For the treatment of ischemic cerebrovascular diseases, there is no treatment method that can effectively protect neuronal damage so far. Recently, animal experiments have shown that a new intervention, remote isehemic preconditioning (rIPC), can reduce the volume of cerebral infarction and provide effective cerebral protection. However, the exact mechanism is still unclear, and its clinical application is currently uncommon in China and abroad. Therefore, we conducted this clinical study to investigate the effectiveness and safety of rlPC in the treatment of ischemic cerebrovascular diseases. The study was conducted to investigate the efficacy and safety of rlPC in the treatment of ischemic wins cerebrovascular diseases. After standardized treatment, the risk factors such as hypertension, blood glucose and lipids were controlled within the stopping range, and there were 145 patients. The diagnosis was in accordance with the criteria set by the Fourth National Academic Conference on Cerebrovascular Diseases in 1995 and confirmed by CT/MRI examination of the head. The symptoms of the enrolled patients included headache, dizziness, limb weakness, limb numbness, blurred vision, and speech disorders. The patients were randomly divided into 85 cases in the limb rlPC group and 60 cases in the control group according to the ratio of 3:2. There was no statistically significant difference in age, gender and disease history between the two groups; patients with cerebral infarction were scored by National Institutes of Health Stroke Scale (NIHSS) and patients with TIA were scored by ABCD2 (this scale was used to predict the risk of stroke in TIA patients in the short term. a is age, b is blood pressure, c is clinical features, d is duration of symptoms; 0- 3 is low risk, 4-5 is moderate risk, and 6-7 is high risk).12], the difference between the two groups was also not statistically significant. See Table l. 1.2 Inclusion and exclusion criteria Inclusion criteria: ① Multiple carotid or cerebral artery stenoses with at least one stenosis ≥50% on transcranial Doppler ultrasound (TCD) and/or magnetic resonance angiography (MRA), with the stenotic vessel being the responsible vessel for symptoms. ②Patients who refuse or cannot undergo stenting or carotid endarterectomy. (iii) Controllable risk factors were controlled to normal range by standard drug therapy. Blood pressure ≤140/90 mill Hg, fasting glucose ≤7.0 mmol/L, LDL <2.60 mmol/L (≤1.80 mmol/L in combination with multiple stroke risk factors such as diabetes and smoking history), homocysteine ≤20 mmoVL. Avoid smoking and limit alcohol. ④Patients and family members should give informed consent. Table exclusion criteria: ①Poor general condition. ②Patients with potential cardiogenic cerebral embolism. ③Psychiatric disease. ④Severe liver and renal impairment or malignancy. ⑤Brain m blood. ⑥Cervical spondylosis or non-ischemic lesions resulting in dizziness symptoms. (⑦Pregnancy or lactation. ⑧Patients who are taking medications that are in the study period or are participating in other research trials.1. 3 Treatment The risk gaps in both groups were controlled strictly according to the 2011 US guidelines for secondary prevention of stroke and TIA. rIPC group underwent limb ischemia training while using the same dosing criteria as the control group. For details, refer to the literature [3]. The IPC I906 double-arm sphygmomanometer from Beijing Renqiao Cerebrovascular Disease Institute was used to pressurize both upper extremities to 180-200 mill Hg, maintained for 5 min, and Ran deflated and rested for 5 min for one cycle, and each training was performed for 5 consecutive cycles, 1 time/d, for a total of 6 months of treatment. The treatment was operated by the subject staff in the early stage, and the patients were treated at home after the training of the patients and their families by the subject staff in the later stage. Telephone follow-up was done once every 2 weeks. Patients' treatment was supervised and guided. Blood glucose, blood lipids, homocysteine and other indicators were checked once every 3 months. Assessment of safety during treatment, mainly observing the blood pressure, heart rate and other maladaptive reactions of patients after treatment_1. 1.1.4 Judgment of treatment results 1.4.1 l Judgment of clinical symptoms: 6 months after treatment, no recurrence of TIA was considered as improvement. The NIHSS score of patients with infarction of the internal organs, basic healing: reduction of neurological deficit score ≥ 90%; significant progress: reduction of functional deficit score 46% to 89%; progress: reduction of functional deficit score 18% a 45%; no change: reduction or increase of functional deficit score < 18%; deterioration: increase of functional deficit score > 18% or more [4 J. Number of improvement cases = basic healing + Significant improvement + progress. MRI was repeated 6 months after treatment to compare the presence or absence of new cerebral infarction.’ 1.4.2 Judgment of SPECT results: ① Qualitative diagnosis: two experienced nuclear medicine physicians read the films individually (at least one was a deputy chief physician or above) and observed the distribution of radioactivity at each level of cerebral perfusion imaging by visualization. If a brain region showed significant radioactive hypo-, hypo- or hyper-activity at three levels and more than two consecutive levels compared with the contralateral side, it was considered abnormal. ②Semi-quantitative method: Using the region of interest (re-gio. of interest, ROI), the radioactivity counts of bilateral frontal, temporal, parietal and occipital lobes, basal nucleus and thalamus were measured using the mirror ratio method. If the ratio of radioactivity count between the affected side and the corresponding area on the opposite side is >1.15 or <0.85, it is abnormal; 0.90 to 1.10 is normal. The ratio of radioactivity counts between the affected side and the corresponding area on the contralateral side was considered to be improved if it was closer to normal than before treatment.1-5 Statistical analysis SPSS 11.5 software was used to process the data. The difference between the two groups was tested for significance, and the x2 test and Fisher test were used for the count data; the t test was used for the measurement data. p<0.05 was considered statistically significant. 2 Results 2.1 Comparison of clinical symptoms between the two groups before and after treatment and before treatment, there were 7l cases (83.5%) with improvement in symptoms in the rlPC group after treatment, and 40 cases (66.7%) with improvement in symptoms in the control group. The rate of symptom improvement in the rIPC group was significantly higher than that in the control group, and the difference was statistically significant, P<0.05. See Table 2. 2.2 Imaging examination 2.2.1 MRI examination: MRI examination was performed before and after treatment for all patients. 3 cases (3.5%) in the rIPC group and 8 cases (13.3%) in the control group had new cerebral infarction, and the incidence of reinfarction in the rIPC group was significantly lower than that in the control group, and the difference was statistically significant, P<0.05. The difference was statistically significant, P<0.05. See Table 2. 2.2.2 Single photon emission computed tomography (SPECT) examination: Among 145 patients, 6l patients received SPECT examination before and after treatment, including 35 cases in the rlPC group and 26 cases in the control group. 29 cases (82.9%) in the rIPC group and 13 cases (50.0%) in the control group had improved blood flow metabolism compared with before. The difference in the rate of improvement of blood flow and metabolism between the two groups was statistically significant, P<0.01. See Table 2, Figure 1. Table 2 Clinical symptoms and imaging improvement in the two groups of patients with ischemic Il[L stroke after 6 months of treatment f cases (%)] Note: The difference in the rate of improvement of symptoms and reinfarction between the dPc group and the control group was statistically significant (P