aetiology of subarachnoid haemorrhage

Last reviewed 12/2022

Aneurysmal rupture accounts for the vast majority of cases.

Classification:

  • 80% due to "congenital" / berry aneursym - peak age from 40 to 50 years
  • 10-15% due to other aneurysms:
    • arteriosclerotic / fusiform
    • inflammatory / mycotic
    • traumatic
  • 5% due to arteriovenous malformations - peak age from 20 to 40 years
  • less than 5% due to:
    • bleeding diasthesis anticoagulants, e.g. warfarin
    • tumours