Brain Damage in Climbers

A worrying finding, for someone who enjoys both climbing and thinking and wants to be at least moderately accomplished in both. From SciAm Mind Matters:

…neurologists Nicholas Fayed and colleagues at the Clinica Queron and Miguel Servet University Hospital in Zarogoza, Spain, gave MRI brain scans to 35 climbers (12 professionals and 23 amateurs) who had returned from high-altitude expeditions, including 13 who had attempted Everest.

The results on the Everest climbers are the most stark. Of the thirteen climbers, three had made the summit, at 8480 meters, three had reached 8100 meters, and seven topped out between 6500 and 7500 meters. Though the expedition suffered no major mishaps and none of the 12 professional climbers suffered any obvious signs of high-altitude illness, only one of the 13 climbers returned with a normal brain scan. The brain scans showed that all but one climber suffered cortical atrophy and enlargement of the Virchow-Robin spaces. These are spaces surrounding brain blood vessels that drain brain fluid and communicate with the lymph system. Widening of these VR spaces is seen in the elderly, but rarely in young people. The amateur climber’s brain had also suffered subcortical lesions in the frontal lobes.

OK, I don’t intend to attempt Everest even in the distant future, but even relatively low-altitude challenges like Mont Blanc (~4800m) can result in brain damage. The study [1] referred to in the SciAm post included seven amateurs who attempted Mont Blanc. These amateurs lived for most of their lives below 200m and had never ascended higher than 3000m. (Interestingly, there were 8 such amateurs in the study who attempted Aconcagua — brave souls! Unsurprisingly, only 2 of that group made the summit.) Of the 7 Mont Blanc climbers, 1 had cortical atrophy, 2 had enlargement of their Virchow-Robin spaces, and 1 had subcortical lesions. Quite worrying considering that I’ve climbed above 4800m on a couple of occasions. The authors also scanned 7 amateurs who attempted Kilimanjaro (which was one of my >4800m trips), and only 1 of them showed any brain abnormalities, even though Kili is more than 1000m higher than Mont Blanc. This puzzled me until I read the details and found that all the 7 Mont Blanc subjects reached the summit of Mont Blanc, but only three of the Kili subjects summited Kili, 2 having stopped at 4600m, 1 at 5000m, and the other at a lower altitude. So on average the Kili subjects hadn’t climbed 1000m higher than the Mont Blanc subjects.

1. Nicolás Fayed, Pedro J. Modrego, Humberto Morales. Evidence of Brain Damage after High-altitude Climbing by Means of Magnetic Resonance Imaging. The American Journal of Medicine Volume 119, Issue 2, February 2006, Pages 168.e1-168.e6. doi:10.1016/j.amjmed.2005.07.062