What is a Brain Aneurysm?
A brain aneurysm, also known as a cerebral aneurysm, is a type of cerebrovascular disease caused by an area of weakness on a blood vessel. It occurs when the wall of a blood vessel in your brain becomes weak and bulges. The pressure inside the blood vessel causes that weak area to balloon out. If the weakened area ruptures, it can cause a hemorrhagic stroke that can lead to brain damage or even death. Most aneurysms happen in arteries, the blood vessels that carry blood to your tissues.
Types of brain aneurysms include:
- Berry or saccular: This is most common type. It looks like a rounded sac off the side of the artery.
- Fusiform: This type of aneurysm bulges out on all sides of the artery.
- Mycotic aneurysm: This is a rare type of saccular aneurysm caused by an infection in the artery wall.
Brain aneurysms are relatively common, affecting about three percent of people. About one in 1000 people with a cerebral aneurysm experience a hemorrhagic stroke. If hemorrhagic stroke occurs, the risk of death is about 40 percent.
Our specialists in neurology and cerebrovascular surgery have deep experience in the diagnosis and treatment of brain aneurysms. We provide individualized care and advanced treatments to reduce your risk of stroke.
Brain Aneurysm Symptoms
Symptoms vary depending on the condition of the aneurysm (unruptured, ruptured or leaking).
Signs of an Unruptured Aneurysm
Unruptured brain aneurysms are usually silent and don’t cause symptoms. If the aneurysm grows, it can press on nerves and tissues in your brain. This can cause:
- Dilated pupil in one eye
- Pain above and behind one eye
- Paralysis, weakness or numbness on one side of the face
- Vision changes or double vision
Signs of a Ruptured Aneurysm
The main sign of a hemorrhagic stroke is a “thunderclap headache”, which many people describe as the worst headache of their life. Other symptoms include:
- Double vision
- Light sensitivity
- Nausea and vomiting
- Neck stiffness
- Seizures
- Loss of consciousness
- Cardiac arrest
A ruptured aneurysm is a medical emergency. Call 911 immediately. Read more about the Penn Stroke Center.
Signs of a Leaking Aneurysm
Some cerebral aneurysms may start to leak before they rupture, causing a sudden severe headache. This symptom, also called a sentinel headache, is a warning sign of a major rupture. Many patients report a sentinel headache six to 20 days before a rupture.
Seek immediate medical care if you experience this type of headache, especially if you have any other aneurysm-related symptoms.
What Causes Brain Aneurysms?
Brain aneurysm causes typically involve any disease or condition that weakens or damages the wall of a blood vessel in the brain.
Some people are born with diseases associated with brain aneurysms, such as:
Other factors that increase your risk brain aneurysm include:
- Atherosclerosis
- Alcohol abuse
- Brain tumor
- Cigarette smoking
- Cocaine or amphetamine use
- Family history of aneurysms
- Head trauma
- High blood pressure
- Infection in the artery wall (mycotic aneurysm)
- Intravenous drug use (mycotic aneurysm)
- Over 40 years of age
Brain Aneurysm Diagnosis
Most people don’t know they have a cerebral aneurysm until it ruptures. Doctors often find brain aneurysms during imaging tests they order for another reason.
If you have symptoms, a family history or other risk factors, your doctor may recommend brain aneurysm screening. Tests doctors use to diagnose brain aneurysms include:
- Cerebral angiography: This is a minimally invasive test in which your doctor inserts a thin tube (catheter) into a blood vessel in your groin or wrist. They thread the catheter to the affected area and release a contrast dye. The dye highlights any bulging or bleeding areas on imaging tests. Your doctor can also treat the aneurysm during the angiography.
- Medical imaging tests: MRI and CT scans allow your doctor to assess the blood vessels in your head and neck. CT angiography (CTA) and MR angiography (MRA) involve the injection of contrast dye into a vein before imaging. The dye shows your blood vessels in greater detail.
In the event of a hemorrhagic stroke, a CT scan rapidly detects bleeding in your brain. Your doctor may also perform a spinal tap (lumbar puncture). This test looks for blood in the cerebrospinal fluid that surrounds your brain and spinal cord.
Brain Aneurysm Treatment at Penn Medicine
Treatment for a cerebral aneurysm depends on the size and location of the aneurysm and whether it has ruptured. Your age, overall health and medical history may also affect the treatment you receive.
For small, unruptured aneurysms, your cerebrovascular expert may recommend a “watch and wait” approach. You’ll need routine check-ups to monitor the growth of the aneurysm and any underlying health conditions. You should also stop smoking and control you blood pressure to reduce the risk of rupture.
Larger unruptured or ruptured brain aneurysms usually require treatment. Your treatment may include a minimally invasive or surgical procedure:
- Endovascular procedures: Endovascular treatments occur inside the artery using catheters inserted into a blood vessel in your wrist or groin. They include a wide range of techniques to block blood flow to the aneurysm and stabilize the artery. Explore the different types of endovascular neurosurgery procedures.
- Aneurysm clipping: This is a type of microsurgical procedure performed under general anesthesia. The surgeon cuts off blood flow to the aneurysm by attaching a metal clip to the base of the aneurysm. Read more about aneurysm clipping.
Neurorehabilitation
If you suffer a hemorrhagic stroke, you may need therapy to regain lost function. Penn Medicine offers comprehensive neurorehabilitation services to assist with recovery after a stroke. The goals of neurorehabilitation are to:
- Improve speech, mobility and strength
- Increase the skills you need to participate in daily activities
Learn more about neurorehabilitation.
Request an Appointment
To make an appointment, please call 800-789-7366 or request a callback.