The Joint Department of Medical Imaging, The Toronto Western Hospital, The University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
13
|
Abstract
Blood oxygen level dependent (BOLD) fMRI is a common technique for measuring brain activation that could be affected by low-level carbon monoxide (CO) exposure from, e.g. smoking. This study aimed to probe the vulnerability of BOLD fMRI to CO and determine whether it may constitute a significant neuroimaging confound. Low-level (6 ppm exhaled) CO effects on BOLD response were assessed in 12 healthy never-smokers on two separate experimental days (CO and air control). fMRI tasks were breath-holds (hypercapnia), visual stimulation and fingertapping. BOLD fMRI response was lower during breath holds, visual stimulation and fingertapping in the CO protocol compared to the air control protocol. Behavioural and physiological measures remained unchanged. We conclude that BOLD fMRI might be vulnerable to changes in baseline CO, and suggest exercising caution when imaging populations exposed to elevated CO levels. Further work is required to fully elucidate the impact on CO on fMRI and its underlying mechanisms.
Collapse
Affiliation(s)
- Caroline Bendell
- Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Shakeeb H Moosavi
- Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Mari Herigstad
- Biomolecular Sciences Research Centre, Department of Biosciences and Chemistry, Sheffield Hallam University, Sheffield, UK
| |
Collapse
|
14
|
Zhang Y, Yin Y, Li H, Gao JH. Measurement of CMRO 2 and its relationship with CBF in hypoxia with an extended calibrated BOLD method. J Cereb Blood Flow Metab 2020; 40:2066-2080. [PMID: 31665954 PMCID: PMC7786846 DOI: 10.1177/0271678x19885124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) are physiological parameters that not only reflect brain health and disease but also jointly contribute to blood oxygen level-dependent (BOLD) signals. Nevertheless, unsolved issues remain concerning the CBF-CMRO2 relationship in the working brain under various oxygen conditions. In particular, the CMRO2 responses to functional tasks in hypoxia are less studied. We extended the calibrated BOLD model to incorporate CMRO2 measurements in hypoxia. The extended model, which was cross-validated with a multicompartment BOLD model, considers the influences of the reduced arterial saturation level and increased baseline cerebral blood volume (CBV) and deoxyhemoglobin concentration on the changes of BOLD signals in hypoxia. By implementing a pulse sequence to simultaneously acquire the CBV-, CBF- and BOLD-weighted signals, we investigated the effects of mild hypoxia on the CBF and CMRO2 responses to graded visual stimuli. Compared with normoxia, mild hypoxia caused significant alterations in both the amplitude and the trend of the CMRO2 responses but did not impact the corresponding CBF responses. Our observations suggested that the flow-metabolism coupling strategies in the brain during mild hypoxia were different from those during normoxia.
Collapse
Affiliation(s)
- Yaoyu Zhang
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yayan Yin
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China
| | - Huanjie Li
- School of Biomedical Engineering, Dalian University of Technology, Dalian, China
| | - Jia-Hong Gao
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,McGovern Institute for Brain Research, Peking University, Beijing, China
| |
Collapse
|
15
|
Liu J, Li S, Qian L, Xu X, Zhang Y, Cheng J, Zhang W. Effects of acute mild hypoxia on cerebral blood flow in pilots. Neurol Sci 2020; 42:673-680. [PMID: 32654008 DOI: 10.1007/s10072-020-04567-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 07/02/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Pilots often face and need to overcome a diverse range of unfavorable conditions, of which hypoxic exposure is the most common. Studies have reported that hypoxia can induce a decrease in cerebral blood flow (CBF) in the brains of both humans and animals. Hypoxia and the associated cerebral hemodynamic changes can contribute to cognitive performance deficits that may endanger flight safety and increase the risk of accidents. AIM In this study, we aimed to identify region-specific alterations in CBF in male pilots after exposure to hypoxia. MATERIAL AND METHODS We used 3D pseudo-continuous arterial spin labeling sequences in 35 healthy male pilots (mean age: 30.6 ± 4.82 years) under simulated hypoxic conditions with a 3.0-T magnetic resonance imaging scanner. The generated CBF maps were measured and averaged in several regions of interest. RESULTS Hypoxia decreased CBF in various brain regions, including the right temporal and bilateral occipital lobes, the anterior and posterior lobes of the cerebellum, the culmen and declive, and the inferior semilunar lobule of the cerebellum. CONCLUSION These changes may impact the functional activity of the brains of pilots experiencing hypoxia in flight, but the related mechanisms require further investigation.
