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Wang X, Wang T, Jin J, Wang H, Li Y, Liu Z, Yin T. Anesthesia inhibited corticospinal excitability and attenuated the modulation of repetitive transcranial magnetic stimulation. BMC Anesthesiol 2022; 22:111. [PMID: 35439927 PMCID: PMC9016971 DOI: 10.1186/s12871-022-01655-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 04/11/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Lots of studies have measured motor evoked potential (MEP) induced by transcranial magnetic stimulation (TMS) in anesthetized animals. However, in awake animals, the measurement of TMS-induced MEP is scarce as lack of sufficient restraint. So far, the explicit study of anesthesia effects on corticospinal excitability and repetitive TMS (rTMS) induced modulation is still lacking. This study aimed to: (1) measure TMS-induced MEP in both awake restrained and anesthetized rats, (2) investigate the effect of anesthesia on corticospinal excitability, and (3) on rTMS-induced modulation. METHODS MEP of eighteen rats were measured under both wakefulness and anesthesia using flexible binding and surface electrodes. Peak-to-peak MEP amplitudes, resting motor threshold (RMT) and the slope of stimulus response (SR) were extracted to investigate anesthesia effects on corticospinal excitability. Thereafter, 5 or 10 Hz rTMS was applied with 600 pulses, and the increase in MEP amplitude and the decrease in RMT were used to quantify rTMS-induced modulation. RESULTS The RMT in the awake condition was 44.6 ± 1.2% maximum output (MO), the peak-to-peak MEP amplitude was 404.6 ± 48.8 μV at 60% MO. Under anesthesia, higher RMT (55.6 ± 2.9% MO), lower peak-to-peak MEP amplitudes (258.6 ± 32.7 μV) and lower slope of SR indicated that the corticospinal excitability was suppressed. Moreover, under anesthesia, high-frequency rTMS still showed significant modulation of corticospinal excitability, but the modulation of MEP peak-to-peak amplitudes was weaker than that under wakefulness. CONCLUSIONS This study measured TMS-induced MEP in both awake and anesthetized rats, and provided explicit evidence for the inhibitory effects of anesthesia on corticospinal excitability and on high-frequency rTMS-induced modulation of MEP.
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Affiliation(s)
- Xin Wang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Tengfei Wang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Jingna Jin
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - He Wang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Ying Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Zhipeng Liu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.
| | - Tao Yin
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China. .,Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China.
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DeMorrow S, Cudalbu C, Davies N, Jayakumar AR, Rose CF. 2021 ISHEN guidelines on animal models of hepatic encephalopathy. Liver Int 2021; 41:1474-1488. [PMID: 33900013 PMCID: PMC9812338 DOI: 10.1111/liv.14911] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/05/2021] [Accepted: 04/01/2021] [Indexed: 02/07/2023]
Abstract
This working group of the International Society of Hepatic Encephalopathy and Nitrogen Metabolism (ISHEN) was commissioned to summarize and update current efforts in the development and characterization of animal models of hepatic encephalopathy (HE). As defined in humans, HE in animal models is based on the underlying degree and severity of liver pathology. Although hyperammonemia remains the key focus in the pathogenesis of HE, other factors associated with HE have been identified, together with recommended animal models, to help explore the pathogenesis and pathophysiological mechanisms of HE. While numerous methods to induce liver failure and disease exist, less have been characterized with neurological and neurobehavioural impairments. Moreover, there still remains a paucity of adequate animal models of Type C HE induced by alcohol, viruses and non-alcoholic fatty liver disease; the most common etiologies of chronic liver disease.
