1
|
Kobayashi M, Hirata S, Fujimaki T. Neuroprotective Effects of Artificial Cerebrospinal Fluid: Analysis of Brainstem Auditory-Evoked Potential Monitoring During Microvascular Decompression in 117 Consecutive Patients. Neurosurgery 2023; 94:00006123-990000000-00994. [PMID: 38084994 PMCID: PMC10990391 DOI: 10.1227/neu.0000000000002793] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 10/25/2023] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND AND OBJECTIVES To study the efficacy of irrigation with artificial cerebrospinal fluid (aCSF) for protection of cranial nerves during surgery; the time required for recovery of brainstem auditory-evoked potentials (BAEPs) that would reflect cochlear function was analyzed in comparison with that for saline irrigation. METHODS This retrospective study included 117 consecutive patients (95 women, mean age 51.5 ± 11.4 year) who underwent microvascular decompression for hemifacial spasm. During surgery, BAEPs were monitored to avoid damage to the auditory pathways. When a delayed latency of >1 ms or a decrease in amplitude of >50% was detected in BAEP wave V, surgical maneuvers were halted, and the operative field was irrigated with saline or aCSF. Saline was used for irrigation in 58 patients and aCSF in the other 59. The time required for BAEP recovery at the first halt in each patient was analyzed, and the results were compared between the groups. RESULTS Surgical procedures were interrupted because of BAEP latency delays or decreases in amplitude in 51 of the patients in the saline group and 54 in the aCSF group. In both groups, the latencies and amplitudes recovered significantly with time and both recovered earlier after aCSF irrigation than after saline irrigation. Hearing outcome was not significantly different between 2 groups. CONCLUSION aCSF is effective for protection of cochlear nerve and promotes recovery from transient dysfunction during surgery. The protective effect may be attributed to multiple factors including conditioned pH, electrolyte composition, glucose, and microelements, such as magnesium and phosphate.
Collapse
Affiliation(s)
| | - Sachiko Hirata
- Department of Neurosurgery, Saitama Medical University, Saitama, Japan
| | | |
Collapse
|
2
|
Gouvea Bogossian E, Battaglini D, Fratino S, Minini A, Gianni G, Fiore M, Robba C, Taccone FS. The Role of Brain Tissue Oxygenation Monitoring in the Management of Subarachnoid Hemorrhage: A Scoping Review. Neurocrit Care 2023; 39:229-240. [PMID: 36802011 DOI: 10.1007/s12028-023-01680-x] [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: 09/20/2022] [Accepted: 01/19/2023] [Indexed: 02/19/2023]
Abstract
Monitoring of brain tissue oxygenation (PbtO2) is an important component of multimodal monitoring in traumatic brain injury. Over recent years, use of PbtO2 monitoring has also increased in patients with poor-grade subarachnoid hemorrhage (SAH), particularly in those with delayed cerebral ischemia. The aim of this scoping review was to summarize the current state of the art regarding the use of this invasive neuromonitoring tool in patients with SAH. Our results showed that PbtO2 monitoring is a safe and reliable method to assess regional cerebral tissue oxygenation and that PbtO2 represents the oxygen available in the brain interstitial space for aerobic energy production (i.e., the product of cerebral blood flow and the arterio-venous oxygen tension difference). The PbtO2 probe should be placed in the area at risk of ischemia (i.e., in the vascular territory in which cerebral vasospasm is expected to occur). The most widely used PbtO2 threshold to define brain tissue hypoxia and initiate specific treatment is between 15 and 20 mm Hg. PbtO2 values can help identify the need for or the effects of various therapies, such as hyperventilation, hyperoxia, induced hypothermia, induced hypertension, red blood cell transfusion, osmotic therapy, and decompressive craniectomy. Finally, a low PbtO2 value is associated with a worse prognosis, and an increase of the PbtO2 value in response to treatment is a marker of good outcome.