Collapse
Affiliation(s)
- Jie Liu
- Department of MRI, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Dong Road, Erqi District, Zhengzhou, Henan Province, China
| | - Shujian Li
- Department of MRI, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Dong Road, Erqi District, Zhengzhou, Henan Province, China
| | - Long Qian
- GE Healthcare China, Floor 1, Yongchang North Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Xianrong Xu
- Department of Air Duty, The Air Force General Hospital in Beijing, No. 30 Fucheng Road, Haidian District, Beijing, West Diaoyutai, China
| | - Yong Zhang
- Department of MRI, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Dong Road, Erqi District, Zhengzhou, Henan Province, China
| | - Jingliang Cheng
- Department of MRI, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Dong Road, Erqi District, Zhengzhou, Henan Province, China.
| | - Wanshi Zhang
- Department of Radiology, The Air Force General Hospital in Beijing, No. 30 Fucheng Road, Haidian District, Beijing, West Diaoyutai, China
| |
Collapse
|
16
|
Coloigner J, Vu C, Borzage M, Bush A, Choi S, Miao X, Chai Y, Galarza C, Lepore N, Tamrazi B, Coates TD, Wood JC. Transient Hypoxia Model Revealed Cerebrovascular Impairment in Anemia Using BOLD MRI and Near-Infrared Spectroscopy. J Magn Reson Imaging 2020; 52:1400-1412. [PMID: 32648323 DOI: 10.1002/jmri.27210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Obstructive sleep apnea and nocturnal oxygen desaturations, which are prevalent in sickle cell disease (SCD) and chronic anemia disorders, have been linked to risks of stroke and silent cerebral infarcts (SCI). Cerebrovascular response to intermittent desaturations has not been well studied and may identify patients at greatest risk. PURPOSE To investigate the cerebral dynamic response to induced desaturation in SCD patients with and without SCI, chronic anemia, and healthy subjects. STUDY TYPE Prospective. SUBJECTS Twenty-six SCD patients (age = 21 ± 8.2, female 46.2%), including 15 subjects without SCI and nine subjects with SCI, 15 nonsickle anemic patients (age = 22 ± 5.8, female 66.7%), and 31 controls (age = 28 ± 12.3, female 77.4%). FIELD STRENGTH/SEQUENCE 3T, gradient-echo echo-planar imaging. ASSESSMENT A transient hypoxia challenge of five breaths of 100% nitrogen gas was performed with blood oxygen level-dependent (BOLD) MRI and near-infrared spectroscopy (NIRS) acquisitions. Hypoxia responses were characterized by desaturation depth, time-to-peak, return-to-baseline half-life, and posthypoxia recovery in the BOLD and NIRS time courses. SCI were documented by T2 fluid-attenuation inversion recovery (FLAIR). STATISTICAL TESTS Univariate and multivariate regressions were performed between hypoxic parameters and anemia predictors. Voxelwise two-sample t-statistic maps were used to assess the regional difference in hypoxic responses between anemic and control groups. RESULTS Compared to controls, SCD and chronically anemic patients demonstrated significantly higher desaturation depth (P < 0.01) and shorter return-to-baseline timing response (P < 0.01). Patients having SCI had shorter time-to-peak (P < 0.01), return-to-baseline (P < 0.01), and larger desaturation depth (P < 0.01) in both white matter regions at risk and normal-appearing white matter than patients without infarcts. On multivariate analysis, desaturation depth and timing varied with age, sex, blood flow, white blood cells, and cell-free hemoglobin (r2 = 0.25 for desaturation depth; r2 = 0.18 for time-to-peak; r2 = 0.37 for return-to-baseline). DATA CONCLUSION Transient hypoxia revealed global and regional response differences between anemic and healthy subjects. SCI was associated with extensive heterogeneity of desaturation dynamics, consistent with extensive underlying microvascular remodeling.
