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What is an Arteriovenous Malformation (AVM)?
Arteriovenous malformations (AVMs) are abnormal tangles of arteries and veins that belong to a group of disorders known as vascular malformations. Although not completely understood, they typically develop in the womb or soon after birth and may be linked to genetic mutations. When AVMs are located in the brain or spinal cord, they're called neurological AVMs.

Although people are born with AVMs, symptoms may not develop until adulthood, often between 20 to 40 years of age, after the condition progresses, and in most adults, they cause no health problems. About 1 percent of those affected, however, experience life-threatening complications.

Serious complications occur when AVMs:

Disrupt the flow of blood and reduce the amount of oxygen reaching the brain or spine
Rupture and bleed into surrounding tissues
Become so large that they compress or displace parts of the brain or spinal cord

The most severe risk is bleeding, called a hemorrhage, in the brain, which can lead to a debilitating or fatal stroke.

At UCSF Medical Center, our Neurovascular Disease and Stroke Center is one of the world's leaders in diagnosing and treating AVMs. We treat more than 100 AVM patients a year. Our team includes neurologists, neurosurgeons and neuroradiologists who offer a wide range of treatments, including an advanced endovascular techniques, called embolization, which is an alternative to surgery.

What are the Possible Symptoms of an Arteriovenous Malformation (AVM)?
Most people with arteriovenous malformations don't experience any symptoms. For those that do have symptoms, the most common include:

Abnormal sensations such as numbness or tingling
Dizziness
Headache
Seizures

Symptoms can vary widely, depending on the location of the AVM. Other symptoms are memory loss, muscle weakness, and visual distrubances, such as partial vision. Some researchers believe the condition can cause subtle learning or behavioral disorders, long before other symptoms emerge.

The most serious complication is bleeding in the brain, resulting in a stroke.

Damage from AVMs tend to build-up over time. In women, pregnancy can sometimes trigger symptoms due to increases in blood volume and blood pressure.

If no symptoms occur by the time people reach their late forties or early fifties, AVMs typically remain stable.

Because AVMs may not produce symptoms, they may be discovered during treatment for other disorders.

In children, AVMs are the leading cause of hemorrhagic stroke.

How are Arteriovenous Malformations (AVMs) Diagnosed?

The following tests may be used to diagnose your arteriovenous malformation (AVM), as well as help identify its size, location and blood-flow pattern.

Angiography — This special X-ray exam shows the structure of a person's blood vessels and is essential in the diagnosis and treatment planning of AVMs. During this procedure, a harmless dye that can be seen on X-rays is injected into an artery that supplies blood to the brain. The dye follows the path of the brain's blood flow and can show any obstructions or leaks.

Computed Tomography (CT) Scan
— With this test, X-ray beams are used to create a 3-dimensional image of the brain. A CT scan typically can detect bleeding into the brain, called a hemorrhage, which indicates an AVM.

Magnetic Resonance Angiography (MRA)
— This procedure is a magnetic resonance imaging (MRI) study of the blood vessels and provides detailed images of blood vessels. Using a strong magnetic field, an MRI generates a 3-D image of the brain to detect, diagnose and aid the treatment of vascular disorders. The procedure is painless.

How are Arteriovenous Malformations (AVMs) Treated?

Today, there are many safe and highly effective therapies available to treat arteriovenous malformations (AVM). These include surgery, radiation therapy, embolization and radiosurgery using a device called a Gamma Knife.

Conventional Surgery
— In many cases, surgery may be recommended to completely remove the AVM. This is appropriate when the AVM is small and located on the surface of the brain or spinal cord. When the AVM is deep in the brain, other minimally invasive techniques are used to prevent damage to surrounding tissue.

Embolization — Embolization is a technique used to reduce blood flow to the AVM by obstructing surrounding blood vessels. During this procedure, the AVM is filled with specially designed coils, glues or spheres that plug its vessels and decrease the flow of blood. Embolization usually doesn't permanently resolve the AVM but makes it more manageable for future procedures such as surgery.

Radiosurgery
— The Gamma Knife, an advanced radiosurgery treatment, is often recommended for people with complex, deep-seated or brain-stem AVMs. Despite its name, the Gamma Knife isn't a knife at all. It delivers a single, very finely focused, high dose of radiation precisely to its target, while causing little or no damage to surrounding tissue. The high dose of radiation damages and eventually closes the walls of the blood vessel. Radiosurgery can be used alone or in combination with other treatments, such as conventional surgery.

What is a Brain Aneurysm?

A brain aneurysm is a balloon or bubble-like growth that typically develops where a major artery branches into smaller arteries, often at the base of the brain.

