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Vestergaard SB, Damsbo AG, Pedersen NL, Zachariassen K, Drasbek KR, Østergaard L, Andersen G, Dalby RB, Mortensen JK. Exploring vascular contributions to cognitive impairment and dementia (ENIGMA): protocol for a prospective observational study. BMC Neurol 2024; 24:110. [PMID: 38570800 PMCID: PMC10988942 DOI: 10.1186/s12883-024-03601-7] [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: 12/20/2023] [Accepted: 03/15/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Post-stroke cognitive impairment (PSCI) is common. However, the underlying pathophysiology remains largely unknown. Understanding the role of microvascular changes and finding markers that can predict PSCI, could be a first step towards better screening and management of PSCI. Capillary dysfunction is a pathological feature of cerebral small vessel disease and may play a role in the mechanisms underlying PSCI. Extracellular vesicles (EVs) are secreted from cells and may act as disease biomarkers. We aim to investigate the role of capillary dysfunction in PSCI and the associations between EV characteristics and cognitive function one year after acute ischemic stroke (AIS) and transient ischemic attack (TIA). METHODS The ENIGMA study is a single-centre prospective clinical observational study conducted at Aarhus University Hospital, Denmark. Consecutive patients with AIS and TIA are included and followed for one year with follow-up visits at three and 12 months. An MRI is performed at 24 h and 12 months follow-up. EV characteristics will be characterised from blood samples drawn at 24 h and three months follow-up. Cognitive function is assessed three and 12 months after AIS and TIA using the Repeatable Battery for the Assessment of Neuropsychological Status. DISCUSSION Using novel imaging and molecular biological techniques the ENIGMA study will provide new knowledge about the vascular contributions to cognitive decline and dementia. TRIAL REGISTRATION The study is retrospectively registered as an ongoing observational study at ClinicalTrials.gov with the identifier NCT06257823.
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Affiliation(s)
- Sigrid Breinholt Vestergaard
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Andreas Gammelgaard Damsbo
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Niels Lech Pedersen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Neuroradiology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Katrine Zachariassen
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Kim Ryun Drasbek
- Department of Clinical Medicine Center of Functionally Integrative Neuroscience, Aarhus University, Universitetsbyen 3, Aarhus C, 8000, Denmark
| | - Leif Østergaard
- Department of Clinical Medicine Center of Functionally Integrative Neuroscience, Aarhus University, Universitetsbyen 3, Aarhus C, 8000, Denmark
| | - Grethe Andersen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
| | - Rikke Beese Dalby
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark
- Department of Radiology and Nuclear Medicine, University Hospital of Southern Denmark, Finsensgade 35, Esbjerg, 6700, Denmark
| | - Janne Kærgård Mortensen
- Department of Neurology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark.
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, Aarhus N, 8200, Denmark.
- Department of Clinical Medicine, Department of Neurology, Aarhus University, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, J109, Aarhus N, 8200, Denmark.
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Korkmazer B, Karaman AK, Ustundag A, Arslan S, Kızılkılıç O, Koçer N, Islak C. Magnetic resonance perfusion imaging findings following flow diversion in patients with complex middle cerebral artery bifurcation aneurysms: a single-center analysis regarding the jailed cortical branches. J Neurointerv Surg 2023; 16:8-14. [PMID: 36963822 DOI: 10.1136/jnis-2023-020124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/07/2023] [Indexed: 03/26/2023]
Abstract
BACKGROUND Flow diverter (FD) devices provide a safe and effective treatment option especially for wide-necked intracranial aneurysms. One of the main concerns in patients treated with FD devices is patency of arterial branches jailed by the stent. However, there are no long-term data from magnetic resonance perfusion (MRP) studies regarding jailed branches. In this study we aimed to reveal the MRP findings in patients with jailed middle cerebral artery (MCA) cortical branches during long-term follow-up after flow diversion. METHODS Patients who underwent FD stent treatment for MCA aneurysms with a resulting jailed cortical branch were included. Follow-up clinical, angiographic, and MRP examination findings were recorded. Different MRP parameters were measured in the MCA territory regarding the jailed branches. RESULTS Eighteen patients treated endovascularly with flow diversion for a total of 20 MCA aneurysms were included. At angiographic follow-up (median 35 months, range 7-95 months) complete occlusion was observed in 13 (65%) aneurysms and partial occlusion was observed in 6 (30%). The mean transit time (MTT) prolongation, MTT ratio, time-to peak (TTP) prolongation, and TTP ratio were 1.34, 1.20, 1.18, and 1.06 s, respectively, when compared with the contralateral side in the MCA territory. MTT, TTP, and cerebral blood volume values of the patients showed statistically significant differences compared with the contralateral side (P<0.05). CONCLUSIONS Flow diversion treatment of complex bifurcation aneurysms can be effective and safe. MRP examination may reveal perfusion changes in the territory vascularized via a jailed branch, and these changes are rarely accompanied by clinical findings.
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Affiliation(s)
- Bora Korkmazer
- Division of Neuroradiology, Department of Radiology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Ahmet Kursat Karaman
- Department of Radiology, Sureyyapasa Chest Diseases and Chest Surgery Training and Research Hospital, Istanbul, Turkey
| | - Ahmet Ustundag
- Department of Radiology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Serdar Arslan
- Division of Neuroradiology, Department of Radiology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Osman Kızılkılıç
- Division of Neuroradiology, Department of Radiology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Naci Koçer
- Division of Neuroradiology, Department of Radiology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Civan Islak
- Division of Neuroradiology, Department of Radiology, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
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Bordoni L, Thoren AE, Gutiérrez‐Jiménez E, Åbjørsbråten KS, Bjørnstad DM, Tang W, Stern M, Østergaard L, Nagelhus EA, Frische S, Ottersen OP, Enger R. Deletion of aquaporin-4 improves capillary blood flow distribution in brain edema. Glia 2023; 71:2559-2572. [PMID: 37439315 PMCID: PMC10952478 DOI: 10.1002/glia.24439] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/14/2023]
Abstract
Brain edema is a feared complication to disorders and insults affecting the brain. It can be fatal if the increase in intracranial pressure is sufficiently large to cause brain herniation. Moreover, accruing evidence suggests that even slight elevations of intracranial pressure have adverse effects, for instance on brain perfusion. The water channel aquaporin-4 (AQP4), densely expressed in perivascular astrocytic endfeet, plays a key role in brain edema formation. Using two-photon microscopy, we have studied AQP4-mediated swelling of astrocytes affects capillary blood flow and intracranial pressure (ICP) in unanesthetized mice using a mild brain edema model. We found improved regulation of capillary blood flow in mice devoid of AQP4, independently of the severity of ICP increase. Furthermore, we found brisk AQP4-dependent astrocytic Ca2+ signals in perivascular endfeet during edema that may play a role in the perturbed capillary blood flow dynamics. The study suggests that astrocytic endfoot swelling and pathological signaling disrupts microvascular flow regulation during brain edema formation.
