According to the etiology, cerebral infarction can be divided into 5 categories (TOAST classification)
1. Large artery atherosclerosis (LA): stenosis (>50%) or occlusion of intracranial and extracranial arteries, caused by atherosclerosis. Hypertension, diabetes, smoking, hyperlipidemia, obesity, less exercise, and hyperhomocysteinemia are common risk factors. After decades of arteriosclerosis, plaque in the artery (chronic course) is formed. Once it falls off and blocks the artery, paralysis, aphasia and other symptoms will occur (acute onset).
2. Cardiogenic cerebral embolism (CE): This category refers to the falling off of embolus in the heart, which blocks internal and external intracranial arteries. Atrial fibrillation and mechanical mitral valve were the main inducements.
3. Small artery occlusion stroke (SA): This type includes patients with lacunar stroke often mentioned in other classifications. Hypertension is the main cause.
4. Ischemic stroke caused by other causes: this category includes cerebral infarction caused by other rare causes (infectious, immune, non immune vascular diseases, blood diseases, sporadic vascular diseases, etc., drug abuse, etc.). Other examinations should exclude the evidence of cardiogenic diseases and large atherosclerotic lesions.
5. Stroke of other unknown etiology: this type includes: patients whose etiology has not been found after extensive evaluation; Patients with incomplete assessment data; Cases with two or more causes that cannot be finally diagnosed.
Among the five etiological criteria, the first three are common types in clinical practice, and the fourth type is rare. Individual examination should be carried out according to the specific conditions of patients to determine the cause.
