Intracranial stenosis is the medical term for severe narrowing of a cerebral artery that restricts blood flow to areas of the brain. Such narrowing stems from focal, progressive atherosclerosis of the affected vessel. Intracranial stenosis is responsible for about 10% of strokes annually, and the rate of recurrent strokes without treatment can be alarmingly high. Current optimal medical treatment includes antiplatelet or anticoagulation medications such as aspirin or warfarin, anticholesterol agents, control of hypertension, and aggressive control of blood glucose in patients with diabetes.
Computed tomography (CT) angiography, magnetic resonance (MR) angiography, and catheter-based angiography can be used to visualize the region of vessel narrowing. Typical areas of intracranial stenosis include the internal carotid artery, middle cerebral artery, vertebral artery, and basilar artery. Other diagnostic tests can evaluate the adequacy of blood flow to the brain. Computed tomography (CT) perfusion with and without acetazolamide, positron emission tomography (PET), stable xenon CT, and single photon emission CT (SPECT) are all specialized tools used to evaluate adequate blood flow to the brain. PET also has the ability to evaluate the oxygen extraction fraction, a parameter that correlates with risk of stroke.
Intracranial angioplasty and stenting is a minimally invasive way to open up very narrowed arteries inside the skull that supply the brain. When the narrowing of the artery is significant (greater then 70% decrease in diameter) or if the narrowing is causing symptoms (strokes or mini-strokes) despite medical treatment, then intracranial angioplasty with or without stenting is recommeded.
- Intracranial Atherosclerosis