Brain aneurysm

A brain aneurysm (AN-yoo-riz-um) is a bulge or ballooning in a blood vessel in the brain. It's also known as a cerebral aneurysm or intracranial aneurysm. One type of aneurysm called a berry or saccular aneurysm looks like a berry hanging on a stem.

Experts think brain aneurysms form and grow because blood flowing through the blood vessel puts pressure on a weak area of the vessel wall. This can increase the size of the brain aneurysm. If the brain aneurysm leaks or ruptures, it causes bleeding in the brain, known as a hemorrhagic stroke.

Most often, a ruptured brain aneurysm happens in the space between the brain and the thin tissues covering the brain. This type of hemorrhagic stroke is called a subarachnoid hemorrhage.

Brain aneurysms are common. But most brain aneurysms aren't serious, especially if they're small. Most brain aneurysms don't rupture. They usually don't cause symptoms or cause health problems. In many people, brain aneurysms are found during tests for other conditions.

However, if an aneurysm ruptures it can quickly become life-threatening and requires emergency treatment.

If a brain aneurysm hasn't ruptured, treatment may be right for some people. There are many factors to be considered. If it is felt that the treatment risk is lower than the future risk of aneurysm rupture, then treatment of an unruptured brain aneurysm may be recommended. Talk about your treatment options with your healthcare professional.

Ruptured aneurysm symptoms

A sudden, severe headache is the key symptom of a ruptured aneurysm. This headache is often described by people as the worst headache they've ever experienced.

In addition to a severe headache, symptoms of a ruptured aneurysm can include:

• Nausea and vomiting.
• Stiff neck.
• Blurred or double vision.
• Sensitivity to light.
• Seizure.
• Loss of consciousness.
• Confusion.

'Leaking' aneurysm symptoms

In some cases, an aneurysm may leak a small amount of blood. When this happens, a more severe rupture often follows. Leaks may happen days or weeks before a more severe rupture.

Leaking brain aneurysm symptoms may include a sudden, extremely severe headache that may last several days and up to two weeks.

Unruptured aneurysm symptoms

An unruptured brain aneurysm may not have any symptoms, especially if it's small. However, a larger unruptured aneurysm may press on brain tissues and nerves.

Symptoms of an unruptured brain aneurysm may include:

• Pain above and behind one eye.
• A dilated pupil.
• A change in vision or double vision.
• Numbness of one side of the face.
• Seizures.

When to see a doctor

Seek medical attention right away if you develop a sudden, extremely severe headache. If you're with someone who complains of a sudden, severe headache or who loses consciousness or has a seizure, call 911 or your local emergency number.

Brain aneurysms are caused by thinning artery walls. Aneurysms often form at forks or branches in arteries because those areas of the vessels are weaker. Although aneurysms can happen anywhere in the brain, they're most common in arteries at the base of the brain.

Several factors can cause weakness in an artery wall. These factors may increase the risk of a brain aneurysm or aneurysm rupture. Some of these risk factors develop over time while others are present at birth.

Risk factors include:

• Age. Brain aneurysms can happen at any age. However, they're more common in adults between ages 30 and 60.
• Being female. Brain aneurysms are more common in women than in men.
• Cigarette smoking. Smoking is a risk factor for brain aneurysms to form and for brain aneurysms to rupture.
• High blood pressure. This condition can weaken arteries. Aneurysms are more likely to form and to rupture in weakened arteries.
• Drug use, particularly using cocaine. Drug use raises blood pressure. If illicit drugs are used in a vein, it can lead to an infection, which may cause an aneurysm.
• Heavy alcohol use. This also can increase blood pressure.
• Inherited connective tissue conditions, such as Ehlers-Danlos syndrome. These conditions weaken blood vessels.
• Polycystic kidney disease. This inherited condition results in fluid-filled sacs in the kidneys. It also may increase blood pressure.
• A narrow aorta, also called coarctation of the aorta. The aorta is the large blood vessel that delivers oxygen-rich blood from the heart to the body.
• Brain arteriovenous malformation, also called brain AVM. In this condition, arteries and veins in the brain are tangled. This affects blood flow.
• A family history of brain aneurysm. The risk is higher if you have family members who have had a brain aneurysm. This is particularly true if two or more first-degree relatives — such as a parent, sibling or child — have had a brain aneurysm. If you have a family history, ask your healthcare professional about getting screened for a brain aneurysm.

