Intracranial atherosclerotic stenosis.

Abstract

Ischemic stroke is a significant global health problem associated with mortality and disability. Intracranial atherosclerotic stenosis (ICAS) is a leading cause of stroke and contributes to recurrent stroke, especially in Asian population. Because of the different pathophysiology and mechanisms of ICAS resulting in ischemic stroke compared to extracranial atherosclerotic stenosis (ECAS), treatment strategies for secondary prevention would be different. It is associated with traditional vascular risk factors and the degree of the stenosis is one of the important predictors for the occurrence of stroke. Because non-atherosclerotic vasculopathies are frequently observed in ischemic stroke patients caused by large artery disease in East Asia, it is important to differentiate the specific etiologies of intracranial artery stenoses. Recently developed diagnostic neuroimaging techniques, such as high-resolution MRI (HR-MRI) would be helpful in differentiating them. For stroke prevention in patients with both asymptomatic and symptomatic intracranial artery stenosis, the intensive management, including strict control of modifiable risk factors and antiplatelet therapies is essential. There have been no clear guidelines about the duration and combination of antiplatelet therapies. Nowadays, short-term dual antiplatelet therapies for 90 days are recommended to reduce the recurrence of stroke in symptomatic severe ICAS (70-99%). Cilostazol is also suggested as a good choice for the second-line therapy, following the most widely used clopidogrel. In addition, endovascular or surgical interventions could be considered as alternatives for limited cases of symptomatic severe ICAS that is hemodynamically unstable.