Magnetic Resonance Imaging Evidence of Cytotoxic Cerebral Edema in Acute Mountain Sickness

作者：Kai Kallenberg, Damian Miles Bailey, Stefan Christ, Alexander Mohr, Robin Roukens, Elmar Menold, Thorsten Steiner, Peter Bärtsch, Michael Knauth · 发表于：Journal of Cerebral Blood Flow & Metabolism · 年份：2006 · DOI：10.1038/sj.jcbfm.9600404 · 被引用次数：176 · 研究领域：High Altitude and Hypoxia、Neuroscience of respiration and sleep、Chronic Obstructive Pulmonary Disease (COPD) Research

The present study applied T2- and diffusion-weighted magnetic resonance imaging to examine if mild cerebral edema and subsequent brain swelling are implicated in the pathophysiology of acute mountain sickness (AMS). Twenty-two subjects were examined in normoxia (21% O2), after 16 hours passive exposure to normobaric hypoxia (12% O2) corresponding to a simulated altitude of 4,500 m and after 6 hours recovery in normoxia. Clinical AMS was diagnosed in 50% of subjects during hypoxia and corresponding headache scores were markedly elevated (P<0.05 versus non-AMS). Hypoxia was associated with a mild increase in brain volume (+7.0+/-4.8 ml, P<0.05 versus pre-exposure baseline) that resolved during normoxic recovery. Hypoxia was also associated with an increased T2 relaxation time (T2rt) and a general trend toward an increased apparent diffusion coefficient (ADC). During the normoxic recovery, brain volume and T2rt recovered to pre-exposure baseline values, whereas a more marked reduction in ADC in the splenium of the corpus callosum (SCC) was observed (P<0.05). While changes in brain volume and T2rt were not selectively different in AMS, ADC values were consistently lower (P<0.05 versus non-AMS) and associated with the severity of neurologic symptoms. Acute mountain sickness was also characterized by an increased brain to intracranial volume ratio (P<0.05 versus non-AMS). These findings indicate that mild extracellular vasogenic edema contributes to the generalized brain swelling o...