A Q: Smog, sounds like a strange disease, what is called smog?
Director: Smog is a cerebrovascular disease characterized by chronic progressive stenosis or occlusion of the end of the internal carotid arteries and the beginning of the anterior and middle cerebral arteries, and secondary to the formation of a characteristic abnormal vascular network at the base of the skull, which is named smog because its cerebral angiographic features show that the new skull base vessels are like smoke. In layman’s terms, it is a disease in which the main blood vessels of the brain are blocked, causing a series of symptoms due to ischemia or hemorrhage in the brain. The disease is prevalent in Japan, Korea, South Korea and China, with an incidence rate of about 1 per 1,000, of which ischemic smog accounts for about 80% and hemorrhagic smog accounts for about 20%.
Smog, like cerebral infarction and cerebral hemorrhage, is a kind of cerebrovascular disease and is not a strange disease. Due to the lack of awareness of smog, the majority of patients with smog are not diagnosed and treated in a timely manner, and it is more common in children under 10 years old and adults around 40 years old. In the past, the disease was considered rare, but with the popularity of magnetic resonance angiography and cerebral angiography, the number of cases detected has increased significantly in recent years.
Second question: What causes smog?
Director: The etiology of smog is not fully understood, and experts and scholars at home and abroad do not agree on this disease, but at present, based on clinical, pathological, immunological and animal experimental studies, it can be considered that this disease is a group of acquired occlusive cerebrovascular diseases. Most scholars believe that smog is genetically related, but it may also be related to infection, autoimmune status, and growth environment.
It is important to emphasize that smog must be a bilateral lesion with an unknown etiology. For example, some intracranial vascular occlusive lesions caused by atherosclerosis, encephalitis, and leptospirosis can also cause vascular smoke-like changes on angiographic images, and this kind of known cause is called smog syndrome.
Three questions: What are the symptoms I should suspect if I have smog? What are the signs of smog?
Director: In general, children or adults with unexplained headache, epilepsy, limb weakness, numbness, aphasia, epilepsy, blurred vision, transient black haze, etc., should consider whether it is smog, and need to go to the hospital for further examination. In addition, some children with mental retardation, slow development, and some mental abnormalities should also be examined in the hospital to rule out whether it is caused by smog.
Smog can be divided into two types, one is ischemic smog and the other is hemorrhagic smog. In mild cases, the symptoms are transient transient cerebral ischemia, headache, epilepsy, limb weakness, sensory abnormalities and visual field changes, while in severe cases, the disease starts with cerebral infarction or cerebral hemorrhage, resulting in hemiplegia, aphasia, coma or even life-threatening.
In ischemic smog, cerebral infarction results in hemiparesis, inability to speak clearly or to speak, and in some cases, vision loss, difficulty seeing, or visual field defects. There are other less common symptoms such as inability to extend the tongue and difficulty swallowing. In severe cases, the patient may become unconscious and unconscious.
In the hemorrhagic form of smoldering disease, the patient usually acts like a normal person, but once the attack occurs, he will have a sudden and severe headache, followed by nausea and vomiting, and soon he will be in a coma. When they go to the hospital, it is a brain hemorrhage, and then further examination is due to brain hemorrhage caused by smog. This part of the patient’s condition is very serious, serious has been in a coma state, even after active treatment patients awake also have serious neurological limb dysfunction.
Q4: Since smog is a blockage of cerebral blood vessels causing cerebral ischemia, why are some patients with cerebral hemorrhage also suffering from smog?
