Advances in study on risk factors related to cerebral microbleeds and on treatment decision-making when cerebral microbleeds merging related diseases

Abstract

Cerebral microbleeds， belongs to the category of cerebral small blood vessel disease， is a vascular lesion of subcortical or deep brain tissue caused by a variety of risk factors. In recent years, with the development of imaging and the wide use of antithrombotic drugs, the detection rate of cerebral microbleeds has gradually increased. Although mostly regarded as asymptomatic, cerebral microbleeds may increase the risk of cognitive dysfunction, hemorrhagic transformation after cerebral infarction, cerebral hemorrhage, etc. It is of great significance to summarize the progress of the epidemiology and related risk factors of cerebral microbleeds. Risk factors for cerebral microbleeds include genetic factors (ApoE ε4 gene (OR=2.54), NOTCH3 mutation, homozygous mutation in HTRA 1 gene, Fabry disease), advanced age and male (P=0.043), smoking (OR=5.791) and alcohol consumption (OR=7.306), hypertension (OR=1. 049), diabetes (P=0.005), dyslipidemia (P<0.05), cerebral amyloid angiopathy (OR=2.210), hyperhomocysteemia (P<0.05), hyperuricemia (OR:1. 98), renal dysfunction and dialysis (P=0.0041), critical illness (60% of patients had cerebral microhemorrhage after ECMO). Other rare risk factors include cardiac surgery, infective endocarditis, reversible posterior encephalopathy syndrome, moyamoya disease, obstructive sleep apnea syndrome, craniocerebral radiotherapy, and traumatic brain injury can all lead to the occurrence of cerebral microbleeds. At present, age, hypertension and ApoE gene polymorphism are specific risk factors for cerebral microhemorrhage. Whether other risk factors has not reached the overwhelming consensus. Cerebral microbleeds does not require treatment, but in clinical practice, patients with cerebral infarction or atrial fibrillation combined with cerebral microbleeds should be carefully considered. For patients with ischemic stroke/TIA complicated with cerebral microbleeds, antiplatelet therapy is still beneficial, and cerebral microbleeds should not be a contraindication to intravenous thrombolysis (intravenous thrombolysis, IVT) or endovascular treatment (endovascular therapy, EVT). However, for patients with high-load (>10) cerebral microbleeds, even with the IVT/EVT treatment indications, the pros and cons should also be weighed according to the patient's specific situation. For patients with atrial fibrillation complicated with cerebral microbleeds, when the number of cerebral microbleeds is larger or lesions located in the cortical areas, and the risk of cerebral microbleeds is higher, safer new anticoagulants are recommended. At present, there is no consensus between the domestic and foreign medical circles on the risk factors of cerebral microbleeds and the treatment plan and individualized intervention of ischemic stroke combined with cerebral microbleeds, and large-scale clinical studies are still needed for further exploration.

Keywords

• |cerebral microbleeds|susceptibility-weighted imaging|antithrombotic therapy|intravenous thrombolysis|endovascular therapy