What is an intracranial aneurysm? Intracranial aneurysms are not intracranial tumors, but are caused by localized congenital defects in the walls of the cerebral arteries and based on increased intraluminal pressure. Aneurysms rank third among patients with cerebrovascular accidents, after cerebral thrombosis and hypertensive cerebral hemorrhage. The disease occurs in middle-aged and elderly people aged 40 to 60 years old, and is rare in adolescents. According to statistics, after the first rupture of an aneurysm, the mortality rate is as high as 30-40%, half of which die within 48 hours after the onset of the disease, and of the surviving cases, 1/3 may suffer from rebleeding, and the mortality rate of those who suffer from rebleeding is as high as 70-80%. Cerebral arteriovenous malformations account for about 10-15% of patients with subarachnoid hemorrhage, and the mortality rate of initial hemorrhage is about 10%. Therefore, intracranial aneurysms and cerebral arteriovenous malformations are called “untimely bombs in the human body”. What are the causes of intracranial aneurysms? The causes of aneurysms are not well understood. They include congenital factors (congenital defects in the arterial wall), atherosclerosis, infection, head trauma, and other factors. In addition to these, a common factor is the hemodynamic shock factor. Some patients have triggers such as exertion and emotional excitement before bleeding, while others have no obvious triggers or develop during sleep. What are the symptoms of intracranial aneurysm? 1.Prognostic symptoms: Small and medium-sized aneurysms without rupture and bleeding can be clinically asymptomatic. Some patients have unilateral orbital or retrobulbar pain with oculogyric nerve palsy, sometimes accompanied by nausea and vomiting and dizziness. The aura symptoms are usually caused by a small amount of subarachnoid blood leakage, or the aneurysm wall may be acutely dilated or ischemic due to blood breaking into the aneurysm layer, which should be alert to the ensuing subarachnoid hemorrhage. 2, aneurysm rupture and bleeding symptoms: Once the aneurysm ruptures and bleeds, the clinical manifestation is severe subarachnoid hemorrhage, with rapid onset, the patient has severe headache, described as “head is about to explode”. Frequent vomiting, profuse sweating, fever, neck stiffness, and possible impaired consciousness or even coma. After subarachnoid hemorrhage, red blood cell destruction releases a variety of vasoactive substances on the cerebral vessels, resulting in vasospasm and extensive cerebral vasospasm, which can lead to cerebral infarction and even death. 2.Focal symptoms: It depends on the site of aneurysm, adjacent anatomical structure and size of aneurysm. For example, actinic nerve palsy is commonly seen in internal carotid artery-posterior communicating artery aneurysm and aneurysm of posterior cerebral artery, which manifests as unilateral ptosis, pupil dilatation and diplopia. What tests are required for intracranial aneurysm? 1.Cranial CT: In the acute stage of hemorrhage, the positive rate of CT to confirm the diagnosis of subarachnoid hemorrhage is very high, safe, rapid and reliable. 2.MRI and MRA can suggest different parts of aneurysm; 3.CTA or 3D-CT: it provides detailed information for surgical clamping of aneurysm and removal of huge aneurysm. 4.DSA examination: facilitate the diagnosis and embolization of aneurysm. How is intracranial aneurysm treated? The surgical treatment of cerebral aneurysm is different from the treatment of other intracranial tumors. The purpose of surgery is not to remove the tumor after craniotomy, but to clamp the aneurysm, control the formation and extinction of the aneurysm. The surgery is extremely dangerous and requires a very experienced senior neurosurgeon to perform. Current treatment options for intracranial aneurysms include direct craniotomy treatment of the aneurysm and endovascular embolization. Once a brain aneurysm is diagnosed, it should be treated surgically in order to cure it and avoid the risk of hemorrhage. Approximately 70% of patients who are treated conservatively will die from aneurysm rebleeding. Microsurgical aneurysm clamping surgery has reduced the surgical mortality rate of aneurysm to less than 2%. Since 2000, Professor Meiqing Lou of Neurosurgery Department of our hospital has successfully performed hundreds of aneurysm clamping operations, and has rich experience, mature technology and perfect equipment in dealing with various kinds of difficult aneurysms including huge aneurysms, multiple aneurysms and aneurysms in special areas, and the success rate of treatment is advanced in Shanghai, and now the “Cerebrovascular Disease Treatment Center” has been established. “The Center for Cerebrovascular Disease Treatment has been established.