Some types of aneurysms may happen after a head injury or from certain blood infections.

Risk factors for a ruptured aneurysm

There are some factors that make it more likely an aneurysm will rupture. They include:

• Having a large aneurysm.
• Having aneurysms in certain locations.
• Having an irregular shape of the aneurysm or having an outpouching on the aneurysm, called a daughter sac.
• Smoking cigarettes.
• Having untreated high blood pressure.

When a brain aneurysm ruptures, the bleeding usually lasts only a few seconds. However, the blood can cause direct damage to surrounding cells and can kill brain cells. It also increases pressure inside the skull.

If the pressure becomes too high, it may disrupt the blood and oxygen supply to the brain. Loss of consciousness or even death may occur.

Complications that can develop after the rupture of an aneurysm include:

• Re-bleeding. An aneurysm that has ruptured or has leaked is at risk of bleeding again. Re-bleeding can cause further damage to brain cells.
• Narrowed blood vessels in the brain. After a brain aneurysm ruptures, blood vessels in the brain may contract and narrow. This is known as vasospasm. Vasospasm can cause an ischemic stroke, in which there's limited blood flow to brain cells. This may cause more cell damage and loss.
• A buildup of fluid within the brain, known as hydrocephalus. Most often, a ruptured brain aneurysm happens in the space between the brain and the thin tissues covering the brain. The blood can block the movement of the spinal fluid that surrounds the brain and spinal cord. As a result, a buildup of fluid puts pressure on the brain and can damage tissues.
• Change in sodium level. Bleeding in the brain can disrupt the balance of sodium in the blood. A drop in blood sodium levels can lead to swelling of brain cells and permanent damage.

Screening tests and procedures used to detect and diagnose brain aneurysms include:

• CT scan. This specialized X-ray is usually the first test used to assess for bleeding in the brain or another type of stroke. The test produces images that are 2D slices of the brain.

  A CT angiogram can create detailed images of the arteries providing blood flow in the brain. The test involves injecting dye into the vein that makes it easier to observe blood flow. It also can detect the presence of an aneurysm.

• Lumbar puncture, known as a spinal tap. If you've had a subarachnoid hemorrhage, there will most likely be red blood cells in the fluid surrounding your brain and spine. This fluid is called cerebrospinal fluid. If you have symptoms of a ruptured aneurysm but a CT scan doesn't show evidence of bleeding, a test of your cerebrospinal fluid can help make a diagnosis.

  The procedure to draw cerebrospinal fluid from your back with a needle is called a lumbar puncture.

• MRI. This imaging test uses a magnetic field and radio waves to create detailed images of the brain. These images may be either 2D or 3D images and can show if there's bleeding in the brain.

  A type of MRI that captures images of the arteries in detail is called MR angiography. This type of MRI can detect the size, shape and location of an aneurysm.

• Cerebral angiogram. During this procedure, a thin, flexible tube called a catheter is used. The catheter is inserted into an artery, usually in the groin or the wrist. The catheter threads past your heart to the arteries in your brain. A special dye injected into the catheter travels to arteries throughout your brain.

  A series of X-rays can then reveal details about the conditions of your arteries and detect an aneurysm. A cerebral angiogram — also called a cerebral arteriogram — is usually used when other diagnostic tests don't provide enough information.

