Cerebral Aneurysm

A cerebral aneurysm is the bulging or ballooning out of part of the wall of a vein or artery in the brain.


Common causes include:

  • Congenital (present since birth) defects.

  • High blood pressure.

  • The build-up of fatty deposits in the arteries (atherosclerosis).

  • Blood vessels that develop abnormally.

  • Diseases that cause weakening and damage to the walls of blood vessels.

Uncommon causes include:

  • Head trauma (damage caused by an accident).

  • Infection.

  • Tumors.

  • Drug abuse (mostly from cocaine, heroin, and amphetamine use).

Cerebral aneurysms can occur at any age. They are more common in adults than in children. They and are slightly more common in women than in men.


The signs and symptoms of an unruptured cerebral aneurysm will partly depend on its size and rate of growth.

A small, unchanging aneurysm will generally produce no symptoms. A larger aneurysm that is steadily growing may produce symptoms such as headache, neck stiffness or pain, loss of feeling in the face or problems with the eyes.

If an aneurysm bursts, the problem can be life-threatening. Symptoms may include:

  • A sudden and usually severe headache.

  • Neck stiffness or pain.

  • Confusion and/or drowsiness.

  • Problems speaking.

  • Weakness in an arm and/or a leg.

  • Nausea (feeling sick to your stomach).

  • Vision impairment.

  • Vomiting.

  • Loss of consciousness.

Rupture of a cerebral aneurysm results in bleeding in the brain, causing a stroke. Or, blood can leak into the area around the brain and develop into a blood clot within the skull. More problems can occur as a result of the aneurysm breaking. These include:

  • Re-bleeding.

  • Hydrocephalus (an increase in normal brain fluid in the chambers inside the brain).

  • Vasospasm (blood vessels decrease in size and starve the brain of nutrients and oxygen).


Emergency treatment for a ruptured cerebral aneurysm generally includes restoring breathing, and reducing pressure inside the head. Immediate emergency surgery may be recommended to help prevent damage caused by hydrocephalus and to reduce the risk of re-bleeding.

When aneurysms are discovered before rupture occurs, microcoil thrombosis or balloon embolization may be performed on patients for whom surgery is considered too risky. During these procedures, a thin, hollow tube (catheter) is inserted through an artery to travel up to the brain. Once the catheter reaches the aneurysm, tiny balloons or coils are used to block blood flow through the aneurysm. Other treatments may include:

  • Bed rest.

  • Drug therapy.

  • Hypertensive-hypervolemic therapy (which elevates blood pressure, increases blood volume, and thins the blood) to drive blood flow through and around blocked arteries and control vasospasm.


The prognosis for a patient with a ruptured cerebral aneurysm depends on:

  • The extent and location of the aneurysm.

  • The person's age.

  • General health.

  • Neurological condition.

Some people with a ruptured cerebral aneurysm die from the initial bleeding. Others recover with little or no problems. Early diagnosis and treatment are important.