Neuroepithelial tumors are collectively referred to as gliomas, including astrocytomas, oligodendrogliomas, mixed gliomas, ventricular meningiomas, choroid plexus tumors, neuroglial tumors of unknown origin, neuronal and mixed neuron-glial tumors, neuronal cell tumors, pineal parenchyma tumors, and embryonal tumors. Diagnostic basis 1, medical history: there is a big difference in the development process of the disease, most of the low-grade gliomas present a chronic course, but if the lesion is located in the vicinity of the cerebrospinal fluid circulatory pathway or the functional area, it can be caused by the secondary hydrocephalus or epileptic seizures resulting in a relatively shorter duration of the disease, or even manifested as an acute process. High-grade gliomas may have an acute or subacute onset. In the process of taking patients’ medical history, attention should be paid to whether there is any previous history of tumor disease in other parts of the body, and whether there is any family history of tumor disease or genetic disease. Symptoms and signs: They should be divided into general increased intracranial pressure and focal symptoms and signs. (1) Increased intracranial pressure: Increased intracranial pressure is caused by the increase of tumor volume or edema of surrounding tissues, which is usually a slow and gradual aggravation process, typically manifested as headache, nausea and vomiting, and fundus optic papillae edema. If the tumor blocks the cerebrospinal fluid circulation pathway, acute intracranial pressure increase may occur. In the advanced stage of intracranial pressure increase, it may cause blindness, and the fundus examination may show papillary edema or combined with secondary atrophy. In the elderly, due to cerebral atrophy, the intracranial space is relatively large, so the increase in intracranial pressure may be relatively insignificant. (2) Focal symptoms and signs: (1) Cerebral hemispheric glioma: the tumor is located in or near the functional area, and the neurological localization may appear in the early stage, as follows: a. Conotruncal fasciculus injury: the opposite side of the tumor is weak in half-body or a single limb, and paralysis is gradual. At the beginning of the disease, the abdominal wall reflex of one side is weakened or disappeared, and then the tendon reflex of the opposite side of the lesion is hyperreflexia, increased muscle tone and positive pathological reflexes; b. Sensory abnormality: the main manifestation is the impairment of cortical sensation, such as the joint position sensation of the limb on the opposite side of the tumor, the two-point discrimination sensation, the graphic sensation, the solid sensation and so on; c. Aphasia and visual field alteration: if the tumor is located in the posterior part of the frontal-inferior gyrus of the dominant hemisphere and the deep part of the temporo-occipital lobe, the corresponding manifestations may be shown; d. Mental symptoms: personality changes and memory changes, Psychiatric symptoms, such as personality change and memory loss, such as slow reaction, lazy life, memory loss, poor judgment, or irritability, agitation or euphoria, etc.; e. Epileptic seizures, including generalized and limited seizures. Seizures mostly start from one side of the limb, and some of them manifest as ictal sensory abnormalities. Cerebellar glioma: the tumor is located in the cerebellar hemisphere, the earth’s part, or the bridge cerebellar angle, etc., causing the corresponding manifestations as follows: a. Cerebellar hemisphere: manifestation of the affected side of the limb ataxia, such as the finger-nose test, the heel-knee test is inaccurate, the alternation test is slow and clumsy, etc.. b. Cerebellar hemisphere: manifested as trunk ataxia, such as walking with the feet too far apart, hobbling gait. c, Cerebellar pontine horn symptoms: cranial nerve symptoms in the middle and posterior groups on the same side of the lesion, such as tinnitus, deafness, vertigo, facial numbness, facial muscle twitching, facial muscle paralysis, hoarseness, choking and coughing on eating, cerebellar ataxia on the side of the lesion, and so on. (iii) Brainstem glioma: manifested by multiple cranial nerve deficits, long conduction bundle signs, ataxia, or the combined appearance of any two signs, such as the presence of oculomotor deficits, diplopia, facial paralysis, hoarseness of voice, unsteady gait, and crossed paralysis, peripheral paralysis of cranial nerves on the side of the lesion, and central paralysis of the limbs on the contralateral side of the lesion. ④ Posterior third ventricle glioma: the tumor is located in the pineal region of the posterior third ventricle, which mainly causes intracranial pressure increase due to cerebrospinal