Paresthesias of the extremities and of the lips are common. Visual effects may result from its mild diuretic action by lowering the production of aqueous humor. HACE presents with altered mental status, progressing to ataxia, coma, and death. Less common symptoms include hallucinations and seizures and progression to fatal outcome may take from 12 hours to 1-3 days. Retinal hemorrhages and fever may be present.
Rapid descent is critical.
MRI studies point to a reversible vasogenic etiology, most prominent in the corpus callosum with edema of white matter. If not corrected, cytotoxic neurologic damage follows with permanent neurologic deterioration and death. With AMS there is increased pulmonary interstitial edema and elevated pulmonary artery pressures. Hypoxemia probably leads to increased pulmonary vascular endothelium permeability which can progress to HAPE, the most common cause of death related to high altitude. The incidence of HAPE in troops may reach 15 percent, depending upon rate of ascent, final altitude, severity of cold weather, level of exertion, and use of depressant sleeping medications.