Collapse
Affiliation(s)
- Elisa Gouvea Bogossian
- Department of Intensive Care, Université Libre de Bruxelles, Erasme Hospital, Route de Lennik, 808, 1070, Brussels, Belgium.
| | - Denise Battaglini
- Anesthesia and Intensive Care, Instituto di Ricovero e Cura a carattere scientifico for Oncology and Neuroscience, San Martino Policlinico Hospital, Genoa, Italy
- Department of Medicine, University of Barcelona, Barcelona, Spain
| | - Sara Fratino
- Department of Intensive Care, Université Libre de Bruxelles, Erasme Hospital, Route de Lennik, 808, 1070, Brussels, Belgium
| | - Andrea Minini
- Department of Intensive Care, Université Libre de Bruxelles, Erasme Hospital, Route de Lennik, 808, 1070, Brussels, Belgium
| | - Giuseppina Gianni
- Department of Intensive Care, Université Libre de Bruxelles, Erasme Hospital, Route de Lennik, 808, 1070, Brussels, Belgium
| | - Marco Fiore
- Department of Women, Child, and General and Specialized Surgery, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Chiara Robba
- Anesthesia and Intensive Care, Instituto di Ricovero e Cura a carattere scientifico for Oncology and Neuroscience, San Martino Policlinico Hospital, Genoa, Italy
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
| | - Fabio Silvio Taccone
- Department of Intensive Care, Université Libre de Bruxelles, Erasme Hospital, Route de Lennik, 808, 1070, Brussels, Belgium
| |
Collapse
|
3
|
Panahi Y, Mojtahedzadeh M, Najafi A, Ghaini MR, Abdollahi M, Sharifzadeh M, Ahmadi A, Rajaee SM, Sahebkar A. The role of magnesium sulfate in the intensive care unit. EXCLI JOURNAL 2017; 16:464-482. [PMID: 28694751 PMCID: PMC5491924 DOI: 10.17179/excli2017-182] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/22/2017] [Indexed: 01/27/2023]
Abstract
Magnesium (Mg) has been developed as a drug with various clinical uses. Mg is a key cation in physiological processes, and the homeostasis of this cation is crucial for the normal function of body organs. Magnesium sulfate (MgSO4) is a mineral pharmaceutical preparation of magnesium that is used as a neuroprotective agent. One rationale for the frequent use of MgSO4 in critical care is the high incidence of hypomagnesaemia in intensive care unit (ICU) patients. Correction of hypomagnesaemia along with the neuroprotective properties of MgSO4 has generated a wide application for MgSO4 in ICU.
Collapse
Affiliation(s)
- Yunes Panahi
- Clinical Pharmacy Department, Faculty of Pharmacy, Baqiyatallah University of Medical Sciences, Tehran, Iran
- Clinical Pharmacy Department, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Mojtahedzadeh
- Clinical Pharmacy Department, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran
| | - Atabak Najafi
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Ghaini
- Department of Neurosurgery and Neurology, Sina Hospital, Tehran University, Iran
| | - Mohammad Abdollahi
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sharifzadeh
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Arezoo Ahmadi
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyyed Mahdi Rajaee
- Clinical Pharmacy Department, Faculty of Pharmacy, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
4
|
Huang Z, Filipovic Z, Mp N, Ung C, Troy EL, Colburn RW, Iaci JF, Hackett C, Button DC, Caggiano AO, Parry TJ. AC105 Increases Extracellular Magnesium Delivery and Reduces Excitotoxic Glutamate Exposure within Injured Spinal Cords in Rats. J Neurotrauma 2016; 34:685-694. [PMID: 27503053 DOI: 10.1089/neu.2016.4607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Magnesium (Mg2+) homeostasis is impaired following spinal cord injury (SCI) and the loss of extracellular Mg2+ contributes to secondary injury by various mechanisms, including glutamate neurotoxicity. The neuroprotective effects of high dose Mg2+ supplementation have been reported in many animal models. Recent studies found that lower Mg2+ doses also improved neurologic outcomes when Mg2+ was formulated with polyethylene glycol (PEG), suggesting that a PEG/ Mg2+ formulation