Featured Research

from universities, journals, and other organizations

High-altitude Climbing Causes Subtle Loss Of Brain Cells And Motor Function, Says Everest And K2 Study

Date:
October 16, 2008
Source:
Wiley - Blackwell
Summary:
A study of professional mountain climbers has shown that high-altitude exposure can cause subtle white and grey matter changes to the area of the brain involved in motor activity.

A study of professional mountain climbers has shown that high-altitude exposure can cause subtle white and grey matter changes to the area of the brain involved in motor activity, according to the October issue of the European Journal of Neurology.

Italian researchers took MRI scans of nine world-class mountain climbers, who had been climbing for at least 10 years, before and after expeditions to Mount Everest (8,848 metres) and K2 (8,611 metres) without an oxygen supply. They compared their MRI brain scans with 19 age and sex matched healthy control subjects.

Both the climbers and controls were carefully checked to exclude the presence of any major systemic, psychiatric or neurological illnesses. None of the control group subjects had any history of high-altitude exposure over 3,000 metres.

The results demonstrated that the climbers showed a reduction in both the density and volume of white matter in the left pyramidal tract, near the primary and supplementary motor cortex, when their baseline measurements were compared with the control group.

And when the researchers compared the before and after scans for the climbers, they also found a reduction in the density and volume of grey matter in the left angular gyrus.

“The aim of our study was to measure the quantitative loss of white and grey matter, using voxel-based morphometry, which takes spatial, unbiased MRI measurements independent of the operator” explains lead author Dr Margherita Di Paola from the Neuroimaging Laboratory at the IRCCS Fondazione Santa Lucia in Rome.

“The scans were then assessed by two experienced observers who were unaware of whether the scans belonged to the climbers or control group.”

All the climbers who took part in the study - carried out in collaboration with the National Research Council, Institute of Biomedical Technologies, Milan, and the Ev-K2-CNR Committee – were male.

They ranged from 31 to 52 years, with an average age of just under 38, and were used to climbing to altitudes of at least 4,000 metres several times a year.

The researchers took the first scans eight weeks before the expedition began and the second set eight weeks after they returned.

One climber reached the top of Everest and K2 and two reached the top of one mountain. The remainder reached altitudes of over 7,500 metres and spent at least 15 days over altitudes of 6,500 metres.

A number of neuropsychological tests were also carried out to assess the climber’s cognitive abilities, such as memory and motor functions.

“Despite the loss of grey and white matter, the climbers in our study did not suffer any significant neuropsychological changes after the expedition” says Dr Di Paola.

“Some of the subjects did show abnormal scores on the neuropsychological tests, but in these cases there was no significant difference between the baseline and follow up results. This suggests that there were no significant changes as a result of a single expedition.

“As they had been carefully checked for any pathological conditions that could cause these abnormal scores, we conclude that these test results are most likely to be due to progressive, subtle, brain insults caused by repeated high-altitude exposure.”

Overall, the researchers found that the cognitive abilities that were most likely to be affected were the climbers’ executive function and memory. Indeed, six of the nine climbers had lower than average scores on the Digit Symbol test, which measures executive functions such as the ability to anticipate outcomes and adapt to changing situations.

Four scored lower than average on the Block Design test, which measures visuo-motor functions, and three out of nine scored lower than average on the Prose Memory test (immediate recall) and on the Rey’s Figure test (delayed recall), which measure the verbal and visuo-spatial memory respectively.

“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.”


Story Source:

The above story is based on materials provided by Wiley - Blackwell. Note: Materials may be edited for content and length.


Journal Reference:

  1. Paola et al. Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas. European Journal of Neurology, 2008; 15 (10): 1050 DOI: 10.1111/j.1468-1331.2008.02243.x

Cite This Page:

Wiley - Blackwell. "High-altitude Climbing Causes Subtle Loss Of Brain Cells And Motor Function, Says Everest And K2 Study." ScienceDaily. ScienceDaily, 16 October 2008. <www.sciencedaily.com/releases/2008/10/081016084045.htm>.
Wiley - Blackwell. (2008, October 16). High-altitude Climbing Causes Subtle Loss Of Brain Cells And Motor Function, Says Everest And K2 Study. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2008/10/081016084045.htm
Wiley - Blackwell. "High-altitude Climbing Causes Subtle Loss Of Brain Cells And Motor Function, Says Everest And K2 Study." ScienceDaily. www.sciencedaily.com/releases/2008/10/081016084045.htm (accessed July 25, 2014).

Share This




More Mind & Brain News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

University Quiz Implies Atheists Are Smarter Than Christians

University Quiz Implies Atheists Are Smarter Than Christians

Newsy (July 25, 2014) An online quiz from a required course at Ohio State is making waves for suggesting atheists are inherently smarter than Christians. Video provided by Newsy
Powered by NewsLook.com
Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

AFP (July 24, 2014) A so-called drugs rehab 'clinic' is closed down in Pakistan after police find scores of ‘patients’ chained up alleging serial abuse. Duration 03:05 Video provided by AFP
Powered by NewsLook.com
New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins