Hypertensive cerebral hemorrhage, as its name implies, is caused by hypertension. In fact, hypertensive cerebral hemorrhage is not a day's work. First of all, people's cerebral vessels will develop atherosclerosis with age, especially when they are combined with risk factors such as hypertension, diabetes, hyperlipidemia and smoking. In addition, people's cerebral vessels are thinner than other blood vessels in the whole body. Due to emotions, weather, constipation, breath holding and other actions, blood pressure will suddenly rise, leading to the rupture of hardened blood vessels. The most common ruptured blood vessels are the perforating branches originating from the great vessels at the skull base, which mainly supply the basal ganglia, thalamus and pons. Therefore, hypertensive cerebral hemorrhage is most common in basal ganglia (figure 1), thalamus and pons (figure 2), cerebellum, cerebral cortex and ventricle. Because the bleeding site is deep and located in the important functional area of the human brain, the mortality and disability rate of hypertensive cerebral hemorrhage are extremely high, and the surgical effect is not good. So prevention is more important than cure. With the aging of hypertension, diabetes and hyperlipidemia, hypertensive cerebral hemorrhage is no longer a patent for the elderly, and it is not uncommon for young people. If you find hypertension, hyperlipidemia and hyperglycemia, you must treat them in time to prevent them before they happen.
Another kind of cerebral hemorrhage-cerebral hemorrhage caused by arteriovenous malformation, is more common in young people. As the name implies, the so-called malformation refers to the congenital abnormal development of cerebral vessels, specifically, a group of abnormal blood vessels with different diameters intertwined with feeding arteries and drainage veins in the brain, which is called AVM for short (Figure 3 and Figure 4). There is no capillary between the feeding artery and the draining vein of AVM, but many sinuses are directly formed. Blood flows from the feeding artery into the deformed blood vessel mass and directly into the vein through the sinus. Due to the lack of capillary structure, imperfect vascular wall development and long-term blood flow impact, it is easy to have tiny aneurysms inside the deformed pattern, causing bleeding. AVM hemorrhage is common in cerebral cortex, but also in ventricles and lateral fissure. In addition to bleeding, patients with AVM may also have epilepsy or headache. The main treatment methods of AVM are surgical resection and interventional embolization, which method needs doctors to decide according to the position, size and angiographic results of AVM.
The first two kinds of cerebral hemorrhage are generally manifested as cerebral parenchymal hemorrhage, and there is a more dangerous cerebral hemorrhage-spontaneous subarachnoid hemorrhage (Figure 5), which refers to spontaneous subarachnoid hemorrhage. Most of this bleeding is caused by the rupture of cerebral aneurysms (Figure 6), which usually occur in the large blood vessels of the human brain. These large blood vessels first enter the skull and then form in the subarachnoid space at the bottom of the brain. Compared with extracranial vessels, the lack of elastic fibers in the inner and outer membranes of cerebral vessels, less muscle fibers in the middle layer, thinner outer membrane, more developed and bulging inner elastic layer, less support from connective tissue in subarachnoid space and hemodynamic changes can all promote the formation of aneurysms. The destruction of the acquired internal elastic layer is a necessary condition for the formation of cystic cerebral aneurysms. Arteriosclerosis, inflammatory reaction and increased proteolytic enzyme activity promote the degradation of the inner elastic layer. Hypertension is not the main pathogenic factor of aneurysm, but it can promote the formation and development of cystic aneurysm. Simply put, intracranial aneurysm is like a bulge in a car tire, usually caused by arterial inflammation or long-term blood flow shock. Due to the lack of complete vascular structure, the aneurysm wall is easy to rupture and bleed. Because aneurysms usually occur in large intracranial vessels, once they rupture and bleed, they are generally very dangerous, with a mortality rate of about 25% and a disability rate of nearly 50% for survivors. For typical subarachnoid hemorrhage, intracranial aneurysm should be highly suspected. If the aneurysm can be clamped or embolized as soon as possible, this is the only way to save the patient.
There is also a common cerebral hemorrhage in the elderly called chronic subdural hemorrhage (Figure 7). This kind of bleeding generally develops slowly, and most of them have a slight history of trauma, and some injuries are so slight that they can't even be recalled, so generally only half of the patients can recall a recent history of trauma, such as falling and kowtowing. Chronic subdural hematoma mostly occurs in weeks to months after trauma, especially in the elderly. It is related to the brain atrophy of the elderly and the relative easy displacement of brain tissue, which leads to concealment. Early symptoms are mild, such as headache, poor mental condition, and serious walking instability or limb weakness may occur. Therefore, for the elderly with a recent history of trauma, once there is limb weakness and unstable walking, it is necessary to take the elderly to have a head CT to rule out chronic subdural hematoma, and the treatment effect of chronic subdural hematoma is generally better. Therefore, for chronic subdural hematoma, early detection and early treatment are necessary, and the prognosis is generally good.
The above mentioned are the common types of cerebral hemorrhage. Of course, besides hypertension, arteriovenous malformation, aneurysm, craniocerebral trauma and other reasons, there are other rare causes of cerebral hemorrhage, such as moyamoya disease, arteriovenous fistula, cavernous vascular malformation, venous malformation and so on. Therefore, once cerebral hemorrhage is found, professional doctors need to carefully identify it according to the patient's age, medical history and imaging examination, and adopt different treatment schemes for cerebral hemorrhage of different reasons.
Twain, Yao Yuqiang, neurosurgery
Some pictures originated from the Internet.