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Affiliation(s)
- S DeMorrow
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Texas, USA; Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Texas, USA; Research division, Central Texas Veterans Healthcare System, Temple Texas USA.,Correspondance: Sharon DeMorrow, PhD, ; tel: +1-512-495-5779
| | - C Cudalbu
- Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - N Davies
- Institute for Liver and Digestive Health, University College London, Royal Free Campus, London, United Kingdom
| | - AR Jayakumar
- General Medical Research, Neuropathology Section, R&D Service and South Florida VA Foundation for Research and Education Inc; Obstetrics, Gynecology and Reproductive Sciences, University of Miami School of Medicine, Miami FL, USA
| | - CF Rose
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, Montreal, Canada
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Cudalbu C, Taylor-Robinson SD. Brain Edema in Chronic Hepatic Encephalopathy. J Clin Exp Hepatol 2019; 9:362-382. [PMID: 31360029 PMCID: PMC6637228 DOI: 10.1016/j.jceh.2019.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 01/15/2019] [Accepted: 02/06/2019] [Indexed: 02/07/2023] Open
Abstract
Brain edema is a common feature associated with hepatic encephalopathy (HE). In patients with acute HE, brain edema has been shown to play a crucial role in the associated neurological deterioration. In chronic HE, advanced magnetic resonance imaging (MRI) techniques have demonstrated that low-grade brain edema appears also to be an important pathological feature. This review explores the different methods used to measure brain edema ex vivo and in vivo in animal models and in humans with chronic HE. In addition, an in-depth description of the main studies performed to date is provided. The role of brain edema in the neurological alterations linked to HE and whether HE and brain edema are the manifestations of the same pathophysiological mechanism or two different cerebral manifestations of brain dysfunction in liver disease are still under debate. In vivo MRI/magnetic resonance spectroscopy studies have allowed insight into the development of brain edema in chronic HE. However, additional in vivo longitudinal and multiparametric/multimodal studies are required (in humans and animal models) to elucidate the relationship between liver function, brain metabolic changes, cellular changes, cell swelling, and neurological manifestations in chronic HE.
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Key Words
- 1H MRS, proton magnetic resonance spectroscopy
- ADC, apparent diffusion coefficient
- ALF, acute liver failure
- AQP, aquaporins
- BBB, blood-brain barrier
- BDL, bile duct ligation
- CNS, central nervous system
- CSF, cerebrospinal fluid
- Cr, creatine
- DTI, diffusion tensor imaging
- DWI, diffusion-weighted imaging
- FLAIR, fluid-attenuated inversion recovery
- GM, gray matter
- Gln, glutamine
- Glx, sum of glutamine and glutamate
- HE, hepatic encephalopathy
- Ins, inositol
- LPS, lipopolysaccharide
- Lac, lactate
- MD, mean diffusivity
- MRI, magnetic resonance imaging
- MRS, magnetic resonance spectroscopy
- MT, magnetization transfer
- MTR, MT ratio
- NMR, nuclear magnetic resonance
- PCA, portocaval anastomosis
- TE, echo time
- WM, white matter
- brain edema
- chronic hepatic encephalopathy
- in vivo magnetic resonance imaging
- in vivo magnetic resonance spectroscopy
- liver cirrhosis
- mIns, myo-inositol
- tCho, total choline
- tCr, total creatine
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Affiliation(s)
- Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Simon D. Taylor-Robinson
- Division of Integrative Systems Medicine and Digestive Disease, Department of Surgery and Cancer, St Mary's Hospital Campus, Imperial College London, London, United Kingdom
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García-Lezana T, Oria M, Romero-Giménez J, Bové J, Vila M, Genescà J, Chavarria L, Cordoba J. Cerebellar neurodegeneration in a new rat model of episodic hepatic encephalopathy. J Cereb Blood Flow Metab 2017; 37:927-937. [PMID: 27154504 PMCID: PMC5363476 DOI: 10.1177/0271678x16649196] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hepatic encephalopathy has traditionally been considered a reversible disorder. However, recent studies suggested that repeated episodes of hepatic encephalopathy cause persistent impairment leading to neuronal loss. The aims of our study were the development of a new animal model that reproduces the course of episodic hepatic encephalopathy and the identification of neurodegeneration evidences. Rats with portacaval anastomosis underwent simulated episodes of hepatic encephalopathy, triggered by the regular administration of ammonium acetate, and/or lipopolysaccharide. The neurological status was assessed and neuronal loss stereologically quantified in motor areas. During the simulated episodes, ammonia induced reversible motor impairment in portacaval anastomosis rats. In cerebellum, stereology showed a reduction in Purkinje cell population in portacaval anastomosis and PCA+NH3 groups and morphological changes. An increase in astrocyte size in PCA+NH3 group and activated microglia in groups treated with ammonium acetate and/or lipopolysaccharide was observed. A modulation of neurodegeneration-related genes and the presence of apoptosis in Bergmann glia were observed. This new animal model reproduces the clinical course of episodic hepatic encephalopathy when ammonia is the precipitant factor and demonstrates the existence of neuronal loss in cerebellum. The persistence of over-activated microglia and reactive astrocytes could participate in the apoptosis of Bergmann glia and therefore Purkinje cell degeneration.
