Chronic subdural hematoma is defined as an accumulation of blood from intracranial hemorrhage in the subdural cavity and the onset of symptoms more than three weeks after injury. There is no uniform understanding of the source and pathogenesis of hematomas. The incidence of hematoma accounts for about 10% of intracranial hematomas, which often occur on the convex surface of the frontoparietal temporal hemisphere and can accumulate up to 100-300 ml of blood. The clinical manifestations are mainly increased intracranial pressure, headache is more prominent, some have mental symptoms such as dementia, apathy and mental retardation, and a few may have focal brain symptoms such as hemiplegia, aphasia and focal epilepsy. Clinical manifestations 1. Symptoms of increased intracranial pressure: headache, vomiting, optic nerve papillary edema. Infants and children often have convulsions, vomiting, feeding difficulties, bulging fontanelle and enlarged head circumference, etc. 2, mental disorders; dementia, apathy, memory loss, disorientation and mental retardation, etc. 3, focal brain symptoms: hemiplegia, numbness, aphasia and focal epilepsy, etc. Examination methods 1.Cranial X-ray is included in the routine examination, which can suggest signs of increased intracranial pressure, such as deepening of the cerebral gyrus pressure traces, enlargement of the pterygoid saddle and bone resorption, and local cranial thinning. In patients who have had the disease for many years, the hematoma wall may have rounded bars of calcification. In infants and young children, there may be enlargement of the anterior chimney, separation of cranial sutures and enlargement of the skull. CT or MRI examination of the head is a more ideal diagnostic method, with the advantages of simplicity, safety, and the ability to show the location, size and number of hematomas in a short time. For bilateral hematomas that are difficult to be shown simultaneously by cerebral angiography, CT examination can accurately diagnose them. When the hematoma shown by CT and MRI is of equal density, enhanced scanning or MR examination can be performed. Diagnosis basis 1. There is often a history of minor head injury or neglected injury, and symptoms often appear more than 3 weeks after the injury. Chronic intracranial elevation symptoms such as headache, vomiting and optic nerve papillary edema, convulsions, vomiting, bulging fontanelle and enlarged head circumference in infants and children, and brain herniation in late stages. In some patients, psychiatric symptoms are more prominent or focal brain symptoms are predominant. 3. Head X-ray mostly shows chronic intracranial pressure increase, and a few can see calcification signs of hematoma. In the case of supratentorial hematoma, the midline wave of ultrasound examination is shifted to the opposite side. Cerebral angiography, CT or MRI of the head can show the site and scope of hematoma. 4, Cranial borehole exploration reveals subdural blood. 5. Infant patients often have a history of emergency delivery or delivery difficulties. Treatment Once the symptoms of increased intracranial pressure appear, surgical treatment should be performed. First, the preferred method is drilling and drainage, which is satisfactory and has a good prognosis if there are no other complications. Therefore, even if the patient is old and sickly, we should try our best to save the patient and even perform bedside cone drainage, as long as the treatment is timely, we can often turn the crisis into a safe one. 1, drilling or cone hole flushing drainage: according to the site and size of the hematoma, choose the front and rear holes (one high and one low). Under local anesthesia, the cranial borehole is drilled in the anterior part or the cranial cone hole is used to enter the cavity of the hematoma, and then old blood and brown blood clots flow out, and then the cystic cavity is carefully placed with silicone tube or No. 8 urinary catheter, the length of which should not exceed the radius of the hematoma cavity to further drain the liquid hematoma. In the same way, the lower part (posterior part) was re-drilled or tapered to drain the cyst and a catheter was placed, followed by repeated flushing with saline gently through both catheters until the flushing fluid became clear. After the operation, the two drains were separately drained out of the skull through separate scalp punctures and connected to sterile sealed drainage bags. The high drainage tube was drained and the low drainage tube was removed in about 3 to 5 days. Recently, it has been reported that simple cone cranial irrigation can be used, which can be done directly at the bedside through scalp cone cranial, draining the old blood and rinsing with saline until clear, and repeating cone cranial irrigation every 3 to 4 days, generally about 2 to 4 times, until the brain pressure is released and the midline structure is reset under CT monitoring. 