• Progression of intracranial arterial stenosis after two years
  

• Cardiovascular events (ischemic stroke, cardiac infarctin, and other vascular events ）,
  
• death (stroke death, vascular death except for stroke ）,
  
• serious adverse events, new silent brain infarcts, and degrees of activity of daily living.
  

Intracraial arterial stenosis (IAS) is more common in Asia, including Japanese, than in Cocasian. Also, stroke recurrence rate is high in patients with such lesions, despite medical treatment. Accoding to the result of WASID (N Engl J Med 2005;352:1305-16), warfarin is not recommended because of the concern of safety (higher risk of intracranial hemorrhage and death when compared with aspirin), wheras the efficacy of aspirin is not enough in symptomatic IAS patients. Under these conditions, we planned to conduct a nationwide multi-center, open labelled, randomized controlled trial to compare the effect of aspirin plus cilostazol (phosphodiestrase type 3 inhibitor) and aspirin alone on the progression of IAS in 200 IAS patients with ischemic stroke after 2 weeks to 6 months of onset. Patients are randomly allocated to either of two groups. Aspirin 100mg/day plus cilostazol 200 mg/day is given to the 100 patients in one group, and aspirin 100 mg/day alone is given to 100 patients in another group.

Follow-up period is at least two years. The primary endpoint is progression of IAS on MRA at two years after randomization. The secondary endpoints are cardiovascular events (ischemic stroke, myocardial infarct, and other vascular events), death, serious adverse events, new silent brain infarcts, and activity of daily life. The purpose of this study is to establish the best medical treatment in symptomatic IAS patients. This study will also provide important information for the future randomized controlled study to compare medical treatment alone and intravascular intervetnion (PTA and/or stenting) in these patients.