Brain Aneurysm


Cerebral Aneurysm




Normal
Abnormal
  • The brain has many arterial blood vessels that supply blood pumped by the heart.  When the wall of a blood vessel becomes weak and/or thin, it forms a bulge or a bubble.  This bulge or bubble is called an aneurysm.
  • An aneurysm may press on areas of the brain and cause various symptoms (below). Aneurysms may also rupture, causing bleeding in the brain.  This bleeding results in Subarachnoid Hemorrhage (bleeding into the subarachnoid space of the brain).

  • Often asymptomatic
  • Focal neurological deficits depending on location; for example, if the aneurysm compresses the area of brain controlling the left leg, then left leg weakness will occur.
  • Mild headaches
  • Nausea
  • Neck stiffness
  • Severe "thunderclap" headaches if the aneurysm ruptures (Subarachnoid Hemorrhage)


  • Examination:
    1. Focal neurological deficits (explained above)
    2. Neck stiffness if aneurysm has ruptured
  • Imaging:
    1. Cerebral Angiography (dye is injected into the carotid artery to get an image of the blood vessels of the brain)
    2. CT scan will usually show bleeding after an aneurysmal rupture
    3. MRI
  • Laboratories:

- Lumbar puncture (spinal tap) -- cerebrospinal fluid will show blood after an interval of time if there is aneurysm rupture.


  • Unruptured aneurysms:
    1. Large Aneurysms are surgically clipped at their bases to prevent rupture.
    2. Small (less than 1/2 centimeter) ones without symptoms are usually followed with repeated cerebral angiographies.
  • Ruptured aneurysms:
    1. Surgical clip placed at the base of the aneurysm
    2. Aminocaproic acid may be considered, but has complications
    3. Calcium channel blockers such as Nimodipine may prevent spasm of the artery where the aneurysm ruptured.


  • Point of Clarification

- As stated above, a Subarachnoid Hemorrhage is bleeding into a space in the brain, generally causing significant and dangerous symptoms (see Subarachnoid Hemorrhage).  A ruptured Cerebral Aneurysm is just one cause of Subarachnoid Hemorrhage.