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Affiliation(s)
- Teresa García-Lezana
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Marc Oria
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
- 4 Center for Fetal, Cellular and Mollecular Therapy, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center (CCHMC), OH, US
| | - Jordi Romero-Giménez
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Jordi Bové
- 5 Neurodegenerative Diseases Research Group, Institut de Recerca Valld'Hebron (VHIR) - Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Barcelona, Spain
| | - Miquel Vila
- 5 Neurodegenerative Diseases Research Group, Institut de Recerca Valld'Hebron (VHIR) - Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Barcelona, Spain
- 6 Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- 7 Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Joan Genescà
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Laia Chavarria
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Juan Cordoba
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
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Bémeur C, Cudalbu C, Dam G, Thrane AS, Cooper AJL, Rose CF. Brain edema: a valid endpoint for measuring hepatic encephalopathy? Metab Brain Dis 2016; 31:1249-1258. [PMID: 27272740 DOI: 10.1007/s11011-016-9843-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 05/19/2016] [Indexed: 12/12/2022]
Abstract
Hepatic encephalopathy (HE) is a major complication of liver failure/disease which frequently develops during the progression of end-stage liver disease. This metabolic neuropsychiatric syndrome involves a spectrum of symptoms, including cognition impairment, attention deficits and motor dysfunction which eventually can progress to coma and death. Pathologically, HE is characterized by swelling of the astrocytes which consequently leads to brain edema, a common feature found in patients with acute liver failure (ALF) as well as in cirrhotic patients suffering from HE. The pathogenic factors involved in the onset of astrocyte swelling and brain edema in HE are unresolved. However, the role of astrocyte swelling/brain edema in the development of HE remains ambiguous and therefore measuring brain edema as an endpoint to evaluate HE is questioned. The following review will determine the effect of astrocyte swelling and brain edema on neurological function, discuss the various possible techniques to measure brain edema and lastly to propose a number of neurobehavioral tests to evaluate HE.
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Affiliation(s)
- Chantal Bémeur
- Département de nutrition, Université de Montréal, Montréal, Québec, Canada
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, Montréal, Québec, Canada
| | - Cristina Cudalbu
- Centre d'Imagerie Biomédicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Gitte Dam
- Department of Medicine V (Hepatology and Gastroenterology), Aarhus, Denmark
| | - Alexander S Thrane
- Department of Ophthalmology, Haukeland University Hospital, 5012, Bergen, Norway
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, New York, 14642, USA
| | - Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, 10595, USA
| | - Christopher F Rose
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, Montréal, Québec, Canada.
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6
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Amodio P, Montagnese S. Clinical neurophysiology of hepatic encephalopathy. J Clin Exp Hepatol 2015; 5:S60-8. [PMID: 26041960 PMCID: PMC4442865 DOI: 10.1016/j.jceh.2014.06.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 06/05/2014] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND/OBJECTIVES Hepatic encephalopathy (HE) has relevant impact on the quality of life of patients and their caregivers and causes relevant costs because of hospitalizations and work days lost. Its quantification is important to perform adequate clinical trials on this relevant complication of cirrhosis and portal-systemic shunting. Clinical neurophysiology, which detects functional alterations of the nervous system, has been applied to the study of HE for over 60 years. This review aims at summarizing and clarifying the role of neurophysiologic techniques in the study of HE. METHODS A narrative review was performed aiming at interpreting the cited papers and the techniques on the basis of their physiological and pathophysiological meaning. RESULTS The potential role of EEG, quantified EEG, evoked potentials-both exogenous, endogenous and motor-have been clarified to the reader that may be unfamiliar with neurophysiology. CONCLUSIONS The EEG, reflecting the oscillatory changes of neural network is the preferable tool to detect and monitor HE, with the exception of its most severe stage, when EEG flattens. SSEP and MEP have indication to detect and monitor transmission alterations that are likely related to myelin changes and microedema.
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Key Words
- BAEPs, brainstem acoustic evoked potentials
- EEG
- EEG, electroencephalogram
- EPs, evoked potentials
- ERPs, event related potentials
- HE, hepatic encephalopathy
- MEG, magnetoencephalogram
- MEPs, motor evoked potentials
- SSEPs, somatosensory evoked potential
- VEPs, visual evoked potentials
- cirrhosis
- evoked potentials
- fVPS, flash visual evoked potentials
- hepatic encephalopathy
- neurophysiology
- pVEPs, pattern reversal visual evoked potentials
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Affiliation(s)
- Piero Amodio
- Address for correspondence: Piero Amodio, Department of Medicine, DIMED, University of Padua, via Giustiniani, 2; 35128 Padova, Italy. Fax: +39 049 7960903.