Aneurysms have the potential to leak or rupture, causing bleeding into the brain or the surrounding area called the subarachnoid space. This subarachnoid hemorrhage can cause a stroke, leading to brain damage or death.

About 3 percent to 5 percent of the American population is affected by a brain aneurysm. The condition most commonly affects adults between the ages of 35 to 60 years old, although children can develop aneurysms. Aneurysms affect women more frequently than men. They can develop from continuous wear and tear on the artery walls and can be caused by factors such as genetics, injury or infection

At UCSF Medical Center, our Neurovascular Disease and Stroke Center is recognized as one of the world's leaders in diagnosing and treating brain aneurysms. We care for more than 300 aneurysm patients each year. Our team includes neurologists, neurosurgeons and neuroradiologists who are experts in a wide range of treatment approaches, including microsurgical techniques, skull base surgery and advanced therapies such as blocking the artery with platinum coils.

We also treat complex and "giant" aneurysms that cannot be treated with conventional surgery.

What are the Symptoms of a Brain Aneurysm?

Brain aneurysms typically don't cause symptoms until they leak or rupture, causing bleeding into the brain and are discovered during tests for other conditions. Even when they cause no symptoms, these aneurysms should be treated to prevent future ruptures.

The hallmark symptom of a ruptured aneurysm is a sudden and extremely severe headache that may occur with nausea, vomiting, stiff neck, impaired consciousness, seizures or coma.

Symptoms of an unruptured aneurysm may include:

Cranial nerve palsy or erratic muscle movements
Dilated pupils
Double vision
Localized headache
Pain above and behind the eye

How are Brain Aneurysms Diagnosed?

A ruptured brain aneurysm is a very serious conditions that in some cases can be fatal. A quick and accurate diagnosis is essential for your recovery. Tests commonly used in the diagnosis of aneurysms include:

Cerebral Angiography — This test is commonly used to diagnose aneurysms. A special dye that can be seen on X-rays is injected into an artery that supplies blood to the brain. The dye flows through the brains blood vessels and can show any obstructions or leaks.
Magnetic Resonance Angiography (MRA) — Using a strong magnetic field, an MRI can generate a 3-D image of the brain and a detailed image of blood vessels that can be used to detect, diagnose and aid the treatment of aneurysms. The procedure is painless.
Computed Tomography (CT) Scan — With this test, X-ray beams create a 3-D image of the brain. A CT scan can detect bleeding in the artery after the aneurysm has burst.

How are Brain Aneurysms treated?

Almost all brain aneurysms should be treated to prevent them from rupturing or repair ruptured aneurysms as quickly as possible and strengthen the arteries to prevent future ruptures.

The following are some of the surgical techniques used to treat aneurysms.


3-D Computer Modeling — This technique, first performed by neurosurgeons at UCSF Medical Center, is used for difficult to treat and rare aneurysms. It produces 3-D images of the aneurysm and blood flowing through the arteries to the aneurysm. Dye is injected into arteries to track blood flow. A computer superimposes that information over brain scans to compose a 3-D model of the aneurysm. Using a computer, surgeons can test if different surgical techniques would alter blood flow enough to ease "hot spots" of pressure inside the aneurysm.

Microsurgical Clipping — A majority of aneurysms can be treated with microsurgical clipping. Aneurysms are accessed through an opening in the skull. A surgeon, using high-magnification operating microscopes, spreads apart brain tissue. A small metal clip is placed at the base of the aneurysm to tie off the bulging section of the artery. The clip must be placed without tearing the artery and causing a stroke.

Skull Base Surgery
— This surgery is typically used for deep and complex aneurysms located beneath the brain. The aneurysm is accessed through the bone at the base of the skull. A surgeon accesses the aneurysm from underneath or the side of the artery. The shorter pathway causes less disturbance.

Vascular Bypass Grafting
— Some aneurysms, such as those that are complex and large, require vascular bypass grafting. A vein is taken from the leg and used to connect an artery in the neck and an artery in the brain to bypass the aneurysm.

A minimally invasive alternative to surgery is endovascular treatment of brain aneurysms, known as Endovascular Coiling. The procedure does not require an incision in the head. It is performed under general anesthesia or light sedation, and has a shorter recovery time and hospital stay compared to conventional surgery. Endovascular therapy, however, is not recommended for all patients.

The procedure involves placing small, metal coils inside the aneurysm using a catheter or long, flexible tube. The catheter is inserted into an artery in the leg and navigated through the vascular system, into the head and aneurysm.

