Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas
Version of Record online: 20 AUG 2008
© 2008 The Author(s). Journal compilation © 2008 EFNS
European Journal of Neurology
Volume 15, Issue 10, pages 1050–1057, October 2008
How to Cite
Paola, M. D., Bozzali, M., Fadda, L., Musicco, M., Sabatini, U. and Caltagirone, C. (2008), Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas. European Journal of Neurology, 15: 1050–1057. doi: 10.1111/j.1468-1331.2008.02243.x
- Issue online: 5 SEP 2008
- Version of Record online: 20 AUG 2008
- Received 19 November 2007 Accepted 29 May 2008
- high altitude;
- longitudinal and cross-sectional study;
- motor impairment;
- mountain climbers;
- neuropsychological assessment;
- structural MRI;
- voxel-based morphometry
Background and purpose: At high altitudes barometric pressure is reduced and, thus, less oxygen is inhaled. Reduced oxygen concentration in brain tissue can lead to cerebral damage and neurological and cognitive deficits. The present study was designed to explore the effects of high-altitude exposure using a quantitative MRI technique, voxel-based morphometry.
Methods: We studied nine world-class mountain climbers before (baseline) and after (follow-up) an extremely high-altitude ascent of Everest and K2. We investigated the effects of repeated extremely high-altitude exposures by comparing mountain climbers’ scans at baseline with scans of 19 controls. In addition, we measured the effects of a single extremely high-altitude expedition by comparing mountain climbers’ scans at baseline and follow-up.
Results: A region of reduced white matter density/volume was found in the left pyramidal tract near the primary (BA 4) and supplementary (BA 6) motor cortex when mountain climbers at baseline were compared with controls. Further, when mountain climbers’ scans before and after the expedition were compared, a region of reduced grey matter density/volume was found in the left angular gyrus (BA 39).
Conclusion: These findings suggest that extremely high-altitude exposures may cause subtle white and grey matter changes that mainly affect brain regions involved in motor activity.