Intracranial Artery Stenosis

Intracranial stenosis, also known as intracranial artery stenosis, is the narrowing of an artery in the brain, which can lead to a stroke. The narrowing is caused by a buildup and hardening of fatty deposits called plaque. This process is known as atherosclerosis.

A stroke occurs when plaque causes the artery to become blocked and that area of the brain is deprived of blood, which damages and kills nerves in the brain. As a result, the part of the body controlled by the damaged area of the brain cannot work properly.

The four arteries most likely to be affected by intracranial stenosis are:

  • Internal carotid artery (ICA), which supplies the front area of the brain with blood
  • Middle cerebral artery (MCA), which is the largest branch of the ICA
  • Vertebral arteries, which supply blood to the back areas of the brain
  • Basilar artery, which is formed where the right and left vertebral arteries join in the skull

Symptoms

The first symptom of intracranial stenosis is most often a transient ischemic attack (TIA) or ischemic stroke. A TIA, often referred to as a warning stroke, has symptoms similar to an ischemic stroke, but which last just 2 to 30 minutes.

Symptoms occur suddenly, and time is vital. If you notice one or more of these signs in another person or in yourself, do not wait to seek help. Call 9-1-1 immediately.

The signs of a stroke are:

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


Causes and Risk Factors

Plaque can begin building in arteries in early adulthood, but symptoms may not be evident for many years. African Americans, Asians and Hispanics are the most commonly affected populations.

The risk of developing atherosclerosis and intracranial stenosis is increased by:

Diagnosis

Diagnosis of intracranial stenosis usually begins with a physical exam and a review of the patient's medical history and symptoms. Because the condition is often noticed after a stroke has occurred, seeking immediate medical attention is very important.

Imaging tests, such as magnetic resonance imaging (MRI) and computed tomography (CT) angiography, are used to diagnose the condition and observe the area affected by the stroke if one has occurred. Other diagnostic tests look exclusively at the blood vessels and blood flow within the body, such as the transcranial Doppler (TCD) ultrasound or an angiogram.

Treatments

Treatment of intracranial stenosis will depend on whether the patient has had a TIA or stroke.

For patients who have not, a surgical procedure known as stenting is often performed to widen the narrowed artery. The surgeon may also clean out the plaque that has built up in the artery by performing a carotid endarterectomy.

For patients who have experienced a stroke, the intracranial stenosis will be treated along with the effects of the stroke. The Stroke Program at Cedars-Sinai provides a multidisciplinary treatment approach unique to each patient.

Patient care is generally broken down into three categories: stroke prevention, treatment immediately after a stroke, and post-stroke rehabilitation.

Patients who have experienced a stroke due to an obstruction in the artery may be treated with medication to dissolve the blood clot blocking the artery, known as tissue plasminogen activator (tPA). This medication must be given within three hours of when the patient first noticed stroke symptoms.

Other treatments may include neurosurgical procedures to remove the obstruction.

During a patient's recovery and rehabilitation, physical and occupational therapy are often key components of the treatment plan. These therapies aid patients in restoring muscle movement, coordination and balance, and can help patients relearn daily activities. Speech therapy may also be prescribed if a patient is having trouble talking or swallowing.