fluid circulation obstruction, and local signs may appear in the involved peripheral tissues. a. Tetralogy of Fallot: binocular upward vision disorder; pupillary light reflex and regulation disorder; hearing disorder and so on. b. Cerebellar signs: the tumor develops downward and compresses the supracerebellar earth part, which causes unsteady gait and holding objects, horizontal nystagmus, and so on. 3, Auxiliary examination: Diagnosis of glioma is mainly based on imaging examination: it is mainly based on enhanced CT or MRI, in addition, hospitals with the condition can choose MRS, fMRI, PET, MEG, etc. for further differentiation or functional diagnosis. CT and MRI can diagnose the tumor based on direct and indirect images of the tumor, including the abnormal density and signal area of the tumor tissue itself, as well as the compression and displacement of the tumor on the ventricular and cerebral pool system. Most low-grade gliomas do not enhance on CT and MRI slices, and usually show low density on CT scan and low signal on T1-weighted image of MRI. On the other hand, malignant gliomas usually enhance, with high signal in the T2-weighted image, and the edematous tissues around the tumor also show high signal. Diagnosis A preliminary diagnosis can be made based on the patient’s clinical presentation, signs and symptoms of intracranial hypertension, and signs and symptoms caused by localized lesions. Definitive diagnosis should be based on the results of imaging examinations. （Differential diagnosis 1. Cerebral parasitosis: patients often have a history of contact with the source of infection, and the pathogenetic examination of worm eggs and serum complement binding test may show positive results. 2.Metastatic tumor: patients often have history of extracranial tumor, the lesions are often multifocal, CT shows that the tumor is mostly near the cortex, the tumor is small and the edema is heavy. Cerebrovascular accident: patients are older, most of them have history of hypertension, CT shows hemorrhagic foci and relatively light edema. Brain abscess: patients with history of infection, mostly with signs of meningeal irritation, CT shows low density shadow surrounded by ring-shaped enhancement. Glioma treatment (I) Surgical treatment includes direct craniotomy, cranial biopsy or stereotactic biopsy, shunt surgery, endoscopic tricuspid fistula, etc. The treatment of glioma includes direct craniotomy, cranial biopsy or stereotactic biopsy. 1.Before surgical treatment, in addition to specialized imaging examination, all routine examinations should be perfected to understand whether the basic physiological condition of the patient can tolerate the surgery, and the items include: (1) Blood routine and blood type. (2) Urine routine. (3) Coagulation function. (4) Liver and kidney function, electrolytes. (5) Screening for infectious diseases (including hepatitis B, hepatitis C, AIDS, syphilis). (6) Electrocardiogram. (7) Chest X-ray. (8) Others: echocardiography, cardiac function tests, pulmonary function, hormone levels, electroencephalogram, visual field, neurophysiology, psychological and intellectual scores, etc., if necessary, according to the needs of the condition. 2.Direct craniectomy: Since most of the gliomas are difficult to be cured by surgery, the goal of surgery should be to resect the tumor as much as possible under the premise of fully considering the safety of the patient and function preservation, and to minimize the load of the tumor cells, i.e., the principle of maximum safety resection. 3.Surgical resection of the tumor is beneficial to the subsequent radiation therapy: (1) Define the pathological nature of glioma and changes in molecular pathological indexes, which is conducive to the formulation of radiotherapy treatment plan. (2) Surgery can reduce the tumor volume, alleviate the occupying effect of the tumor, relieve the clinical symptoms such as cranial hypertension, and at the same time, achieve the reduction of tumor cells and reduce the tumor cells that are not sensitive to radiotherapy, so as to facilitate the smooth progress of radiotherapy. (3) The reduction of tumor volume may reduce the irradiation volume of radiotherapy, enhance the effect of radiotherapy and reduce the damage. 