Cerebrovascular disease is any disorder that affects the disease in the blood vessels that feed oxygen-rich blood to the face and brain. Most often, this term is used to describe “hardening” (atherosclerosis) of the carotid arteries, which supply the brain with blood.

This form of cerebrovascular disease is similar to coronary artery disease, which occurs in the blood vessels that supply the heart with oxygen-rich blood. It is also referred to as ischemic disease, or a disease that causes a lack of blood flow. Because it occurs in blood vessels outside the heart, this condition is also considered to be a type of peripheral artery disease.

Ischemic cerebrovascular disease is particularly dangerous because it often has no symptoms. Yet it can cause stroke, either when the plaque ruptures and pieces of plaque block a narrowed portion of the artery, or when the carotid artery becomes completely blocked by the buildup.

In contrast to ischemic cerebrovascular disease, in which the brain does not receive enough blood, hemorrhagic cerebrovascular disease is characterized by too much blood in the brain. This form of cerebrovascular disease occurs when a blood vessel in the brain ruptures. Depending on the nature of the bleeding, symptoms may take hours or days to become apparent, or they may begin abruptly and rapidly progress to coma.

Although it can be difficult to detect cerebrovascular disease, there are known risk factors that might alert a physician. Uncontrollable risk factors include gender, age, ethnicity and family history. Risk factors that can be controlled include smoking, lack of regular exercise, diet, obesity and uncontrolled diabetes. In addition, unhealthy cholesterol levels, high blood pressure, and emotional factors may increase the risk of cerebrovascular disease.

Diagnosis of cerebrovascular disease depends on the variety and severity of the condition. If the condition is only suspected and there are no acute symptoms, diagnosis typically begins with a medical history and physical examination. These may be followed by more complex testing such as duplex imaging, magnetic resonance angiogram (MRA) and/or an angiogram. Treatment may involve medications (e.g., antiplatelets), modification of risk factors and/or more invasive treatments or procedures.

Cerebrovascular disease is any disorder that occurs in the blood vessels that feed oxygen-rich blood to the face and brain. Most often, this term is used to describe “hardening” (atherosclerosis) of the carotid arteries.

The two carotid arteries are located on the front part of the neck (one on the left and one on the right) and supply the front two-thirds of the brain with blood. About halfway up the neck, each carotid artery splits into two branches, one going straight to the brain (the internal carotid artery) and the other supplying the face (the external carotid artery).

The artery widens at this branch point, which is referred to as the “carotid bulb,” then narrows into the smaller arteries. Because of this structure, lesions in the carotid arteries tend to affect this branch point and the first few centimeters of the internal carotid arteries.

This form of cerebrovascular disease is referred to as carotid artery disease. It is by far the most common form of cerebrovascular disease, accounting for more than 95 percent of cases. The condition can be classified as a type of ischemic disease, or a disease that causes a lack of blood flow, and as a type of peripheral artery disease.

Carotid cerebrovascular disease is particularly dangerous because it often has no symptoms. The major concern with this condition is that pieces of the plaque may break off (rupture) and travel to the brain (becoming an embolism). This condition may cause a stroke or transient ischemic attack (TIA). Treatment of carotid artery disease is designed to prevent stroke and the subsequent damage from the event.

In contrast to ischemic disease, which involves a lack of blood flow to the brain, hemorrhagic cerebrovascular disease is characterized by bleeding into the brain. This bleeding can be slow and gradual, often caused by trauma or high blood pressure. It also may be acute, caused by a rupture in the artery wall (aneurysm). Treatment of hemorrhagic cerebrovascular disease is aimed at stopping the bleeding and preventing the reoccurrence.

According to the Centers for Disease Control (CDC), there were over 162,000 cerebrovascular-related deaths in the United States in 2003. The majority of these deaths occurred in people age 65 and older. The most recent statistics from the American Heart Association (AHA) estimate that over 5 million people have experienced a stroke.

The signs and symptoms of cerebrovascular disease depend on whether the underlying condition is carotid artery disease or bleeding into the brain (hemorrhage).

