What are the causes and symptoms of lacunar infarction?

Lacunar infarction is a special type of cerebral infarction. It is caused by lesions in small perforating arteries deep in the brain on the basis of hypertension and arteriosclerosis. So what are the causes and symptoms of lacunar infarction?

I. Definition

Lacunar infarction is a type of cerebral infarction, accounting for about 20% of all cerebral infarctions. It refers to ischemic micro-infarction lesions caused by occlusion of small penetrating arteries deep in the cerebral hemisphere or brainstem. The diameter of this lesion is mostly 3-4mm, generally not exceeding 1.5cm, and the number of lesions may be multiple, even up to dozens.

With the widespread clinical application of magnetic resonance imaging (MRI), more and more patients with acute lacunar infarction are diagnosed.

2. Causes

The most common cause of lacunar infarction is hypertensive arteriosclerosis.

Long-term, chronic hypertension damages the small arteries in the brain, leading to hyaline degeneration of the walls of small arteries and micro-arteries, causing the lumen to narrow, and small artery occlusion may occur under the inducement of certain hemodynamic factors or changes in blood composition. Most of these arteries are small arteries called deep perforating branches, which are actually the terminal branches of the cerebral arteries, also known as "terminal branches." Since the blood supply range of deep perforating arteries is limited, the blockage of a single branch only causes ischemic necrosis of a very small area of ​​brain tissue, forming the so-called lacunar infarction. Because the lesions are small and often located in relatively quiet areas of the brain, many cases cannot be recognized clinically during the acute onset of the disease.

Other less common causes include:

1. Atherosclerosis of the middle cerebral artery and basilar artery and the small thrombi formed block the deep perforating arteries and cause lacunar cerebral infarction;

2. Abnormal hemodynamics, such as a sudden drop in blood pressure that significantly reduces blood flow in the distal end of a severely narrowed artery, resulting in a micro-infarction;

3. Various small emboli, such as red blood cells, fibrin, cholesterol, air, cancer cells and atherosclerotic plaques, block small arteries and form micro-infarctions;

4. The detachment of atherosclerotic plaques in the extracranial segment of the carotid artery system can also block intracranial arterioles, leading to the occurrence of lacunar cerebral infarction.

3. Main symptoms

General manifestations:

u Mostly occurs in middle-aged and elderly people aged 40-60 and above

uIt is more common in men than in women and is often accompanied by high blood pressure.

u Onset is hidden during daytime activities and is often sudden.

uClinical manifestations are diverse, with more than 20 clinical syndromes.

uThe symptoms are mild, the signs are simple, and the prognosis is good.

No headache, increased intracranial pressure, or impaired consciousness.