Subarachnoid Haemorrhage

Spontaneous arterial bleeding into the subarachnoid space; accounts for 5% of strokes

Aetiology

  • Saccular (Berry) aneurysms
  • Arteriovenous malformation
  • Rare assocations include bleeding disorders, tumours, Marfans or Ehlers-Danlos syndromes

Clinical presentation

Symptoms

  • Sudden, very severe headache, often occipital - ‘thunderclap headache’ often described as like being hit on the back of the head
  • Headache is usually followed by vomiting and often by coma and death
  • Survivors of SAH may remain comatose or drowsy for hours, days or longer

Signs

  • Following major SAH, there is neck stiffness and a positive Kernig’s sign (like in meningitis)
  • Papilloedema is sometimes present

Investigations

  • CT brain - irregular shaped bleed, hyperattenuation in the subarachnoid space
  • In the event of a negative CT scan, lumbar puncture may confirm the diagnosis with the presence of blood in the cerebrospinal fluid, or xanthochromia, the yellowing of the CSF due to haemolysis in older bleeds

Management

  • Bed rest and supportive measures
  • Control hypertension
  • Nimodipine (a CCB) reduces mortality - prevents vasospasm, thus optimising cerebral perfusion