Abstract
Background and Objective
A 26-year-old male Marine Corps Corpsman experienced high altitude cerebral edema (HACE) at a relatively low altitude (3110 m). His case and its significance are discussed.
Results and Timeline
The individual was participating in a Mountain Medicine training course at the Marine Corps Mountain Warfare Training Center (MWTC) in Bridgeport, California, and had agreed to participate in a prospective observational study looking for objective biomarkers of hypobaric hypoxia. Informed consent was obtained and baseline testing (optic ultrasound, blood labs, and the Lake Louise Acute Mountain Sickness [AMS] Survey) was performed the night before ascent (2061 m). The participant ascended to 3110 m on training day 2. Routine monitoring by training staff at approximately 15 hours post-ascent (at approximately 01:00 hours) revealed the participant to be in obvious distress, complaining of a severe pulsating headache associated with nausea and photophobia/phonophobia (his “usual” headaches never included photophobia/phonophobia), as well as fatigue, faint anxiety, and disrupted sleep. The course instructors suspected AMS and elected to move him to lower altitude (2061 m). Upon evaluation by MWTC medical staff, the patient disclosed a history of refractory headache and emesis requiring descent after summiting Pikes Peak, Colorado. A careful neurological examination revealed moderate encephalopathy and obvious truncal ataxia. The patient was treated with prednisone and studies were initiated (vitals/pulse oximetry, basic chemistries, chest radiograph, optic ultrasound), and the patient was evacuated to higher-level care for an MRI of the brain, electroencephalogram, and a lumbar puncture. The final clinical diagnosis remained HACE.
Conclusions
This is a clear case of HACE, diagnosed clinically, and is significant because 1) this is likely to be the first HACE patient to receive such an extensive and diverse battery of biomarkers applied to his medical evaluation; 2) it is among the lowest altitudes wherein HACE has been documented; and 3) the patient's history of severe altitude illness at Pikes Peak suggests the possibility of a genetic predisposition to HACE.