Smog is a rare and dangerous disease that can cause cerebral infarction or brain hemorrhage at any time, with serious and sometimes fatal consequences. So many people with smog may face life-threatening consequences at any time. So how does such a dangerous disease develop? According to the research of neurosurgical medical experts, smog is a congenital or acquired malformation of the cerebral blood vessels. It is a chronic progressive stenosis or occlusion of the main branches of the cerebral artery ring, including the siphon section of the internal carotid artery, the anterior cerebral artery, the middle cerebral artery, and sometimes the posterior cerebral artery, which can easily cause cerebral blood supply deficiency and cerebral infarction; secondly, the abnormal compensatory expansion of the skull base vascular network due to this stenosis and occlusion, forming a thin and fragile smoke-like vessel, which The walls of the smoky vessels are very thin and can easily rupture, causing cerebral hemorrhage. This is the process of smoldering disease formation. Of course, sometimes the lesion may also be unilateral in the brain, and this is called smog syndrome.