Screening for brain aneurysms

Screening for unruptured brain aneurysms is typically only used if you are at high risk. Talk to your healthcare professional about screening if you have:

• A family history of brain aneurysms or a hemorrhagic stroke. Particularly if two first-degree relatives — your parents, siblings or children — have had a brain aneurysm or hemorrhagic strokes.
• A condition that increases your risk of developing a brain aneurysm. These disorders include polycystic kidney disease, coarctation of the aorta or Ehlers-Danlos syndrome, among others.

Most aneurysms don't rupture. And for many people, an unruptured aneurysm never causes symptoms. But if the aneurysm ruptures, several factors may affect the outcome, which is known as the prognosis. They include:

• The person's age and health.
• Whether the person has other conditions.
• The size and location of the aneurysm.
• How much bleeding has happened.
• How much time passed before receiving medical care.

About 25% of people who experience a ruptured aneurysm die within 24 hours. Another 25% have complications that lead to death within six months.

Surgery

There are two common treatment options for repairing a ruptured brain aneurysm. For some people, these procedures may be considered to treat an unruptured aneurysm. However, the potential treatment risks may outweigh the potential benefits for some unruptured aneurysms.

Surgical clipping

Surgical clipping is a procedure to close off an aneurysm. The neurosurgeon removes a section of your skull to access the aneurysm. The neurosurgeon then locates the blood vessel that feeds the aneurysm. The surgeon places a tiny metal clip on the neck of the aneurysm to stop blood flow into it.

Surgical clipping can be very effective. Typically, aneurysms that are clipped don't return. The risks of surgical clipping include bleeding in the brain or loss of blood flow to the brain. These risks are low.

Recovery from surgical clipping usually takes about 4 to 6 weeks. When surgical clipping is done for an unruptured aneurysm, many people can leave the hospital a day or two after surgery. For those who have surgical clipping because of a ruptured aneurysm, the hospital stay is typically much longer as they recover from the aneurysm rupture.

Endovascular treatment

This is a less invasive procedure than surgical clipping, and it may be safer. Endovascular treatment involves accessing the aneurysm by threading a small plastic tube called a catheter through the artery. The catheter is moved into the brain arteries. Then coils may be placed.

• Endovascular coils. During this procedure, a neurosurgeon inserts the catheter into an artery, usually in the groin or wrist. Then the surgeon threads it through the body to the aneurysm. A tiny coil shaped like a spiral is placed inside the aneurysm. This prevents blood from flowing into the aneurysm. The coil also causes the blood that's in the aneurysm to clot.
• Endovascular stents. A stent is a small tube that may be used with an endovascular coil for some types of brain aneurysms. A stent can hold the coil in place.

Like surgical clipping, endovascular treatment carries the risk of bleeding in the brain or loss of blood flow to the brain. Also, there's a risk that the aneurysm may again appear over time. If that happens, the procedure may need to be repeated. You'll likely need follow-up imaging tests to be sure the aneurysm hasn't returned.

Flow diversion

Flow diversion is an endovascular treatment option for treatment of a brain aneurysm. The procedure involves placing a stent in the blood vessel to divert blood flow away from the aneurysm. The stent that's placed is called a flow diverter.

With less blood flow going to the aneurysm, there's less risk of rupture. It also allows the body to heal. The stent prompts the body to grow new cells that seal the aneurysm.

Flow diversion may be particularly useful in larger aneurysms that can't be treated with other options and in locations that are more difficult to treat with surgery or standard endovascular treatments.

Other procedures for ruptured aneurysms

Other procedures to treat ruptured aneurysms and complications of the rupture may include:

• Angioplasty. This is a procedure to expand a narrowed blood vessel in the brain caused by vasospasm. The procedure also can help prevent a stroke.
• Ventricular or lumbar draining catheters and shunt surgery can lessen pressure on the brain from a buildup of cerebrospinal fluid. A catheter may be placed in the spaces that are filled with fluid inside the brain. Or it can be placed in the area surrounding the brain and spinal cord. The catheter drains the excess fluid into an external bag or into the abdomen for more permanent drainage.

