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Berhouma M, Eker OF, Dailler F, Rheims S, Balanca B. Cortical Spreading Depolarizations in Aneurysmal Subarachnoid Hemorrhage: An Overview of Current Knowledge and Future Perspectives. Adv Tech Stand Neurosurg 2022; 45:229-244. [PMID: 35976452 DOI: 10.1007/978-3-030-99166-1_7] [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] [Indexed: 06/15/2023]
Abstract
Despite significant advances in the management of aneurysmal subarachnoid hemorrhage (SAH), morbidity and mortality remain devastating particularly for high-grade SAH. Poor functional outcome usually results from delayed cerebral ischemia (DCI). The pathogenesis of DCI during aneurysmal SAH has historically been attributed to cerebral vasospasm, but spreading depolarizations (SDs) are now considered to play a central role in DCI. During SAH, SDs may produce an inverse hemodynamic response leading to spreading ischemia. Several animal models have contributed to a better understanding of the pathogenesis of SDs during aneurysmal SAH and provided new therapeutic approaches including N-methyl-D-aspartate receptor antagonists and phosphodiesterase inhibitors. Herein we review the current knowledge in the field of SDs' pathogenesis and we detail the key experimental and clinical studies that have opened interesting new therapeutic approaches to prevent DCI in aneurysmal SAH.
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Affiliation(s)
- Moncef Berhouma
- Department of Neurosurgical Oncology and Vascular Neurosurgery, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France.
- Creatis Lab, CNRS UMR 5220, INSERM U1206, Lyon 1 University, INSA Lyon, Lyon, France.
| | - Omer Faruk Eker
- Creatis Lab, CNRS UMR 5220, INSERM U1206, Lyon 1 University, INSA Lyon, Lyon, France
- Department of Interventional Neuroradiology, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
| | - Frederic Dailler
- Department of Neuro-Anesthesia and Neuro-Critical Care, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
| | - Sylvain Rheims
- Department of Functional Neurology and Epileptology, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
- Lyon's Neurosciences Research Center, INSERM U1028/CNRS, UMR 5292, University of Lyon, Lyon, France
| | - Baptiste Balanca
- Department of Neuro-Anesthesia and Neuro-Critical Care, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
- Lyon's Neurosciences Research Center, INSERM U1028/CNRS, UMR 5292, University of Lyon, Lyon, France
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2
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Lidington D, Wan H, Bolz SS. Cerebral Autoregulation in Subarachnoid Hemorrhage. Front Neurol 2021; 12:688362. [PMID: 34367053 PMCID: PMC8342764 DOI: 10.3389/fneur.2021.688362] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/25/2021] [Indexed: 12/28/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is a devastating stroke subtype with a high rate of mortality and morbidity. The poor clinical outcome can be attributed to the biphasic course of the disease: even if the patient survives the initial bleeding emergency, delayed cerebral ischemia (DCI) frequently follows within 2 weeks time and levies additional serious brain injury. Current therapeutic interventions do not specifically target the microvascular dysfunction underlying the ischemic event and as a consequence, provide only modest improvement in clinical outcome. SAH perturbs an extensive number of microvascular processes, including the “automated” control of cerebral perfusion, termed “cerebral autoregulation.” Recent evidence suggests that disrupted cerebral autoregulation is an important aspect of SAH-induced brain injury. This review presents the key clinical aspects of cerebral autoregulation and its disruption in SAH: it provides a mechanistic overview of cerebral autoregulation, describes current clinical methods for measuring autoregulation in SAH patients and reviews current and emerging therapeutic options for SAH patients. Recent advancements should fuel optimism that microvascular dysfunction and cerebral autoregulation can be rectified in SAH patients.
