Chapter

Effects of Altitude on the Brain

Gary A. Rosenberg

in Molecular Physiology and Metabolism of the Nervous System

Published on behalf of Oxford University Press

Published in print April 2012 | ISBN: 9780195394276
Published online April 2013 | e-ISBN: 9780199322831 | DOI: http://dx.doi.org/10.1093/med/9780195394276.003.0009

Series: Contemporary Neurology Series

Effects of Altitude on the Brain

Show Summary Details

Preview

The concentration of ambient oxygen is maintained at 21%, but the amount of oxygen in the air that is breathed depends on the altitude. As the altitude increases and the atmospheric pressure is reduced, the amount of oxygen is also reduced, reaching dangerously low levels on the highest mountains in the world. Hypobaric hypoxia initiates a series of reactions to compensate for the reduced oxygen content of the air. Acute reductions in oxygen cause a constellation of cerebral symptoms that includes initially headache, ataxia, and short-term memory impairment, and can progress to cerebral edema with papilledema, coma, and death. Acute mountain sickness (AMS) is the first stage of this sequence of events. Most patients with severe cerebral symptoms have high-altitude pulmonary edema (HAPE). The life-threatening high-altitude cerebral edema (HACE) is seen with rapid ascent to over 6000 m. Air travel has increased the number of individuals exposed to hypobaric hypoxia at the summits of mountains such as Mount Everest (8848 m) and Kilmanjaro (5895 m). Exposure to high altitudes after coming from sea level leads to a high incidence of AMS, with smaller but significant numbers of people developing HAPE and HACE.

Chapter.  4191 words.  Illustrated.

Subjects: Neurology

Full text: subscription required

How to subscribe Recommend to my Librarian

Buy this work at Oxford University Press »

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.