A brain aneurysm is a weakness in the wall of an artery causing a pouch or a swelling in the blood vessel. The thin walls of an aneurysm can burst and cause bleeding into the tissues of the brain.
There usually are few symptoms of a brain aneurysm. Sometimes, brain aneurysms press on a nerve or leak small amounts of blood before a major rupture, thus producing warning signs. These symptoms, which can occur minutes to weeks before a rupture, include:
- Severe headache
- Facial pain
- Double vision, droopy eyelid or other vision problems
An actual rupture can produce the following symptoms:
- A sudden, severe headache
- A brief loss of consciousness that often follows the onset of the headache. Some people remain in a coma, but most often patients wake up feeling confused and sleepy. Within a few minutes or few hours, the patient may again begin to feel confused and sleepy.
- Vomiting
- Dizziness
- Frequent fluctuations in the heartbeat and breathing rate often occur
- Seizures
- Paralysis on one side of the body or neurologic problems (usually occuring in about 25% of the people who have subarachnoid hemorrhages)
Because brain aneurysms are silent until they cause bleeding into the brain, a timely diagnosis can be difficult. The diagnosis of a subarachnoid hemorrhage can usually be made with a computed tomography (CT) scan. If the CT scan is not conclusive, a lumbar puncture (spinal tap) can be done to confirm or rule out the diagnosis.
Approximately one-third of those who have a subarachnoid hemorrhage die during the hemorrhage because of extensive brain damage. Without proper treatment for the brain aneurysm, 20 to 30% will have a second bleed within the first month and those who survive three months have approximately a 3% chance every year of having another episode of bleeding. Recurrent bleeding has a 70% mortality rate. Because of the ominous prognosis with delayed definitive therapy, referral to a center of excellence with experience in treating subarachnoid hemorrhage is imperative.
Symptoms of a subarachnoid hemorrhage require emergency evaluation and treatment. If a subarachnoid hemorrhage is confirmed and the patient is medically and neurologically stable, members of the stroke team will confer about the timing and choice of the best diagnostic and treatment options. Usually, magnetic resonance angiography (MRA), CT angiography (CTA) and/or contrast angiography are used to determine the exact size and location of the brain aneurysm. Depending on the results, an interventional radiology, neurosurgical or combination approach is chosen. It is critical to have doctors with the experience, judgment and technical know-how to make the right choices for each patient.