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Affiliation(s)
- Darcy Lidington
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto Centre for Microvascular Medicine at the Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Toronto, ON, Canada
| | - Hoyee Wan
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto Centre for Microvascular Medicine at the Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Toronto, ON, Canada
| | - Steffen-Sebastian Bolz
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto Centre for Microvascular Medicine at the Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Toronto, ON, Canada.,Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, ON, Canada
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3
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Balbi M, Vega MJ, Lourbopoulos A, Terpolilli NA, Plesnila N. Long-term impairment of neurovascular coupling following experimental subarachnoid hemorrhage. J Cereb Blood Flow Metab 2020; 40:1193-1202. [PMID: 31296132 PMCID: PMC7238370 DOI: 10.1177/0271678x19863021] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CO2-reactivity and neurovascular coupling are sequentially lost within the first 24 h after subarachnoid hemorrhage (SAH). Whether and when these impairments recover is not known. Therefore, we investigated the reactivity of pial and intraparenchymal vessels by in vivo two-photon microscopy one month after experimental SAH. C57BL/6 mice were subjected to either sham surgery or SAH by filament perforation. One month later, cerebral blood flow following CO2-challenge and forepaw stimulation was assessed by laser Doppler fluxmetry. Diameters of pial and intraparenchymal arterioles were quantified by in vivo two-photon microscopy. One month after SAH, pial and parenchymal vessels dilated in response to CO2. Neurovascular coupling was almost completely absent after SAH: vessel diameter did not change upon forepaw stimulation compared to a 20% increase in sham-operated mice. The current results demonstrate that neurovascular function differentially recovers after SAH: while CO2-reactivity normalizes within one month after SAH, neurovascular coupling is still absent. These findings show an acute and persistent loss of neurovascular coupling after SAH that may serve as a link between early brain injury and delayed cerebral ischemia, two distinct pathophysiological phenomena after SAH that were so far believed not to be directly related.
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Affiliation(s)
- Matilde Balbi
- Institute for Stroke and Dementia Research (ISD), Munich University Hospital, Munich, Germany.,Graduate School of Systemic Neurosciences (GSN), Munich University Hospital, Munich, Germany.,Munich Cluster of Systems Neurology (Synergy), Munich, Germany
| | - Max Jativa Vega
- Graduate School of Systemic Neurosciences (GSN), Munich University Hospital, Munich, Germany
| | - Athanasios Lourbopoulos
- Institute for Stroke and Dementia Research (ISD), Munich University Hospital, Munich, Germany.,Munich Cluster of Systems Neurology (Synergy), Munich, Germany
| | - Nicole A Terpolilli
- Institute for Stroke and Dementia Research (ISD), Munich University Hospital, Munich, Germany.,Munich Cluster of Systems Neurology (Synergy), Munich, Germany.,Department of Neurosurgery, Munich University Hospital, Munich, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD), Munich University Hospital, Munich, Germany.,Graduate School of Systemic Neurosciences (GSN), Munich University Hospital, Munich, Germany.,Munich Cluster of Systems Neurology (Synergy), Munich, Germany
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Ashayeri Ahmadabad R, Khaleghi Ghadiri M, Gorji A. The role of Toll-like receptor signaling pathways in cerebrovascular disorders: the impact of spreading depolarization. J Neuroinflammation 2020; 17:108. [PMID: 32264928 PMCID: PMC7140571 DOI: 10.1186/s12974-020-01785-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/24/2020] [Indexed: 02/08/2023] Open
Abstract
Cerebral vascular diseases (CVDs) are a group of disorders that affect the blood supply to the brain and lead to the reduction of oxygen and glucose supply to the neurons and the supporting cells. Spreading depolarization (SD), a propagating wave of neuroglial depolarization, occurs in different CVDs. A growing amount of evidence suggests that the inflammatory responses following hypoxic-ischemic insults and after SD plays a double-edged role in brain tissue injury and clinical outcome; a beneficial effect in the acute phase and a destructive role in the late phase. Toll-like receptors (TLRs) play a crucial role in the activation of inflammatory cascades and subsequent neuroprotective or harmful effects after CVDs and SD. Here, we review current data regarding the pathophysiological role of TLR signaling pathways in different CVDs and discuss the role of SD in the potentiation of the inflammatory cascade in CVDs through the modulation of TLRs.
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Affiliation(s)
- Rezan Ashayeri Ahmadabad
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | | | - Ali Gorji
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran.
- Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Department of Neurology, Westfälische Wilhelms-Universität Münster, Münster, Germany.