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Affiliation(s)
- Luca Bordoni
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
- Department of BiomedicineAarhus UniversityAarhusDenmark
| | - Anna E. Thoren
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | - Eugenio Gutiérrez‐Jiménez
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical MedicineAarhus UniversityAarhusDenmark
| | - Knut S. Åbjørsbråten
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | - Daniel M. Bjørnstad
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | - Wannan Tang
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
- Department of Clinical and Molecular MedicineNorwegian University of Science and TechnologyTrondheimNorway
- Department of Neurology, NeuroclinicSt. Olavs HospitalTrondheimNorway
| | - Mette Stern
- Department of BiomedicineAarhus UniversityAarhusDenmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical MedicineAarhus UniversityAarhusDenmark
- Department of NeuroradiologyAarhus University HospitalAarhusDenmark
| | - Erlend A. Nagelhus
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | | | - Ole P. Ottersen
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | - Rune Enger
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
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Sperring CP, Savage WM, Argenziano MG, Leifer VP, Alexander J, Echlov N, Spinazzi EF, Connolly ES. No-Reflow Post-Recanalization in Acute Ischemic Stroke: Mechanisms, Measurements, and Molecular Markers. Stroke 2023; 54:2472-2480. [PMID: 37534511 DOI: 10.1161/strokeaha.123.044240] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Acute ischemic stroke remains the primary cause of disability worldwide. For patients with large vessel occlusions, intravenous thrombolysis followed by mechanical thrombectomy remains the standard of care. Revascularization of the large vessel is typically successful. However, despite reopening of the occluded vessel, many patients fail to return to independence. Functional failure, despite macrovascular recanalization, is often referred to as the no-reflow phenomenon. Even with an extensive characterization of reperfusion in animal models, numerous mechanisms may explain no-reflow. Further, uniform measurements of this microvascular dysfunction and prognostic markers associated with no-reflow are lacking. In this review, we highlight a number of mechanisms that may explain no-reflow, characterize current multimodal measurements, and assess its molecular markers.
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Affiliation(s)
- Colin P Sperring
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - William M Savage
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - Michael G Argenziano
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - Valia P Leifer
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - Julia Alexander
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - Nicolas Echlov
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - Eleonora F Spinazzi
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
| | - E Sander Connolly
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital
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5
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Goyal M, Rinkel LA, Ospel JM. A Review on Adjunctive Therapies for Endovascular Treatment in Acute Ischemic Stroke. JOURNAL OF NEUROENDOVASCULAR THERAPY 2023; 17:263-271. [PMID: 38025256 PMCID: PMC10657729 DOI: 10.5797/jnet.ra.2023-0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/24/2023] [Indexed: 12/01/2023]
Abstract
Endovascular treatment (EVT) has revolutionized the management of acute ischemic stroke (AIS), but almost half of patients undergoing EVT do not achieve a good outcome. Adjunctive therapies have been proposed to improve the outcomes of EVT in AIS. This review aims to summarize the current evidence on the use of adjunctive therapies in EVT for AIS, including antithrombotic agents, intra-arterial thrombolytics, cerebroprotective agents, normobaric oxygen, and hypothermia. Several adjunctive therapies have shown promise in improving the outcomes of EVT in AIS, but phase 3 clinical trials are needed to establish clinical efficacy. We summarize the advantages and disadvantages of adjunctive EVT treatments and outline the challenges that each of these therapies will face before being adopted in clinical practice.
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Affiliation(s)
- Mayank Goyal
- Department of Diagnostic Imaging and Clinical Neurosciences, Foothills Medical Center, University of Calgary, Calgary, AB, Canada
| | - Leon A Rinkel
- Department of Diagnostic Imaging and Clinical Neurosciences, Foothills Medical Center, University of Calgary, Calgary, AB, Canada
- Department of Neurology, Amsterdam University Medical Center, Amsterdam, the Netherlands
| | - Johanna M Ospel
- Department of Diagnostic Imaging and Clinical Neurosciences, Foothills Medical Center, University of Calgary, Calgary, AB, Canada
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Novorolsky RJ, Kasheke GDS, Hakim A, Foldvari M, Dorighello GG, Sekler I, Vuligonda V, Sanders ME, Renden RB, Wilson JJ, Robertson GS. Preserving and enhancing mitochondrial function after stroke to protect and repair the neurovascular unit: novel opportunities for nanoparticle-based drug delivery. Front Cell Neurosci 2023; 17:1226630. [PMID: 37484823 PMCID: PMC10360135 DOI: 10.3389/fncel.2023.1226630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 06/22/2023] [Indexed: 07/25/2023] Open
Abstract
The neurovascular unit (NVU) is composed of vascular cells, glia, and neurons that form the basic component of the blood brain barrier. This intricate structure rapidly adjusts cerebral blood flow to match the metabolic needs of brain activity. However, the NVU is exquisitely sensitive to damage and displays limited repair after a stroke. To effectively treat stroke, it is therefore considered crucial to both protect and repair the NVU. Mitochondrial calcium (Ca2+) uptake supports NVU function by buffering Ca2+ and stimulating energy production. However, excessive mitochondrial Ca2+ uptake causes toxic mitochondrial Ca2+ overloading that triggers numerous cell death pathways which destroy the NVU. Mitochondrial damage is one of the earliest pathological events in stroke. Drugs that preserve mitochondrial integrity and function should therefore confer profound NVU protection by blocking the initiation of numerous injury events. We have shown that mitochondrial Ca2+ uptake and efflux in the brain are mediated by the mitochondrial Ca2+ uniporter complex (MCUcx) and sodium/Ca2+/lithium exchanger (NCLX), respectively. Moreover, our recent pharmacological studies have demonstrated that MCUcx inhibition and NCLX activation suppress ischemic and excitotoxic neuronal cell death by blocking mitochondrial Ca2+ overloading. These findings suggest that combining MCUcx inhibition with NCLX activation should markedly protect the NVU. In terms of promoting NVU repair, nuclear hormone receptor activation is a promising approach. Retinoid X receptor (RXR) and thyroid hormone receptor (TR) agonists activate complementary transcriptional programs that stimulate mitochondrial biogenesis, suppress inflammation, and enhance the production of new vascular cells, glia, and neurons. RXR and TR agonism should thus further improve the clinical benefits of MCUcx inhibition and NCLX activation by increasing NVU repair. However, drugs that either inhibit the MCUcx, or stimulate the NCLX, or activate the RXR or TR, suffer from adverse effects caused by undesired actions on healthy tissues. To overcome this problem, we describe the use of nanoparticle drug formulations that preferentially target metabolically compromised and damaged NVUs after an ischemic or hemorrhagic stroke. These nanoparticle-based approaches have the potential to improve clinical safety and efficacy by maximizing drug delivery to diseased NVUs and minimizing drug exposure in healthy brain and peripheral tissues.
