| Cerebral diffusion and T(2): MRI predictors of acute mountain sickness during sustained high-altitude hypoxia. | |
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MedLine Citation:
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PMID: 23211961 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
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Diffusion magnetic resonance imaging (MRI) provides a sensitive indicator of cerebral hypoxia. We investigated if apparent diffusion coefficient (ADC) and transverse relaxation (T(2)) predict symptoms of acute mountain sickness (AMS), or merely indicate the AMS phenotype irrespective of symptoms. Fourteen normal subjects were studied in two groups; unambiguous AMS and no-AMS at 3,800 m altitude (intermediate AMS scores were excluded). T(2) relaxation was estimated from a T(2) index of T(2)-weighted signal normalized by cerebrospinal fluid signal. Measurements were made in normoxia and repeated after 2 days sustained hypoxia (AMS group symptomatic and no-AMS group asymptomatic) and after 7 days hypoxia (both groups asymptomatic). Decreased ADC directly predicted AMS symptoms (P<0.05). Apparent diffusion coefficient increased in asymptomatic subjects, or as symptoms abated with acclimatization. This pattern was similar in basal ganglia, white matter, and gray matter. Corpus callosum behaved differently; restricted diffusion was absent (or rapidly reversed) in the splenium, and was sustained in the genu. In symptomatic subjects, T(2,index) decreased after 2 days hypoxia and further decreased after 7 days. In asymptomatic subjects, T(2,index) initially increased after 2 days, but decreased after 7 days. T(2,index) changes were not predictive of AMS symptoms. These findings indicate that restricted diffusion, an indicator of diminished cerebral energy status, directly predicts symptoms of AMS in humans at altitude.Journal of Cerebral Blood Flow & Metabolism advance online publication, 5 December 2012; doi:10.1038/jcbfm.2012.184. |
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Authors:
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John S Hunt; Rebecca J Theilmann; Zachary M Smith; Miriam Scadeng; David J Dubowitz |
Publication Detail:
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Type: JOURNAL ARTICLE Date: 2012-12-05 |
Journal Detail:
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Title: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism Volume: - ISSN: 1559-7016 ISO Abbreviation: J. Cereb. Blood Flow Metab. Publication Date: 2012 Dec |
Date Detail:
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Created Date: 2012-12-5 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8112566 Medline TA: J Cereb Blood Flow Metab Country: - |
Other Details:
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Languages: ENG Pagination: - Citation Subset: - |
Affiliation:
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Department of Radiology, Center for Functional MRI, University of California San Diego, La Jolla, California, USA. |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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