Collapse
Affiliation(s)
- Julie Coloigner
- CIBORG Laboratory, Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.,Univ Rennes, CNRS, Inria, Inserm, IRISA UMR 6074, Rennes, France
| | - Chau Vu
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Matthew Borzage
- Division of Neonatology, Fetal and Neonatal Institute, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Adam Bush
- Department of Radiology and Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Soyoung Choi
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Xin Miao
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Yaqiong Chai
- CIBORG Laboratory, Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Cristina Galarza
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Natasha Lepore
- CIBORG Laboratory, Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.,Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Benita Tamrazi
- Department of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Thomas D Coates
- Division of Hematology-Oncology, Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, California, USA.,Department of Pediatrics and Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - John C Wood
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.,Division of Cardiology, Department of Pediatrics and Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA
| |
Collapse
|
17
|
Dixon B, MacLeod DB. Assessment of a Non Invasive Brain Oximeter in Volunteers Undergoing Acute Hypoxia. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2020; 13:183-194. [PMID: 32669881 PMCID: PMC7335769 DOI: 10.2147/mder.s250102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 06/09/2020] [Indexed: 12/03/2022] Open
Abstract
INTRODUCTION Research in traumatic brain injury suggests better patient outcomes when invasive oxygen monitoring is used to detect and correct episodes of brain hypoxia. Invasive brain oxygen monitoring is, however, not routinely used due to the risks, costs and technical challengers. We are developing a non-invasive brain oximeter to address these limitations. The monitor uses the principles of pulse oximetry to record a brain photoplethysmographic waveform and oxygen saturations. We undertook a study in volunteers to assess the new monitor. PATIENTS AND METHODS We compared the temporal changes in the brain and skin oxygen saturations in six volunteers undergoing progressive hypoxia to reach arterial saturations of 70%. This approach provides a method to discriminate potential contamination of the brain signal by skin oxygen levels, as the responses in brain and skin oxygen saturations are distinct due to the auto-regulation of cerebral blood flow to compensate for hypoxia. Conventional pulse oximetry was used to assess skin oxygen levels. Blood was also collected from the internal jugular vein and correlated with the brain oximeter oxygen levels. RESULTS At baseline, a photoplethysmographic waveform consistent with that expected from the brain was obtained in five subjects. The signal was adequate to assess oxygen saturations in three subjects. During hypoxia, the brain's oximeter oxygen saturation fell to 74%, while skin saturation fell to 50% (P<0.0001). The brain photoplethysmographic waveform developed a high-frequency oscillation of ~7 Hz, which was not present in the skin during hypoxia. A weak correlation between the brain oximeter and proximal internal jugular vein oxygen levels was demonstrated, R2=0.24, P=0.01. CONCLUSION Brain oximeter oxygen saturations were relatively well preserved compared to the skin during hypoxia. These findings are consistent with the expected physiological responses and suggest skin oxygen levels did not markedly contaminate the brain oximeter signal.
Collapse
Affiliation(s)
| | - David B MacLeod
- Human Pharmacology and Physiology Laboratory, Department of Anesthesiology and School of Nursing, Duke University, Durham, NC, USA
| |
Collapse
|
18
|
Khan FA, McIntyre C, Khan AM, Maslov A. Headache and Methemoglobinemia. Headache 2019; 60:291-297. [PMID: 31724752 DOI: 10.1111/head.13696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2019] [Indexed: 11/27/2022]
Abstract
AIM This basic review is intended to summarize the current knowledge of methemoglobinemia as an important cause of secondary headache with the hope of generating a growing interest in studying this phenomenon. BACKGROUND We describe the pathological underpinnings of headaches generated by hypoxia. Possible mechanisms include cerebral vasodilation-associated stretching of the vessel nociceptors, sensitization of perivascular nociceptors mediated by nitric oxide, cerebral calcitonin gene-related peptide, activation of the cyclic adenosine monophosphate pathway, cortical spreading depression, disruption of the blood-brain barrier, and neurogenic inflammation. We review the clinical features, pathophysiology, and management of methemoglobinemia. We conducted a literature review of reports of symptomatic methemoglobinemia with headache. In addition, we describe a case report of a patient who presented with an acute onset of severe holocranial headache associated with rapidly progressive perioral paresthesia, cyanosis in lips and hands, nausea, and mild dyspnea on exertion. These features can be misinterpreted as an acute attack of migraine with pain-related hyperventilation syndrome and anxiety leading to clinically detrimental delay in the management of the progressive hypoxia. Her symptoms resolved following treatment with methylene blue. The complex relationship of migraine and hypoxia-related headaches is also reviewed. We propose that methemoglobinemia-associated headaches are possibly generated by stretching of the nociceptor nerve endings during cerebral vasodilation and hypoxia-mediated oxidative stress. CONCLUSIONS The case highlights the need to broaden the formulated differential diagnosis of an acute onset severe holocranial headache and pay careful attention to other signs and symptoms that may provide hints on potential mechanism(s) for secondary headaches. We provide justification for the need to incorporate "Headache attributed to Methemoglobinemia" as a subtype under the section "Headache attributed to hypoxia and/or hypercapnia" of the International Classification of Headache Disorders to support clinical decision making.
