Brain Aneurysm (Cerebral Aneurysm)
Benjamin Wedro, MD, FACEP, FAAEM
Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
- Brain aneurysm facts
- What is a brain aneurysm and what causes a brain aneurysm?
- What are the signs and symptoms of brain aneurysm?
- How is brain aneurysm diagnosed?
- What is the treatment for brain aneurysm?
- What is the outcome of brain aneurysm?
- What are future directions for the treatment of brain aneurysm?
Brain aneurysm facts
- Four major blood vessel supply blood to the brain. They join together at the Circle of Willis at the base of the brain. Smaller arteries leave the circle and branch out to supply brain cells with oxygen and nutrients.
- Artery junction points may become weak, causing a ballooning of the blood vessel wall to potentially form a small sac or aneurysm.
- Cerebral aneurysms are common, but most are asymptomatic and are found incidentally at autopsy.
- Aneurysms can leak or rupture causing symptoms from severe headache to stroke-like symptoms, or death.
- The health care practitioner needs to maintain a high incidence of suspicion to make the diagnosis, since many patients may have an initial small leak of blood causing symptoms hours or days before a catastrophic bleed occurs.
- Diagnosis of a brain aneurysm may require CT scans, lumbar puncture, or angiography.
- Treatment to repair the aneurysm may involve neurosurgery to put a clip across the weak blood vessel wall. Instead of surgery, some patients may be treated by an interventional radiologist or neurologist who may use a coil to fill the aneurysm to prevent bleeding.
What is a brain aneurysm and what causes a brain aneurysm?
The Circle of Willis is the junction of the four many arteries, two carotid arteries and two vertebral arteries, that supply the brain with nutrition (especially oxygen and glucose). This loop of arteries is located at the base of the brain and sends out smaller branch arteries to all parts of the brain. The junctions where these arteries come together may develop weak spots. These weak spots can balloon out and fill with blood, creating the outpouchings of blood vessels known as aneurysms. These sac-like areas may leak or rupture, spilling blood into surrounding brain tissue.
There are other rare causes of aneurysms. Mycotic aneurysms are caused by infections of the artery wall. Tumors and trauma can also cause aneurysms to form. Drug abuse, especially cocaine, can cause the artery walls to inflame and weaken.
Brain aneurysms are a common occurrence. At autopsy, incidental aneurysms that have never caused any symptoms or issues are found in more than 1% of people. Most aneurysms remain small and are never diagnosed. Some, however, may gradually become larger and exert pressure on surrounding brain tissue and nerves and may be diagnosed because of stroke-like symptoms including:
- numbness, or weakness of one side of the face,
- a dilated pupil, or
- change in vision.
The greater concern is a brain aneurysm that leaks or ruptures, and potentially causes stroke or death. Blood may leak into one of the membranes (meninges) that covers the brain and spinal canal and is known as a subarachnoid hemorrhage (sub= beneath + arachnoid=one of the brain coverings + hemorrhage=bleeding).
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