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Affiliation(s)
- Robyn J. Novorolsky
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Gracious D. S. Kasheke
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Antoine Hakim
- School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Marianna Foldvari
- School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Gabriel G. Dorighello
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Israel Sekler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben Gurion University, Beersheva, Israel
| | | | | | - Robert B. Renden
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Justin J. Wilson
- Department of Chemistry and Chemical Biology, College of Arts and Sciences, Cornell University, Ithaca, NY, United States
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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7
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Staehr C, Giblin JT, Gutiérrez‐Jiménez E, Guldbrandsen HØ, Tang J, Sandow SL, Boas DA, Matchkov VV. Neurovascular Uncoupling Is Linked to Microcirculatory Dysfunction in Regions Outside the Ischemic Core Following Ischemic Stroke. J Am Heart Assoc 2023; 12:e029527. [PMID: 37232244 PMCID: PMC10381981 DOI: 10.1161/jaha.123.029527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/19/2023] [Indexed: 05/27/2023]
Abstract
Background Normal brain function depends on the ability of the vasculature to increase blood flow to regions with high metabolic demands. Impaired neurovascular coupling, such as the local hyperemic response to neuronal activity, may contribute to poor neurological outcome after stroke despite successful recanalization, that is, futile recanalization. Methods and Results Mice implanted with chronic cranial windows were trained for awake head-fixation before experiments. One-hour occlusion of the anterior middle cerebral artery branch was induced using single-vessel photothrombosis. Cerebral perfusion and neurovascular coupling were assessed by optical coherence tomography and laser speckle contrast imaging. Capillaries and pericytes were studied in perfusion-fixed tissue by labeling lectin and platelet-derived growth factor receptor β. Arterial occlusion induced multiple spreading depolarizations over 1 hour associated with substantially reduced blood flow in the peri-ischemic cortex. Approximately half of the capillaries in the peri-ischemic area were no longer perfused at the 3- and 24-hour follow-up (45% [95% CI, 33%-58%] and 53% [95% CI, 39%-66%] reduction, respectively; P<0.0001), which was associated with contraction of an equivalent proportion of peri-ischemic capillary pericytes. The capillaries in the peri-ischemic cortex that remained perfused showed increased point prevalence of dynamic flow stalling (0.5% [95% CI, 0.2%-0.7%] at baseline, 5.1% [95% CI, 3.2%-6.5%] and 3.2% [95% CI, 1.1%-5.3%] at 3- and 24-hour follow-up, respectively; P=0.001). Whisker stimulation at the 3- and 24-hour follow-up led to reduced neurovascular coupling responses in the sensory cortex corresponding to the peri-ischemic region compared with that observed at baseline. Conclusions Arterial occlusion led to contraction of capillary pericytes and capillary flow stalling in the peri-ischemic cortex. Capillary dysfunction was associated with neurovascular uncoupling. Neurovascular coupling impairment associated with capillary dysfunction may be a mechanism that contributes to futile recanalization. Hence, the results from this study suggest a novel treatment target to improve neurological outcome after stroke.
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Affiliation(s)
- Christian Staehr
- Department of BiomedicineAarhus UniversityAarhusDenmark
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
| | - John T. Giblin
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
| | - Eugenio Gutiérrez‐Jiménez
- Center of Functionally Integrative Neuroscience, Institute for Clinical MedicineAarhus UniversityAarhusDenmark
| | | | - Jianbo Tang
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
- Department of Biomedical EngineeringSouthern University of Science and TechnologyShenzhenChina
| | - Shaun L. Sandow
- Biomedical Science, School of HealthUniversity of the Sunshine CoastSippy DownsAustralia
- Centre for Clinical Research, Faculty of MedicineThe University of QueenslandBrisbaneAustralia
| | - David A. Boas
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
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8
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How can imaging in acute ischemic stroke help us to understand tissue fate in the era of endovascular treatment and cerebroprotection? Neuroradiology 2022; 64:1697-1707. [PMID: 35854136 DOI: 10.1007/s00234-022-03001-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 06/21/2022] [Indexed: 10/17/2022]
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9
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Bøgh N, Olin RB, Hansen ESS, Gordon JW, Bech SK, Bertelsen LB, Sánchez-Heredia JD, Blicher JU, Østergaard L, Ardenkjær-Larsen JH, Bok RA, Vigneron DB, Laustsen C. Metabolic MRI with hyperpolarized [1- 13C]pyruvate separates benign oligemia from infarcting penumbra in porcine stroke. J Cereb Blood Flow Metab 2021; 41:2916-2927. [PMID: 34013807 PMCID: PMC8756460 DOI: 10.1177/0271678x211018317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/15/2021] [Accepted: 04/19/2021] [Indexed: 01/17/2023]
Abstract
Acute ischemic stroke patients benefit from reperfusion in a short time-window after debut. Later treatment may be indicated if viable brain tissue is demonstrated and this outweighs the inherent risks of late reperfusion. Magnetic resonance imaging (MRI) with hyperpolarized [1-13C]pyruvate is an emerging technology that directly images metabolism. Here, we investigated its potential to detect viable tissue in ischemic stroke. Stroke was induced in pigs by intracerebral injection of endothelin 1. During ischemia, the rate constant of pyruvate-to-lactate conversion, kPL, was 52% larger in penumbra and 85% larger in the infarct compared to the contralateral hemisphere (P = 0.0001). Within the penumbra, the kPL was 50% higher in the regions that later infarcted compared to non-progressing regions (P = 0.026). After reperfusion, measures of pyruvate-to-lactate conversion were slightly decreased in the infarct compared to contralateral. In addition to metabolic imaging, we used hyperpolarized pyruvate for perfusion-weighted imaging. This was consistent with conventional imaging for assessment of infarct size and blood flow. Lastly, we confirmed the translatability of simultaneous assessment of metabolism and perfusion with hyperpolarized MRI in healthy volunteers. In conclusion, hyperpolarized [1-13C]pyruvate may aid penumbral characterization and increase access to reperfusion therapy for late presenting patients.
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Affiliation(s)
- Nikolaj Bøgh
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Rie B Olin
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Esben SS Hansen
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jeremy W Gordon
- Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, USA
| | - Sabrina K Bech
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lotte B Bertelsen
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Juan D Sánchez-Heredia
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Jakob U Blicher
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Jan H Ardenkjær-Larsen
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
- GE Healthcare, Brøndby, Denmark
| | - Robert A Bok
- Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, USA
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, USA
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California San Francisco and University of California, Berkeley, CA, USA
| | - Christoffer Laustsen
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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10
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Fang J, Chopp M, Xin H, Zhang L, Wang F, Golembieski W, Zhang ZG, He L, Liu Z. Plasminogen deficiency causes reduced angiogenesis and behavioral recovery after stroke in mice. J Cereb Blood Flow Metab 2021; 41:2583-2592. [PMID: 33853408 PMCID: PMC8504962 DOI: 10.1177/0271678x211007958] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Plasminogen is involved in the process of angiogenesis; however, the underlying mechanism is unclear. Here, we investigated the potential contribution of plasmin/plasminogen in mediating angiogenesis and thereby contributing to functional recovery post-stroke. Wild-type plasminogen naive (Plg+/+) mice and plasminogen knockout (Plg-/-) mice were subjected to unilateral permanent middle cerebral artery occlusion (MCAo). Blood vessels were labeled with FITC-dextran. Functional outcomes, and cerebral vessel density were compared between Plg+/+ and Plg-/- mice at different time points after stroke. We found that Plg-/- mice exhibited significantly reduced functional recovery, associated with significantly decreased vessel density in the peri-infarct area in the ipsilesional cortex compared with Plg+/+ mice. In vitro, cerebral endothelial cells harvested from Plg-/- mice exhibited significantly reduced angiogenesis assessed using tube formation assay, and migration, as evaluated using Scratch assays, compared to endothelial cells harvested from Plg+/+ mice. In addition, using Western blots, expression of thrombospondin (TSP)-1 and TSP-2 were increased after MCAo in the Plg-/- group compared to Plg+/+ mice, especially in the ipsilesional side of brain. Taken together, our data suggest that plasmin/plasminogen down-regulates the expression level of TSP-1 and TSP-2, and thereby promotes angiogenesis in the peri-ischemic brain tissue, which contributes to functional recovery after ischemic stroke.
