| Noninvasive assessment of brain injury in a canine model of hypothermic circulatory arrest using magnetic resonance spectroscopy. | |
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MedLine Citation:
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PMID: 16631640 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: Studies have confirmed the neuroprotective effect of diazoxide in canines undergoing hypothermic circulatory arrest (HCA). A decreased N-acetyl-asparate:choline (NAA:Cho) ratio is believed to reflect the severity of neurologic injury. We demonstrated that noninvasive measurement of NAA:Cho with magnetic resonance spectroscopy facilitates assessment of neuronal injury after HCA and allows for evaluation of neuroprotective strategies. METHODS: Canines underwent 2 hours of HCA at 18 degrees C and were observed for 24 hours. Animals were divided into three groups (n = 15 in each group): normal (unoperated), HCA (HCA only), and HCA+diazoxide (pharmacologic treatment before HCA). The NAA:Cho ratios were obtained 24 hours after HCA by spectroscopy. Brains were immediately harvested for fresh tissue NAA quantification by mass spectrometry. Separate cohorts of HCA (n = 16) and HCA+diazoxide (n = 23) animals were kept alive for 72 hours for daily neurologic assessment. RESULTS: Cortical NAA:Cho ratios were significantly decreased in HCA versus normal animals (1.01 +/- 0.29 versus 1.31 +/- 0.23; p = 0.004), consistent with severe neurologic injury. Diazoxide pretreatment limited neurologic injury versus HCA alone, reflected in a preserved NAA:Cho ratio (1.21 +/- 0.27 versus 1.01 +/- 0.29; p = 0.05). Data were substantiated with fresh tissue NAA extraction. A significant decrease in cortical NAA was observed in HCA versus normal (7.07 +/- 1.9 versus 8.54 +/- 2.1 micromol/g; p = 0.05), with maintenance of normal NAA levels after diazoxide pretreatment (9.49 +/- 1.1 versus 7.07 +/- 1.9 micromol/g; p = 0.0002). Clinical neurologic scores were significantly improved in the HCA+diazoxide group versus HCA at all time points. CONCLUSIONS: Neurologic injury remains a significant complication of cardiac surgery and is most severe after HCA. Magnetic resonance spectroscopy assessment of NAA:Cho ratios offers an early, noninvasive means of potentially evaluating neurologic injury and the effect of neuroprotective agents. |
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Authors:
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Christopher J Barreiro; Jason A Williams; Torin P Fitton; Mary S Lange; Mary E Blue; Lisa Kratz; Peter B Barker; Mahaveer Degaonkar; Vincent L Gott; Juan C Troncoso; Michael V Johnston; William A Baumgartner |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: The Annals of thoracic surgery Volume: 81 ISSN: 1552-6259 ISO Abbreviation: Ann. Thorac. Surg. Publication Date: 2006 May |
Date Detail:
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Created Date: 2006-04-24 Completed Date: 2006-05-25 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 15030100R Medline TA: Ann Thorac Surg Country: Netherlands |
Other Details:
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Languages: eng Pagination: 1593-8 Citation Subset: AIM; IM |
Affiliation:
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Division of Cardiac Surgery, Kennedy-Krieger Research Institute, Baltimore, Maryland, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Aspartic Acid / analogs & derivatives, metabolism Cardiopulmonary Bypass Cerebellum / metabolism Cerebral Cortex / metabolism Choline / metabolism Circulatory Arrest, Deep Hypothermia Induced* Diazoxide / therapeutic use Dogs Hippocampus / metabolism Hypoxia, Brain / diagnosis*, metabolism Magnetic Resonance Spectroscopy* Male Models, Animal Neurons / pathology Neuropsychological Tests Vasodilator Agents / therapeutic use |
| Grant Support | |
ID/Acronym/Agency:
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R37NS31238-10/NS/NINDS NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Vasodilator Agents; 364-98-7/Diazoxide; 56-84-8/Aspartic Acid; 62-49-7/Choline; 997-55-7/N-acetylaspartate |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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