The coils detach from the catheter and are placed in the aneurysm, where they block blood flow and cause blood to clot, destroying the aneurysm. Coils are made of platinum so they're visible on an X-ray and flexible so they can conform to the shape of the aneurysm.

What are Dural Arteriovenous Fistulae (DAVF)?
Dural arteriovenous fistulae (DAVF) are rare, abnormal connections between arteries and veins in a protective membrane on the outer layer of the brain and spine, called the dura. These abnormal blood vessels divert blood from the normal paths. If the volume of diverted blood flow is large, tissue downstream may not receive an adequate blood and oxygen supply.

An unusually heavy blood flow also can lead to aneurysms or ruptures in the veins.

This condition can be caused by head trauma, infection, surgery or blood clots in the brain, called thrombosis, or may be a congenital or birth defect.

DAVFs are part of a group of conditions called arteriovenous malformations (AVM). Some fistulas are life-threatening and may cause headaches, seizures or strokes, if they rupture. Others are benign and go undetected until discovered during treatment for other conditions.

At UCSF Medical Center, our Neurovascular Disease and Stroke Center is one of the world's leaders in diagnosing and treating these fistulaes. Our team includes neurologists, neurosurgeons and neuroradiologists who are experts in identifying DAVFs and designing the best possible treatment, including minimally invasive surgical techniques.

What are the Symptoms of Dural Arteriovenous Fistulae (DAVF)?

The symptoms of dural arteriovenous fistulae (DAVF) can vary widely, depending on the location of the fistulae. Some DAVFs have no symptoms at all and aren't discovered until patients are evaluated for other neurological or vascular conditions.

Some of the common symptoms include:

Headaches — Headaches are among the most common symptoms with all types of DAVFs
Ringing in Ears — An unusual ringing or humming in the ears may be symptom, particularly when the DAVF is near the ear. Some patients hear a pulsating noise caused by blood flow through the fistula.
Stroke-like Symptoms — All types of DAVFs can cause stroke-like symptoms and seizures, if they rupture. Bleeding in the brain is the most serious side effect and can cause permanent disability or death.
Visual Problems — When DAVFs are located near the eye, patients often complain of impaired vision, eye redness and swelling, and sinus congestion.

How are Dural Arteriovenous Fistulae (DAVF) Diagnosed?

The following tests may be used to diagnose your dural arteriovenous fistulae (DAVF) and help identify its size, location and blood-flow pattern.

Cerebral Angiography — This X-ray exam shows the structure of blood vessels and is the most important test in diagnosing DAVF. A harmless dye, visible on X-rays, is injected into an artery that supplies blood to the brain. As the dye flows through blood vessels to the brain, it will show any obstructions or leaks.
Computed Tomography (CT) Scan — During this test, X-ray beams are used to create a 3-D image of the brain and may help identify any bleeding or hemorrhage. For more precise images of blood vessels, the cerebral angiography and magnetic resonance angiography (MRA) are performed.
Magnetic Resonance Angiography (MRA) — An MRA uses magnetic resonance imaging to create detailed images of blood vessels. Using a strong magnetic field, it generates a 3-D image of the brain to detect, diagnose and aid the treatment of DAVFs and other vascular disorders. In some cases, a dye is injected intravenously.

How are Dural Arteriovenous Fistulae (DAVF) Treated?
Treatment for dural arteriovenous fistulae (DAVF) depends on the blood vessels involved. Endovascular techniques, which are minimally invasive procedures that are performed through the blood vessels, have been developed to safely treat DAVFs.

An approach, called embolization, reduces blood flow to the DAVF by obstructing surrounding blood vessels. During this procedure, the DAVF is filled with specially designed coils, glues or spheres that plug the vessels.

Some fistulas can't be completely blocked with embolization and may require surgery to disconnect or close them. In some cases, doctors may try to close the fistula with what's called stereotactic radiosurgery or the Gamma Knife.

What is a Stroke?

Stroke is the fourth leading cause of death and the leading cause of disability in the United States. When a stroke occurs, a blood vessel in the brain becomes blocked or bursts, sometimes causing permanent brain injury or even death. However, prompt treatment and follow-up care may protect brain cells and help patients lead healthy, productive lives.

There are two main types of strokes:

Ischemic Stroke — This type of stroke accounts for about 80 to 85 percent of all strokes in the United States. With ischemic stroke, the blood supply to a part of the brain becomes blocked. This prevents oxygen and nutrients from reaching brain cells. Within a few minutes, these cells may begin to die.

