cerebral oedema

Last reviewed 01/2018

This is an excess of brain water. It often develops around an intrinsic lesion within the brain tissue e g. a tumour or an abscess, or in relation to trauma or ischaemic brain damage.

Cerebral oedema may complicate a variety of conditions, for example:

  • acute hepatic failure
  • benign intracranial hypertension
  • Reye's syndrome
  • excess fluid infusion in a dehydrated/hypernatraemic patient
  • rarely in diabetic ketoacidosis

High altitude cerebral oedema may result from an abrupt increase in cerebral blood flow at 3500 - 4000 m upwards.

Different forms of cerebral oedema are described:

  • vasogenic:
    • caused by excessive protein rich fluid leakage into the extracellular space through damaged capillaries
    • particularly affects the white matter
    • treated with systemic corticosteroids

  • cytotoxic:
    • damage is intracellular, within the neurones and glia

  • interstitial:
    • CSF leaks into the extracellular space e.g. non-communicating hydrocephalus

Cerebral oedema appears as a hypodense area on CT scans.