CASE Medicine
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NEWS: 13th Aug 2010
Neuroscience at high altitude

Our neuroscience team is working to understand how altitude affects blood flow and oxygen delivery to the brain. Using a combination of cerebral oxymetry (Fore-sight, Casmed Inc.), transcranial doppler (Sonosite) and novel technology from the University of Pennsylvania (diffuse correlation spectroscopy or DCS) we are examining the dynamic changes occurring to cerebral blood flow as we ascend to altitude.

To this end we are pursuing two separate but related studies. The first is part of the larger study into the effects of a dietary intervention affecting nitrate levels. We are investigating the effects of the dietary intervention on brain blood flow, brain oxygenation and acute mountain sickness symptomatology. Our other investigation focuses on changes in blood flow as measured by DCS as we acclimatize and how exertion changes cerebral blood flow and oxygenation at altitude.

The nitric oxide system, which we are testing through our dietary intervention, has been implicated as a key regulator of blood flow to the brain. Team member Matt Sanborn, a neurosurgery resident from the University of Pennsylvania, hopes to translate findings from this expedition to research dealing with patients with ruptured cerebral aneurysms in the intensive care unit.

We have completed the first day of measurements on our subjects from group 1 in smooth day of testing. Part of the protocol involves breathing rapidly and deeply to reduce carbon dioxide levels. Side effects were particularly pronounced at altitude and included cramping up of the hands and tingling around the mouth and fingers. Our subjects tolerated the tests amazingly well.

Written by Mark Edsell and Matt Sanborn