Carotid artery disease (CAD), the most common form of cerebrovascular disease, is particularly dangerous because it often has no symptoms. Most major strokes occur without any prior symptoms. It is estimated that anywhere from one-third to one-half of all strokes occur as the result of a lesion forming in the carotid bulb. For that reason, individuals with a high risk of carotid disease should have a careful evaluation of the carotid arteries, even if there are no symptoms. This evaluation usually involves a simple, noninvasive, and painless ultrasound of the carotid arteries performed in a facility specializing in vascular studies (and carrying I.C.A.V.L. accreditation).

People over age 65 are at increased risk for carotid artery disease. Several recent studies have shown that women have increased risk of stroke. Other specific risk factors for carotid disease include:

In many cases, carotid artery disease will cause temporary stroke-like symptoms. These episodes are known as transient ischemic attacks (TIAs). A TIA is an important indicator of future stroke, and it should be treated as a serious medical situation. Recent research has found that TIAs with symptoms that last only 24 hours can result in permanent damage to the brain. In addition, individuals who receive treatment with tissue plasminogen activator (tPA) at the first signs of a TIA or stroke may prevent permanent damage from the event. However, tPA must be administered within the first three hours of the initial symptoms. Individuals should seek immediate medical attention and evaluation if any of the following symptoms are present:

• Vision impairment, especially blindness or vision field problems in one eye
  
  
• Loss of strength, coordination or sensation on one side of the body
  
  
• Confusion or disorientation
  
  
• Dizziness or loss of balance
  
  
• Seizures
  
  
• Severe (and blinding) headache similar to a migraine
  
  
• Slurred or abnormal speech
  
  
• Comprehension difficulties
  
  
• Drooling or difficulty eating or swallowing

The symptoms that accompany hemorrhagic disease depend on the severity of the bleeding. In general, there are two causes of hemorrhagic disease: intracerebral hemorrhage and subarachnoid hemorrhage. An intracerebral hemorrhage occurs when the small arteries in the brain bleed directly into the brain. Accumulation of blood occurs over minutes or hours and symptoms gradually worsen. Symptoms may include headaches, lethargy, nausea or vomiting.

A subarachnoid hemorrhage occurs when a blood vessel ruptures, usually because of an aneurysm, or a defective blood vessel. In this case, blood spreads quickly throughout the cranial cavity, and it may result in death or coma. Symptoms are usually abrupt and serious, and may include:

• Loss of memory
• Severe onset of headache
• Vomiting
• Pain in the neck
• Motor difficulties
• Difficulty speaking or understanding

Most diagnostic and imaging tests for cerebrovascular disease are designed to detect carotid artery disease (CAD) before it results in a stroke. Unlike hemorrhagic disease, which has symptoms, this form of cerebrovascular disease often progresses for years with no symptoms, and it accounts for about 95 percent of cerebrovascular disease. Tests to detect carotid artery disease include:

• Physical examination. When a stethoscope is placed on the neck an abnormal sound of blood flow may be heard, called a bruit (pronounced: BRU-ee). When the level of atherosclerosis in the carotid arteries is severe a bruit is less common, making it an unreliable test by itself. However, anytime a significant bruit is heard, more tests are necessary to determine the nature and seveity of the condition.
  
  
• Carotid duplex ultrasound. This test refers to the use of ultrasound to generate an image of the carotid arteries in the neck and blood flow through the arteries. This is a highly accurate test when performed by vascular ultrasound technicians who specialize in vascular testing (known as RVTs or Registered Vascular Technicians) and in a laboratory that carries the I.C.A.V.L. accreditation.
  
  Carotid duplex ultrasound has become the most important test in the diagnosis and follow-up of CAD. The test involves lying relatively still in a reclining chair for about 30 minutes. It is noninvasive, requires no medication, is painless and is virtually risk-free. Most vascular specialists use this test without any others (e.g., angiogram, magnetic resonance angiogram, described below). In centers without “full-time” vascular specialists or an accredited ultrasound facility, arteriograms and MRA provide excellent imaging. Procedures and risks involved in cartoid ultrasound are similar to those of an echocardiogram.
  
