The purpose of this study is to investigate the effects of rosuvastatin treatment on degree of intracranial arterial stenosis.

The purpose of this study is to investigate the effects of rosuvastatin treatment on degree of intracranial arterial stenosis in two years. Dyslipidemia patients with intracranial arterial stenosis will be enrolled under informed consent in this study. Rosuvastatin (5mg) will be orally administered once daily. Dose of rosuvastatin will be adjusted to control serum LDL-c level under 1.8mmol/L. Primary outcome is the progression of intracranial stenosis on magnetic resonance angiography (MRA) after two years.

Inclusion Criteria:

1. Male or female patients between 30 and 80 years of age.
2. Patients with noncardioembolic ischemic stroke
3. Patients with intracranial arterial stenosis ≥50% in supraclinoid internal carotid artery, M1 portion of middle cerebral artery, A1 portion of anterior cerebral artery, P1 portion of posterior cerebral artery, or basilar artery.
4. LDL-C level is more than 100 mg/dl (2.6 mmol/L) or under treatment of dyslipidemia
5. Patients taking clopidogrel as antiplatelet therapy when providing informed consent
6. Patients considered to be able to visit the study site
7. Patients who provided written informed consent

Exclusion Criteria:

1. Any haemorrhagic stroke or haemorrhagic infarction
2. Familial hypercholesterolemia
3. Patients with uncontrolled angina pectoris or congestive heart failure
4. Patients with severe liver or renal dysfunction
5. Patients with a malignant tumor requiring treatment
6. Patients with uncontrolled diabetes mellitus
7. Patients with secondary dyslipidemia (due to corticosteroid etc)
8. Patients with a history of myopathy
9. Patients considered by the investigator to be unsuitable for participating in this study