Cerebral circulation and brain

Abstract

It should be noted that Dr. J.W. Severinghaus was the expert author of this chapter (Cerebral circulation at high altitude) in the First Edition of this textbook. Moreover, in updating this area, we also amalgamate from the First Edition the detailed chapter titled The High-Altitude Brain, which was authored by Drs. M.S. Raichle and T.F. Hornbein. Readers are directed to these original and elegant comprehensive reviews (Severinghaus: High altitude; exploration of human adaptation, New York, Basel; Raichle: High altitude; exploration of human adaptation, New York, Basel). Rather than reproduce this information here, and while summarizing some of this original material in the context of new findings within the last decade, we provide an update within the broad topic of the cerebral circulation and brain at high altitude. This chapter is comprised of seven sections. The introduction is followed by the major factors which regulate cerebral blood flow (CBF) are initially presented in order to emphasize the integrated mechanisms by which CBF is controlled. Next, detailed discussion is provided to examine the influence of exposure to high-altitude exposure on these aforementioned mechanisms which regulate CBF. We then briefly review recent advances in the understanding of neurological clinical syndromes that occur on exposure to high altitudes. The next two sections summarize the influence of high altitude on cognitive function and highlight other neurological-based symptoms and events that can occur upon exposure to high altitude. Finally, we suggest avenues for future research.