Multiple brain aneurysms

Case contribution: Prof. Ahmad Sobri Muda


  • An 80 years old lady. She is known hypertension on medication
  • Presented with severe headache followed by loss of consciousness.
  • She regain consciousness on arrival but GCS not full (13-14/15).
Plain CT brain in axial plane soft tissue window

CT scan findings:

  • There is extensive subarachnoid haemorrhage seen on CT without contrast (white arrows). Hunt and Hess at least grade II.
  • The haemorrhages are most prominent at the interpeduncular cistern.
  • No intraventricular haemorrhages or significant haemorrhage in the cerebellopontine cisterns.
  • There is only minimal blood seen at the quadrigeminal cistern.
  • Mild hydrocephalus is seen.
3D reformatted image from CT angiography

CT angiography findings:

  • There are multiple aneurysms, with anterior communicating artery and left vertebral artery fusiform complex aneurysms (arrows).
  • Irregular shape of both aneurysms but the SAH appears to be more prominent in interpeduncular cisterns, most likely the ruptured aneurysm is acom.
  • Left vertebral artery aneurysm is most likely a dissecting aneurysm
Cerebral angiogram images

Cerebral angiogram images:

  • Confirm presence of both vertebral and ACom Artery aneurysms

Diagnosis: Multiple brain aneurysms (anterior communicating and left vertebral) with most likely ruptured anterior communicating artery aneurysm.


  • Aneurysms are focal abnormal dilatation of a blood vessel. They typically occur in arteries. Venous aneurysm are rare.
  • Morphologically there are two main types of aneurysms.
    1. saccular aneurysm: eccentric, involving only a portion of the circumference of the vessel wall. (“Berry” aneurysm).
    2. fusiform aneurysm: concentric, involving full circumference of the vessel wall
  • Prevalence of saccular cerebral aneurysms in the asymptomatic general population has been reported over a wide range (0.2-8.9%) when examined angiographically
  • In 15-30% of these patients, multiple aneurysms are found.
  • Cerebral aneurysms typically occur at branch points of larger vessels but can occur at the origin of small perforators which may not be seen on imaging. Approximately 90% of such aneurysms arise from the anterior circulation, and 15-30% of these patients have multiple aneurysms 4.
    • anterior circulation: ~90%
      • ACA/ACoA complex (30-40%), supraclinoid ICA and ICA/PCoA junction (30%) and MCA (M1/M2 junction) bi/trifurcation (20-30%)
    • posterior circulation: ~10%
      • basilar tip, SCA and PICA
  • Five-year cumulative risk of rupture of anterior circulation aneurysms:
    • <7 mm: 0%
    • 7-12 mm: 2.6%
    • 13-24 mm: 14.5%
    • >25 mm: 40%

    Five-year cumulative risk of rupture of posterior circulation aneurysms:

    • <7 mm: 2.5%
    • 7-12 mm: 14.5%
    • 13-24 mm: 18.4%
    • >25 mm: 50%
Author: radhianahassan