ANEURYSM, WHAT IS IT?,IT'S EFFECT ON OUR DAILY LIVING.

An aneurysm is an abnormal bulge or ballooning in your blood vessels.

You may have one of several types of aneurysms, including:

Aortic aneurysm. An aortic aneurysm forms in your aorta, a major blood vessel about the size of a garden hose. Your aorta carries blood from your heart to your vital organs. You may not know you have an aneurysm because they usually don't cause symptoms, even when they are large. However, an aneurysm can burst (rupture) or split (dissect), causing internal bleeding and often leading to death.

Abdominal aortic aneurysms form along the aorta in the section that passes through your abdomen. Thoracic aortic aneurysms form along the aorta in the section that passes through your chest area. Thoracoabdominal aortic aneurysms form along the section of the aorta between your chest area and abdomen.

Brain aneurysm. A brain aneurysm occurs in a blood vessel supplying your brain, usually at branching points of arteries. The weakened area forms a small sac or balloon that fills with blood. Brain aneurysms can rupture and cause bleeding into your brain, resulting in a subarachnoid hemorrhage.

Some small brain aneurysms, especially those located on the arteries in the front part of your brain, have a low risk of rupture. Doctors will assess the size, location and appearance of the aneurysm to clarify the risk of rupture. Medical and family history also can help clarify the risk. Doctors will then compare that risk to the risk of treatment and decide whether to manage or treat the aneurysm.

Peripheral aneurysm. A peripheral aneurysm forms in other blood vessels in your body, including arteries in your legs, 

CAUSES

Brain aneurysms develop as a result of thinning artery walls. Aneurysms often form at forks or branches in arteries because those sections of the vessel are weaker.

Although aneurysms can appear anywhere in the brain, they are most common in arteries at the base of the brain.

RISK FACTORS

A number of factors can contribute to weakness in an artery wall and increase the risk of a brain aneurysm. Brain aneurysms are more common in adults than in children and more common in women than in men.

Some of these risk factors develop over time; others are present at birth.

Risk factors that develop over time

These include:

• Older age
• Smoking
• High blood pressure (hypertension)
• Hardening of the arteries (arteriosclerosis)
• Drug abuse, particularly the use of cocaine
• Head injury
• Heavy alcohol consumption
• Certain blood infections
• Lower estrogen levels after menopause

Risk factors present at birth

These include:

• Inherited connective tissue disorders, such as Ehlers-Danlos syndrome, that weaken blood vessels
• Polycystic kidney disease, an inherited disorder that results in fluid-filled sacs in the kidneys and usually increases blood pressure
• Abnormally narrow aorta (coarctation of the aorta), the large blood vessel that delivers oxygen-rich blood from the heart to the body
• Cerebral arteriovenous malformation (brain AVM), an abnormal connection between arteries and veins in the brain that interrupts the normal flow of blood between them
• Family history of brain aneurysm, particularly a first-degree relative, such as a parent, brother or sister

COMPLICATIONS

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

If the pressure becomes too elevated, the blood and oxygen supply to the brain may be disrupted to the point that 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 leaked is at risk of bleeding again. Re-bleeding can cause further damage to brain cells.
• Vasospasm. After a brain aneurysm ruptures, blood vessels in your brain may narrow erratically (vasospasm). This condition can limit blood flow to brain cells (ischemic stroke) and cause additional cell damage and loss.

• Hydrocephalus. When an aneurysm rupture results in bleeding in the space between the brain and surrounding tissue (subarachnoid hemorrhage) — most often the case — the blood can block circulation of the fluid surrounding the brain and spinal cord (cerebrospinal fluid).

  This condition can result in an excess of cerebrospinal fluid that increases pressure on the brain and can damage tissues (hydrocephalus).

• Hyponatremia. Subarachnoid hemorrhage from a ruptured brain aneurysm can disrupt the balance of sodium in the blood supply. This may occur from damage to the hypothalamus, an area near the base of the brain.

  A drop in blood sodium levels (hyponatremia) can lead to swelling of brain cells and permanent damage.

PREPARING FOR YOUR APPOINTMENT

Brain aneurysms are most often detected after they've ruptured and become medical emergencies. However, a brain aneurysm may be detected when you've undergone head-imaging tests for another condition.

