Library of Information

Use our searchable repository to locate information on your specific condition diagnosis, symptoms, treatment options and recovery information.

Whether you are planning your first consultation after diagnosis, or if you've just begun discussing treatment options with your physician, the glossary of terms can serve as a helpful reference tool.

Brain Aneurysms
Strokes
AVM- Vascular Malformations
Skull Base Surgery

Brain aneurysms

Diagnosis

What is a brain aneurysm?

An aneurysm begins at the base of the brain as a small thinned out area on the wall of an artery. Over time, the blood flow within the artery pounds against the thinned portion of the wall causing it to weaken. As the artery wall becomes gradually thinner from the dilation, the blood flow causes the weakened wall to swell outward. This pressure may cause the aneurysm to rupture and allow blood to escape into the space around the brain. A ruptured aneurysm commonly requires advanced surgical treatment.

Why do aneurysms form?

There is currently no proven cause for aneurysms. Although it has been theorized that since most arteries in the body have walls with three layers and the brain's arteries have segments where one layer is missing, the artery wall of the brain is more likely to weaken. It is also believed by some doctors that people may be predisposed at birth, while others feel that high blood pressure and conditions that induce stress on the arteries are significant contributors.

How are aneurysms diagnosed after they rupture?

When an aneurysm ruptures, the bleeding can be minimal, moderate or severe. A person's physical response to the hemorrhage will most often be related to the amount of blood that escapes from the aneurysm and around the brain. The initial evaluation of the aneurysm will typically occur in the emergency room following symptoms of a severe headache.

Symptoms

Ruptured aneurysms

The most common way for someone to find out that they have an aneurysm is for it to bleed. When blood escapes into the space around the brain, it causes a sudden, excruciating headache. Other symptoms may include: sensitivity to light, neck stiffness, nausea and vomiting.

Unruptured aneurysms

Unruptured aneurysms (that do not bleed) rarely cause symptoms other than headaches. Since aneurysms are typically small in size, usually only one half inch in diameter, symptoms are less likely to occur. However, larger aneurysms can press on the brain or the nerves stemming out of the brain and result in double vision, weakness, numbness, seizures and difficulty speaking.

Treatment

A brain aneurysm, also called a cerebral or intracranial aneurysm, is potentially life-threatening, especially if it ruptures (bleeds). The severity and location of your brain aneurysm will determine whether a neurovascular expert advises observation or surgery. The neurologist or family practitioner you normally see may recommend a neurosurgeon.

Observation

Is when no direct action is taken. Your surgeon considers it safer to monitor the unruptured aneurysm than it is to attempt other invasive procedures. The neurologist or surgeon may suggest following-up with an MRA (magnetic resonance angiography used to detect suspected aneurysms) or a CTA scan (special x-ray used to detect a ruptured aneurysm) from six months to one year after the initial diagnosis to observe any changes in the aneurysm's growth. Observation is rarely an option once the aneurysm has ruptured. There is a high risk of a ruptured aneurysm to rebleed, so patients usually undergo surgical treatment.

Surgical treatment

Surgical treatment procedures for aneurysms include clipping and coiling. Determining which of these options to pursue should be decided mutually between you and your physician. Keeping in mind that aneurysm surgery carries potential risks, our team will make recommendations based on a complete evaluation of your condition.

Clipping
The neurosurgeon opens the skull and delicately separates the aneurysm from the surrounding tissue. A small titanium clip, which opens and closes like a clothespin, is then placed across the base of the aneurysm. Once the clip is secured, blood can no longer flow in or out of the aneurysm sac. By using a needle to drain the remaining blood out of the aneurysm, the sac should empty and eventually collapse. When the blood flow is preserved through the main artery, the aneurysm is not likely to return. To ensure accuracy, an angiogram is performed, where a tiny camera takes an X-Ray picture of the surgical area. This tells the surgeon that the aneurysm has been completely clipped without hitting any nerves or other arteries.

Coiling
Also known as endovascular therapy, coiling is an innovative, less invasive surgical treatment option. This procedure does not involve craniotomy (the opening of the skull), and is performed from inside the blood vessel. A catheter is inserted into the patient's groin area and is guided up toward the brain. A fine wire is then threaded into the catheter and directed into the aneurysm. Once inside the aneurysm, the wire twists into small coils and continues filling the aneurysm sac until it eventually clots off.

Recovery

The recovery process will vary depending on the circumstances of your condition. The overall length of stay may be from one to four weeks following surgery. The length of your hospital stay will depend on:

The size and type of the aneurysm
Whether the aneurysm ruptured or remained unruptured
Where the aneurysm was located in the brain
The treatment procedure that was performed

Strokes

What is a stroke?

A stroke occurs when a blood vessel that brings oxygen and nutrients to the brain becomes clogged or bursts, stopping blood supply to a portion of the brain. When blood can't reach an area of the brain, abilities and functions controlled by that part of the brain might become impaired or lost.

