Cerebrovascular arteriovenous malformation
Introduction
Introduction A congenital malformation consisting of entangled dilated blood vessels, in which the input blood flow of the artery directly enters the output channel of the vein, lacking the resistance of the formation of the capillary bed. The consequences of this special deformity structure are deformed blood vessels. Progressive expansion, through compression, stimulation, shunt blood supply or bleeding, damage to adjacent nerve tissue, resulting in a variety of neurological abnormalities. Arteriovenous malformation (AVM) is particularly prone to the junction between the various arterial beds of the brain, most It is common in the frontal-top zone, the frontal lobe, the parenchyma of the lateral part of the cerebellum or the occipital lobe covered.
Cause
Cause
Congenital malformations composed of entangled dilated blood vessels, the main pathophysiology is brain stealing blood, a large number of cerebral arterial blood loss through AV, leading to a series of brain hemodynamic changes.
Examine
an examination
Related inspection
Brain CT examination, brain MRI, EEG, cerebral angiography
Can cause three relatively distinct neurological signs:
(1) intracerebral parenchymal hemorrhage or subarachnoid hemorrhage, accounting for about half. AVM hemorrhage is characterized by the neurological destructive symptoms they cause are generally milder than hypertensive cerebral hemorrhage or congenital aneurysm rupture, and continuous bleeding The recurrence rate is high.
(2) Localized epilepsy can occur, and the specific symptoms are related to the location of the deformity.
(3) Progressive sensory-motor neuropathy can occur because the expanding deformity plays a role in occupying or causing progressive ischemia.
Diagnosis
Differential diagnosis
(1) Intracranial aneurysms.
(2) Spongiform blood vessels can be repeatedly and repeatedly bleeding, and there are no other characteristic symptoms and signs. Cerebral angiography can be negative. CT scans show that the lesions have different density of honeycomb tissue, mixed with calcified plaques. The contrast agent was slightly enhanced after injection of the contrast agent, but no enlarged supply artery and early-stage drainage veins were seen.
(C) venous cerebrovascular malformation and AVM can cause SAH or intracerebral hemorrhage, often accompanied by increased intracranial pressure. There are no abnormal vascular clusters in cerebral angiography, and there is no thickened blood supply artery. Only a few small veins are combined to form a large abnormal vein.
(D) Stroke patients are older, have a history of hypertension atherosclerosis, CT scan and cerebral angiography can be seen with intracerebral hematoma or cerebral infarction, but no abnormal vascular mass.
(5) Other diseases that cause SAH such as blood diseases, leukemia, intracranial inflammation, various arteritis, moyamoya disease, systemic lupus erythematosus, etc. It should be excluded according to the characteristics of each disease for examination or laboratory test. AVM with epileptic seizures should be differentiated from epilepsy. Common idiopathic epilepsy has few objective signs of the nervous system. There is no history of bleeding in the course of the disease. EEG shows signs of epilepsy. CT and cerebral angiography are negative.
The tumor-type AVM should be differentiated from various brain tumors rich in blood supply, among which the more important ones are:
1. The blood supply-rich glioma progresses rapidly, and symptoms of increased intracranial pressure may occur at an early stage. CT scan showed obvious enhanced tumor tissue, cerebral angiography showed significant vascular displacement, but abnormal vascular clusters were scattered, no large supply of arteries and early veins.
2. Vascular reticuloma is more common in the cerebellar hemisphere and ankle, has a family tendency, tends to form cysts, and has a manifestation of hemocytosis. Both CT and cerebral angiography can be seen with vascular masses and supply arteries, but there are also cases of cerebral vascular displacement.
3. The symptoms of increased intracranial pressure in hemangioblastic meningiomas are obvious. The morphology of tumor vascular mass and AVM is different, and the displacement of normal cerebral arteries is obvious.
4. Metastatic cancer, especially lung cancer, breast cancer, kidney cancer, choriocarcinoma, melanoma, brain metastasis can often cause SAH, but the progression of the disease is fast, the patient has a history of primary cancer, so it is not difficult to find clues from the medical history. In addition, neurological dysfunction is already obvious before the bleeding, often accompanied by increased intracranial pressure, can also help identify, not necessarily rely on CT and cerebral angiography.
5. Jugular bulbar tumor often has a history of ear canal hemorrhage, intracranial vascular murmur, multiple cranial nerve damage, especially partial involvement of 6 to 12 cranial nerves, and obvious damage to the rock cone and skull base fracture, etc. Identification. However, cerebral angiography is due to the presence of a significantly dilated blood supply artery (generally the thick pharyngeal ascending artery and its branches) and the presence of obvious arteries and venous fistulas, sometimes causing confusion. AVM of cerebral ischemic disease should be differentiated from various diseases that cause cerebral ischemia. Carotid stenosis and occlusion, carotid dissection aneurysms, various cerebral arteritis, moyamoya disease, cerebrovascular embolism and TIA Wait. Differences can be made by cerebral angiography.
Can cause three relatively distinct neurological signs: (1) intraparenchymal hemorrhage or subarachnoid hemorrhage, accounting for about half. AVM hemorrhage is characterized by the neurological destructive symptoms they cause are generally higher than hypertensive cerebral hemorrhage or congenital The aneurysm rupture is mild, and the recurrence rate of continuous bleeding is high. (2) Localized epilepsy can occur. The specific symptoms are related to the location of the deformity. (3) Progressive sensory-motor neurological disorder can occur because of the expanding Malformations act as a placeholder or cause progressive ischemia.