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Affiliation(s)
- Jinghuan Fang
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA.,Department of Neurology, West China Hospital of Sichuan University, Chengdu, PR China
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA.,Department of Physics, Oakland University, Rochester, MI, USA
| | - Hongqi Xin
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA
| | - Li Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA
| | - Fengjie Wang
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA
| | | | | | - Li He
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, PR China
| | - Zhongwu Liu
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA
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11
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Crespo Pimentel B, Sedlacik J, Schröder J, Heinze M, Østergaard L, Fiehler J, Gerloff C, Thomalla G, Cheng B. Comprehensive Evaluation of Cerebral Hemodynamics and Oxygen Metabolism in Revascularization of Asymptomatic High-Grade Carotid Stenosis. Clin Neuroradiol 2021; 32:163-173. [PMID: 34487195 PMCID: PMC8894147 DOI: 10.1007/s00062-021-01077-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 07/22/2021] [Indexed: 11/25/2022]
Abstract
Introduction Revascularization procedures in carotid artery stenosis have shown a positive effect in the restoration of cerebral oxygen metabolism as assessed by T2’ (T2 prime) imaging as well as capillary homeostasis by measurement of capillary transit time heterogeneity (CTH); however, data in patients with asymptomatic carotid stenosis without manifest brain lesions are scarce. Patients and Methods The effect of revascularization on the hemodynamic profile and capillary homeostasis was evaluated in 13 patients with asymptomatic high-grade carotid stenosis without ischemic brain lesions using dynamic susceptibility contrast perfusion imaging and oxygenation-sensitive T2’ mapping before and 6–8 weeks after revascularization by endarterectomy or stenting. The cognitive performance at both timepoints was further assessed. Results Perfusion impairment at baseline was accompanied by an increased CTH (p = 0.008) in areas with a time to peak delay ≥ 2 s in the affected hemisphere compared to contralateral regions. Carotid intervention improved the overall moderate hemodynamic impairment at baseline by leading to an increase in normalized cerebral blood flow (p = 0.017) and a decrease in mean transit time (p = 0.027), oxygen extraction capacity (OEC) (p = 0.033) and CTH (p = 0.048). The T2’ values remained unchanged. Conclusion This study presents novel evidence of a state of altered microvascular function in patients with high-grade carotid artery stenosis in the absence of ischemic brain lesions, which shows sustained normalization after revascularization procedures. Supplementary Information The online version of this article (10.1007/s00062-021-01077-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Jan Sedlacik
- Centre for the Developing Brain & Biomedical Engineering Department, School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK
| | - Julian Schröder
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Marlene Heinze
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Fiehler
- Department of Neuroradiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Gerloff
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Götz Thomalla
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Bastian Cheng
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
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12
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Cai H, Fan S, Bian Y, Yang Q, Long Z, Chen L, Tang W, Zhang N, Zhen Y, Li Z. Two-way comparison of brain perfusion image processing software for patients with acute ischemic strokes in real-world. Neuroradiology 2021; 64:161-169. [PMID: 34331546 DOI: 10.1007/s00234-021-02771-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/11/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE Perfusion imaging generates multimaps of ischemic tissues and is a proven decision-making tool in patients with acute ischemic stroke. However, the reliability of perfusion post-processing outcomes has been debated, given disparate results of various software applications, especially for patients with small ischemic core volume. This study was undertaken to compare ischemic volume estimates determined by imSTROKE (a software with new imaging protocol) and RAPID computer applications, respectively. METHODS A total of 611 patients qualified for study, each having met inclusion and exclusion criteria of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN trial). Subjects were examined by computed tomography perfusion (CTP) imaging (n = 349) or perfusion-weighted (PWI) and diffusion-weighted (DWI) imaging (n = 262). Ischemic volumes estimated by imSTROKE and RAPID applications were then compared. We used Bland-Altman analysis and intraclass correlation coefficients (ICCs) to ascertain agreement between applications. Accuracies of estimated core infarct and penumbra volumes were tested at specific thresholds (core: 25 mL, 50 mL, and 70 mL; penumbra: 45 mL, 90 mL, and 125 mL). RESULTS Median core infarct volumes by imSTROKE and RAPID were 29.18 mL and 29.53 mL, respectively (ICC = 0.9880, 95% confidence interval [CI]: 0.9860-0.9898). Median penumbra volumes by imSTROKE and RAPID were 68.20 mL and 68.55 mL, respectively (ICC = 0.9885, 95% CI: 0.9865-0.9902). CONCLUSION In estimating core infarct and penumbra volumes, imSTROKE and RAPID applications showed high-level agreement. For patients with small ischemic core volume, compared with RAPID, imSTROKE may have better sensitivity.
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Affiliation(s)
- Heng Cai
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Clinical Medical Research Center in Nervous System Disease, Shenyang, 110004, People's Republic of China
| | - Shengyu Fan
- Nanjing Yuexi Medical Technology Co., Ltd., Nanjing, 210000, People's Republic of China
| | - Yueyan Bian
- Nanjing Yuexi Medical Technology Co., Ltd., Nanjing, 210000, People's Republic of China
| | - Qi Yang
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China
| | - Zhenhai Long
- Department of Neurosurgery, Central Hospital of Fuxin, Fuxin, Liaoning, 123001, People's Republic of China
| | - Liangyu Chen
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Clinical Medical Research Center in Nervous System Disease, Shenyang, 110004, People's Republic of China
| | - Wei Tang
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Clinical Medical Research Center in Nervous System Disease, Shenyang, 110004, People's Republic of China
| | - Nan Zhang
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
- Liaoning Clinical Medical Research Center in Nervous System Disease, Shenyang, 110004, People's Republic of China
| | - Yongyu Zhen
- Department of Neurosurgery, Central Hospital of Fuxin, Fuxin, Liaoning, 123001, People's Republic of China
| | - Zhiqing Li
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China.
- Liaoning Clinical Medical Research Center in Nervous System Disease, Shenyang, 110004, People's Republic of China.
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13
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Terman D, Chen L, Hannawi Y. Mathematical modeling of cerebral capillary blood flow heterogeneity and its effect on brain tissue oxygen levels. J Theor Biol 2021; 527:110817. [PMID: 34157352 DOI: 10.1016/j.jtbi.2021.110817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 05/06/2021] [Accepted: 06/15/2021] [Indexed: 11/29/2022]
Abstract
Maintaining cerebral blood flow is critical for adequate neuronal function. Previous computational models of brain capillary networks have predicted that heterogeneous cerebral capillary flow patterns result in lower brain tissue partial oxygen pressures PO2). However, these previous models have often considered simple capillary networks in terms of their geometric properties. In this current work, we developed and analyzed computational models of brain capillary networks to determine how perturbations of network properties impact tissue oxygen levels. The models include variabilities in both their geometric (segment lengths and diameters) and three-dimensional, topological structure. Two classes of capillary network models are considered. The first consists of equations for the oxygen partial pressure, PO2, in both a capillary network and the surrounding tissue. In order to gain insight into the behavior of this detailed model, we also consider a reduced model for changes in PO2 in just the capillary network. The main result is that for a general class of networks, random perturbations of either segment diameters or conductances will always, on average, decrease the average tissue oxygen levels. This result is supported through both simulations of the models and mathematical analysis. Our results promise to expand our understanding of cerebral capillary blood flow and its impact on the brain function in health and disease.