might increase Mg2+ delivery to the injured spinal cord, compared with that of MgSO4 alone. Here, we assessed spinal extracellular Mg2+ and glutamate levels following SCI in rats using microdialysis. Basal levels of extracellular Mg2+ (∼0.5 mM) were significantly reduced to 0.15 mM in the core and 0.12 mM in the rostral peri-lesion area after SCI. A single intravenous infusion of saline or of MgSO4 at 192 μmoL/kg did not significantly change extracellular Mg2+ concentrations. However, a single infusion of AC105 (a MgCl2 in PEG) at an equimolar Mg2+ dose significantly increased the Mg2+ concentration to 0.3 mM (core area) and 0.25 mM (rostral peri-lesion area). Moreover, multiple AC105 treatments completely restored the depleted extracellular Mg2+ concentrations after SCI to levels in the uninjured spinal cord. Repeated MgSO4 infusions slightly increased the Mg2+ concentrations while saline infusion had no effect. In addition, AC105 treatment significantly reduced extracellular glutamate levels in the lesion center after SCI. These results indicate that intravenous infusion of PEG-formulated Mg2+ normalized the Mg2+ homeostasis following SCI and reduced potentially neurotoxic glutamate levels, consistent with a neuroprotective mechanism of blocking excitotoxicity.
Collapse
Affiliation(s)
| | | | | | - Chia Ung
- Acorda Therapeutics, Inc. , Ardsley, New York
| | | | | | | | | | | | | | - Tom J Parry
- Acorda Therapeutics, Inc. , Ardsley, New York
| |
Collapse
|
5
|
Rodríguez-Rubio L, Solis Garcia Del Pozo J, Nava E, Jordán J. Interaction between magnesium sulfate and neuromuscular blockers during the perioperative period. A systematic review and meta-analysis. J Clin Anesth 2016; 34:524-34. [PMID: 27687446 DOI: 10.1016/j.jclinane.2016.06.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 05/19/2016] [Accepted: 06/15/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Laura Rodríguez-Rubio
- Grupo de Neurofarmacología, Instituto de Investigación en Discapacidades Neurológicas-UCLM, Albacete, España; Servicio de Anestesia y Reanimación, Hospital de Almansa, Albacete, España.
| | - Julian Solis Garcia Del Pozo
- Grupo de Neurofarmacología, Instituto de Investigación en Discapacidades Neurológicas-UCLM, Albacete, España; Servicio de Medicina Interna, Hospital General de Villarrobledo, Albacete, España
| | - Eduardo Nava
- Departamento de Ciencias Médicas, Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, España
| | - Joaquín Jordán
- Grupo de Neurofarmacología, Instituto de Investigación en Discapacidades Neurológicas-UCLM, Albacete, España; Departamento de Ciencias Médicas, Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, España
| |
Collapse
|
6
|
Kundra S, Mahendru V, Gupta V, Choudhary AK. Principles of neuroanesthesia in aneurysmal subarachnoid hemorrhage. J Anaesthesiol Clin Pharmacol 2014; 30:328-37. [PMID: 25190938 PMCID: PMC4152670 DOI: 10.4103/0970-9185.137261] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage is associated with high mortality. Understanding of the underlying pathophysiology is important as early intervention can improve outcome. Increasing age, altered sensorium and poor Hunt and Hess grade are independent predictors of adverse outcome. Early operative interventions imposes an onus on anesthesiologists to provide brain relaxation. Coiling and clipping are the two treatment options with increasing trends toward coiling. Intraoperatively, tight control of blood pressure and adequate brain relaxation is desirable, so that accidental aneurysm rupture can be averted. Patients with poor grades tolerate higher blood pressures, but are prone to ischemia whereas patients with lower grades tolerate lower blood pressure, but are prone to aneurysm rupture if blood pressure increases. Patients with Hunt and Hess Grade I or II with uneventful intraoperative course are extubated in operation theater, whereas, higher grades are kept electively ventilated. Postoperative management includes attention toward fluid status and early management of vasospasm.