Medicines for ruptured brain aneurysms

Medicines may be used after a ruptured brain aneurysm to relieve symptoms and manage complications. Medicines may include:

• Pain relievers, such as acetaminophen (Tylenol, others), may be used to treat headache pain.

• Calcium channel blockers prevent calcium from entering cells of the blood vessel walls. These medicines may lessen the risk of having symptoms from the narrowing of blood vessels, known as vasospasm. Vasospasm may be a complication of a ruptured aneurysm.

  One of these medicines, nimodipine (Nymalize), has been shown to reduce the risk of delayed brain injury caused by insufficient blood flow. This can happen after subarachnoid hemorrhage from a ruptured aneurysm.

• Medicines to open blood vessels. A medicine can be given to dilate the blood vessels. This can be given through an IV in the arm or with a catheter directly into the arteries supplying the brain. This can help prevent a stroke by allowing the blood to flow freely. Blood vessels also can be expanded using medicines known as vasodilators.
• Anti-seizure medicines may be used to treat seizures related to a ruptured aneurysm. The medicines typically aren't given if a seizure hasn't happened.

Rehabilitative therapy may be used after a brain aneurysm ruptures. Damage to the brain from a subarachnoid hemorrhage may result in the need for physical, speech and occupational therapy to relearn skills.

Treating unruptured brain aneurysms

A surgical clip, an endovascular coil or a flow diverter can be used to seal off an unruptured brain aneurysm. This can help prevent a future rupture. However, the risk of rupture may be extremely low in some unruptured aneurysms, and the known risks of the procedures may outweigh the potential benefits.

A neurologist working with a neurosurgeon or interventional neuroradiologist can help you decide if treatment is right for you.

If you have an unruptured brain aneurysm, you may lower the risk of rupture by making these lifestyle changes:

• Don't smoke cigarettes. If you smoke, talk to your healthcare professional. They can suggest strategies or a treatment program to help you quit.
• Manage your blood pressure if you have high blood pressure.
• Eat a healthy diet and exercise. Changes in diet and exercise can help lower blood pressure. Talk to your healthcare professional about changes that are right for you.
• Don't use alcohol in excess.
• Don't use recreational drugs such as cocaine, methamphetamine or others. If you do use these drugs and would like to quit, talk to your healthcare professional.

The Brain Aneurysm Foundation offers information on connecting with support groups in many states and in other countries.

If test results show you have a brain aneurysm, you'll need to talk with a specialist in brain and nervous system conditions. These specialists include neurologists, neurosurgeons and neuroradiologists.

Here's some information to help you get ready for your appointment.

What you can do

• Be aware of anything you need to do ahead of time. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
• Write down symptoms you have, including any that may not seem related to the reason for which you scheduled the appointment.
• Write down important personal information, including major stresses or recent life changes.
• Make a list of all medicines, vitamins and supplements you're taking and the doses.
• Take a family member or friend along. It can be hard to remember all the information provided during an appointment. Someone who goes with you may remember something that you missed or forgot.
• Write down questions to ask your healthcare team.

Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For unruptured brain aneurysms, some basic questions to ask include:

• What do you know about the size, location and overall appearance of the aneurysm?
• How likely is my aneurysm to rupture?
• What treatment do you recommend at this time? What are the risks of treatment?
• If treatment is not indicated currently, how often will I need to have follow-up scans for the aneurysm?
• What steps can I take to lower the risk of an aneurysm rupturing?

Don't hesitate to ask other questions.

What to expect from your doctor

Be prepared to answer questions, such as:

• Do you smoke cigarettes?
• How much alcohol do you drink?
• Do you use recreational drugs?
• Are you being treated for high blood pressure?
• Do you take your medicines as prescribed by your healthcare professional?
• Is there a history of brain aneurysm or brain aneurysm rupture in your family?
• What is your medical history?