“Our results provide evidence that extremely high-altitude climbs with no external oxygen supply may cause subtle changes in brain tissue, even when well acclimatised individuals do not experience any neurological symptoms” concludes Dr Di Paola.
“These changes in white and grey matter appear to be highly specific to regions of the brain involved in motor activity.”
This article is based on a scientific study published in the European Journal of Neurology. It contains detailed information about brain anatomy and function, and since my brain has forgotten most of what it once knew about brain anatomy and function, the article made my head hurt.
However, if you only climb the peaks in Northern California, which top out a bit over 14,000 feet, you should be OK.