Michael Knauth MD, PhD, Presenter: Speakers Bureau, Penumbra, Inc Speakers Bureau, Siemens AG Speakers Bureau, Acandis GmbH & Co KG Speakers Bureau, Johnson & Johnson

Kai Kallenberg MD, Abstract Co-Author: Speakers Bureau, Acandis GmbH & Co KG

Kai Schommer MD, Abstract Co-Author: Nothing to Disclose

Peter Bartsch MD, Abstract Co-Author: Nothing to Disclose

HACE is life threatening. We reported 3 cases of nonfatal HACE showing microhemorrhages (MH) in the corpus callosum while 3 control subjects who had suffered from severe acute mountain sickness (AMS) were free of MH (Kallenberg, JCBFM 2008). We hypothesized that brain MH only occur in HACE while extreme altitude climbers without any high altitude illness, climbers with severe AMS or isolated high altitude pulmonary edema (HAPE) do not show MH. We performed a cross-sectional study on extreme altitude climbers and on mountaineers who had well-documented episodes of AMS, HACE or HAPE.  

Brain MRI with T2*- and susceptibility-weighted-sequences was performed in the following groups of mountaineers: w/o history of high altitude illness who reached an altitude >7000m (n=7) history of severe AMS (n=11) history of isolated HAPE (n=8) history of HACE (n=10). Clinical severity of HACE was scored. Based on previous findings two neuroradiologists assessed all brain MRI blinded to the group identity of the mountaineers. MRI were classified as HACE-positive, HACE-negative or HACE-uncertain. An MRI score regarding the severity (number/location) of MH was established.

Microhemorrhages were found almost exclusively found in the brains of HACE survivors. The MRI results in the different groups of mountaineers were: extreme altitude climbers: 5 HACE-negative, 2 HACE-uncertain; severe AMS: 10 HACE-negative, 1 HACE-positive; HAPE without HACE: 7 HACE-negative, 1 HACE-positive; HACE: 2 HACE-uncertain, 8 HACE-positive. Clinical and MRI HACE-scores: the most severely clinically affected HACE-subjects showed the highest HACE-MRI-scores. MH were found predominantly in the corpus callosum (splenium>corpus>rostrum). In more severe HACE subjects the cerebral white matter was also affected.

MRI showed brain microhemorrhages (MH) in almost all and almost exclusively in HACE-survivors. MH had a characteristic distribution involving predominantly the corpus callosum. The clinically most severely affected HACE survivors were the ones with the most prominent MRI changes. The distribution of MH is a new and sensitive MRI sign of HACE and can be detected years after HACE.

Microhemorrhages in brains of HACE-survivors show a characteristic distribution different from other diseases (e.g. vasculitis, amyloid angiopathy)

Knauth, M, Kallenberg, K, Schommer, K, Bartsch, P, High Altitude Climbing: Are Microhemorrhages Only Found in the Brains of Survivors of High Altitude Cerebral Edema (HACE)? A Cross Sectional Study including Healthy Extreme Altitude Climbers and Those with Different High Altitude Illnesses.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12030009.html