Collapse
Affiliation(s)
- Fawad Ahmed Khan
- The McCasland Family Comprehensive Headache Center, Ochsner Neuroscience Institute, Ochsner Clinic Foundation, New Orleans, LA, USA.,The University of Queensland School of Medicine, Ochsner Clinical School, New Orleans, LA, USA.,Tulane University School of Medicine, New Orleans, LA, USA
| | - Caley McIntyre
- The University of Queensland School of Medicine, Ochsner Clinical School, New Orleans, LA, USA.,Department of Hospital Medicine, Ochsner Clinic Foundation, New Orleans, LA, USA
| | - Abdul Mukhtadir Khan
- Department of Pulmonary and Critical Care Medicine, Ochsner Clinic Foundation, New Orleans, LA, USA
| | - Alexander Maslov
- The University of Queensland School of Medicine, Ochsner Clinical School, New Orleans, LA, USA
| |
Collapse
|
19
|
De Bels D, Pierrakos C, Bruneteau A, Reul F, Crevecoeur Q, Marrone N, Vissenaeken D, Borgers G, Balestra C, Honoré PM, Theunissen S. Variation of Cognitive Function During a Short Stay at Hypobaric Hypoxia Chamber (Altitude: 3842 M). Front Physiol 2019; 10:806. [PMID: 31316394 PMCID: PMC6611417 DOI: 10.3389/fphys.2019.00806] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
Objective To observe the effects of a fast-acute ascent to high altitude on brain cognitive function and transcranial doppler parameters in order to understand the physiological countermeasures of hypoxia. Methods 17 high-altitude-naïve male subjects (mean age was 26.3 ± 8.1 years) participated in the study. We measured Critical Flicker Fusion Frequency (CFFF), blood oxygen saturation, Psychology Experiment Building (PEBL) including three tests (Modified Math Processing Task, Perceptual Vigilance Task, and Time Estimation Task), as well as Cerebral Blood Flow index (CBFi), mean cerebral artery Systolic and diastolic velocities, Cerebral Pulsatility index (CPi), and heart Rate. All were measured at sea level, at least 1 h after arrival at the hypobaric hypoxia equivalent of 3842 m and 1 h after return to sea level. Results Under acute exposure to hypobaric hypoxic conditions, significant decrease in CFFF [42.1 ± 1 vs. 43.5 ± 1.7 Hz at sea level (asl), p < 0.01], CBFi (611 ± 51 vs. 665 ± 71 asl, p < 0.01) and blood oxygen saturation (83 ± 4% vs. 98 ± 1% asl, p < 0.001) as compared to pre-ascent values were observed. Physiological countermeasures to hypoxia could be involved as there was no significant change in neuropsychometric tests, Systolic and Diastolic velocities and CPi. A significant increase in Heart Rate (81 ± 15 bpm vs. 66 ± 15 bpm asl, p < 0.001) was observed. All parameters returned to their basal values 1 h after regaining sea level. Conclusion Hypoxia results in a decrease in CFFF, CBFi and oxygen saturation and in an increase in heart rate. As it decreased, Cerebral Blood Flow index does not seem to be the physiological measurement of choice to hypoxia explaining the maintenance of cognitive performance after acute exposure to hypobaric hypoxia and requires further investigation. Cerebral oxygen delivery and extraction could be one of the underlying mechanisms.
Collapse
Affiliation(s)
- D De Bels
- Department of Intensive Care Medicine, Brugmann University Hospital, Brussels, Belgium.,Unit of Oxygen Study, Translational Research Laboratory, Université Libre de Bruxelles, Brussels, Belgium.,Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - C Pierrakos
- Department of Intensive Care Medicine, Brugmann University Hospital, Brussels, Belgium.,Unit of Oxygen Study, Translational Research Laboratory, Université Libre de Bruxelles, Brussels, Belgium
| | - A Bruneteau
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - F Reul
- Faculty of Medicine, Université catholique de Louvain, Brussels, Belgium
| | - Q Crevecoeur
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - N Marrone
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - D Vissenaeken
- Hypobaric Chamber, Queen Astrid Military Hospital, Brussels, Belgium
| | - G Borgers
- Hypobaric Chamber, Queen Astrid Military Hospital, Brussels, Belgium
| | - C Balestra
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - P M Honoré
- Department of Intensive Care Medicine, Brugmann University Hospital, Brussels, Belgium
| | - S Theunissen
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| |
Collapse
|
20
|