If such test results indicate you have a brain aneurysm, you'll need to discuss the results with a specialist in brain and nervous system disorders (neurologist or neurosurgeon).

TESTS AND DIAGNOSIS

If you have a sudden, severe headache or other symptoms possibly related to a ruptured aneurysm, you will have a test or series of tests to determine if you have had bleeding into the space between your brain and surrounding tissues (subarachnoid hemorrhage) or another type of stroke.

If bleeding has occurred, then your emergency care team will determine if a ruptured aneurysm is the cause.

If you have symptoms of an unruptured brain aneurysm — such as pain behind the eye, changes in vision and paralysis on one side of the face — you will likely have the same tests.

Diagnostic tests include:

• Computerized tomography (CT). A CT scan, a specialized X-ray exam, is usually the first test used to determine if you have bleeding in the brain. The test produces images that are 2-D "slices" of the brain.

  With this test, you may also receive an injection of a dye that makes it easier to observe blood flow in the brain and may indicate the site of a ruptured aneurysm. This variation of the test is called CT angiography.

• Cerebrospinal fluid test. If you've had a subarachnoid hemorrhage, there will most likely be red blood cells in the fluid surrounding your brain and spine (cerebrospinal fluid). Your doctor will order a test of the cerebrospinal fluid if you have symptoms of a ruptured aneurysm but a CT scan hasn't shown evidence of bleeding.

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

• Magnetic resonance imaging (MRI). An MRI uses a magnetic field and radio waves to create detailed images of the brain, either 2-D slices or 3-D images.

  A type of MRI that assesses the arteries in detail (MRI angiography) may detect the site of a ruptured aneurysm.

• Cerebral angiogram. During this procedure, also called a cerebral arteriogram, your doctor inserts a thin, flexible tube (catheter) into a large artery — usually in your groin — and threads it 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-ray images can then reveal details about the conditions of your arteries and the site of a ruptured aneurysm. This test is more invasive than others and is usually used when other diagnostic tests don't provide enough information.

Screening for brain aneurysms

The use of imaging tests to screen for unruptured brain aneurysms is generally not recommended. However, you may want to discuss with your doctor the potential benefit of a screening test if you have:

• A parent or sibling who has had a ruptured brain aneurysm, particularly if you have two such first-degree family members with brain aneurysms
• A congenital disorder that increases your risk of a brain aneurysm

TREATMENTS AND DRUGS

Surgery

There are two common treatment options for a ruptured brain aneurysm.

• Surgical clipping is a procedure to close off an aneurysm. The neurosurgeon removes a section of your skull to access the aneurysm and locates the blood vessel that feeds the aneurysm. Then he or she places a tiny metal clip on the neck of the aneurysm to stop blood flow to it.

• Endovascular coiling is a less invasive procedure than surgical clipping. The surgeon inserts a hollow plastic tube (catheter) into an artery, usually in your groin, and threads it through your body to the aneurysm.

  He or she then uses a guide wire to push a soft platinum wire through the catheter and into the aneurysm. The wire coils up inside the aneurysm, disrupts the blood flow and causes blood to clot. This clotting essentially seals off the aneurysm from the artery.

Both procedures pose risks, particularly bleeding in the brain or loss of blood flow to the brain. The endovascular coil is less invasive and may be initially safer, but it also has a higher risk of subsequent re-bleeding, and additional procedures may be necessary.

There are new treatments available for brain aneurysm, including those called flow diverters. These may be particularly useful in larger aneurysms which cannot be safely treated with other options.

Your neurosurgeon or interventional neuroradiologist, in collaboration with your neurologist, will make a recommendation based on the size, location and overall appearance of the brain aneurysm, your ability to undergo a procedure, and other factors.

Other treatments

Other treatments for ruptured brain aneurysms are aimed at relieving symptoms and managing complications.

• 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 medications may lessen the erratic narrowing of blood vessels (vasospasm) that may be a complication of a ruptured aneurysm.

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

• Interventions to prevent stroke from insufficient blood flow include intravenous injections of a drug called a vasopressor, which elevates blood pressure to overcome the resistance of narrowed blood vessels.

  An alternative intervention to prevent stroke is angioplasty.