Cerebral Oedema
Cerebral oedema is an abnormal build-up of fluid within brain tissue, causing pressure to rise inside the skull. Because the skull cannot expand, even modest swelling can compress vital structures rapidly. It is a medical emergency, and outcomes depend almost entirely on how quickly treatment begins.
Key points
- Because the rigid skull cannot expand, even a modest build-up of fluid in brain tissue can compress vital structures quickly.
- Recognised triggers include stroke, traumatic head injury, brain tumours or severe infection, high-altitude exposure and metabolic causes such as severe hyponatraemia.
- Dexamethasone lessens vessel permeability around the swollen tissue, while osmotic agents like mannitol draw excess fluid out of the brain instead.
Why it develops and how it is managed
The most common triggers include traumatic head injury, stroke, brain tumours, severe infections such as bacterial meningitis, and altitude sickness in travellers to high altitudes. Metabolic causes, including severe hyponatraemia, account for a significant share of hospital cases.
Corticosteroids are a mainstay where oedema surrounds a tumour or is driven by inflammation. Dexamethasone reduces the permeability of blood vessels around the affected tissue and is widely used in tertiary hospitals in these settings. Osmotic agents such as mannitol draw excess water out of brain tissue and are used alongside or instead of steroids depending on the cause.
Any sudden severe headache, confusion, vomiting, seizure, or loss of consciousness warrants immediate emergency assessment.