The current treatment based on evidence-based medicine for acute ischemic stroke mainly includes reperfusion (intravenous thrombolysis, mechanical thrombolysis), anti-platelet and stroke units. About 1/3 patients can obtain good prognosis through intravenous thrombolysis. Good prognosis can be gotten from about 50 percent of patients with big artery disease by mechanical embolization. However, only a small proportion of the population can be treated with restoration perfusion in the time window. The main purpose of antiplatelet therapy is to prevent the recurrence and progression of stroke, and stroke unit is a kind of management mode. How to improve the neurological function of patients has been a hot and difficult problem in clinical practice.

A large number of basic and clinical studies have proved that remote ischemic conditioning (RIC) has protective effect on ischemic stroke. Hahn et al showed that RIC could play a neuroprotective role in cerebral ischemia-reperfusion injury in MCAO model. Other studies have also confirmed that preconditioning RIC has a neuroprotective effect on cerebral ischemia in animal models. One open label study by Hougaard et al shows that RIC can improve the NIHSS score in acute ischemic stroke patients. One recent study found that 300 consecutive days RIC therapy for the patients with symptomatic intracranial atherosclerotic stenosis significantly reduced the recurrence rate of stroke, improved the mRS score and recovered the blood flow in the lesion site. Furthermore, several studies have also shown that RIC can not only improve the neurological function of patients with cerebral infarction after intravenous thrombolysis and mechanical thrombolysis, but also protect the secondary brain injury after carotid stenting. These results suggest that RIC has a neuroprotective effect on ischemic stroke and deserves further study.

Based on the above discussion, this study aims to explore the efficacy and safety of RIC in the treatment of acute moderate ischemic stroke.

Inclusion Criteria:

1. Patient age ≥18 years;
2. From onset to treatment ≤ 48 hours;
3. Ischemic stroke confirmed by head CT or MRI;
4. 6≤NIHSS score ≤ 16;
5. Premorbid mRS ≤ 1;
6. Signed informed consent.

Exclusion Criteria:

1. Serious neurological deficits before onset ( mRS ≥ 2)；
2. The aetiology of cardiogenic embolism, such as rheumatic mitral or aortic stenosis, artificial heart valve, atrial fibrillation, atrial flutter, sick sinus syndrome, left atrial myxoma, left ventricular wall thrombus or valve neoplasm, congestive heart failure, bacterial endocarditis, etc;
3. Uncontrolled severe hypertension (Systolic pressure ≥180 mmHg or diastolic pressure ≥110 mmHg after drug treatment);
4. Subclavian artery stenosis ≥ 50% or subclavian steal syndrome;
5. Intracranial tumor, arteriovenous malformation or aneurysm;
6. Severe abnormalities in coagulation;
7. Any contraindication for remote ischemic adaptation: the upper limb has serious soft tissue injury, fracture or vascular injury, distal upper limb perivascular lesions, etc.;
8. Comorbidity with any serious diseases and life expectancy is less than half a year;
9. Participating in other clinical trials within 3 months;
10. Patients not suitable for this clinical studies considered by researcher;