  
• Carotid angiogram. Before ultrasound was perfected, minimally invasive angiograms (also called arteriograms) were the only way to diagnose and develop a treatment plan for carotid artery disease. They remain highly accurate tests in showing the severity and location of a carotid lesion as well as showing all of the vessels before and after the lesion. This test is primarily used when the physician needs to have an understanding of the vessels beyond the area where the lesion is located. An angiogram involves a catheter, which is inserted through the skin (usually in the groin) and advanced through the blood vessels to the neck area. At that point, a contrast medium (dye) is injected and x-rays are taken to show a picture of the arteries. Though the area being imaged is different, a carotid angiogram is similar in terms of procedures and risks to a cerebral angiogram.
  
  
• Magnetic resonance angiogram (MRA). This type of magnetic resonance imaging (MRI) involves using the natural properties of the blood (e.g. flow direction, water content) to produce images in a scanner. For this test, patients lie flat on a scanner table that goes through a small tunnel where the images are obtained. Some patients may have a difficult time being enclosed in a small space or staying still for the required time. For these patients, a mild sedative may be given or the test may be performed in an open MRI scanner. Patients with pacemakers and other metal implants cannot have a magnetic resonance scan.
  
  This nonivasive or minimally invasive test is appealing for the diagnosis of CAD because it produces images similar to a carotid angiogram, sometimes without using a contrast medium. For that reason it is also very low risk. However, the test may not be able to produce clear images of arteries that have turbulent blood flow, which is common with CAD. This renders the test less accurate than an ultrasound or angiogram. MRA is often used when more information about blood vessels in the brain is needed or to confirm a questionable ultrasound result.
  
  MRA technology is advancing very rapidly and its role in carotid disease may become more prominent in the future as physicians learn how to differentiate different kinds of arterial plaque. However, MRA technology is not available at all medical facilities.
  
  
• Computed tomography arteriography (CT-A). Also known as multi-slice computed tomography (MSCT), this is a relatively new technique that uses a CT scanner to generate pictures of the carotid arteries. The test is nearly identical to a carotid angiogram except that the contrast medium is put into the veins instead of the arteries and therefore has a lower risk of complications. CTA is being studied as a means to detect blockages in the coronary arteries in place of the more invasive cardiac catheterization.

Imaging techniques are also allowing physicians to better describe the characteristics of carotid plaque. For example, many researchers classify plaque as homogeneous or heterogeneous. Homogeneous plaque has a smooth surface and is basically the same texture throughout. Heterogeneous plaque has an irregular surface with areas of hemorrhage. Studies have found that heterogeneous plaque may be prevalent among individuals who have had a stroke or transient ischemic attack.

It is believed that therapy for carotid artery disease will eventually be influenced by such characteristics of carotid plaque, in addition to the degree of narrowing (stenosis) of the carotid artery.

Treatment options for cerebrovascular disease depend on the nature and severity of the disease. The goal with hemorrhagic disease is to stop the bleeding and prevent the reoccurrence of bleeding. This can be accomplished with surgery or, in some cases, catheters and wire-mesh stents. It is crucial that hemorrhagic disease be treated quickly to prevent serious damage.

By contrast, the goal with carotid artery disease is to prevent an embolism. An embolism is a piece of plaque or blood clot that breaks away (ruptures) from the wall of the vessel and then travels with the blood flow until it becomes lodged in a smaller artery. In the case of CAD, there is a danger of an embolism blocking an artery inside the brain, which can cause a stroke. Physicians may choose to treat this disease with medication and lifestyle changes, or with more invasive techniques such as surgery and catheters.

Anitplatelet medications have been proven effective in preventing embolism in patients with CAD. These medications inhibit the blood clotting process and therefore reduce the risk of blood clot formation and subsequent stroke.

Aspirin is a strong and irreversible antiplatelet drug and is the first line of therapy for CAD. A more recent addition to drug therapy is clopidogrel, an antiplatelet even stronger than aspirin.

More and more research shows the value of cholesterol-controlling drugs in reducing the risk of cerebrovascular as well as cardiovascular disease. In 2005 a review of 14 trials involving 90,000 people showed that statins cut the risk of stroke and heart attack in people at high risk of vascular and heart disease, even if they did not have unhealthy levels of cholesterol. Also in 2005 researchers reported that a five-year trial involving 19,000 people found that newer antihypertensive drugs, especially when combined with cholesterol drugs, could prevent more than half of all strokes and heart attacks in people with high blood pressure.