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Affiliation(s)
- David Terman
- Department of Mathematics, The Ohio State University, Columbus, OH 43210 USA.
| | - Liam Chen
- Department of Mathematics, The Ohio State University, Columbus, OH 43210 USA
| | - Yousef Hannawi
- Division of Cerebrovascular Diseases and Neurocritical Care, Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH 43210 USA
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14
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Hofmann BB, Fischer I, Engel A, Jannusch K, Donaldson DM, Karadag C, van Lieshout JH, Beseoglu K, Muhammad S, Turowski B, Hänggi D, Kamp MA, Rubbert C. MTT Heterogeneity in Perfusion CT Imaging as a Predictor of Outcome after Aneurysmal SAH. AJNR Am J Neuroradiol 2021; 42:1387-1395. [PMID: 34083263 DOI: 10.3174/ajnr.a7169] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/09/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Impairment of tissue oxygenation caused by inhomogeneous microscopic blood flow distribution, the so-called capillary transit time heterogeneity, is thought to contribute to delayed cerebral ischemia after aneurysmal SAH but has so far not been systematically evaluated in patients. We hypothesized that heterogeneity of the MTT, derived from CTP parameters, would give insight into the clinical course of patients with aneurysmal SAH and may identify patients at risk of poor outcome. MATERIALS AND METHODS We retrospectively analyzed the heterogeneity of the MTT using the coefficient of variation in CTP scans from 132 patients. A multivariable logistic regression model was used to model the dichotomized mRS outcome. Linear regression was used to eliminate variables with high linear dependence. T tests were used to compare the means of 2 groups. Furthermore, the time of the maximum coefficient of variation for MTT after bleeding was evaluated for correlation with the mRS after 6 months. RESULTS On average, each patient underwent 5.3 CTP scans during his or her stay. Patients with high coefficient of variation for MTT presented more often with higher modified Fisher (P = .011) and World Federation of Neurosurgical Societies grades (P = .014). A high coefficient of variation for MTT at days 3-21 after aneurysmal SAH correlated significantly with a worse mRS score after 6 months (P = .016). We found no correlation between the time of the maximum coefficient of variation for MTT after bleeding and the patients' outcomes after 6 months (P = .203). CONCLUSIONS Heterogeneity of MTT in CTP after aneurysmal SAH correlates with the patients' outcomes. Because the findings are in line with the pathophysiologic concept of the capillary transit time heterogeneity, future studies should seek to verify the coefficient of variation for MTT as a potential imaging biomarker for outcome.
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Affiliation(s)
- B B Hofmann
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - I Fischer
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - A Engel
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - K Jannusch
- Department of Diagnostic and Interventional Radiology (K.J., B.T., C.R.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - D M Donaldson
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - C Karadag
- Medical Faculty (C.K.), University Düsseldorf, Düsseldorf, Germany
| | - J H van Lieshout
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - K Beseoglu
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - S Muhammad
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - B Turowski
- Department of Diagnostic and Interventional Radiology (K.J., B.T., C.R.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - D Hänggi
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - M A Kamp
- From the Department of Neurosurgery (B.B.H., I.F., A.E., D.M.D., C.K., J.H.v.L., K.B., S.M., D.H., M.A.K.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
| | - C Rubbert
- Department of Diagnostic and Interventional Radiology (K.J., B.T., C.R.), Medical Faculty, University Düsseldorf, Düsseldorf, Germany
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15
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Kaczmarz S, Göttler J, Petr J, Hansen MB, Mouridsen K, Zimmer C, Hyder F, Preibisch C. Hemodynamic impairments within individual watershed areas in asymptomatic carotid artery stenosis by multimodal MRI. J Cereb Blood Flow Metab 2021; 41:380-396. [PMID: 32237952 PMCID: PMC7812517 DOI: 10.1177/0271678x20912364] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Improved understanding of complex hemodynamic impairments in asymptomatic internal carotid artery stenosis (ICAS) is crucial to better assess stroke risks. Multimodal MRI is ideal for measuring brain hemodynamics and has the potential to improve diagnostics and treatment selections. We applied MRI-based perfusion and oxygenation-sensitive imaging in ICAS with the hypothesis that the sensitivity to hemodynamic impairments will improve within individual watershed areas (iWSA). We studied cerebral blood flow (CBF), cerebrovascular reactivity (CVR), relative cerebral blood volume (rCBV), relative oxygen extraction fraction (rOEF), oxygen extraction capacity (OEC) and capillary transit-time heterogeneity (CTH) in 29 patients with asymptomatic, unilateral ICAS (age 70.3 ± 7.0 y) and 30 age-matched healthy controls. In ICAS, we found significant impairments of CBF, CVR, rCBV, OEC, and CTH (strongest lateralization ΔCVR = -24%), but not of rOEF. Although the spatial overlap of compromised hemodynamic parameters within each patient varied in a complex manner, most pronounced changes of CBF, CVR and rCBV were detected within iWSAs (strongest effect ΔCVR = +117%). At the same time, CTH impairments were iWSA independent, indicating widespread dysfunction of capillary-level oxygen diffusivity. In summary, complementary MRI-based perfusion and oxygenation parameters offer deeper perspectives on complex microvascular impairments in individual patients. Furthermore, knowledge about iWSAs improves the sensitivity to hemodynamic impairments.
