Remote Ischemic Conditioning for Avoiding Recurrence of Symptomatic Intracranial Atherosclerotic Stenosis (sICAS)

Inclusion Criteria: 1. Male or female with age from 40 to 80 years old. 2. Patients having an ischemic stroke or a TIA prior to randomization. * Patient having an ischemic stroke within 30 days with mRS score≤4 at baseline. * Patient having a TIA within 15 days with Oxfordshire Community Stroke Project on the basis of age, blood pressure (BP), clinical features, and duration of TIA symptoms (ABCD2) score≥4 at baseline. 3. The entry event is attributed to symptomatic atherosclerotic stenosis (50-99%) in an intracranial qualifying artery (carotid artery, middle cerebral artery (M1), vertebral artery, or basilar artery) that is documented by magnetic resonance angiography (MRA) or computed tomographic angiography (CTA). 4. Informed consent obtained. Exclusion Criteria: 1. Thrombolytic therapy within 24 hours prior to enrollment. 2. Progressive neurological signs within 24 hours prior to enrollment. 3. Cerebral venous thrombosis/stenosis. 4. Intracranial arterial stenosis due to arterial dissection, Moya Moya disease; any known vasculitic disease; herpes zoster, varicella zoster or other viral vasculopathy; neurosyphilis; any other intracranial infection; any intracranial stenosis associated with cerebrospinal fluid (CSF) pleocytosis; radiation induced vasculopathy; fibromuscular dysplasia; sickle cell disease; neurofibromatosis; benign angiopathy of central nervous system; post-partum angiopathy; suspected vasospastic process, suspected recanalized embolus. 5. Any of the following unequivocal cardiac source of embolism: rheumatic mitral and or aortic stenosis, prosthetic heart valves, atrial fibrillation, atrial flutter, sick sinus syndrome, left atrial myxoma, patent foramen ovale, left ventricular mural thrombus or valvular vegetation, congestive heart failure, bacterial endocarditis, or any other cardiovascular condition interfering with the participation. 6. Uncontrolled severe hypertension \[sitting systolic blood pressure (SBP) \>180 mmHg and/or sitting diastolic blood pressure (DBP) \>110 mmHg after medication\]. 7. Patients with abnormal laboratory parameters: aspartate transaminase (AST) and/or alanine transaminase (ALT) \>3×upper limit of normal range; creatinine clearance \<0.6 ml/s and/or serum creatinine \>265 μmol/l (\>3.0 mg/dl); platelets \<100×109/L. 8. Any intracranial hemorrhage (parenchymal, subarachnoid, subdural, epidural) within 90 days prior to enrollment. 9. Intracranial neoplasm, cerebral aneurysm or arteriovenous malformation. 10. Known retinal hemorrhage or visceral bleeding within 30 days prior to enrollment. 11. Severe hemostatic disorder or severe coagulation dysfunction. 12. Subclavian arterial stenosis≥50% or subclavian steal syndrome. 13. Extracranial stenosis ≥50%. 14. Previous treatment of target lesion with a stent, angioplasty, or other mechanical device, or plan to perform one of these procedures within 12 months after enrollment. 15. Major surgery (including open femoral, aortic, or carotid surgery, cardiac) within previous 30 days or scheduled in the 12 months after enrollment. 16. Contraindication for remote ischemic conditioning: severe soft tissue injury, fracture, or peripheral vascular disease in the upper limbs. 17. Life expectancy\<3 years. 18. Pregnant or breast-feeding women. 19. Unwilling to be followed up or poor compliance for treatment. 20. Patients being enrolled or having been enrolled in other clinical trial within 3 months prior to this clinical trial. 21. Patients unsuitable for enrollment in the clinical trial according to investigators decision making.