Atherosclerosis is the accumulation of plaque inside arteries, which may elevate the risk of stroke. At Columbia Neurosurgery, we specialize in diagnosing and treating atherosclerosis relevant to the brain. Common treatment options include angioplasty, arterial stenting and carotid endarterectomy.
Two types of atherosclerosis have the potential to impact brain function:
- Atherosclerosis of the carotid arteries, known as carotid artery disease
- Atherosclerosis of the cerebral arteries, known as intracranial atherosclerosis
Plaque buildup causes artery walls to become thick and stiff. (Atherosclerosis is sometimes called “hardening of the arteries.”) Eventually, the thickened vascular walls may interfere with blood flow, and if the blockage prevents blood from reaching the brain, the result is ischemic stroke. A stroke is a medical emergency.
Plaques may also cause ischemic stroke if they rupture. When a plaque ruptures, a blood clot forms. The clot may block the flow of blood there, or a piece may break off, travel through the artery and block blood flow elsewhere.
Atherosclerosis may have its beginnings as early as childhood, but usually only causes symptoms after age 40.
Symptoms of atherosclerosis vary, and the condition may be asymptomatic until an artery is significantly blocked and blood flow is greatly reduced. When this occurs, the situation is a potential medical emergency.
One possible sign of carotid artery disease is bruit. The presence of bruit alone is not sufficient to make the diagnosis of carotid artery disease, but it is a sign that often prompts further investigation.
Blockage of a carotid artery or a cerebral artery can produce potentially serious conditions:
- Stroke: A medical emergency caused by interruption of blood flow to the brain. Stroke can cause brain damage or death. The earlier treatment for a stroke begins, the better the chances of recovery. Symptoms of a stroke may include:
- Sudden severe headache
- Numbness or weakness in the face, arm or leg, especially on one side only
- Dizziness or loss of balance
- Sudden trouble seeing
- Confusion, problems speaking or understanding
- Transient ischemic attack (TIA): Sometimes called “mini-strokes,” TIAs can have the same symptoms as regular strokes, but in the case of a TIA, blood flow to the area is promptly restored and the symptoms resolve. Even though the symptoms may disappear, however, mini-strokes should be evaluated at an emergency department. They indicate a high risk for stroke in the coming days, weeks or months. Evaluating and treating the causes of a TIA may prevent a stroke.
- Aneurysm: A weak, ballooning area in the wall of an artery. An aneurysm can rupture, causing uncontrolled bleeding. In the brain, this is called a hemorrhagic stroke. An aneurysm with a slow leak may develop a blood clot, which itself may block blood flow.
To diagnose atherosclerosis, a doctor will ask about a patient’s medical and family history, conduct a physical examination and perhaps order blood tests or scans.
In patients with no symptoms or signs of atherosclerosis, the doctor usually evaluates risk of atherosclerosis by analyzing the patient’s risk factors. To determine blood cholesterol levels, the doctor may order a blood test called a lipid profile, which may need to be performed after a period of fasting.
In patients who have had signs or symptoms of atherosclerosis, further tests may be conducted to identify the location(s) of any problems.
At Columbia Neurosurgery, our specialists may diagnose carotid or cerebral atherosclerosis using the following procedures:
- Angiography: In this procedure, a dye that can be seen on X-ray is injected into blood vessels, and X-ray pictures are taken.
- CT angiography: A computer and a special type of X-ray are used along with angiography to produce 3-D images.
- SPECT scanning: A small amount of radioactive dye is injected into the bloodstream, and a special camera is used to produce 3-D images. SPECT stands for Single-Photon Emission Computed Tomography.
- Intravascular ultrasonography: An ultrasound is a safe and painless way to produce images of the body using sound waves. In intravascular ultrasonography, an ultrasound device at the end of a catheter is threaded through the blood vessels. It can produce pictures of the inside of an artery.
The causes of atherosclerosis are not completely understood. The most widely accepted theory is that atherosclerosis begins with injury to blood vessel walls. The injury causes inflammation in the area and begins a cascade of reactions that results in plaque formation.
There are many risk factors for atherosclerosis, some of which are independent of lifestyle. These include:
- Having a family history of early atherosclerosis
- Being male
Other risk factors, called modifiable risk factors, can be mitigated. These include:
- Diabetes mellitus
- Cigarette smoking
- Certain forms of elevated cholesterol
- Sedentary lifestyle
Atherosclerosis can occur without the presence of any of these risk factors, but each additional risk factor increases the likelihood of atherosclerosis.
At Columbia Neurosurgery, we treat cases of atherosclerosis of the carotid or cerebral arteries that may require surgical management.
Surgical options for atherosclerosis of the carotid and cerebral arteries include:
- Angioplasty: The positioning and inflation of a medical “balloon” that expands the narrowed artery
- Arterial stenting: The implantation and expansion of a small tube that helps the artery stay open
- Carotid endarterectomy: The surgical removal of a plaque from the carotid artery