Study of high-altitude cerebral edema using multimodal imaging

Abstract

ObjectiveTo analyze the brain imaging features of high-altitude cerebral edema (HACE) using computed tomography (CT) and multi-sequence magnetic resonance imaging (MRI) and to explore its injury characteristics.Materials and methodsWe selected 30 patients with HACE diagnosed between January 2012 to August 2022 as the experimental group and 60 patients with dizziness on traveling from the plain to the plateau or from lower altitude to higher altitude in a short period of time as the control group. We collected general clinical data from the experimental group and classified it according to clinical symptoms. In both groups, we then performed a head CT and multi-sequence MRI (T1WI, T2WI, FLAIR, and DWI). Among them, nine patients with HACE were also scanned using susceptibility-weighted imaging (SWI). Finally, we analyzed the images.ResultsAccording to clinical symptoms, we divided the 30 cases of HACE into 12 mild cases and 18 severe cases. There was no significant difference in sex, age, leukocyte, neutrophil, or glucose content between mild and severe HACE. The sensitivity and specificity of the MRI diagnosis were 100 and 100%, respectively, while the sensitivity and specificity of the CT diagnosis were 23.3 and 100%, respectively. The distribution range of deep and juxtacortical white matter edema was significantly larger in severe HACE than in mild HACE (p < 0.001). The corpus callosum edema distribution range in severe HACE was significantly larger than that in mild HACE (p = 0.001). The ADC value of the splenium of the corpus callosum was significantly lower in severe HACE than in mild HACE (p = 0.049). In mild and severe HACE, the signal intensity of the DWI sequence was significantly higher than that of conventional MRI sequences (T1WI, T2WI, FLAIR) (p = 0.008, p = 0.025, respectively). In severe HACE, seven cases showed bilateral corticospinal tract edema at the thalamic level, and SWI showed cerebral microbleeds (CMBs) in five cases, especially in the corpus callosum.ConclusionsMRI has more advantages than CT in the evaluation of HACE, especially in the DWI sequence. The white matter injury of severe HACE is more severe and extensive, especially in the corpus callosum, and some CMBs and corticospinal tract edema may also appear.

High-altitude Cerebral Edema and High-altitude Pulmonary Edema Diagnosed in the Desert: A Case Report

“…Findings revealed a 100% sensitivity and 100% specificity of MRI diagnosis, and a 23.3% sensitivity and 100% specificity of CT diagnosis. 12 Unfortunately, brain MRI was not done on our patient during hospitalization. Given the broad potential findings on CT head with its poor sensitivity, if clinical suspicion is high enough treatment should not be delayed due to negative CT head imaging.…”

“…This is especially true in individuals with HACE due to the cerebral edema and risk of brain herniation. 2,12 Wilderness Medical Society Guidelines recommend that rather than treating patients based on altitude only, treatment should be based on symptoms. 9 Symptoms usually resolve after descent of 300-1,000 m (~980-3,200 ft) above sea level.…”

“…However, current literature recommends consideration of its use in AMS. 12 For HAPE, acetazolamide may cause hypotension, especially if there is concomitant dehydration, which can worsen dyspnea. 9 Loop diuretics should be avoided in HACE due to associated dehydration.…”

Rehabilitation after Hypoxic and Metabolic Brain Injury in a Mountain Climber

“…HACE will also present with ataxia and altered mental status 6 7. CT imaging of the brain is not useful for detecting changes related to HACE 8. HACE has an incidence of 1% at altitudes of 4000–5000 m. AMS may affect upwards of 50% of unaccustomed trekkers above 4500 m 9.…”