4. Indications for surgery: (1) Patients whose clinical and imaging data cannot obtain a definite diagnosis. (2) Patients with symptoms of cranial hypertension. (3) The tumor is associated with epilepsy, and the epileptogenic foci are confirmed to be consistent with or adjacent to the tumor site by examination. (4) To postpone adjuvant therapy and its adverse effects on children (especially children younger than 5 years old). (5) If there are signs of brain herniation and it is expected that the patient’s prognosis may be good. 5. Contraindications to surgery: (1) Poor general condition of the patient, who cannot tolerate anesthesia and surgery. (2) Those who have primary diseases of other organs and need special treatment. (3) The tumor is very extensive. (4) The tumor site is deep or involves important functional areas, and the prognosis is not good according to preoperative judgment. (5) Those whose family members or patients refuse surgery. Surgical methods: According to the tumor site, select the appropriate surgical approach. For the lesions that are not easy to recognize the boundary of the tumor, deep brain and near the functional areas, some auxiliary localization equipment or measures, such as stereotactic, image navigation technology, intraoperative MRI, ultrasound, electrophysiological monitoring and other technologies, can be used during the operation. 7, perioperative treatment: (1) preoperative ① epileptic people need to carry out anti-epileptic treatment. ② Those with obvious cerebral edema and cranial hypertension can be given glucocorticoids and dehydrating agents. ③ Prophylactic antibiotics should be used 30 minutes before surgery. (2) Postoperative ①People with preoperative epilepsy should continue antiepileptic treatment; for patients with supratentorial tumors without preoperative epileptic symptoms, antiepileptic drugs can be used prophylactically for 3 months after surgery. ② Postoperative treatment to maintain access and electrolyte balance. ③ Postoperative treatment for lowering intracranial pressure, such as glucocorticoid and dehydration agent. ④ Early postoperative review of MRI or CT, review of blood routine, blood biochemistry, liver and kidney function, electrolytes, as well as the corresponding tests done before surgery can be reviewed for control and efficacy evaluation. ⑤ For patients with supratentorial glioma who undergo craniotomy, antiepileptic drugs can be used prophylactically when the cranium is closed. Intraoperative biopsy: According to the site of tumor, craniotomy biopsy and stereotactic biopsy can be chosen, and the leakage rate of the former is low. The former has a low leakage rate. It is mainly suitable for: (1) The tumor is located in the important functional area or the part that is difficult to be reached by surgery. (2) Patients with poor general condition who can hardly bear anesthesia or surgery. (3) Patients with extensive and diffuse tumors, or tumors that are not easy to identify according to the existing clinical and imaging data, but need to be clearly diagnosed for the selection of further treatment options. (4) Large tumors combined with minor neurological dysfunction. Indications of shunt surgery and triple ventriculostomy: It is suitable for patients whose tumors are located in the cerebrospinal fluid circulation pathway or adjacent parts, and there is obvious hydrocephalus, but there is no need or inability to perform tumor resection. (ii) Radiation therapy Radiation therapy is one of the important adjuvant treatments for glioma. It includes conventional radiotherapy, non-conventional segmentation radiotherapy, precise conformal radiotherapy, interstitial radiotherapy, stereotactic radiotherapy and so on. Indications: (1) Tumors that cannot be completely resected by surgery. (2) Surgically resected tumors with higher degree of malignancy. (3) Deep location or located in important functional areas not suitable for surgical resection. (4) After simple biopsy. (5) Those who are not suitable for surgical resection but have better effect of radiotherapy, such as medulloblastoma. (6) Glioma recurrence after surgery is not suitable for reoperation. Contraindications: (1) Recurrence within a short period of time after receiving sufficient irradiation. (2) Those who are accompanied by serious intracranial pressure increase and have not taken decompression measures. (3) The common dose of external radiation therapy for malignant glioma is 50-60 Gy. It can be divided into local external radiation therapy and whole brain external radiation therapy. Compared with localized external radiation therapy, total brain external radiation therapy does not significantly prolong the survival of patients, and the adverse effects are larger. (4) It is recommended that all malignant gliomas (WHO classification III and above) should be treated with radiotherapy; for low-grade gliomas (WHO classification II and below), radiotherapy is recommended if the patient is >40 years of age and/or there is a heterozygous deletion of 1p/19q; if the patient is ≤40 years of age and there is no heterozygous deletion of 1p/19q, active radiotherapy is not recommended. Follow-up MRI (with enhancement) is recommended every 3-6 months, and if there is no sign of recurrence within 5 years, then annual MRI is recommended.