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7
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Oria M, Jalan R. Brain lactate in hepatic encephalopathy: friend or foe? J Hepatol 2014; 60:476-7. [PMID: 24308990 DOI: 10.1016/j.jhep.2013.11.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 11/26/2013] [Indexed: 01/12/2023]
Affiliation(s)
- Marc Oria
- Liver Failure Group, UCL Institute for Liver and Digestive Health, The Royal Free Hospital, Pond Street, London NW3 2PF, United Kingdom
| | - Rajiv Jalan
- Liver Failure Group, UCL Institute for Liver and Digestive Health, The Royal Free Hospital, Pond Street, London NW3 2PF, United Kingdom.
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Abstract
Liver failure affects brain function, leading to neurological and psychiatric alterations; such alterations are referred to as hepatic encephalopathy (HE). Early diagnosis of minimal HE reveals an unexpectedly high incidence of mild cognitive impairment and psychomotor slowing in patients with liver cirrhosis - conditions that have serious health, social and economic consequences. The mechanisms responsible for the neurological alterations in HE are beginning to emerge. New therapeutic strategies acting on specific targets in the brain (phosphodiesterase 5, type A GABA receptors, cyclooxygenase and mitogen-activated protein kinase p38) have been shown to restore cognitive and motor function in animal models of chronic HE, and NMDA receptor antagonists have been shown to increase survival in acute liver failure. This article reviews the latest studies aimed at understanding how liver failure affects brain function and potential ways to ameliorate these effects.
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Jover-Cobos M, Noiret L, Sharifi Y, Jalan R. Ornithine phenylacetate revisited. Metab Brain Dis 2013; 28:327-31. [PMID: 23456516 DOI: 10.1007/s11011-013-9391-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 02/19/2013] [Indexed: 12/12/2022]
Abstract
In patients with liver failure hyperammonemia is associated with the development of hepatic encephalopathy (HE) and immune impairment. Treatment of hyperammonemia is an unmet clinical need. Ornithine phenylacetate (OP) is a novel drug that is targeted at reducing ammonia concentration in patients with liver disease and therefore a potential treatment for HE. This review describes the mechanism of action of OP and its effect on plasma ammonia levels, brain function and inflammation of OP in both acute and chronic liver failure. Ammonia levels could shown to be reduced for up to 24 h in animal models until 120 h in patients with repeated dosing of the drug. Reduction of plasma ammonia levels is due to the stimulation of ammonia removal in the form of glutamine (through glutamine synthetase), the direct excretion of ammonia in the form phenylacetylglutamine and to a normalisation of glutaminase activity in the gut. Administration of OP is associated with a reduction of brain oedema in rats with chronic bile duct ligation and diminution of intracranial hypertension in a pig model of ALF. Studies to date have indicated that it is safe in humans and trials in overt HE are underway to establish OP as a treatment for this major complication of liver disease.
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Affiliation(s)
- Maria Jover-Cobos
- Liver Failure Group, UCL Institute for Liver and Digestive Health, The Royal Free Hospital, University College London, Pond Street, London NW3 2PF, UK.
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Bosoi CR, Rose CF. Brain edema in acute liver failure and chronic liver disease: similarities and differences. Neurochem Int 2013; 62:446-57. [PMID: 23376027 DOI: 10.1016/j.neuint.2013.01.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 12/12/2022]
Abstract
Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome that typically develops as a result of acute liver failure or chronic liver disease. Brain edema is a common feature associated with HE. In acute liver failure, brain edema contributes to an increase in intracranial pressure, which can fatally lead to brain stem herniation. In chronic liver disease, intracranial hypertension is rarely observed, even though brain edema may be present. This discrepancy in the development of intracranial hypertension in acute liver failure versus chronic liver disease suggests that brain edema plays a different role in relation to the onset of HE. Furthermore, the pathophysiological mechanisms involved in the development of brain edema in acute liver failure and chronic liver disease are dissimilar. This review explores the types of brain edema, the cells, and pathogenic factors involved in its development, while emphasizing the differences in acute liver failure versus chronic liver disease. The implications of brain edema developing as a neuropathological consequence of HE, or as a cause of HE, are also discussed.
