Brain bleeds bug high altitude climbers
Mountaineers experiencing high altitude sickness have traces of bleeding in the brain years after the incident, say a new study.
High altitude cerebral edema (HACE) is a severe and often fatal condition that can affect mountain climbers, hikers, skiers and travellers at high altitudes - typically above 7,000 feet, or 2,300 meters.
HACE results from swelling of brain tissue due to leakage of fluids from the capillaries. Symptoms include headache, loss of coordination and decreasing levels of consciousness.
"HACE is a life-threatening condition," said Michael Knauth, neuroradiologist from the University Medical Centre, Goettingen, Germany.
"It usually happens in a hostile environment where neither help nor proper diagnostic tools are available."
Knauth and colleagues at the University Hospitals in Goettingen and Heidelberg, compared brain MRI findings among four groups of mountaineers: climbers with well documented episodes of HACE; climbers with a history of high altitude illness; climbers with a history of severe acute mountain sickness (AMS).
And lastly climbers with a history of isolated high altitude pulmonary edema (HAPE), a life-threatening accumulation of fluid in the lungs that occurs at high altitudes, according to University Medical Centre statement.
Two neuroradiologists assessed the brain MRI findings without knowing the status of the mountaineers and assigned a score based on the number and location of any microhemorrhages.
"In most cases, these microhemorrhages are so small that they are only visible with a special MRI technique called susceptibility-weighted imaging," Knauth said.
"With this technique, the microhemorrhages are depicted as little black spots."
"It was previously thought that HACE did not leave any traces in the brains of survivors," Knauth said.
"Our studies show that this is not the case. For several years after, microhemorrhages or microbleeds are visible in the brains of HACE survivors."
These findings were presented at the annual meeting of the Radiological Society of North America (RSNA).