Mostly caused by acute cerebrovascular disease and its primary disease. The main cause of acute cerebrovascular disease is the injury of motor center of cerebral hemisphere cortex. According to the division of labor in human cerebral hemisphere, the right cerebral hemisphere manages the movement of the left limb through the motor center; The left hemisphere controls the movement of the right limb through the motor nerve. Lesions on either side will lead to contralateral hemiplegia. The internal capsule is the most prone to pathological changes in both hemispheres of the brain. Because here, the blood is mainly supplied by a small blood vessel called lentiform artery, which is a vertical branch of the middle cerebral artery with small diameter and high pressure, and it is easy to rupture and bleed when it is impacted by blood flow. So it is also called bleeding artery. It is the prone site of cerebral hemorrhage, but when the blood pressure drops and the blood flow is slow, it is prone to thrombosis. However, the nerve fibers in the internal capsule area are closely arranged, and both ascending and descending fibers pass through here. Once damaged, there will be contralateral hemiplegia, hemiparalysis and hemianopia, which is the so-called three-deviation sign.

The causes of hemiplegia are diverse and complicated. Generally speaking, they are inextricably linked with diseases such as elevated blood lipids and increased blood viscosity. To sum up, there are the following points:

1. Atherosclerosis is the main cause of stroke, and 70% of stroke patients suffer from atherosclerosis. Hyperlipidemia is one of the main causes of arteriosclerosis.

2. Hypertension is the most common symptom of stroke, and 93% patients with cerebral hemorrhage have a history of hypertension.

3. Congenital cerebrovascular abnormality is a common cause of subarachnoid hemorrhage and cerebral hemorrhage.

4, heart disease, such as endocarditis, may produce double-walled thrombosis; Bradycardia may lead to insufficient blood supply to the brain.

5. Among metabolic diseases, diabetes has the closest relationship with stroke, and 30-40% of stroke patients suffer from diabetes.

The onset of hemiplegia is sudden, but the pathological process is mostly slow. In this pathological change process, the inducing factors of stroke promote the sudden escalation of this change process and the occurrence of stroke. The inducing factors of stroke are roughly as follows:

1, in a bad mood (angry, excited);

2. Poor diet (overeating, improper drinking).

3. Overwork; Excessive force; Excessive exercise; Sudden posture changes, such as sitting up and getting up.

4. Climate change; Pregnancy; Dry stool; Watching TV for too long; Improper use of the brain, etc.

5. Various disease factors, such as diabetes, hypertension, hyperlipidemia, hemophilia, heart disease, hyperviscosity, bradycardia and arteriosclerosis.

6, improper medication, such as improper use of antihypertensive drugs.

Brain injury of any cause may lead to hemiplegia, and cerebrovascular disease is the most common cause of hemiplegia. Craniocerebral trauma, cerebrovascular malformation, cerebral aneurysm, brain tumor, brain infection, brain degeneration and demyelinating diseases can all cause hemiplegia.