- Neuroscience research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
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Abstract
Cortical spreading depolarizations (SD) are strongly associated with worse tissue injury and clinical outcomes in the setting of aneurysmal subarachnoid hemorrhage (SAH). Animal studies have suggested a causal relationship, and new therapies to target SDs are starting to be tested in clinical studies. A recent set of single-center randomized trials assessed the effect of the phosphodiesterase inhibitor cilostazol in patients with SAH. Cilostazol led to improved functional outcomes and SD-related metrics in treated patients through a putative mechanism of improved cerebral blood flow. Another promising therapeutic approach includes attempts to block SDs with, for example, the NMDA receptor antagonist ketamine. SDs have emerged not only as a therapeutic target but also as a potentially useful biomarker for brain injury following SAH. Additional clinical and preclinical experimental work is greatly needed to assess the generalizability of existing therapeutic trials and to better delineate the relationship between SDs, SAH, and functional outcome.
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Affiliation(s)
- Kazutaka Sugimoto
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, 6403, Charlestown, MA, 02129, USA
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - David Y Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, 6403, Charlestown, MA, 02129, USA.
- Division of Neurocritical Care, Department of Neurology, Boston Medical Center, Boston, MA, USA.
- Division of Neurocritical Care, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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Marinesco S, Ungvari Z, Galvan V. Age-related impairment of metabovascular coupling during cortical spreading depolarizations. Am J Physiol Heart Circ Physiol 2017; 313:H1209-H1212. [PMID: 28842440 PMCID: PMC5814652 DOI: 10.1152/ajpheart.00514.2017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 11/22/2022]
Affiliation(s)
- Stephane Marinesco
- Lyon Neuroscience Research Center, Team TIGER and AniRA-Neurochem Technological Platform, INSERM U1028, CNRS UMR5292, University Claude Bernard Lyon I, Lyon, France
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma
| | - Veronica Galvan
- Barshop Institute for Longevity and Aging Studies and Department of Cellular and Integrative Physiology, University of Texas Health San Antonio , San Antonio, Texas
- South Texas Veterans Health Care System and Geriatric Research Education and Clinical Center, United States Department of Veterans Affairs , San Antonio, Texas
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Helbok R, Kofler M, Schiefecker AJ, Gaasch M, Rass V, Pfausler B, Beer R, Schmutzhard E. Clinical Use of Cerebral Microdialysis in Patients with Aneurysmal Subarachnoid Hemorrhage-State of the Art. Front Neurol 2017; 8:565. [PMID: 29163332 PMCID: PMC5676489 DOI: 10.3389/fneur.2017.00565] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 10/09/2017] [Indexed: 01/04/2023] Open
Abstract
Objective To review the published literature on the clinical application of cerebral microdialysis (CMD) in aneurysmal subarachnoid hemorrhage (SAH) patients and to summarize the evidence relating cerebral metabolism to pathophysiology, secondary brain injury, and outcome. Methods Study selection: Two reviewers identified all manuscripts reporting on the clinical use of CMD in aneurysmal SAH patients from MEDLINE. All identified studies were grouped according to their focus on brain metabolic changes during the early and subacute phase after SAH, their association with mechanisms of secondary brain injury and outcome. Results The review demonstrated: (1) limited literature is available in the very early phase before the aneurysm is secured. (2) Brain metabolic changes related to early and delayed secondary injury mechanisms may be used in addition to other neuromonitoring parameters in the critical care management of SAH patients. (3) CMD markers of ischemia may detect delayed cerebral ischemia early (up to 16 h before onset), underlining the importance of trend analysis. (4) Various CMD-derived parameters may be associated with patient outcome at 3–12 months, including CMD-lactate-to-pyruvate-ratio, CMD-glucose, and CMD-glutamate. Conclusion The clinical use of CMD is an emerging area in the literature of aneurysmal SAH patients. Larger prospective multi-center studies on interventions based on CMD findings are needed.
