Natural history of asymptomatic intracranial arterial stenosis.

The prevalence and natural history of asymptomatic intracranial arterial stenosis are not very well characterized. Existing data suggest that incidentally discovered asymptomatic intracranial stenosis presents a fairly low risk of stroke, though substantial uncertainty remains. Patients may be at greater risk if there are tandem stenoses. Methods to stratify the risk of stroke with asymptomatic intracranial atherosclerotic lesions have yet to be established and validated. In general, aggressive intervention for an asymptomatic intracranial stenosis is not currently recommended.