Zhang J, Chen J, Fan C, Li J, Lin J, Yang T, Fan M. Alteration of Spontaneous Brain Activity After Hypoxia-Reoxygenation: A Resting-State fMRI Study. High Alt Med Biol 2017; 18:20-26. [PMID: 28266873 DOI: 10.1089/ham.2016.0083] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Zhang, Jiaxing, Ji Chen, Cunxiu Fan, Jinqiang Li, Jianzhong Lin, Tianhe Yang, and Ming Fan. Alteration of spontaneous brain activity after hypoxia-reoxygenation: A resting-state fMRI study. High Alt Med Biol. 18:20-26, 2017.-The present study was designed to investigate the effect of hypoxia-reoxygenation on the spontaneous neuronal activity in brain. Sixteen sea-level (SL) soldiers (20.5 ± 0.7 years), who garrisoned the frontiers in high altitude (HA) (2300-4400 m) for two years and subsequently descended to sea level for one to seven days, were recruited. Control group consisted of 16 matched SL natives. The amplitude of low-frequency fluctuations (ALFF) of regional brain functional magnetic resonance imaging signal in resting state and functional connectivity (FC) between brain regions was analyzed. HA subjects showed significant increases of ALFF at several sites within the bilateral occipital cortices and significant decreases of ALFF in the right anterior insula and extending to the caudate, putamen, inferior frontal orbital cortex, temporal pole, and superior temporal gyrus; lower ALFF values in the right insula were positively correlated with low respiratory measurements. The right insula in HA subjects had increases of FC with the right superior temporal gyrus, postcentral gyrus, rolandic operculum, supramarginal gyrus, and inferior frontal triangular area. We thus demonstrated that hypoxia-reoxygenation had influence on the spontaneous neuronal activity in brain. The decrease of insular neuronal activity may be related to the reduction of ventilatory drive, while the increase of FC with insula may indicate a central compensation.
Collapse
Affiliation(s)
- Jiaxing Zhang
- 1 Department of Physiology, Medical College of Xiamen University , Xiamen, China
| | - Ji Chen
- 1 Department of Physiology, Medical College of Xiamen University , Xiamen, China
| | - Cunxiu Fan
- 1 Department of Physiology, Medical College of Xiamen University , Xiamen, China
| | - Jinqiang Li
- 2 Department of Clinical Psychology, Gulangyu Sanatorium of PLA , Xiamen, China
| | - Jianzhong Lin
- 3 Magnetic Resonance Center, Zhongshan Hospital Xiamen University , Xiamen, China
| | - Tianhe Yang
- 3 Magnetic Resonance Center, Zhongshan Hospital Xiamen University , Xiamen, China
| | - Ming Fan
- 4 Department of Cognitive Sciences, Institute of Basic Medical Sciences , Beijing, China
| |
Collapse
|
21
|
Peng SL, Ravi H, Sheng M, Thomas BP, Lu H. Searching for a truly "iso-metabolic" gas challenge in physiological MRI. J Cereb Blood Flow Metab 2017; 37:715-725. [PMID: 26980756 PMCID: PMC5381460 DOI: 10.1177/0271678x16638103] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 01/14/2016] [Accepted: 01/25/2016] [Indexed: 11/16/2022]
Abstract
Hypercapnia challenge (e.g. inhalation of CO2) has been used in calibrated fMRI as well as in the mapping of vascular reactivity in cerebrovascular diseases. An important assumption underlying these measurements is that CO2 is a pure vascular challenge but does not alter neural activity. However, recent reports have suggested that CO2 inhalation may suppress neural activity and brain metabolic rate. Therefore, the goal of this study is to propose and test a gas challenge that is truly "iso-metabolic," by adding a hypoxic component to the hypercapnic challenge, since hypoxia has been shown to enhance cerebral metabolic rate of oxygen (CMRO2). Measurement of global CMRO2 under various gas challenge conditions revealed that, while hypercapnia (P = 0.002) and hypoxia (P = 0.002) individually altered CMRO2 (by -7.6 ± 1.7% and 16.7 ± 4.1%, respectively), inhalation of hypercapnic-hypoxia gas (5% CO2/13% O2) did not change brain metabolism (CMRO2 change: 1.5 ± 3.9%, P = 0.92). Moreover, cerebral blood flow response to the hypercapnic-hypoxia challenge (in terms of % change per mmHg CO2 change) was even greater than that to hypercapnia alone (P = 0.007). Findings in this study suggest that hypercapnic-hypoxia gas challenge may be a useful maneuver in physiological MRI as it preserves vasodilatory response yet does not alter brain metabolism.