Director: There are many causes of cerebral hemorrhage, the common ones are hypertensive cerebral hemorrhage, vascular malformation, ruptured aneurysm bleeding and so on. Similarly, smog can also cause cerebral hemorrhage, what is the reason? Let’s say that our brain is like a crop in the field, there are many blood vessels in the brain, and the blood vessels are filled with blood, and the blood is like the water that irrigates the crop. If the blood vessels are blocked, the crops will lack water, the brain will lack blood, and the crops will gradually wither and turn yellow (cerebral ischemia), and if we don’t solve the problem of lack of water in time, the crops will slowly die (cerebral infarction), which is the reason why smog causes cerebral ischemia and cerebral infarction. If we do not think to solve the problem of lack of water for the crops and lack of blood for the brain as soon as possible, in time, the crops will die of drought and the brain will suffer from brain infarction. But our brain is very “smart”, the large blood vessels are blocked, he will automatically generate some “smoky blood vessels”. But these smoky blood vessels are not original after all, the walls are very thin, easy to rupture and bleed, once the rupture and bleeding, it will cause a “flood” in the brain, as can drown the crops, affecting neurological function. So smog can cause both cerebral ischemia (drought) and cerebral hemorrhage (flooding). Patients with cerebral hemorrhage from smog are mostly young adults in their 30s and 40s. Therefore, for unexplained cerebral hemorrhage in young adults, it is important to consider whether it is caused by smog.
Five questions: How to diagnose smog?
Director: In terms of clinical symptoms, if a child or adult has unexplained facial or limb numbness, aphasia or slurred speech, blurred vision or transient black haze, epilepsy, etc., consider whether it is smog and go to the hospital for further examination. In addition, some children with mental retardation, slow development, and some mental abnormalities should also be examined in the hospital to rule out whether it is caused by smog.
In terms of imaging, if the cranial CT and MRI images diagnose cerebral ischemia or cerebral hemorrhage, further cranial CTA or MRA examinations should be performed, and if bilateral internal carotid artery stenosis or occlusion with smoke-like vessel formation is found, the preliminary diagnosis of smog can be made. To confirm the diagnosis, whole brain angiography DSA should be performed, and cerebral angiography is the gold standard for the diagnosis of smog. The diagnosis can be confirmed by clinical symptoms and cranial CTA or MRA findings in children without whole brain angiography DSA.
In terms of cerebral hemodynamics, a series of further tests such as cerebral perfusion CT and PET are needed to further understand the cerebral blood flow and cerebral metabolism of patients, evaluate the degree of cerebral ischemia of patients, and guide treatment.
Clinically, some children or adults with symptoms such as hemiparesis, limb weakness and numbness have been unable to find out the cause. It is because of one less cranial MRI angiography MRA that they have not been diagnosed in time, delaying the treatment and leading to serious disability and serious consequences for the family and the patient.
Six questions: Can smog be treated? How can it be treated?
Director: In previous years, once a patient was diagnosed with smog, the patient was like a death sentence, and the patient and family felt very scared and helpless. Many doctors also believe that the disease is a congenital abnormality, the conservative treatment effect of internal medicine is poor, and there is no radical solution for surgery, so it is incurable. In recent years, with the progress of society and the development of medicine, smog is no longer an incurable disease, and the current application of surgical treatment of smog has received better results. Surgery mainly includes direct revascularization (intracranial and extracranial vascular bypass) and indirect revascularization (cerebral-dural-arterial vascularization (EDAS), multi-point drilling, temporalis muscle patch and dural reversal, etc.) and comprehensive treatment, of which comprehensive surgery is the most advanced treatment plan in the world today, combining the two previous surgical methods. Direct revascularization surgery, which we refer to as vascular bypass, is to connect the superficial temporal artery outside the skull directly to the cortical vessels inside the skull. It is like a blocked pipe in a crop field that prevents the crop from being irrigated, and to alleviate the drought, water is found elsewhere to irrigate it. Bypass bridges can directly improve the blood supply to the brain. Indirect blood flow reconstruction surgery involves attaching extracranial blood supply rich muscles and meningeal tissues, etc. to the surface of the brain inside the skull, from which the brain automatically attracts blood vessels to form spontaneous anastomoses with the cortical vessels. By reconstructing the extracranial blood flow to the intracranial area to relieve the inadequate blood supply of the intracerebral arteries, the intracerebral blood flow is improved by establishing the pathway of blood supply from the normal blood vessels outside the brain to the intracerebral area. After the blood supply of the brain is improved, the demand for smoldering blood vessels will gradually decrease, thus reducing the risk of re-occurrence of cerebral ischemia and cerebral hemorrhage and improving the prognosis of the patients.
Q7: Are all patients with smog, regardless of gender, young or old, eligible for surgery?