Collapse
Affiliation(s)
- Sandeep Kundra
- Department of Anesthesia, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Vidhi Mahendru
- Department of Anesthesia, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Vishnu Gupta
- Department of Neurosurgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | | |
Collapse
|
7
|
Siasios I, Kapsalaki EZ, Fountas KN. Cerebral vasospasm pharmacological treatment: an update. Neurol Res Int 2013; 2013:571328. [PMID: 23431440 PMCID: PMC3572649 DOI: 10.1155/2013/571328] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 12/27/2012] [Indexed: 11/17/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage- (aSAH-) associated vasospasm constitutes a clinicopathological entity, in which reversible vasculopathy, impaired autoregulatory function, and hypovolemia take place, and lead to the reduction of cerebral perfusion and finally ischemia. Cerebral vasospasm begins most often on the third day after the ictal event and reaches the maximum on the 5th-7th postictal days. Several therapeutic modalities have been employed for preventing or reversing cerebral vasospasm. Triple "H" therapy, balloon and chemical angioplasty with superselective intra-arterial injection of vasodilators, administration of substances like magnesium sulfate, statins, fasudil hydrochloride, erythropoietin, endothelin-1 antagonists, nitric oxide progenitors, and sildenafil, are some of the therapeutic protocols, which are currently employed for managing patients with aSAH. Intense pathophysiological mechanism research has led to the identification of various mediators of cerebral vasospasm, such as endothelium-derived, vascular smooth muscle-derived, proinflammatory mediators, cytokines and adhesion molecules, stress-induced gene activation, and platelet-derived growth factors. Oral, intravenous, or intra-arterial administration of antagonists of these mediators has been suggested for treating patients suffering a-SAH vasospam. In our current study, we attempt to summate all the available pharmacological treatment modalities for managing vasospasm.
Collapse
Affiliation(s)
- Ioannis Siasios
- Department of Neurosurgery, University Hospital of Larissa, Faculty of Medicine, University of Thessaly, Biopolis, 41110 Larissa, Greece
| | - Eftychia Z. Kapsalaki
- Department of Diagnostic Radiology, University Hospital of Larissa, Faculty of Medicine, University of Thessaly, Biopolis, 41110 Larissa, Greece
| | - Kostas N. Fountas
- Department of Neurosurgery, University Hospital of Larissa, Faculty of Medicine, University of Thessaly, Biopolis, 41110 Larissa, Greece
- Institute of Biomolecular & Biomedical Research (BIOMED), Center for Research and Technology - Thessaly (CERETETH), 38500 Larissa, Greece
| |
Collapse
|
8
|
Poon WS. Great hospitals of Asia: neurosurgery at Prince of Wales Hospital. World Neurosurg 2011; 75:383-6. [PMID: 21600469 DOI: 10.1016/j.wneu.2011.02.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 02/08/2011] [Indexed: 10/18/2022]
Abstract
Prince of Wales Hospital, a 1400-bed regional referral center, was established in 1984 as the primary teaching hospital of the second medical school in Hong Kong at the Chinese University of Hong Kong. The Academic Division of Neurosurgery was given an autonomous status, the support of 40 acute beds, and a well-equipped and well-staffed intensive care unit (ICU), in developing neurosurgery as a distinct surgical specialty. Over this short 26-year history, we have gone through the difficult time of one-man-band neurosurgery, excelled in emergency neurosurgery, and evolved to an era of organized neurosurgical practice, where clinical services, teaching of undergraduate and postgraduate students, and clinical and translational research have been brought up to international standards.