The underlying cause for this type of obstruction is usually atherosclerosis, a condition in which plaque or fatty deposits within the wall of the arteries in the brain and neck can lead to obstruction or narrowing. These fatty deposits can cause cerebral thrombosis or cerebral embolism. With a cerebral thrombosis, a blood clot forms within the blood vessel. Cerebral embolisms are clots that can form at another location in the circulatory system, break loose from an artery wall or from the inside lining of the heart, travel through the brain's blood vessels and can lodge in an artery in the brain.
Hermorrhagic Stroke — With hemorrhagic stroke a blood vessel within the brain leaks or ruptures and bleeds into the surrounding brain tissue. This is called an intracerebral hemorrhage. The blood can accumulate and exert pressure on the surrounding tissue. High blood pressure is a common cause of intracerebral hemorrhage. In a subarachnoid hemorrhage, blood leaks under the lining of the brain. This is often caused by a small bubble on an artery known as an aneurysm.

What are Risk Factors for Stroke?

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Stroke

Stroke is the fourth leading cause of death and the leading cause of disability in the United States. When a stroke occurs, a blood vessel in the brain becomes blocked or bursts, sometimes causing permanent brain injury or even death. However, prompt treatment and follow-up care may protect brain cells and help patients lead healthy, productive lives.

There are two main types of strokes:

Ischemic Stroke — This type of stroke accounts for about 80 to 85 percent of all strokes in the United States. With ischemic stroke, the blood supply to a part of the brain becomes blocked. This prevents oxygen and nutrients from reaching brain cells. Within a few minutes, these cells may begin to die.

The underlying cause for this type of obstruction is usually atherosclerosis, a condition in which plaque or fatty deposits within the wall of the arteries in the brain and neck can lead to obstruction or narrowing. These fatty deposits can cause cerebral thrombosis or cerebral embolism. With a cerebral thrombosis, a blood clot forms within the blood vessel. Cerebral embolisms are clots that can form at another location in the circulatory system, break loose from an artery wall or from the inside lining of the heart, travel through the brain's blood vessels and can lodge in an artery in the brain.
Hermorrhagic Stroke — With hemorrhagic stroke a blood vessel within the brain leaks or ruptures and bleeds into the surrounding brain tissue. This is called an intracerebral hemorrhage. The blood can accumulate and exert pressure on the surrounding tissue. High blood pressure is a common cause of intracerebral hemorrhage. In a subarachnoid hemorrhage, blood leaks under the lining of the brain. This is often caused by a small bubble on an artery known as an aneurysm.

Risk Factors for Stroke

Risk factors for stroke that cannot be changed:

Family History
— The risk of having a stroke is higher for people whose parents or siblings have had a stroke.
Age — Stroke risk increases with age — doubling every 10 years after age 55.
Gender — Before age 55, men are more likely than women to have strokes. After 55, the risk is the same for men and women. However, women are more likely than men to die of stroke.
History of Prior Stroke, TIA or Heart Attack — A person who has had a stroke in the past is at much greater risk for having another one. Risk of stroke after a TIA is greatest within the first 48 to 72 hours. Therefore, you should seek immediate medical attention for all acute neurologic changes, even if they have resolved.
Race — African Americans have higher incidence of stroke and a higher risk of death from a stroke than Caucasians do. Asian Americans have higher incidence of hemorrhagic stroke than other ethnic groups.

Risk factors for stroke that are modifiable:

High Blood Pressure — This is probably the most important modifiable risk factor for stroke. Controlling high blood pressure will greatly reduce your risk of stroke and heart attack.
Cardiovascular Disease — Congestive heart failure, a previous heart attack, a diseased aortic valve and atrial fibrillation can all raise the risk of stroke.
Cigarette Smoking — The risk of stroke is two to three times greater for smokers versus nonsmokers. The use of oral contraceptives with cigarette smoking greatly increases the risk of stroke.
Carotid Artery Disease — Fatty deposits from atherosclerosis may cause significant narrowing in the carotid arteries. This can limit blood flow to the brain as well as acts as a potential source for cerebral emboli.
Diabetes — Diabetes doubles stroke risk. Many people with diabetes also have high blood pressure, obesity and high cholesterol, which increase their stroke risk even further.
Undesirable Blood Cholesterol Levels — High blood levels of low-density lipoprotein (LDL) cholesterol and low levels of high-density lipoprotein (HDL) cholesterol increase stroke risk.
Obesity — Excess weight can double the risk of an ischemic stroke.
Lack of Exercise and Physical Activity — Both increase the risk of high blood pressure and therefore the risk for stroke. Taking the stairs, going on a brisk walk, doing some kind of activity for at least 30 minutes every day will help decrease your stroke risk.
Use of Birth Control and Hormone Therapy — Women who use birth control pills, especially if they smoke and are over age 35, have a higher risk of stroke. There is also a higher risk of stroke among women using hormone therapy for menopause.