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Affiliation(s)
- Cristina R Bosoi
- Neuroscience Research Unit, Hôpital Saint-Luc (CRCHUM), Université de Montréal, Québec, Canada
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Vaquero J. Therapeutic hypothermia in the management of acute liver failure. Neurochem Int 2012; 60:723-35. [DOI: 10.1016/j.neuint.2011.09.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 09/13/2011] [Accepted: 09/13/2011] [Indexed: 02/07/2023]
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12
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Leke R, de Oliveira DL, Mussulini BHM, Pereira MS, Kazlauckas V, Mazzini G, Hartmann CR, Silveira TR, Simonsen M, Bak LK, Waagepetersen HS, Keiding S, Schousboe A, Portela LV. Impairment of the organization of locomotor and exploratory behaviors in bile duct-ligated rats. PLoS One 2012; 7:e36322. [PMID: 22586467 PMCID: PMC3346757 DOI: 10.1371/journal.pone.0036322] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 03/30/2012] [Indexed: 12/16/2022] Open
Abstract
Hepatic encephalopathy (HE) arises from acute or chronic liver diseases and leads to several problems, including motor impairment. Animal models of chronic liver disease have extensively investigated the mechanisms of this disease. Impairment of locomotor activity has been described in different rat models. However, these studies are controversial and the majority has primarily analyzed activity parameters. Therefore, the aim of the present study was to evaluate locomotor and exploratory behavior in bile duct-ligated (BDL) rats to explore the spatial and temporal structure of behavior. Adult female Wistar rats underwent common bile duct ligation (BDL rats) or the manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent open-field, plus-maze and foot-fault behavioral tasks. The BDL rats developed chronic liver failure and exhibited a decrease in total distance traveled, increased total immobility time, smaller number of rearings, longer periods in the home base area and decreased percentage of time in the center zone of the arena, when compared to the control rats. Moreover, the performance of the BDL rats was not different from the control rats for the elevated plus-maze and foot-fault tasks. Therefore, the BDL rats demonstrated disturbed spontaneous locomotor and exploratory activities as a consequence of altered spatio-temporal organization of behavior.
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Affiliation(s)
- Renata Leke
- Department of Biochemistry, ICBS, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sol, Brazil.
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Oria M, Romero-Giménez J, Arranz JA, Riudor E, Raguer N, Córdoba J. Ornithine phenylacetate prevents disturbances of motor-evoked potentials induced by intestinal blood in rats with portacaval anastomosis. J Hepatol 2012; 56:109-14. [PMID: 21835138 DOI: 10.1016/j.jhep.2011.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 06/20/2011] [Accepted: 06/22/2011] [Indexed: 01/08/2023]
Abstract
BACKGROUND & AIMS Ornithine phenylacetate (OP) is a new drug that has been proposed for the treatment of hepatic encephalopathy (HE) because it decreases plasma ammonia. We performed a study to assess if OP would impact on neuronal function. METHODS Motor-evoked potentials (MEP), a surrogate of hepatic encephalopathy, were assessed (without anesthesia) in rats with portacaval anastomosis (PCA) that received gastrointestinal blood (GIB). Rats were pre-treated with OP prior to GIB. Ammonia and related metabolites (plasma, urine, and brain microdialysis) were assessed by HPLC and mass spectroscopy. RESULTS OP (one dose or 3 days) prevented disturbances in MEP induced by GIB in PCA rats. In rats treated with OP for 3 days, the amplitude and latency of MEP remained stable (-1% and +1%), while in the control group the amplitude decreased -21% and the latency increased +12% (p<0.01). OP attenuated the rise of ammonia in plasma by 45%, ammonia in brain microdialysate by 48%, induced a faster glutamine rise and the appearance of phenylacetylglutamine in plasma and urine. In addition, OP was associated with a lower concentration of ammonia and glutamate in brain microdialysate (approx. 50%). CONCLUSIONS OP prevents abnormalities in MEP precipitated by GIB in a model of HE. This is probably due to the enhancement of glutamine synthesis and metabolism, which results in a lower rise of plasma ammonia and the prevention of changes in glutamate in microdialysate. Thus, OP may be a good drug to prevent HE precipitated by gastrointestinal bleeding.
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Affiliation(s)
- Marc Oria
- Servei de Medicina Interna-Hepatologia, Hospital Vall d'Hebron, Barcelona, Spain
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