Remote Ischemic Conditioning for Chronic Cerebral Artery Occlusion

Chronic cerebral artery occlusion (CCAO), which is characterized by the pathophysiological change of long-term cerebral hemodynamic disorder, is one of the major risk factors affect the occurrence and recurrence of ischemic stroke. However, the mechanism of CCAO injury is not clear and effective treatment is warranted. The purpose of this study is to investigate the protective effect and underlying mechanism of remote ischemic conditioning (RIC) on CCAO.

CCAO is a cerebrovascular disease due to cerebral hypo-perfusion. It is often associated with repeated ischemic stroke or transient neurological symptoms, progressive cognitive decline and reduction of daily ability. Specific and effective treatment is warranted for symptomatic management of CCAO. RIC is a non-invasive strategy to protect the brain. The clinical trials have demonstrated that daily limb RIC seems to be potentially effective in patients with symptomatic intracranial arterial stenosis in cerebral blood flow and metabolism. RIC can also ameliorate cerebral small vessel disease in slowing cognition decline and reducing white matter. Therefore, it is worth to investigate the neuroprotective mechanism of RIC for CCAO.

Eligibility Criteria:
Inclusion Criteria:

* (1) Age range 40-80 years, regardless of gender;
* (2) Digital angiography (DSA) / ultrasound / CT angiography (CTA) / magnetic resonance angiography (MRA) showed unilateral internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion and stenosis of any other cerebral arteries (e.g. the other side of ICA or MCA, basilar artery) \< 50%;
* (3) Modified Rankin Scale (mRS) score 0-2;
* (4) Symptoms of ischemic cerebrovascular disease (ischemic stroke or TIA) due to ICA or MCA occlusions within 12 months prior to enrollment;
* (5) neurological deficits were stable ≥ 30 days after occlusion;
* (6) Magnetic resonance perfusion weighted imaging (PWI) showed mean transit time (MTT) ≥ 4s and related cerebral blood flow (rCBF) (symptomatic side/asymptomatic side) \< 0.95;
* (7) The subject or its legally authorized representative is able to provide informed reports.

Exclusion Criteria:

* (1) Uncontrolled hypertension despite the use of antihypertensive drugs before enrollment (defined as systolic blood pressure ≥200mmHg);
* (2) Stenosis or occlusion of subclavian artery and upper limb artery;
* (3) Previous history of cerebral hemorrhage, including intracranial hemorrhage, ischemic stroke hemorrhage transformation, vascular malformation or intracranial tumor or other parts of the active bleeding disease;
* (4) History of brain tumor or mental illness or acute stroke ≤6 months;
* (5) Suffering from cardiogenic thrombosis diseases, such as mitral stenosis and atrial fibrillation, myocardial infarction, mural thrombosis or valvular vegetations, congestive heart failure or endocarditis within six months;
* (6) Obvious disorder of coagulation mechanism;
* (7) Severe liver or kidney insufficiency, malignant tumor, or serious diseases requiring medical intervention or surgery;
* (8) There is soft tissue or blood vessel injury at the cuff compression site of RIC treatment, or other conditions that cannot tolerate RIC;
* (9) Pregnant or lactating women;
* (10) Life expectancy \<6 months;
* (11) Refusal to sign informed consent, poor compliance, or inability to complete complete treatment, etc.