Cerebrovascular insufficiency can lead to a stroke or transient ischemic attack (TIA or mini-stroke). Without the usual blood supply, neurons will die quickly, resulting in serious complications and even death. Stroke is the third leading cause of death in United States, causing more than 150,000 deaths each year.

Cerebrovascular insufficiency most often is caused by a blockage of the vessels supplying blood to the brain in one of three basic ways:

• The formation of a clot within a blood vessel of the brain or neck, called thrombosis;
• The movement of a clot from another part of the body such as the heart to the neck or brain, called embolism; or
• Narrowing of an artery in or leading to the brain, called stenosis.

Insufficient blood flow may also be caused by other conditions, such as moyamoya disease, which occurs when the arteries become blocked and new blood vessels grow in a tangle in the area.

Symptoms

Cerebrovascular insufficiency may go symptom-free and undetected for years, until the sudden onset of a stroke. The most common symptoms of a cerebrovascular insufficiency are:

• Weakness or numbness of the face, arm, or leg, especially on one side of the body
• Confusion or difficulty speaking or understanding
• Problems with vision such as dimness or loss of vision in one or both eyes
• Dizziness or problems with balance or coordination
• Problems with movement or walking
• Severe headaches with no other known cause

Diagnosis

Cerebrovascular insufficiency is assessed with a physical examination, including assessment of heart function and tests that can reveal specific neurological, motor, and sensory deficits. In addition, physicians may be able to hear changes in blood flow in the carotid arteries with a stethoscope. A complete diagnostic workup may include an angiogram, which provides an image of the blood flow in the brain. Carotid Duplex ultrasound and magnetic resonance imaging (MRI) scans also may be used to provide images of the cerebral arteries.

Treatment

Depending on the degree of insufficiency, the first line of treatment can be anticoagulant medications. In some cases, physicians may recommend carotid angioplasty and stenting, in which a balloon and a small tube are used to open up the obstructed artery, or surgery to remove the occlusion.

A procedure known as neovascularization, a type of bypass surgery, seeks to restore the flow of blood by bypassing the blockage. For neovascularization procedures, the blood supply to a portion of the scalp or a muscle in the area is rerouted to a cerebral artery past the point of the obstruction. The new blood supply can help prevent strokes and TIAs.