• Normally, there are no RBCs in the cerebrospinal fluid
  • Traumatic lumbar tap:
    • Occurs in 20% of lumbar punctures
    • Differentiated from haemorrhagic causes by a falling RBC count across three bottles counted in order of collection
  • Subarachnoid haemorrhage
  • Intracerebral haemorrhage
  • Cerebral infarct