Collapse
Affiliation(s)
- Wai S Poon
- Division of Neurosurgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
| |
Collapse
|
9
|
|
10
|
Sen AP, Gulati A. Use of magnesium in traumatic brain injury. Neurotherapeutics 2010; 7:91-9. [PMID: 20129501 PMCID: PMC5084116 DOI: 10.1016/j.nurt.2009.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 11/30/2022] Open
Abstract
Depletion of magnesium is observed in animal brain and in human blood after brain injury. Treatment with magnesium attenuates the pathological and behavioral changes in rats with brain injury; however, the therapeutic effect of magnesium has not been consistently observed in humans with traumatic brain injury (TBI). Secondary brain insults are observed in patients with brain injury, which adversely affect clinical outcome. Systemic administration studies in rats have shown that magnesium enters the brain; however, inducing hypermagnesemia in humans did not concomitantly increase magnesium levels in the CSF. We hypothesize that the neuroprotective effects of magnesium in TBI patients could be observed by increasing its brain bioavailability with mannitol. Here, we review the role of magnesium in brain injury, preclinical studies in brain injury, clinical safety and efficacy studies in TBI patients, brain bioavailability studies in rat, and pharmacokinetic studies in humans with brain injury. Neurodegeneration after brain injury involves multiple biochemical pathways. Treatment with a single agent has often resulted in poor efficacy at a safe dose or toxicity at a therapeutic dose. A successful neuroprotective therapy needs to be aimed at homeostatic control of these pathways with multiple agents. Other pharmacological agents, such as dexanabinol and progesterone, and physiological interventions, with hypothermia and hyperoxia, have been studied for the treatment of brain injury. Treatment with magnesium and hypothermia has shown favorable outcome in rats with cerebral ischemia. We conclude that coadministration of magnesium and mannitol with pharmacological and physiological agents could be an effective neuroprotective regimen for the treatment of TBI.
Collapse
|
11
|
Kwon BK, Roy J, Lee JH, Okon E, Zhang H, Marx JC, Kindy MS. Magnesium Chloride in a Polyethylene Glycol Formulation as a Neuroprotective Therapy for Acute Spinal Cord Injury: Preclinical Refinement and Optimization. J Neurotrauma 2009; 26:1379-93. [DOI: 10.1089/neu.2009.0884] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Brian K. Kwon
- Combined Neurosurgical and Orthopaedic Spine Program (CNOSP), Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Josee Roy
- Medtronic Spine and Biologics, Memphis, Tennessee
| | - Jae H.T. Lee
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Elena Okon
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Hongbin Zhang
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Mark S. Kindy
- Medical University of South Carolina, Charleston, South Carolina
| |
Collapse
|
12
|
Kwon BK, Roy J, Lee JHT, Okon E, Zhang H, Marx JC, Kindy MS. Magnesium chloride in a polyethylene glycol formulation as a neuroprotective therapy for acute spinal cord injury: preclinical refinement and optimization. J Neurotrauma 2009. [PMID: 19317592 DOI: 10.1089/neu.2009-0884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Intravenously administered magnesium has been extensively investigated as a neuroprotective agent traumatic brain injuries and stroke. Numerous investigators have reported the neuroprotective benefits of magnesium in animal models of spinal cord injury (SCI) as well, but typically with doses that far exceed human tolerability. To develop magnesium into a clinically relevant therapy for SCI, further refinement and improvement of the magnesium formulation is necessary. In this series of experiments, we evaluated the neuroprotective efficacy of magnesium in a polyethylene glycol (PEG) formulation using an acute model of thoracic SCI. Following thoracic contusion (Infinite Horizon) rat SCI model, we independently confirmed the neuroprotective efficacy of the magnesium and PEG combination which had been previously reported in a thoracic clip compression model of SCI (Ditor et al., 2007). We established that the 254 micromol/kg dose of MgCl(2) was superior to 127 micromol/kg MgCl(2) with respect to tissue sparing and locomotor recovery. Additionally, the number of infusions (2, 4, or 6), time between infusions (6 vs 8 hours), and different magnesium salts (MgCl(2) vs MgSO(4)) were evaluated to determine an "optimal" treatment regimen. We observed that an "optimized" regimen of MgCl(2) within PEG conferred greater tissue neuroprotection and improved locomotor recovery compared to methylprednisolone. Further a 4 hour time window of histologic and behavioral efficacy was established. The goal of these experiments was to help guide the treatment parameters for a clinical trial of magnesium within a polyethylene glycol formulation in acute human spinal cord injury.