What are the Symptoms of a Stroke?
Common symptoms of stroke include:

Sudden paralysis of a leg, arm or one side of the face
Sudden trouble speaking or understanding speech
Sudden vision problems, such as blurred or double vision
Sudden loss of coordination or problems with balance
A severe, sudden headache without apparent cause
Sudden numbness, weakness or dizziness
If you are experiencing any symptoms of stroke, you should go to a doctor or hospital right away, preferably by dialing 911.


What is a Transient Ischemic Attack (TIA)?

Transient ischemic attacks are sometimes called "mini-strokes." Although strokes typically occur without warning, some people may feel a temporary numbness, weakness or tingling in one arm or leg, or problems with speech, vision or balance before the actual onset of the stroke. This occurs because the blood supply to the brain is temporarily reduced, called a transient ischemic attack (TIA).

TIAs usually last a few minutes to hours and may not cause immediate permanent injury to the brain. However, a TIA is a sign that the risk of a permanent stroke is great. TIA is an emergency. Patients with TIAs should be seen right away, just like those with stroke symptoms that don't go away.

How is a Stroke Diagnosed
our neurologist will perform a physical examination to determine if you've had a stroke. Your examination may include blood or urine tests, an electrocardiogram (ECG or EKG), electroencephalogram (EEG) or imaging tests.

Imaging tests may include:

Arteriography — This shows arteries in the brain that can't be seen in regular X-rays. An arteriogram may be performed if other tests don't reveal the cause of the stroke. Your doctor will make a small incision, usually in your groin, then insert a catheter, which is a flexible, thin tube, carefully through your arteries and into your carotid or vertebral artery.

Your doctor will then inject a dye into the catheter that helps your cranial arteries appear more clearly in an X-ray image.
Carotid Ultrasonography — This machine sends sound waves into the tissues in your neck, which creates images on a screen. These images may reveal narrowing in the carotid arteries.
Computed Tomography (CT) Scan — With this test, X-ray beams are used to create a three-dimensional image of the brain, the brain's blood vessels and main blood flow.
Magnetic Resonance Angiography (MRA) — This procedure uses a strong magnetic field to show the arteries in the neck and brain.
Magnetic Resonance Imaging (MRI) — Using a strong magnetic field, an MRI can generate a three-dimensional image of the brain. An MRI is often used to locate an area of the brain that's been damaged by an ischemic stroke.

What are the Treatments for Stroke?
The neurovascular team at UCSF Medical Center, along with your primary care doctor, will design a treatment plan tailored to your medical condition, state of health and individual needs. You may need more than one kind of treatment, and you may require several visits to UCSF. You may be referred to additional doctors or other medical professionals.

It is critical to come to the hospital immediately if you experience a stroke because treatments might reduce or completely reverse the brain injury from stroke. These treatments must be given within the first few hours of stroke symptoms, so call 911 to get transportation to the Emergency Room quickly. These treatments include administration of a t-PA — a drug that opens blocked blood vessels — or devices to remove the clot from the brain using a catheter.

The next step in treating a stroke is to carefully control and monitor your blood pressure. Once your blood pressure is under control, we focus on cholesterol, smoking cessation, control of diabetes and analysis of any heart conditions you may have.
Ischemic Stroke

Also, there are surgical techniques that may be used to prevent stroke including:

Carotid Endarterectomy — This surgery is used to remove plaque from carotid arteries to help prevent strokes. The surgeon makes an incision to open up the artery, then removes the plaque and closes the artery.
Angioplasty and Stenting — During this procedure, your surgeon places a small wire tube down a narrowed artery. A balloon attached to the tube is then inflated, which works to widen the artery. A small tube called a stent may be left within the widened artery to help keep it from closing up in the future.

Hemorrhagic Stroke


Treatment for hemorrhagic stroke is designed to allow the brain to heal safely and prevent further hemorrhage. This involves using medications to reduce swelling of brain tissue. Occasionally, surgery can help remove clotted blood from around damaged brain tissue. If you have an aneurysm, it can be repaired either by open surgery or by a technique that eliminates the aneurysm from inside the vessel with the help of arteriography. UCSF Medical Center is one of the premier institutions for treating patients with cerebral aneurysms and subarachnoid hemorrhage.
Endovascular Procedures

UCSF Medical Center has been instrumental in the development of experimental treatments to safely remove clots in patients experiencing a stroke. For example, UCSF doctors were involved in the development of a tiny device that's placed in a catheter and threaded through an artery to reach and remove clots.