If not treated immediately, a stroke can lead to brain damage and disability. Even though the common symptoms of a stroke may not be painful and are easy to ignore, it is critical to recognize the warning signs and CALL 911 immediately.

Warning signs of stroke

If you experience any or all of the following warning signs, CALL 911

Sudden numbness or weakness on one side of the body, face, arm or leg
Sudden confusion, trouble speaking or difficulty understanding
Sudden, severe headache with no known cause
Sudden trouble seeing in one or both eyes
Sudden difficulty walking, dizziness, loss of balance or coordination

Types of stroke

Ischemic stroke

An ischemic stroke occurs when an artery in the brain becomes blocked or clogged, cutting off the blood flow to a portion of the brain.

Types of ischemic stroke:

Thrombotic stroke - is the most common type of stroke and occurs when an artery in the brain narrows, allowing a blood clot to clog the artery and cut off blood flow. Warning signs typically appear suddenly and progress over the course of a few hours. This type of stroke most often occurs at night or early in the morning.

Embolic stroke - is caused by a blood clot that breaks free from an artery or from the heart and flows through the blood stream until it reaches an artery too small for it to pass through. Signs and symptoms depend on the area of the brain that is blocked.

Hemorrhagic stroke

Hemorrhagic strokes can occur when there is bleeding in the brain. They are less common than ischemic strokes and symptoms are usually very sudden and intense.

Types of hemorrhagic stroke:

Intracerebral hemorrhage - occurs when a blood vessel within the brain bursts and blood leaks into the brain. The most common cause is high blood pressure.

Subarachnoid hemorrhage - occurs when a blood vessel just outside the brain bursts and blood leaks into the area around the brain (called the subarachnoid space). Subarachnoid hemorrhage is caused by a blood vessel abnormality, such as an aneurysm.

Stroke treatment

Our stroke care team understands that a fast diagnosis gives patients a better chance at a full recovery. When patients seek treatment immediately following the onset of their symptoms, doctors have more options in using the most advanced technology available. Your stroke treatment will be determined by the kind of stroke, the severity of symptoms and your overall health.

What happens at the emergency room?

At the emergency room, you will receive a general physical and neurological examination. Your doctor will order a CT scan of your head to find out if you are in fact having a stroke and its specific type. This evaluation will help determine the best treatment for your condition.

Treatment for ischemic stroke

"Clot-busting" drug - Intravenous (IV) Ischemic strokes can be treated with a clot-busting drug known as tPA (tissue plasminogen activator). This drug helps to dissolve the blood clot. When given through an IV (usually in the arm), the medication travels through the bloodstream directly to the blockage. It must be administered within three hours of the onset of stroke symptoms.

"Clot-busting" drug - Intra-arterial
This method delivers clot-busting tPA directly to the blockage. During the procedure, the interventional neuroradiologist inserts a thin, flexible catheter into an artery (usually in the groin area) and guides it up to the clot in the brain. The tPA is then administered through the catheter. While this method can expand the treatment time window, it is more invasive than the IV procedure.

Clot retriever device
The National Brain Aneurysm Center also offers a clot retrieval device that "grabs" clots and restores blood flow to the brain. The clot retriever is the first medical device to be cleared by the U.S. Food and Drug Administration (FDA) for patients experiencing an ischemic stroke. The clot retriever is inserted into an artery in the groin and carefully led up to the blockage in the brain. It restores blood flow by capturing and removing the clot.

Treatment for hemorrhagic stroke (intracerebral)

Intracerebral hemorrhages are most often caused by high blood pressure. Doctors choose the best treatment option for each patient and take into account the location and severity of the bleeding.

Observation
When undergoing observation, patients are closely monitored in the hospital, but no direct action (surgery) is taken.

Surgery
A neurosurgeon opens the skull and performs surgery to remove the clot.

Treatment for hemorrhagic stroke (subarachnoid)

Treatments for hemorrhagic strokes caused by ruptured aneurysms include clipping and coiling. Both procedures stop bleeding in the brain.

Clipping
During this surgery, a neurosurgeon opens the skull and separates the aneurysm from surrounding tissue. A small titanium clip will then be placed around the base of the aneurysm so that blood can no longer flow into it. The surgeon then drains the remaining blood out of the aneurysm and the empty aneurysm sac will shrink with time. When clipped correctly, the aneurysm should not return.

Coiling
Coiling is a newer, less invasive form of surgery. Unlike clipping, it does not require a craniotomy (opening of the skull). During the procedure, the interventional neuroradiologist inserts a catheter into the groin area and guides it up into the brain. The doctor then performs an angiogram to view the blood flow in the blood vessels in the brain. A fine wire is threaded into the catheter and carefully guided into the aneurysm. In the aneurysm, the wire twists into small coils. The doctor continues until the aneurysm is full of the tiny coils, causing the aneurysm sac to clot. After a coiling procedure, regular follow-up angiograms are required.

