An aneurysm is an enlarging of an artery caused by weakness in the artery’s wall. A berry aneurysm, which looks like a berry on a narrow stem, is the most common type of brain aneurysm. They make up 90 percent of all brain aneurysms, according to Stanford Health Care. Berry aneurysms tend to appear at the base of the brain where the major blood vessels meet, also known as the Circle of Willis.
Over time, pressure from the aneurysm on the already weak artery wall can cause the aneurysm to rupture. When a berry aneurysm ruptures, blood from the artery moves into the brain. A ruptured aneurysm is a serious condition that needs immediate medical treatment.
Keep in mind that, according to the American Stroke Association, only 1.5 to 5 percent of people will develop a brain aneurysm. Among people who have a brain aneurysm, only 0.5 to 3 percent will experience a rupture.
Berry aneurysms are typically small and symptom free, but larger ones sometimes put pressure on the brain or its nerves. This can cause neurological symptoms, including:
- a headache in a particular area
- large pupils
- blurred or double vision
- pain above or behind the eye
- weakness and numbness
- trouble speaking
Contact your doctor if you experience any of these symptoms.
Ruptured aneurysms usually cause blood from the affected artery to move into the brain. This is called a subarachnoid hemorrhage. Symptoms of a subarachnoid hemorrhage include those listed above as well as:
Causes and risk factors
There are certain factors that make some people more likely to get a berry aneurysm. Some are congenital, meaning people are born with them. Others are medical conditions and lifestyle habits. In general, berry aneurysms are most common in adults over 40 and women.
Congenital risk factors
- connective tissue disorders (e.g., Ehlers-Danlos syndrome, Marfan syndrome, and fibromuscular dysplasia)
- polycystic kidney disease
- an abnormal artery wall
- cerebral arteriovenous malformation
- family history of berry aneurysms
- blood infections
- traumatic head injury
- high blood pressure
- hardened arteries, also called atherosclerosis
- lower levels of estrogen
- drug use, especially cocaine
- heavy alcohol use
Medical risk factors
Lifestyle risk factors
Your doctor can diagnose a berry aneurysm by performing several tests. These include computerized tomography (CT) and magnetic resonance imaging (MRI) scans. While doing either of these scans, your doctor may also inject you with dye to better see the blood flow in your brain.
If those methods don’t show anything, but your doctor thinks you still may have a berry aneurysm, there are other diagnostic tests they can perform.
One such option is a cerebral angiogram. This is performed by inserting a thin tube containing dye into a large artery, usually the groin, and pushing it up to the arteries in your brain. This allows your arteries to easily show up in an X-ray. However, this imaging technique is rarely used today given its invasive nature.
There are three surgical treatment options for both unruptured and ruptured berry aneurisms. Each option comes with its own set of risks of possible complications. Your doctor will consider the size and location of the aneurysm as well as your age, other medical conditions, and family history to choose the safest option for you.
One of the most common berry aneurysm treatments is surgical clipping. A neurosurgeon removes a small piece of the skull to get access to the aneurysm. They place a metal clip on the aneurysm to stop blood from flowing into it.
Surgical clipping is an invasive surgery that usually requires a few nights in the hospital. After that, you can expect four to six weeks of recovery. During that time, you should be able to care for yourself. Just make sure to limit your physical activity to allow your body time to recover. You can slowly start adding in gentle physical activity, such as walking and household tasks. After four to six weeks, you should be able to return to your pre-surgery levels of activity.
The second treatment option is endovascular coiling, which is less invasive than surgical clipping. A small tube is inserted into a large artery and pushed up into the aneurysm. This process is similar to that of the cerebral angiogram your doctor may use to get a diagnosis. A soft platinum wire goes through the tube and into the aneurysm. Once it’s in the aneurysm, the wire coils and causes the blood to clot, which seals the aneurysm.
The procedure usually only requires a one-night hospital stay, and you can return to your usual level of activity within days. While this option is less invasive, it does come with the risk of future bleeding, which may require additional surgery.
Flow diverters are a relatively new treatment option for berry aneurysms. They involve a small tube, called a stent, which is placed on the aneurysm’s parent blood vessel. It redirects blood away from the aneurysm. This immediately reduces blood flow to the aneurysm, which should close completely in six weeks to six months. In patients who aren’t surgical candidates, a flow diverter can be a safer treatment option, since it doesn’t require entering the aneurysm, which increases the risk of the aneurysm rupturing.
If the aneurysm hasn’t ruptured, your doctor may decide it’s safest to just monitor the aneurysm with regular scans and manage any symptoms you have. Options for managing symptoms include:
- pain relievers for headaches
- calcium channel blockers to keep blood vessels from narrowing
- anti-seizure medications for seizures caused by ruptured aneurysms
- angioplasty or an injection of a drug that increases blood pressure to keep blood flowing and prevent a stroke
- draining excess cerebrospinal fluid from a ruptured aneurysm using a catheter or shunt system
- physical, occupational, and speech therapy to address brain damage from a ruptured berry aneurysm
There’s no known way to prevent berry aneurysms, but there are lifestyle changes that can lower your risk. These include:
- quitting smoking and avoiding secondhand smoke
- avoiding recreational drug use
- following a healthy diet that’s low in saturated fats, trans fats, cholesterol, salt, and added sugar
- doing as much physical activity as you can
- working with your doctor to treat high blood pressure or high cholesterol if you have them
- talking with your doctor about risks associated with oral contraceptives
If you already have a berry aneurysm, making these changes can still help you to prevent the aneurysm from rupturing. In addition to these changes, you should also avoid unnecessary straining, such as lifting heavy weights, if you have an unruptured aneurysm.
Many people with berry aneurysms go their entire life without knowing they have one. When a berry aneurysm becomes very large or ruptures, however, it can have serious, lifelong effects. These lasting effects depend mostly on your age and condition, as well as the size and location of the berry aneurysm.
The amount of time between detection and treatment is very important. Listen to your body and seek immediate medical attention if you think you might have a berry aneurysm.