Improving Cerebral Blood Flow and Cognitive Function in Patients With Asymptomatic Intracranial / Carotid Stenosis With Nattokinase (ICC-PACS)

A randomized controlled trial will be conducted. Patients with asymptomatic intracranial / carotid stenosis will be randomized into two arms (1:1): an intervention arm and a control arm. Patients in the intervention arm will be treated with standard medical treatment combined with Natto Products V, whereas Patient in the control arm will be treated with only standard medical treatment . And the impact of Natto Products V on improving cerebral blood flow and cognitive function in patients with asymptomatic intracranial / carotid stenosis will be assessed by neuropsychological scale and multimode magnetic resonance imaging.