Collapse
Affiliation(s)
- Shin-Lei Peng
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, USA
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, USA
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Harshan Ravi
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, USA
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, USA
- Department of Bioengineering, UT Arlington, Arlington, USA
| | - Min Sheng
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, USA
| | - Binu P Thomas
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, USA
| | - Hanzhang Lu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, USA
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, USA
| |
Collapse
|
22
|
Lawley JS, Macdonald JH, Oliver SJ, Mullins PG. Unexpected reductions in regional cerebral perfusion during prolonged hypoxia. J Physiol 2016; 595:935-947. [PMID: 27506309 DOI: 10.1113/jp272557] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 08/04/2016] [Indexed: 01/06/2023] Open
Abstract
KEY POINTS Cognitive performance is impaired by hypoxia despite global cerebral oxygen delivery and metabolism being maintained. Using arterial spin labelled (ASL) magnetic resonance imaging, this is the first study to show regional reductions in cerebral blood flow (CBF) in response to decreased oxygen supply (hypoxia) at 2 h that increased in area and became more pronounced at 10 h. Reductions in CBF were seen in brain regions typically associated with the 'default mode' or 'task negative' network. Regional reductions in CBF, and associated vasoconstriction, within the default mode network in hypoxia is supported by increased vasodilatation in these regions to a subsequent hypercapnic (5% CO2 ) challenge. These results suggest an anatomical mechanism through which hypoxia may cause previously reported deficits in cognitive performance. ABSTRACT Hypoxia causes an increase in global cerebral blood flow, which maintains global cerebral oxygen delivery and metabolism. However, neurological deficits are abundant under hypoxic conditions. We investigated regional cerebral microvascular responses to acute (2 h) and prolonged (10 h) poikilocapnic normobaric hypoxia. We found that 2 h of hypoxia caused an expected increase in frontal cortical grey matter perfusion but unexpected perfusion decreases in regions of the brain normally associated with the 'default mode' or 'task negative' network. After 10 h in hypoxia, decreased blood flow to the major nodes of the default mode network became more pronounced and widespread. The use of a hypercapnic challenge (5% CO2 ) confirmed that these reductions in cerebral blood flow from hypoxia were related to vasoconstriction. Our findings demonstrate steady-state deactivation of the default network under acute hypoxia, which become more pronounced over time. Moreover, these data provide a unique insight into the nuanced localized cerebrovascular response to hypoxia that is not attainable through traditional methods. The observation of reduced perfusion in the posterior cingulate and cuneal cortex, which are regions assumed to play a role in declarative and procedural memory, provides an anatomical mechanism through which hypoxia may cause deficits in working memory.
Collapse
Affiliation(s)
- Justin S Lawley
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Gwynedd, UK.,Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, Dallas, TX, USA
| | - Jamie H Macdonald
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Gwynedd, UK
| | - Samuel J Oliver
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Gwynedd, UK
| | - Paul G Mullins
- Bangor Imaging Centre, School of Psychology, Bangor University, Gwynedd, UK
| |
Collapse
|
23
|
Fan C, Zhao Y, Yu Q, Yin W, Liu H, Lin J, Yang T, Fan M, Gesang L, Zhang J. Reversible Brain Abnormalities in People Without Signs of Mountain Sickness During High-Altitude Exposure. Sci Rep 2016; 6:33596. [PMID: 27633944 PMCID: PMC5025655 DOI: 10.1038/srep33596] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 08/30/2016] [Indexed: 01/23/2023] Open
Abstract
A large proportion of lowlanders ascending to high-altitude (HA) show no signs of mountain sickness. Whether their brains have indeed suffered from HA environment and the persistent sequelae after return to lowland remain unknown. Thirty-one sea-level college students, who had a 30-day teaching on Qinghai-Tibet plateau underwent MRI scans before, during, and two months after HA exposure. Brain volume, cortical structures, and white matter microstructure were measured. Besides, serum neuron-specific enolase (NSE), C-reactive protein, and interleukin-6 and neuropsychiatric behaviors were tested. After 30-day HA exposure, the gray and white matter volumes and cortical surface areas significantly increased, with cortical thicknesses and curvatures changed in a wide spread regions; Anisotropy decreased with diffusivities increased in multiple sites of white matter tracts. Two months after HA exposure, cortical measurements returned to basal level. However, increased anisotropy with decreased diffusivities was observed. Behaviors and serum inflammatory factor did not significant changed during three time-point tests. NSE significantly decreased during HA but increased after HA exposure. Results suggest brain swelling occurred in people without neurological signs at HA, but no negative sequelae in cortical structures and neuropsychiatric functions were left after the return to lowlands. Reoxygenation changed white matter microstructure.