In another advance in prevention of cerebrovascular disease, the U.S. Food and Drug Administration (FDA) in 2005 approved a simple blood test called the PLAC test to screen for risk of ischemic stroke. Previously cleared as a screening tool for heart disease, the test detects a blood protein that is more abundant in stroke patients. The PLAC test is available in physicians' offices.

Patients diagnosed with carotid artery disease may be advised by their physicians to make the following lifestyle changes:

In patients who do not respond to medical treatment, or who possess a significant degree of narrowing in the artery, procedures to treat carotid artery disease may include carotid endarterectomy and carotid artery stenting.

Carotid artery endarterectomy is an open surgical procedure where the carotid artery is exposed through an incision on the side of the neck. The artery is then clamped and the atherosclerotic material is removed. More than 95 percent of patients are discharged the day after the procedure.

Carotid artery stenting is a relatively new approach to the prevention of stroke in patients with carotid artery disease. A catheter is advanced into the carotid artery and a balloon is used to crush the plaque blocking the carotid artery (a procedure called angioplasty) and then a stent, or wire mesh tube, is implanted in the artery to keep it open. Some stents may be coated with drugs that prevent clotting and keep the arteries open. Stenting reduces the risk of a piece of plaque breaking off and traveling to the brain.

Many patients go home the day after the procedure, but some must go to the intensive care unit as a result of blood pressure and heart rate instability that can be caused by stenting. Currently, carotid artery stenting has a stroke rate equal to or greater than carotid endarterectomy. Its benefit is, as of now, in patients who are at higher risk for the “open” procedure as the result of heart disease or prior neck operations. One randomized trial, SAPPHIRE, evaluated surgery versus stent in patients with severe heart or lung disease or certain types of complex neck blockages. Patients who had surgery had twice the risk of death, MI or stroke.

Most physicians agree that stenting is emerging as the best option for patients who require carotid artery therapy and are at very high risk (e.g., prior heart attack, or existing health problem where the patient may not be able to tolerate anesthesia or open surgery). However, balloon angioplasty and stenting for carotid artery disease are currently in the investigation phase for low risk patients. Clinical trials are determining the safety and effectiveness of these techniques, as compared to carotid endarterectomy.

In addition, numerous studies are comparing the effectiveness of angioplasty to drug therapy for patients with stable heart disease. It has been believed that patients with chronic stable heart disease need to be treated with angioplasty or heart bypass surgery. However, a large study known as the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) suggested different results.

The trial found that drug treatment combined with lifestyle changes appeared to be as effective as angioplasty and drug therapy. There were no significant differences in death, nonfatal heart attacks or strokes between patients treated with medication alone and those who received drugs and angioplasty and stenting. These findings only pertained to individuals with stable heart disease and not acute heart attack patients. Researchers continue to examine the most effective prevention and treatment methods for individuals with cerebrovascular disease.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about cerebrovascular disease.

1. Do I have or am I at risk of cerebrovascular disease?
   
   
2. What tests will be used to evaluate my cerebrovascular health?
   
   
3. How and where will these tests be conducted?
   
   
4. What can the tests reveal about my arteries?
   
   
5. When and from whom will I receive the results of my tests?
   
   
6. How often will I need these tests?
   
   
7. What type of cerebrovascular disease do I have? What is its severity?
   
   
8. What is the likely cause of my condition?
   
   
9. What are my treatment options?
   
   
10. What are the benefits and risks of these treatments?
    
    
11. Will I need surgery? If so, what type?
    
    
12. Will I need to take medications? If so, which ones and for how long?
    
    
13. How will my condition be monitored?
    
    
14. What are the chances I will need surgery again in the future?
    
15. What lifestyle changes do you recommend to reduce my cerebrovascular problems?
    
    
16. Am I at risk for a stroke?
    
    
17. What signs will indicate a medical emergency with my condition?
    
    
18. Will my children have a higher risk for cerebrovascular disease?