Neurosurgery notes/Trauma/Primary head Injury/High-altitude cerebral oedema

High-altitude cerebral oedema

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Primary head Injury

Acute high-altitude sickness (AHAS)

  • A systemic disorder that affects individuals usually within 6– 48 hrs after ascent to high altitudes.
  • Clinical features
    • Odema of feet and hands
    • Pulmonary oedema (HAPE= high-altitude pulmonary edema).
    • Ocular findings include
      • Retinal haemorrhages,
      • Nerve fiber layer infarction,
      • Papilledema
      • Vitreous haemorrhage.
    • Cerebral edema (HACE= high-altitude cerebral edema),
      • Usually associated with pulmonary edema
      • May occur in severe cases of AHAS.
      • Symptoms of HACE include:
        • Severe headache,
        • Mental dysfunction (hallucinations, inappropriate behavior, reduced mental status),
        • Neurologic abnormalities (ataxia, paralysis, cerebellar findings).

Acute mountain sickness (AMS)

  • Most common form of AHAS,
  • Symptoms of
    • Nausea, headache, anorexia, dyspnoea, insomnia, and fatigue,
  • Often assessed using the Lake Louise system.
  • Incidence is
    • ≈ 25% at 7,000 feet
    • ≈ 50% at 15,000 feet
  • Theory
    • The unproven “tight-fit” hypothesis postulated that individuals with less compliant CSF systems (smaller ventricles and CSF spaces) were more vulnerable to AMS.
  • Prevention:
    • Gradual ascent,
    • 2–4 day acclimatization at intermediate altitudes (especially to include sleeping at these levels),
    • Avoidance of alcohol or hypnotics.
  • Treatment of cerebral edema:
    • Immediate descent and oxygen (6–12 L/min by NC or face-mask) are recommended.
    • Dexamethasone 8mg PO or IV followed by 4mg q 6 hrs may help temporize