Collapse
Affiliation(s)
- Cunxiu Fan
- Department of Physiology, Medical College of Xiamen University, Xiamen 361102, Fujian, China
| | - Yuhua Zhao
- Institute of high altitude medicine, Tibet Autonomous Region People's Hospital, Lasa 850000, Tibet Autonomous Region, China
| | - Qian Yu
- Department of Physiology, Medical College of Xiamen University, Xiamen 361102, Fujian, China
| | - Wu Yin
- Department of Radiology, Tibet Autonomous Region People's Hospital, Lasa 850000, Tibet Autonomous Region, China
| | - Haipeng Liu
- Department of Radiology, Tibet Autonomous Region People's Hospital, Lasa 850000, Tibet Autonomous Region, China
| | - Jianzhong Lin
- Magnetic Resonance Center, Zhongshan Hospital Xiamen University, Xiamen 361004, Fujian, China
| | - Tianhe Yang
- Magnetic Resonance Center, Zhongshan Hospital Xiamen University, Xiamen 361004, Fujian, China
| | - Ming Fan
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, Beijing 100850, China
| | - Luobu Gesang
- Institute of high altitude medicine, Tibet Autonomous Region People's Hospital, Lasa 850000, Tibet Autonomous Region, China
| | - Jiaxing Zhang
- Department of Physiology, Medical College of Xiamen University, Xiamen 361102, Fujian, China
| |
Collapse
|
24
|
Arterial Spin Labeling Techniques 2009-2014. J Med Imaging Radiat Sci 2016; 47:98-107. [PMID: 31047171 DOI: 10.1016/j.jmir.2015.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 07/03/2015] [Accepted: 08/18/2015] [Indexed: 12/23/2022]
Abstract
PURPOSE Arterial spin labeling (ASL) techniques have been implemented across a diverse range of clinical and experimental applications. This review aims to evaluate the current feasibility of ASL in clinical neuroradiology based on recent improvements to ASL sequences and highlight areas for potential clinical applications. METHODS AND MATERIALS In December 2014, a literature search was conducted on PubMed Central, EMBASE, and Scopus using the search terms: "arterial spin labeling, neuroradiology," for studies published between 2009 and 2014 (inclusive). Of 483 studies matching the inclusion criteria, the number of studies using continuous, pseudocontinuous, pulsed, and velocity-selective ASL sequences was 42, 209, 226, and 3, respectively. Studies were classified based on several common clinical applications according to the type of ASL sequence used. Studies using pulsed ASL and pseudo-continuous ASL were grouped based on common sequences. RESULTS The number of clinical studies was 264. Numerous studies applied ASL to stroke management (43 studies), drug testing (21 studies), neurodegenerative diseases (40 studies), and psychiatric disorders (26 studies). CONCLUSIONS This review discusses several factors hindering the implementation of clinical ASL and ASL-related radiofrequency safety issues encountered in clinical practice. However, a limited number of search terms were used. Further development of robust sequences with multislice imaging capabilities and reduced radiofrequency energy deposition will hopefully improve the clinical acceptance of ASL.
Collapse
|
25
|
Alexandre F, Heraud N, Sanchez AM, Tremey E, Oliver N, Guerin P, Varray A. Brain Damage and Motor Cortex Impairment in Chronic Obstructive Pulmonary Disease: Implication of Nonrapid Eye Movement Sleep Desaturation. Sleep 2016; 39:327-35. [PMID: 26446126 PMCID: PMC4712404 DOI: 10.5665/sleep.5438] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 09/05/2015] [Indexed: 12/14/2022] Open
Abstract
STUDY OBJECTIVES Nonrapid eye movement (NREM) sleep desaturation may cause neuronal damage due to the withdrawal of cerebrovascular reactivity. The current study (1) assessed the prevalence of NREM sleep desaturation in nonhypoxemic patients with chronic obstructive pulmonary disease (COPD) and (2) compared a biological marker of cerebral lesion and neuromuscular function in patients with and without NREM sleep desaturation. METHODS One hundred fifteen patients with COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] grades 2 and 3), resting PaO2 of 60-80 mmHg, aged between 40 and 80 y, and without sleep apnea (apnea-hypopnea index < 15) had polysomnographic sleep recordings. In addition, twenty-nine patients (substudy) were assessed i) for brain impairment by serum S100B (biological marker of cerebral lesion), and ii) for neuromuscular function via motor cortex activation and excitability and maximal voluntary quadriceps strength measurement. RESULTS A total of 51.3% patients (n = 59) had NREM sleep desaturation (NREMDes). Serum S100B was higher in the NREMDes patients of the substudy (n = 14): 45.1 [Q1: 37.7, Q3: 62.8] versus 32.9 [Q1: 25.7, Q3: 39.5] pg.ml(-1) (P = 0.028). Motor cortex activation and excitability were lower in NREMDes patients (both P = 0.03), but muscle strength was comparable between groups (P = 0.58). CONCLUSIONS Over half the nonhypoxemic COPD patients exhibited NREM sleep desaturation associated with higher values of the cerebral lesion biomarker and lower neural drive reaching the quadriceps during maximal voluntary contraction. The lack of muscle strength differences between groups suggests a compensatory mechanism(s). Altogether, the results are consistent with an involvement of NREM sleep desaturation in COPD brain impairment. CLINICAL TRIAL REGISTRATION The study was registered at www.clinicaltrials.gov as NCT01679782.