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Affiliation(s)
- Stephan Kaczmarz
- Department of Neuroradiology, School of Medicine, Technical University of Munich (TUM), Munich, Germany.,TUM Neuroimaging Center (TUM-NIC), Technical University of Munich (TUM), Munich, Germany.,MRRC, Yale University, New Haven, CT, USA
| | - Jens Göttler
- Department of Neuroradiology, School of Medicine, Technical University of Munich (TUM), Munich, Germany.,TUM Neuroimaging Center (TUM-NIC), Technical University of Munich (TUM), Munich, Germany.,MRRC, Yale University, New Haven, CT, USA.,Department of Radiology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Jan Petr
- PET Center, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Mikkel Bo Hansen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Kim Mouridsen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Claus Zimmer
- Department of Neuroradiology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | | | - Christine Preibisch
- Department of Neuroradiology, School of Medicine, Technical University of Munich (TUM), Munich, Germany.,TUM Neuroimaging Center (TUM-NIC), Technical University of Munich (TUM), Munich, Germany.,Clinic for Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
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16
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Erdener ŞE, Tang J, Kılıç K, Postnov D, Giblin JT, Kura S, Chen ICA, Vayisoğlu T, Sakadžić S, Schaffer CB, Boas DA. Dynamic capillary stalls in reperfused ischemic penumbra contribute to injury: A hyperacute role for neutrophils in persistent traffic jams. J Cereb Blood Flow Metab 2021; 41:236-252. [PMID: 32237951 PMCID: PMC8370003 DOI: 10.1177/0271678x20914179] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ever since the introduction of thrombolysis and the subsequent expansion of endovascular treatments for acute ischemic stroke, it remains to be identified why the actual outcomes are less favorable despite recanalization. Here, by high spatio-temporal resolution imaging of capillary circulation in mice, we introduce the pathological phenomenon of dynamic flow stalls in cerebral capillaries, occurring persistently in salvageable penumbra after reperfusion. These stalls, which are different from permanent cellular plugs of no-reflow, were temporarily and repetitively occurring in the capillary network, impairing the overall circulation like small focal traffic jams. In vivo microscopy in the ischemic penumbra revealed leukocytes traveling slowly through capillary lumen or getting stuck, while red blood cell flow was being disturbed in the neighboring segments under reperfused conditions. Stall dynamics could be modulated, by injection of an anti-Ly6G antibody specifically targeting neutrophils. Decreased number and duration of stalls were associated with improvement in penumbral blood flow within 2-24 h after reperfusion along with increased capillary oxygenation, decreased cellular damage and improved functional outcome. Thereby, dynamic microcirculatory stall phenomenon can be a contributing factor to ongoing penumbral injury and is a potential hyperacute mechanism adding on previous observations of detrimental effects of activated neutrophils in ischemic stroke.
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Affiliation(s)
- Şefik E Erdener
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jianbo Tang
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kıvılcım Kılıç
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Dmitry Postnov
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Institute of Biomedical Sciences, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - John T Giblin
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - I-Chun A Chen
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Tuğberk Vayisoğlu
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sava Sakadžić
- Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
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17
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Østergaard L. Blood flow, capillary transit times, and tissue oxygenation: the centennial of capillary recruitment. J Appl Physiol (1985) 2020; 129:1413-1421. [PMID: 33031017 DOI: 10.1152/japplphysiol.00537.2020] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The transport of oxygen between blood and tissue is limited by blood's capillary transit time, understood as the time available for diffusion exchange before blood returns to the heart. If all capillaries contribute equally to tissue oxygenation at all times, this physical limitation would render vasodilation and increased blood flow insufficient means to meet increased metabolic demands in the heart, muscle, and other organs. In 1920, Danish physiologist August Krogh was awarded the Nobel Prize in Physiology or Medicine for his mathematical and quantitative, experimental demonstration of a solution to this conceptual problem: capillary recruitment, the active opening of previously closed capillaries to meet metabolic demands. Today, capillary recruitment is still mentioned in textbooks. When we suspect symptoms might represent hypoxia of a vascular origin, however, we search for relevant, flow-limiting conditions in our patients and rarely ascribe hypoxia or hypoxemia to short capillary transit times. This review describes how natural changes in capillary transit-time heterogeneity (CTH) and capillary hematocrit (HCT) across open capillaries during blood flow increases can account for a match of oxygen availability to metabolic demands in normal tissue. CTH and HCT depend on a number of factors: on blood properties, including plasma viscosity, the number, size, and deformability of blood cells, and blood cell interactions with capillary endothelium; on anatomical factors including glycocalyx, endothelial cells, basement membrane, and pericytes that affect the capillary diameter; and on any external compression. The review describes how risk factor- and disease-related changes in CTH and HCT interfere with flow-metabolism coupling and tissue oxygenation and discusses whether such capillary dysfunction contributes to vascular disease pathology.
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Affiliation(s)
- Leif Østergaard
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Neuroradiology Research Unit, Section of Neuroradiology, Department of Radiology, Aarhus University Hospital, Aarhus, Denmark
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18
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Nielsen RB, Parbo P, Ismail R, Dalby R, Tietze A, Brændgaard H, Gottrup H, Brooks DJ, Østergaard L, Eskildsen SF. Impaired perfusion and capillary dysfunction in prodromal Alzheimer's disease. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12032. [PMID: 32490139 PMCID: PMC7241262 DOI: 10.1002/dad2.12032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Cardiovascular disease increases the risk of developing Alzheimer's disease (AD), and growing evidence suggests an involvement of cerebrovascular pathology in AD. Capillary dysfunction, a condition in which capillary flow disturbances rather than arterial blood supply limit brain oxygen extraction, could represent an overlooked vascular contributor to neurodegeneration. We examined whether cortical capillary transit-time heterogeneity (CTH), an index of capillary dysfunction, is elevated in amyloid-positive patients with mild cognitive impairment (prodromal AD [pAD]). METHODS We performed structural and perfusion weighted MRI in 22 pAD patients and 21 healthy controls. RESULTS We found hypoperfusion, reduced blood volume, and elevated CTH in the parietal and frontal cortices of pAD-patients compared to controls, while only the precuneus showed focal cortical atrophy. DISCUSSION We propose that microvascular flow disturbances antedate cortical atrophy and may limit local tissue oxygenation in pAD. We speculate that capillary dysfunction contributes to the development of neurodegeneration in AD.
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Affiliation(s)
- Rune B. Nielsen
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
| | - Peter Parbo
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
| | - Rola Ismail
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
| | - Rikke Dalby
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
- Department of NeuroradiologyAarhus University HospitalAarhusDenmark
| | - Anna Tietze
- Charité, UniversitätsmedizinInstitute of NeuroradiologyBerlinGermany
| | - Hans Brændgaard
- Dementia ClinicDepartment of NeurologyAarhus University HospitalAarhusDenmark
| | - Hanne Gottrup
- Dementia ClinicDepartment of NeurologyAarhus University HospitalAarhusDenmark
| | - David J. Brooks
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
- Division of NeuroscienceDepartment of MedicineImperial College LondonLondonUK
- Division of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Leif Østergaard
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
- Department of Nuclear Medicine and PET CentreAarhus University HospitalAarhusDenmark
| | - Simon F. Eskildsen
- Center of Functionally Integrative NeuroscienceAarhus UniversityAarhusDenmark
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19
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Dalby RB, Eskildsen SF, Videbech P, Frandsen J, Mouridsen K, Sørensen L, Jeppesen P, Bek T, Rosenberg R, Østergaard L. Oxygenation differs among white matter hyperintensities, intersected fiber tracts and unaffected white matter. Brain Commun 2019; 1:fcz033. [PMID: 32954272 PMCID: PMC7425421 DOI: 10.1093/braincomms/fcz033] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 08/27/2019] [Accepted: 10/01/2019] [Indexed: 01/15/2023] Open
Abstract
White matter hyperintensities of presumed vascular origin are frequently observed on magnetic resonance imaging in normal aging. They are typically found in cerebral small vessel disease and suspected culprits in the etiology of complex age- and small vessel disease-related conditions, such as late-onset depression. White matter hyperintensities may interfere with surrounding white matter metabolic demands by disrupting fiber tract integrity. Meanwhile, risk factors for small vessel disease are thought to reduce tissue oxygenation, not only by reducing regional blood supply, but also by impairing capillary function. To address white matter oxygen supply–demand balance, we estimated voxel-wise capillary density as an index of resting white matter metabolism, and combined estimates of blood supply and capillary function to calculate white matter oxygen availability. We conducted a cross-sectional study with structural, perfusion- and diffusion-weighted magnetic resonance imaging in 21 patients with late-onset depression and 21 controls. We outlined white matter hyperintensities and used tractography to identify the tracts they intersect. Perfusion data comprised cerebral blood flow, blood volume, mean transit time and relative transit time heterogeneity—the latter a marker of capillary dysfunction. Based on these, white matter oxygenation was calculated as the steady state cerebral metabolic rate of oxygen under the assumption of normal tissue oxygen tension and vice versa. The number, volume and perfusion characteristics of white matter hyperintensities did not differ significantly between groups. Hemodynamic data showed white matter hyperintensities to have lower blood flow and blood volume, but higher relative transit time heterogeneity, than normal-appearing white matter, resulting in either reduced capillary metabolic rate of oxygen or oxygen tension. Intersected tracts showed significantly lower blood flow, blood volume and capillary metabolic rate of oxygen than normal-appearing white matter. Across groups, lower lesion oxygen tension was associated with higher lesion number and volume. Compared with normal-appearing white matter, tissue oxygenation is significantly reduced in white matter hyperintensities as well as the fiber tracts they intersect, independent of parallel late-onset depression. In white matter hyperintensities, reduced microvascular blood volume and concomitant capillary dysfunction indicate a severe oxygen supply–demand imbalance with hypoxic tissue injury. In intersected fiber tracts, parallel reductions in oxygenation and microvascular blood volume are consistent with adaptations to reduced metabolic demands. We speculate, that aging and vascular risk factors impair white matter hyperintensity perfusion and capillary function to create hypoxic tissue injury, which in turn affect the function and metabolic demands of the white matter tracts they disrupt.
