Complications

When a brain aneurysm ruptures, the bleeding usually lasts only a few seconds. The blood can cause direct damage to surrounding cells, and the bleeding can damage or kill other cells. It also increases pressure inside the skull.

If the pressure becomes too elevated, the blood and oxygen supply to the brain may be disrupted to the point that loss of consciousness or even death may occur.

Complications that can develop after the rupture of an aneurysm include:

• Re-bleeding. An aneurysm that has ruptured or leaked is at risk of bleeding again. Re-bleeding can cause further damage to brain cells.
• Vasospasm. After a brain aneurysm ruptures, blood vessels in your brain may narrow erratically (vasospasm). This condition can limit blood flow to brain cells (ischemic stroke) and cause additional cell damage and loss.
• Hydrocephalus. When an aneurysm rupture results in bleeding in the space between the brain and surrounding tissue (subarachnoid hemorrhage) — most often the case — the blood can block circulation of the fluid surrounding the brain and spinal cord (cerebrospinal fluid). This condition can result in an excess of cerebrospinal fluid that increases pressure on the brain and can damage tissues (hydrocephalus).

• Hyponatremia. Subarachnoid hemorrhage from a ruptured brain aneurysm can disrupt the balance of sodium in the blood. This may occur from damage to the hypothalamus, an area near the base of the brain.

  A drop in blood-sodium levels (hyponatremia) can lead to swelling of brain cells and permanent damage.