Collapse
Affiliation(s)
- Francois Alexandre
- Movement To Health Laboratory, Euromov, University of Montpellier, Montpellier, France
- Clinique du Souffle La Vallonie, Fontalvie, Lodève, France
| | - Nelly Heraud
- Clinique du Souffle La Vallonie, Fontalvie, Lodève, France
- Clinique du Souffle Les Clarines, Fontalvie, Riom-es-Montagnes, France
| | - Anthony M.J. Sanchez
- UMR866 Dynamique Musculaire et Métabolisme, INRA, University of Montpellier, Montpellier, France
- Laboratoire Performance Santé Altitude, EA 4604, University of Perpignan Via Domitia, Font-Romeu, France
| | - Emilie Tremey
- Clinique du Souffle La Vallonie, Fontalvie, Lodève, France
- Clinique du Souffle Les Clarines, Fontalvie, Riom-es-Montagnes, France
| | - Nicolas Oliver
- Clinique du Souffle La Vallonie, Fontalvie, Lodève, France
| | - Philippe Guerin
- Clinique du Souffle Les Clarines, Fontalvie, Riom-es-Montagnes, France
| | - Alain Varray
- Movement To Health Laboratory, Euromov, University of Montpellier, Montpellier, France
| |
Collapse
|
26
|
Kim CH, Ryan EJ, Seo Y, Peacock C, Gunstad J, Muller MD, Ridgel AL, Glickman EL. Low intensity exercise does not impact cognitive function during exposure to normobaric hypoxia. Physiol Behav 2015; 151:24-8. [PMID: 26160408 DOI: 10.1016/j.physbeh.2015.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/16/2015] [Accepted: 07/02/2015] [Indexed: 11/30/2022]
Abstract
Exposure to hypoxia is associated with cognitive impairment, mediated by cerebral deoxygenation. This can be problematic for individuals who perform mental tasks at high altitude. Eight healthy men completed two experimental trials consisting of 5h of exposure to normobaric hypoxia (12.5% O2). In one of the experimental trials (Hypoxia) subjects remained resting in a seated position the entire 5h; in the other experimental trial (Hypoxia and Exercise) subjects rested 2h, cycled for 1h at constant wattage (workload equivalent to 50% of altitude adjusted VO2max), then rested the last 2h. Cerebral oxygenation was measured continuously via near-infrared spectroscopy and cognitive performance was assessed by Trail Making Test A and B. Cerebral oxygenation and cognitive performance both were impaired during exposure to hypoxia. In the Hypoxia and Exercise trial, subjects experienced further declinations in cerebral oxygenation without concomitant decreases in cognitive function. These data demonstrate that cognitive function declines during exposure to normobaric hypoxia and this decline is not exacerbated by low intensity exercise.
Collapse
Affiliation(s)
- Chul-Ho Kim
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA; Human Integrative and Environmental Physiology, Mayo Clinic, Rochester, MN, USA.
| | - Edward J Ryan
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA; Department of Exercise Science, Chatham University, Pittsburgh, PA, USA
| | - Yongsuk Seo
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA
| | - Corey Peacock
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA
| | - John Gunstad
- Department of Psychology, Kent State University, Kent, OH, USA
| | - Matthew D Muller
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA; Penn State Heart & Vascular Institute, Penn State University College of Medicine, Hershey, PA, USA
| | - Angela L Ridgel
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA
| | - Ellen L Glickman
- Exercise Physiology, School of Health Sciences, Kent State University, Kent, OH, USA
| |
Collapse
|
27
|
Alexandre F, Heraud N, Varray A. Is nocturnal desaturation a trigger for neuronal damage in chronic obstructive pulmonary disease? Med Hypotheses 2015; 84:25-30. [DOI: 10.1016/j.mehy.2014.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/03/2014] [Accepted: 11/09/2014] [Indexed: 01/26/2023]
|