2, anterior chimney lateral angle subdural puncture: pediatric chronic subdural hematoma, the anterior chimney is not closed, feasible anterior chimney subdural puncture to aspirate the accumulated blood. Choose a muscle needle with a short beveled tip, and take a 45-degree angle obliquely through the lateral angle of the anterior chimney to the frontal or parietal subdural, and enter the needle 0.5~1.0cm that there is brownish fluid aspiration, and the amount of each aspiration is 15~20ml. If it is bilateral, it should be punctured alternately on the left and right, and the extracted blood often becomes lighter day by day, and the hematoma volume also decreases, if there is fresh blood extraction and/or the hematoma does not shrink, it is necessary to change to dissection. B. Bone flap craniotomy for chronic subdural hematoma removal: Applicable to chronic subdural hematoma with thicker envelope or calcification. The dissection method has been described as before, after lifting the bone flap, the bruised and thickened dura mater is visible. A small hole is cut first to slowly drain the accumulated blood, and after the intracranial pressure is slightly lowered, the dura and the outer membrane of the hematoma immediately below it are flap-shaped and turned over together to reduce blood leakage. The inner membrane of the hematoma and the arachnoid membrane are easy to separate and should be excised, but they should not be stretched to avoid tearing the border of the inner and outer membrane, which is prone to bleeding and can be cut at 0.5 cm near the edge. After surgery, the bleeding should be properly stopped, the dura mater and scalp layers should be sutured in layers, and the hematoma cavity should be drained for 3 to 5 days. Bilateral hematoma should be staged and operated by side. Treatment of postoperative hematoma recurrence: Whether it is drilled and drained or craniotomized, there is the problem of hematoma recurrence. Common causes of recurrence include: brain atrophy in elderly patients, difficulty in brain expansion after surgery; thick hematoma envelope, subdural cavity cannot be closed; hematoma cavity with blood clots not completely removed; fresh bleeding and hematoma recurrence. Therefore, care should be taken to prevent the recurrence of the hematoma by adopting a low head position, lying on the affected side, drinking more water, not using strong dehydrating agents, and supplementing with hypotonic fluids when necessary; craniotomy should be performed to remove the thick envelope or calcification; when there is a solid clot in the hematoma cavity or fresh bleeding, a bone flap or window should be used to open the cranium and remove it completely. Postoperative drainage tube high exhaust, low drainage, external closed drainage bottle (bag), while the lumbar puncture or ventricular injection of saline; postoperative residual cavity fluid, gas absorption and brain tissue expansion takes 10 to 20 days, so dynamic CT observation should be made, if the clinical symptoms significantly improved, even if there is still subdural fluid, there is no need to rush to operate again. The principle of medication 1, mild patients can be treated symptomatically. 2.Anti-psychotic drugs should be given to those with mental disorders and anti-epileptic drugs to those with epileptic manifestations. 3. For patients with increased intracranial pressure, give dehydrating diuretic drugs to reduce intracranial pressure. 4.Patients with infants and children should be given hemostatic drugs, especially vitamin K. 5.Patients should be given appropriate amount of antibiotics to prevent infection after surgery. 6.Strengthen supportive therapy and prevent complications in critically ill patients. Prognosis 1.Cure: hematoma disappears, symptoms and signs disappear, and normal life and work resume. 2.Progression: hematoma disappears, symptoms improve, neurological dysfunction remains, life can be taken care of, and there is a certain degree of work ability or partial loss of work ability. 3.Unhealed: hematoma does not disappear completely, symptoms and signs do not improve, and life cannot be taken care of. Prevention of common sense This disease is mostly seen in the elderly and infants under 6 months of age. If headache, vomiting, mental disorder or focal brain symptoms appear gradually after a period of time (more than 3 weeks) after head injury, this disease should be considered and should be seen by a specialist in time. Patients who cannot provide a history of head injury and infant patients are sometimes clinically difficult to distinguish from intracranial tumors and congenital hydrocephalus, but CT, magnetic resonance imaging or cerebral angiography can make a clear diagnosis. Surgery is the best treatment, and most patients who have timely surgery have a good prognosis. Some postoperative patients with reappearance of symptoms or poor outcome should be reviewed by CT. Caution The disease presents as a chronic process with satisfactory results if a clear diagnosis and surgery are performed in time. Most of the patients with poor outcome or death are due to untimely diagnosis and treatment, critical condition or complications.