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Affiliation(s)
- Rikke B Dalby
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark.,Centre for Psychiatric Research, Aarhus University Hospital, 8340 Risskov, Denmark.,Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Simon F Eskildsen
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark
| | - Poul Videbech
- Center for Neuropsychiatric Depression Research, Mental Health Center Glostrup, 2600 Glostrup, Denmark
| | - Jesper Frandsen
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark
| | - Kim Mouridsen
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark
| | - Leif Sørensen
- Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Peter Jeppesen
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N., Denmark
| | - Raben Rosenberg
- Centre of Psychiatry Amager, Mental Health Services in the Capital Region of Denmark, 2300 Copenhagen S., Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience & MINDLab, Aarhus University Hospital, 8200 Aarhus C., Denmark.,Department of Neuroradiology, Aarhus University Hospital, 8200 Aarhus N., Denmark
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20
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Affiliation(s)
- Turgay Dalkara
- From the Department of Neurology, Faculty of Medicine and Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey; and Department of Radiology, Massachusetts General Hospital, Harvard University, Boston
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21
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Erdener ŞE, Dalkara T. Small Vessels Are a Big Problem in Neurodegeneration and Neuroprotection. Front Neurol 2019; 10:889. [PMID: 31474933 PMCID: PMC6707104 DOI: 10.3389/fneur.2019.00889] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/01/2019] [Indexed: 12/11/2022] Open
Abstract
The cerebral microcirculation holds a critical position to match the high metabolic demand by neuronal activity. Functionally, microcirculation is virtually inseparable from other nervous system cells under both physiological and pathological conditions. For successful bench-to-bedside translation of neuroprotection research, the role of microcirculation in acute and chronic neurodegenerative disorders appears to be under-recognized, which may have contributed to clinical trial failures with some neuroprotectants. Increasing data over the last decade suggest that microcirculatory impairments such as endothelial or pericyte dysfunction, morphological irregularities in capillaries or frequent dynamic stalls in blood cell flux resulting in excessive heterogeneity in capillary transit may significantly compromise tissue oxygen availability. We now know that ischemia-induced persistent abnormalities in capillary flow negatively impact restoration of reperfusion after recanalization of occluded cerebral arteries. Similarly, microcirculatory impairments can accompany or even precede neural loss in animal models of several neurodegenerative disorders including Alzheimer's disease. Macrovessels are relatively easy to evaluate with radiological or experimental imaging methods but they cannot faithfully reflect the downstream microcirculatory disturbances, which may be quite heterogeneous across the tissue at microscopic scale and/or happen fast and transiently. The complexity and size of the elements of microcirculation, therefore, require utilization of cutting-edge imaging techniques with high spatiotemporal resolution as well as multidisciplinary team effort to disclose microvascular-neurodegenerative connection and to test treatment approaches to advance the field. Developments in two photon microscopy, ultrafast ultrasound, and optical coherence tomography provide valuable experimental tools to reveal those microscopic events with high resolution. Here, we review the up-to-date advances in understanding of the primary microcirculatory abnormalities that can result in neurodegenerative processes and the combined neurovascular protection approaches that can prevent acute as well as chronic neurodegeneration.
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Affiliation(s)
- Şefik Evren Erdener
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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22
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Quantifying effects of radiotherapy-induced microvascular injury; review of established and emerging brain MRI techniques. Radiother Oncol 2019; 140:41-53. [PMID: 31176207 DOI: 10.1016/j.radonc.2019.05.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 12/17/2022]
Abstract
Microvascular changes are increasingly recognised not only as primary drivers of radiotherapy treatment response in brain tumours, but also as an important contributor to short- and long-term (cognitive) side effects arising from irradiation of otherwise healthy brain tissue. As overall survival of patients with brain tumours is increasing, monitoring long-term sequels of radiotherapy-induced microvascular changes in the context of their potential predictive power for outcome, such as cognitive disability, has become increasingly relevant. Ideally, radiotherapy-induced significant microvascular changes in otherwise healthy brain tissue should be identified as early as possible to facilitate adaptive radiotherapy and to proactively start treatment to minimise the influence on these side-effects on the final outcome. Although MRI is already known to be able to detect significant long-term radiotherapy induced microvascular effects, more recently advanced MR imaging biomarkers reflecting microvascular integrity and function have been reported and might provide a more accurate and earlier detection of microvascular changes. However, the use and validation of both established and new techniques in the context of monitoring early and late radiotherapy-induced microvascular changes in both target-tissue and healthy tissue currently are minimal at best. This review aims to summarise the performance and limitations of existing methods and future opportunities for detection and quantification of radiotherapy-induced microvascular changes, as well as the relation of these findings with key clinical parameters.