Director: Generally speaking, once smog is diagnosed and there are symptoms of cerebral ischemia or cerebral hemorrhage, surgery should be considered for both men and women, young and old. The youngest patient we treat is 4 years old and the oldest is 62 years old. The most severe patients are already bedridden and the least severe ones do not even have any symptoms, so there is a wide range of adaptation for this surgery. However, patients with multiple lobe infarcts are not suitable for this surgery, just like bringing water to irrigate a crop that is already dried up will not bring it back to life. Therefore, it is very important to treat smog disease promptly once it is diagnosed.
Q8: What is the most appropriate time for smog patients to receive surgery?
Director: The timing of surgery for smog is very important, and the best results can be achieved only when the disease is stable. Patients with hemorrhagic smog, which often manifests as intracerebroventricular hemorrhage, are not suitable for intracranial and extracranial blood flow reconstruction. For patients with hemorrhagic type, intracranial and extracranial vascular bypass is usually chosen to be performed after 3 months of cerebral hemorrhage. For ischemic type, which is often symptomatic of cerebral infarction, vascular bypass is generally performed only after 1 month after infarction; for patients with acute massive cerebral infarction, dural reversal temporalis muscle patching can be performed in the process of emergency debridement and decompression, so the timing of surgery should be carefully selected according to the specific clinical situation and the patient’s symptoms, and the appropriate surgical approach should be taken.
Smoker’s disease generally manifests bilaterally, and bilateral surgical treatment is the only way to effectively stop the further development of the patient’s condition and reduce the patient’s risk of reoccurrence of cerebral infarction and cerebral hemorrhage. Otherwise, if only one side is done and not the opposite side, then it is at most half cured.
Some family members cannot listen to the doctor’s advice rationally, always worry about the risk of surgery, hope for an unexpected miracle, delay the operation time again and again, and come to the doctor only when they are very sick and can no longer delay, in fact, in the end, the patient is put in a more dangerous situation.
Nine questions: How do I know the treatment is effective after surgery?
Director: In terms of clinical symptoms, we can consider the surgery effective when the patient’s clinical symptoms are relieved or no longer progress, for example, patients with transient ischemic attack no longer have symptoms such as numbness and weakness of the limbs, or the number and degree of symptom attacks have been reduced. In patients who have had a cerebral infarction, the strength of the hemiplegic limb has improved, or the speech function has been restored or partially restored in patients with speech impairment. For patients with cerebral hemorrhage, the probability of rebleeding is greatly reduced after treatment and recovery of consciousness.
From imaging examinations, such as performing MRI MRA, cranial CTA, cerebral angiography DSA, etc. to confirm that blood is supplied to the skull from extracranial vessels, it indicates that the surgery is effective.
The observation of brain tissue metabolism and cerebral blood flow improved and cerebral ischemia curbed from cranial perfusion CT and cranial PET also indicates that the surgery is effective.
Our experience is that for those patients with cerebral ischemia, especially children, it is very effective to detect, diagnose and treat them early. It can also prevent recurrence of cerebral hemorrhage in patients with cerebral hemorrhage.
Q10: What do patients with smog need to pay attention to after surgery?
Director: For smog patients with physical activity disorders and speech disorders, we should actively conduct rehabilitation training because of the rich intracranial blood supply after surgery. Through active training, limb movement and speech functions are restored.
There is no special contraindication for smog patients in terms of diet. However, do not eat foods that are too hot. Eating foods that are too hot, such as noodles, will have an aspirating action, which will easily lead to hyperventilation and trigger cerebral ischemia. Children should eat less jelly and other aspirated foods.
Also from life, pay attention to avoid head and facial trauma, avoid glasses with too tight legs to prevent pinching the blood vessels introduced into the skull.
Families should pay attention to help patients psychologically establish self-confidence, and individuals should avoid heavy physical labor and excessive brain work to ensure that the blood supply to the brain increases slowly and adaptively on a stable basis to ensure postoperative recovery.
Six months after the operation, we should go to the hospital to review the whole brain angiography in time to assess the effect of the operation and provide an objective basis for the patient to develop further individualized treatment plan.