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Affiliation(s)
- Raimund Helbok
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Mario Kofler
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Alois Josef Schiefecker
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Maxime Gaasch
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Verena Rass
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Bettina Pfausler
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ronny Beer
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Erich Schmutzhard
- Neurological Intensive Care Unit, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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Johnson U, Engquist H, Howells T, Nilsson P, Ronne-Engström E, Lewén A, Rostami E, Enblad P. Bedside Xenon-CT Shows Lower CBF in SAH Patients with Impaired CBF Pressure Autoregulation as Defined by Pressure Reactivity Index (PRx). Neurocrit Care 2017; 25:47-55. [PMID: 26842717 DOI: 10.1007/s12028-016-0240-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Subarachnoid hemorrhage (SAH) is a disease with a high rate of unfavorable outcome, often related to delayed cerebral ischemia (DCI), i.e., ischemic injury that develops days-weeks after onset, with a multifactorial etiology. Disturbances in cerebral pressure autoregulation, the ability to maintain a steady cerebral blood flow (CBF), despite fluctuations in systemic blood pressure, have been suggested to play a role in the development of DCI. Pressure reactivity index (PRx) is a well-established measure of cerebral pressure autoregulation that has been used to study traumatic brain injury, but not extensively in SAH. OBJECTIVE To study the relation between PRx and CBF in SAH patients, and to examine if PRx can be used to predict DCI. METHODS Retrospective analysis of prospectively collected data. PRx was calculated as the correlation coefficient between mean arterial blood pressure (MABP) and intracranial pressure (ICP) in a 5 min moving window. CBF was measured using bedside Xenon-CT (Xe-CT). DCI was diagnosed clinically. RESULTS 47 poor-grade mechanically ventilated patients were studied. Patients with disturbed pressure autoregulation (high PRx values) had lower CBF, as measured by bedside Xe-CT; both in the early (day 0-3) and late (day 4-14) acute phase of the disease. PRx did not differ significantly between patients who developed DCI or not. CONCLUSION In mechanically ventilated and sedated SAH patients, high PRx (more disturbed CBF pressure autoregulation) is associated with low CBF, both day 0-3 and day 4-14 after onset. The role of PRx as a monitoring tool in SAH patients needs further studying.
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Affiliation(s)
- Ulf Johnson
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden. .,Department of Surgical Sciences/Radiology, Uppsala University, Uppsala, Sweden.
| | - Henrik Engquist
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden.,Department of Surgical Sciences/Anesthesia and Intensive Care, Uppsala University, Uppsala, Sweden
| | - Tim Howells
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Pelle Nilsson
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden
| | | | - Anders Lewén
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Elham Rostami
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Per Enblad
- Department of Neuroscience/Neurosurgery, Uppsala University, Uppsala, Sweden
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Toth P, Tarantini S, Csiszar A, Ungvari Z. Functional vascular contributions to cognitive impairment and dementia: mechanisms and consequences of cerebral autoregulatory dysfunction, endothelial impairment, and neurovascular uncoupling in aging. Am J Physiol Heart Circ Physiol 2017; 312:H1-H20. [PMID: 27793855 PMCID: PMC5283909 DOI: 10.1152/ajpheart.00581.2016] [Citation(s) in RCA: 320] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/10/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022]
Abstract
Increasing evidence from epidemiological, clinical and experimental studies indicate that age-related cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including Alzheimer's disease. Understanding and targeting the age-related pathophysiological mechanisms that underlie vascular contributions to cognitive impairment and dementia (VCID) are expected to have a major role in preserving brain health in older individuals. Maintenance of cerebral perfusion, protecting the microcirculation from high pressure-induced damage and moment-to-moment adjustment of regional oxygen and nutrient supply to changes in demand are prerequisites for the prevention of cerebral ischemia and neuronal dysfunction. This overview discusses age-related alterations in three main regulatory paradigms involved in the regulation of cerebral blood flow (CBF): cerebral autoregulation/myogenic constriction, endothelium-dependent vasomotor function, and neurovascular coupling responses responsible for functional hyperemia. The pathophysiological consequences of cerebral microvascular dysregulation in aging are explored, including blood-brain barrier disruption, neuroinflammation, exacerbation of neurodegeneration, development of cerebral microhemorrhages, microvascular rarefaction, and ischemic neuronal dysfunction and damage. Due to the widespread attention that VCID has captured in recent years, the evidence for the causal role of cerebral microvascular dysregulation in cognitive decline is critically examined.