Collapse
Affiliation(s)
- Brian K Kwon
- Combined Neurosurgical and Orthopaedic Spine Program (CNOSP), Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada.
| | | | | | | | | | | | | |
Collapse
|
13
|
Campbell K, Meloni BP, Knuckey NW. Combined magnesium and mild hypothermia (35 degrees C) treatment reduces infarct volumes after permanent middle cerebral artery occlusion in the rat at 2 and 4, but not 6 h. Brain Res 2008; 1230:258-64. [PMID: 18644354 DOI: 10.1016/j.brainres.2008.06.110] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 06/25/2008] [Accepted: 06/27/2008] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND PURPOSE Using transient focal and global cerebral ischemia models in the rat, we have previously shown that MgSO4 is not neuroprotective unless it is combined with mild hypothermia. This study establishes a therapeutic time window for combined MgSO4 and mild hypothermia treatment after permanent middle cerebral artery occlusion (MCAO). METHODS Rats were subjected to permanent intraluminal thread MCAO and animals were treated 2, 4 or 6 h after ischemia with a MgSO4 infusion (360 micromol/kg, then 120 micromol/kg/h) and mild hypothermia (35 degrees C) or with vehicle for 24 h. At the 2 h time point, treatment with hypothermia alone and MgSO4 alone were also assessed. Infarct volumes were measured 48 h after MCAO induction. RESULTS After permanent MCAO, combined MgSO4 and hypothermia treatment reduced infarct volumes by 54% at 2 h (P = 0.048) and by 39% at 4 h (P = 0.012), but there was no treatment effect detected at 6 h or in the hypothermia alone or MgSO4 alone groups. CONCLUSIONS These findings support our earlier work highlighting the neuroprotective effect of MgSO4 when combined with mild hypothermia, even when treatment is delayed by several hours.
Collapse
Affiliation(s)
- Kym Campbell
- Centre for Neuromuscular and Neurological Disorders/University of Western Australia, Australian Neuromuscular Research Institute, Department of Neurosurgery/Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | | | | |
Collapse
|
14
|
Threshold to N-methyl-D-aspartate-induced seizures in mice undergoing chronic nutritional magnesium deprivation is lowered in a way partly responsive to acute magnesium and antioxidant administrations. Br J Nutr 2008; 101:317-21. [DOI: 10.1017/s0007114508006752] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Magnesium deficiency may be induced by a diet impoverished in magnesium. This nutritional deficit promotes chronic inflammatory and oxidative stresses, hyperexcitability and, in mice, susceptibility to audiogenic seizures. Potentiation by low-magnesium concentrations of the opening of N-methyl-d-aspartate (NMDA) receptor/calcium channel in in vitro and ex vivo studies, and responsiveness to magnesium of in vivo brain injury states are now well established. By contrast, little or no specific attention has been, however, paid to the in vivo NMDA receptor function/excitability in magnesium deficiency. The present work reports for the first time that, in mice undergoing chronic nutritional deprivation in magnesium (35 v. 930 parts per million for 27 d in OF1 mice), NMDA-induced seizure threshold is significantly decreased (38 % of normal values). The attenuation in the drop of NMDA seizure threshold (percentage of reversal) was 58 and 20 % upon acute intraperitoneal administrations of magnesium chloride hexahydrate (28 mg magnesium/kg) and the antioxidant ebselen (20 mg/kg), respectively. In nutritionally magnesium-deprived animals, audiogenic seizures are completely prevented by these compound doses. Taken as a whole, our data emphasise that chronic magnesium deprivation in mice is a nutritional in vivo model for a lowered NMDA receptor activation threshold. This nutritional model responds remarkably to acute magnesium supply and moderately to acute antioxidant administration.
Collapse
|
15
|
État des connaissances : prise en charge thérapeutique de la prééclampsie. ACTA ACUST UNITED AC 2008; 37:5-15. [DOI: 10.1016/j.jgyn.2007.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 08/23/2007] [Accepted: 09/07/2007] [Indexed: 12/15/2022]
|