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23
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Increased volumes of mildly elevated capillary transit time heterogeneity positively predict favorable outcome and negatively predict intracranial hemorrhage in acute ischemic stroke with large vessel occlusion. Eur Radiol 2019; 29:3523-3532. [DOI: 10.1007/s00330-019-06064-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/05/2019] [Accepted: 02/04/2019] [Indexed: 01/11/2023]
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24
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Anzabi M, Angleys H, Aamand R, Ardalan M, Mouridsen K, Rasmussen PM, Sørensen JCH, Plesnila N, Østergaard L, Iversen NK. Capillary flow disturbances after experimental subarachnoid hemorrhage: A contributor to delayed cerebral ischemia? Microcirculation 2019; 26:e12516. [DOI: 10.1111/micc.12516] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/21/2018] [Accepted: 11/12/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Maryam Anzabi
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
| | - Hugo Angleys
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
| | - Rasmus Aamand
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
| | - Maryam Ardalan
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
- Department of Clinical Medicine; Translational Neuropsychiatry Unit; Aarhus University; Aarhus Denmark
| | - Kim Mouridsen
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
| | - Peter Mondrup Rasmussen
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
| | | | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD); University of Munich Medical Center; Munich Germany
| | - Leif Østergaard
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
- Department of Neuroradiology; Aarhus University Hospital; Aarhus Denmark
| | - Nina Kerting Iversen
- Department of Clinical Medicine; Center of Functionally Integrative Neuroscience (CFIN); Aarhus University; Aarhus Denmark
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Abstract
Recent stroke research has shifted the focus to the microvasculature from neuron-centric views. It is increasingly recognized that a successful neuroprotection is not feasible without microvascular protection. On the other hand, recent studies on pericytes, long-neglected cells on microvessels have provided insight into the regulation of microcirculation. Pericytes play an essential role in matching the metabolic demand of nervous tissue with the blood flow in addition to regulating the development and maintenance of the blood-brain barrier (BBB), leukocyte trafficking across the BBB and angiogenesis. Pericytes appears to be highly vulnerable to injury. Ischemic injury to pericytes on cerebral microvasculature unfavorably impacts the stroke-induced tissue damage and brain edema by disrupting microvascular blood flow and BBB integrity. Strongly supporting this, clinical imaging studies show that tissue reperfusion is not always obtained after recanalization. Therefore, prevention of pericyte dysfunction may improve the outcome of recanalization therapies by promoting microcirculatory reperfusion and preventing hemorrhage and edema. In the peri-infarct tissue, pericytes are detached from microvessels and promote angiogenesis and neurogenesis, and hence positively effect stroke outcome. Expectedly, we will learn more about the place of pericytes in CNS pathologies including stroke and devise approaches to treat them in the next decades.
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Debette S, Strbian D, Wardlaw JM, van der Worp HB, Rinkel GJE, Caso V, Dichgans M. Fourth European stroke science workshop. Eur Stroke J 2018; 3:206-219. [PMID: 31009021 PMCID: PMC6453207 DOI: 10.1177/2396987318774443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 03/23/2018] [Indexed: 12/15/2022] Open
Abstract
Lake Eibsee, Garmisch-Partenkirchen, 16 to 18 November, 2017: The European Stroke Organisation convened >120 stroke experts from 21 countries to discuss latest results and hot topics in clinical, translational and basic stroke research. Since its inception in 2011, the European Stroke Science Workshop has become a cornerstone of European Stroke Organisation's academic activities and a major highlight for researchers in the field. Participants include stroke researchers at all career stages and with different backgrounds, who convene for plenary lectures and discussions. The workshop was organised in seven scientific sessions focusing on the following topics: (1) acute stroke treatment and endovascular therapy; (2) small vessel disease; (3) opportunities for stroke research in the omics era; (4) vascular cognitive impairment; (5) intracerebral and subarachnoid haemorrhage; (6) alternative treatment concepts and (7) neural circuits, recovery and rehabilitation. All sessions started with a keynote lecture providing an overview on current developments, followed by focused talks on a timely topic with the most recent findings, including unpublished data. In the following, we summarise the key contents of the meeting. The program is provided in the online only Data Supplement. The workshop started with a key note lecture on how to improve the efficiency of clinical trial endpoints in stroke, which was delivered by Craig Anderson (Sydney, Australia) and set the scene for the following discussions.
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Affiliation(s)
- S Debette
- Inserm Centre Bordeaux Population Health (U1219), University of Bordeaux, Bordeaux, France
- Department of Neurology, Bordeaux University Hospital, Bordeaux, France
| | - D Strbian
- Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland
| | - JM Wardlaw
- Centre for Clinical Brain Sciences, and UK Dementia Research Institute at the University of Edinburgh, University of Edinburgh, Edinburgh, UK
| | - HB van der Worp
- Department of Neurology and neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands
| | - GJE Rinkel
- Department of Neurology and neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands
| | - V Caso
- Stroke Unit and Division of Cardiovascular Medicine, University of Perugia, Perugia, Italy
| | - M Dichgans
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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27
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Arsava EM, Hansen MB, Kaplan B, Peker A, Gocmen R, Arat A, Oguz KK, Topcuoglu MA, Østergaard L, Dalkara T. The effect of carotid artery stenting on capillary transit time heterogeneity in patients with carotid artery stenosis. Eur Stroke J 2018; 3:263-271. [PMID: 31008357 DOI: 10.1177/2396987318772686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/01/2018] [Indexed: 11/17/2022] Open
Abstract
Introduction Carotid revascularisation improves haemodynamic compromise in cerebral circulation as an additional benefit to the primary goal of reducing future thromboembolic risk. We determined the effect of carotid artery stenting on cerebral perfusion and oxygenation using a perfusion-weighted MRI algorithm that is based on assessment of capillary transit-time heterogeneity together with other perfusion and metabolism-related metrics. Patients and methods A consecutive series of 33 patients were evaluated by dynamic susceptibility contrast perfusion-weighted MRI prior to and within 24 h of the endovascular procedure. The level of relative change induced by stenting, and relationship of these changes with respect to baseline stenosis degree were analysed. Results Stenting led to significant increase in cerebral blood flow (p < 0.001), and decrease in cerebral blood volume (p = 0.001) and mean transit time (p < 0.001); this was accompanied by reduction in oxygen extraction fraction (p < 0.001) and capillary transit-time heterogeneity (p < 0.001), but an overall increase in relative capillary transit-time heterogeneity (RTH: CTH divided by MTT; p = 0.008). No significant change was observed with respect to cerebral metabolic rate of oxygen. The median volume of tissue with MTT > 2s decreased from 24 ml to 12 ml (p = 0.009), with CTH > 2s from 29 ml to 19 ml (p = 0.041), and with RTH < 0.9 from 61 ml to 39 ml (p = 0.037) following stenting. These changes were correlated with the baseline degree of stenosis.Discussion: Stenting improved the moderate stage of haemodynamic compromise at baseline in our cohort. The decreased relative transit-time heterogeneity, which increases following stenting, is probably a reflection of decreased functional capillary density secondary to chronic hypoperfusion induced by the proximal stenosis.Conclusion: Carotid artery stenting, is not only important for prophylaxis of future vascular events, but also is critical for restoration of microvascular function in the cerebral tissue.
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Affiliation(s)
- Ethem M Arsava
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey
| | - Mikkel B Hansen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience, Aarhus University, Denmark
| | - Berkan Kaplan
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey
| | - Ahmet Peker
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Rahsan Gocmen
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Anil Arat
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Kader K Oguz
- Department of Radiology, Faculty of Medicine, Hacettepe University, Turkey
| | - Mehmet A Topcuoglu
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey
| | - Leif Østergaard
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience, Aarhus University, Denmark.,Department of Neuroradiology, Aarhus University Hospital, Denmark
| | - Turgay Dalkara
- Department of Neurology, Faculty of Medicine, Hacettepe University, Turkey.,Institute of Neurological Sciences and Psychiatry, Hacettepe University, Turkey
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