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Affiliation(s)
- Peter Toth
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Pecs, Hungary; and
| | - Stefano Tarantini
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Anna Csiszar
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma;
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
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10
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Chung DY, Oka F, Ayata C. Spreading Depolarizations: A Therapeutic Target Against Delayed Cerebral Ischemia After Subarachnoid Hemorrhage. J Clin Neurophysiol 2016; 33:196-202. [PMID: 27258442 PMCID: PMC4894342 DOI: 10.1097/wnp.0000000000000275] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Delayed cerebral ischemia is the most feared cause of secondary injury progression after subarachnoid hemorrhage. Initially thought to be a direct consequence of large artery spasm and territorial ischemia, recent data suggests that delayed cerebral ischemia represents multiple concurrent and synergistic mechanisms, including microcirculatory dysfunction, inflammation, and microthrombosis. Among these mechanisms, spreading depolarizations (SDs) are arguably the most elusive and underappreciated in the clinical setting. Although SDs have been experimentally detected and examined since the late 1970s, their widespread occurrence in human brain was not unequivocally demonstrated until relatively recently. We now know that SDs occur with very high incidence in human brain after ischemic or hemorrhagic stroke and trauma, and worsen outcomes by increasing metabolic demand, decreasing blood supply, predisposing to seizure activity, and possibly worsening brain edema. In this review, we discuss the causes and consequences of SDs in injured brain. Although much of our mechanistic knowledge comes from experimental models of focal cerebral ischemia, clinical data suggest that the same principles apply regardless of the mode of injury (i.e., ischemia, hemorrhage, or trauma). The hope is that a better fundamental understanding of SDs will lead to novel therapeutic interventions to prevent SD occurrence and its adverse consequences contributing to injury progression in subarachnoid hemorrhage and other forms of acute brain injury.
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Affiliation(s)
- David Y. Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA
- Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Fumiaki Oka
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA
- Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology Massachusetts General Hospital, Harvard Medical School, Boston, MA
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Abstract
To determine the optimal use and indications of electroencephalography (EEG) in critical care management of acute brain injury (ABI). An electronic literature search was conducted for articles in English describing electrophysiological monitoring in ABI from January 1990 to August 2013. A total of 165 studies were included. EEG is a useful monitor for seizure and ischemia detection. There is a well-described role for EEG in convulsive status epilepticus and cardiac arrest (CA). Data suggest EEG should be considered in all patients with ABI and unexplained and persistent altered consciousness and in comatose intensive care unit (ICU) patients without an acute primary brain condition who have an unexplained impairment of mental status. There remain uncertainties about certain technical details, e.g., the minimum duration of EEG studies, the montage, and electrodes. Data obtained from both EEG and EP studies may help estimate prognosis in ABI patients, particularly following CA and traumatic brain injury. Data supporting these recommendations is sparse, and high quality studies are needed. EEG is used to monitor and detect seizures and ischemia in ICU patients and indications for EEG are clear for certain disease states, however, uncertainty remains on other applications.
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12
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Sarrafzadeh AS, Vajkoczy P, Bijlenga P, Schaller K. Monitoring in Neurointensive Care - The Challenge to Detect Delayed Cerebral Ischemia in High-Grade Aneurysmal SAH. Front Neurol 2014; 5:134. [PMID: 25101052 PMCID: PMC4104636 DOI: 10.3389/fneur.2014.00134] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 07/04/2014] [Indexed: 12/25/2022] Open
Abstract
Delayed cerebral ischemia (DCI) is a feared and significant medical complication following aneurysmal subarachnoid hemorrhage (aSAH). It occurs in about 30% of patients surviving the initial hemorrhage, mostly between days 4 and 10 after aSAH. Clinical deterioration attributable to DCI is a diagnosis of exclusion and especially difficult to diagnose in patients who are comatose or sedated. The latter are typically patients with a high grade on the World Federation of Neurosurgical Societies scale (WFNS grade 4-5), who represent approximately 40-70% of the patient population with ruptured aneurysms. In this group of patients, the incidence of DCI is often underestimated and higher when compared to low WFNS grade patients. To overcome difficulties in diagnosing DCI, which is especially relevant in sedated and comatose patients, the article reports the most recent recommendation for definition of DCI and discusses their advantages and problematic issues in neurocritical care practice. Finally, appropriate neuromonitoring techniques and their clinical impact in high-grade SAH patients are summarized.
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Affiliation(s)
- Asita S Sarrafzadeh
- Division of Neurosurgery, Geneva Neuroscience Center, Faculty of Medicine, University of Geneva , Geneva , Switzerland ; Department of Neurosurgery, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Philippe Bijlenga
- Division of Neurosurgery, Geneva Neuroscience Center, Faculty of Medicine, University of Geneva , Geneva , Switzerland
| | - Karl Schaller
- Division of Neurosurgery, Geneva Neuroscience Center, Faculty of Medicine, University of Geneva , Geneva , Switzerland
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