High altitude cerebral edema


  • Also known as HACE
  • Progressive neurologic deterioration in someone with AMS or HAPE (due to ↑ ICP)
  • Almost never occurs at <8000ft

Clinical Features

  • Altered mental status, ataxia, gait disturbance, stupor (most sensitive findings)
    • Progresses to coma if untreated
  • Headache, nausea, and vomiting (not always present)
  • Focal neuro deficits may be seen (3rd/6th CN palsies)
  • Seizures are rare

Differential Diagnosis

High Altitude Illnesses


  • Clinical diagnosis


  • Immediate descent is the treatment of choice
  • If descent not possible use combination of:
    • Supplemental O2 (goal SpO2 90%)[1]
    • Supportive hyperventilation
    • Dexamethasone 8mg initially, then 4mg q6hr
    • Acetazolamide 250mg BID (better as ppx)
    • Hyperbaric bag (Gamow bag) if available


  • Acetazolamide 125mg BID (250mg BID if greater than 100kg)
  • Dexamethasone 4mg q6h PO or IV

See Also


  1. Hackett PH, Roach RC. High altitude cerebral edema. High Alt Med Biol 2004; 5:136-146.