Rehabilitation after stroke

After a stroke, it is important for you to build strength and confidence so that you can continue your lifestyle and daily activities. Your doctor will work with rehabilitation specialists to provide a treatment program specifically suited for you.

Rehabilitation (rehab) begins in the hospital soon after a stroke. For some, it continues at home. Others require more intense rehabilitation.

The rehabilitation specialists include physical, occupational and speech therapists who will assist in:

Self-care such as feeding, grooming, bathing and dressing
Mobility such as transferring or walking
Communication in speech or language
Cognitive skills such as memory or problem solving
Socialization skills including interacting with people

AVM- Vascular Malformations

Arteriovenous malformations (AVMs)

An AVM is a specific type of vascular malformation that may be found in the brain. AVM stands for arteriovenous malformation or artery-vein malformation. It is a disordered tangle of arteries and veins. AVMs can occur anywhere in the brain, and no two are identical in shape, size and location.

Diagnosis

How are AVMs formed?

AVMs are congenital, meaning that people are born with them. They appear to be related to improper development of the capillaries that connect the arteries and veins.

How dangerous are AVMs?

AVMs can potentially be very dangerous. When an AVM bleeds, the blood flows into the surrounding brain, causing a blood clot in the brain. Bleeding from an AVM can cause death or permanent disability.

How are AVMs detected?

Incidental finding In some cases, where an AVM is not producing symptoms, it may go undetected for much of a person's lifetime. It may be discovered only by accident on a CT or MRI scan of the brain for unrelated reasons, such as following a motor vehicle accident.

Headache
An AVM can cause severe or chronic migraine-type headaches. When the patient seeks treatment for the headache, the doctor may order a brain scan that results in the identification of the AVM.

Bleeding
A brain bleed is often the way AVMs come to medical attention. Bleeding from an AVM causes a blood clot in the brain, which can result in death or permanent disability. AVMs that have bled repeatedly should be treated in most cases to prevent further bleeding.

Neurological deficit
Sometimes AVMs cause symptoms by gradually producing a loss of brain function. The specific symptoms will depend on the exact location of the AVM. For example, an AVM in the area of the brain that controls vision may cause progressive loss of vision.

Seizure
AVMs often result in seizures. These can range from mild episodes - a few seconds of staring off into space - to violent shaking with loss of consciousness. Sometimes seizures occur during sleep.

Treatment

Observation
Observation is when no direct action is taken. Your surgeon considers it safer to monitor the AVM than attempt other invasive procedures.

AVMs are congenital, meaning that people are born with them. If an AVM has not caused problems for the patient and is not likely to cause problems during the patient's expected life span, then observation may be a sound course of action, given that any treatment option carries some risk. Treatment should only occur if the risk of treatment is lower than of leaving the AVM alone.

Surgical treatment procedures for AVMs include excision, clipping and coiling. When treatment of an AVM is warranted and surgery is feasible, it is recommended. The alternative treatment of radiosurgery takes several years to work, during which the AVM could bleed.

Microsurgical excision
Surgical removal of a brain AVM is a serious and delicate operation involving craniotomy (the opening of the skull). The risk of a major complication from surgery depends on the size and location of the AVM and the skill of the neurosurgeon.

Clipping
The neurosurgeon opens the skull and delicately separates the AVM from the surrounding tissue. A small titanium clip, which opens and closes like a clothespin, is then placed across the base of the AVM. Once the clip is secured, blood can no longer flow in or out of the AVM. By using a needle to drain the remaining blood out of the AVM, it should empty and eventually collapse.

Coiling
Also known as endovascular therapy, coiling is an innovative, less invasive surgical treatment option. This procedure does not involve craniotomy (the opening of the skull) and is performed from inside the blood vessel. A catheter is inserted into the patient's groin area and guided up toward the brain. A fine wire is then threaded into the catheter and directed into the AVM. Once inside the AVM, the wire twists into small coils and continues filling the AVM until it eventually clots off.

Radiosurgery
High-dose, focused radiation can be used to treat brain AVMs in a technique known as stereotactic radiosurgery. The procedure is not actual surgery and does not involve opening of the skull. The radiation must be delivered in a high dose to be effective, and the beam must be focused precisely on the AVM to avoid damage to surrounding normal brain tissue. Radiosurgery works slowly to cause the AVM to obliterate. After the radiation is given, it may take several years for the AVM to disappear. This means that there is some risk of bleeding while the radiation is working. One risk of radiation is injury to normal brain tissue around the AVM. This can result in neurological deficits such as weakness or paralysis, numbness, speech trouble, vision loss, etc. Not all AVMs respond to radiation. In particular, larger AVMs are less responsive to radiosurgery than smaller ones.