The etiological typing of cerebral infarction mainly adopts the classical TOAST typing, which classifies the etiology of cerebral infarction into the following five major categories: i. Atherosclerotic type of large arteries, which requires vascular imaging to confirm that the stenosis of large intracranial and extracranial arteries corresponding to the neurological deficit of cerebral infarction is at least more than 50% or completely occluded, as well as the presence of high-risk factors for atherosclerosis, such as smoking, hypertension, diabetes high blood pressure, diabetes mellitus, obesity, etc. This type has the same clinical presentation and imaging as the atherosclerotic type, and requires the presence of at least one risk factor for cardiogenic stroke, such as atrial fibrillation, atrial flutter, and patent foramen ovale. Small artery occlusion type, mostly manifested as lacunar cerebral infarction, the main clinical manifestations are various lacunar syndromes without the manifestation of cortical involvement, and its infarct lesion diameter is less than 1.5 cm on imaging. iv. Other etiological types, including vasculitis, myofibrillar dystrophy, hematologic disease, etc. V. Unexplained type.