Gliomas are tumors that occur in the neuroectoderm. The tumors originate from neurointerstitial cells, i.e., glial, ventricular canal, choroid plexus epithelium, and neuroparenchymal cells, i.e., neurons. Most tumors originate from different types of glia, but based on the similar histogenetic origin and biological characteristics, all kinds of review tumor diseases that occur in the neuroectoderm are generally referred to as gliomas. There are many ways to classify gliomas, and clinical workers tend to use the Kernohan classification, which is a relatively simple classification. Among the various types of gliomas, astrocytomas are the most common, followed by glioblastomas, followed by medulloblastomas, ventricular meningiomas, oligodendrogliomas, pineal tumors, mixed gliomas, choroid plexus papillomas, unclassified gliomas, and neuronal tumors. For example, astrocytomas are more common in the cerebral hemisphere in adults and in the cerebellum in children; glioblastomas almost always occur in the cerebral hemisphere; medulloblastomas occur in the cerebellar earth; ventricular meningiomas are more common in the 4th ventricle; and oligodendrogliomas occur mostly in the cerebral hemisphere. Gliomas are more common in males, especially in glioblastoma multiforme and medulloblastoma, which are significantly more common in males than females. Glioblastomas of all types are more common in middle age, ventricular meningiomas are more common in children and young adults, and medulloblastomas almost always occur in children. The location of gliomas is also related to age, for example, astrocytomas and glioblastomas of the brain are most often seen in adults, and gliomas of the cerebellum (astrocytomas, medulloblastomas, and ventricular meningiomas) are most often seen in children. Most gliomas develop slowly, with the time from the onset of symptoms to the time of consultation usually ranging from a few weeks to a few months, and rarely up to several years. The history is shorter for highly malignant and posterior cranial fossa tumors and longer for tumors that are more benign or located in the quiet zone. If a tumor has hemorrhage or cystic changes, the symptoms may suddenly worsen and even have a course similar to cerebrovascular disease. The clinical symptoms of glioma can be divided into two aspects: one is the symptoms of increased intracranial pressure, such as headache, vomiting, vision loss, diplopia and psychiatric symptoms; the other is the focal symptoms produced by tumor compression, infiltration and destruction of brain tissues, which can manifest as irritation symptoms such as limited epilepsy in the early stage and neurological deficit symptoms such as paralysis in the later stage. The diagnosis of glioma is analyzed according to its biological characteristics, age, gender, predilection site and clinical course. Based on medical history and signs, the correct rate of localization is almost 100% and the correct rate of qualitative diagnosis can be over 90% by using auxiliary examinations such as electrophysiology, ultrasound, radionuclide, radiology and MRI. Glioma has a high mortality rate. Glioma originates from glial cells in the brain and is the most common intracranial tumor, accounting for about 45% of all intracranial tumors. It ranks second among childhood malignant tumors. In the past 30 years, the incidence of primary malignant brain tumors has been increasing year by year, with an annual growth rate of about 1.2%, especially in middle-aged and elderly people. According to the literature, the annual incidence of glioma in China is 3-6 per 100,000 people, and the annual number of deaths reaches 30,000. Gliomas usually have no typical symptoms at the beginning of their development. As the tumor continues to grow, it will show the following symptoms: one is the increase of intracranial pressure and other general symptoms, such as headache, vomiting, loss of vision, diplopia, seizures and psychiatric symptoms. The other is the local symptoms caused by the compression, infiltration and destruction of brain tissue by tumor. Glioma is an infiltrative growth, which has no obvious boundary with normal brain tissues and is difficult to be completely removed, not very sensitive to radiotherapy and chemotherapy, and very easy to recur. Chemical drugs and general anti-tumor herbal medicines are not effective due to the blood-brain barrier and other factors, so glioma is still one of the tumors with the worst prognosis among the whole body. The course of glioma varies according to the type of pathology and location, but the time from the appearance of symptoms to the consultation is usually weeks to months, while the number of gliomas can be several years. The history of tumors with high malignancy and posterior cranial fossa is shorter, while the history of more benign tumors or those located in the so-called quiet zone is longer. Tumors with hemorrhage or cyst formation may have a faster progression of symptoms, and some may even resemble the progression of cerebrovascular disease. The symptoms are mainly manifested in two aspects. One is the increase of intracranial pressure and other general symptoms, such as headache, vomiting, loss of vision, diplopia, seizures and psychiatric symptoms. The other is the local symptoms produced by the compression, infiltration and destruction of brain tissue by tumor, resulting in neurological deficits. Headache is mostly caused by the increase of intracranial pressure. The growth of tumor gradually increases the intracranial pressure, which compresses and involves pain-sensitive structures in the skull such as blood vessels, dura mater and certain cranial nerves and produces headache. Most of the headaches are throbbing and swelling pains, mostly in the frontotemporal or occipital area. For tumors in the superficial hemisphere of one side of the brain, the headache may be mainly on the affected side. Vomiting is caused by stimulation of the medullary vomiting center or vagus nerve, and may be jet-like without nausea. In children, the headache is not significant due to the separation of cranial sutures, and the vomiting is more prominent because the posterior cranial fossa tumor is more common. Increased intracranial pressure may produce optic papillar edema and cause secondary optic nerve atrophy and vision loss. If the tumor compresses the optic nerve, primary optic nerve atrophy will occur, which also leads to vision loss. Adductor nerve is easily squeezed and pulled, which often leads to paralysis and diplopia. Some patients with tumors have seizure symptoms, which can be early. The epilepsy begins in adulthood and is usually symptomatic, mostly due to brain tumors. The presence of a brain tumor should be considered in all cases where the seizures are not easily controlled by medication or have a change in nature. Tumors adjacent to the cortex are prone to epilepsy, while those deeper in are less common. Focal epilepsy has localization implications. Some tumors, especially those located in the frontal lobe, may gradually develop psychiatric symptoms, such as personality changes, apathy, decreased speech and activity, inattention, memory loss, lack of concern for things, and lack of awareness of neatness. The local symptoms will be aggravated progressively depending on the location of the tumor. In particular, malignant glioma grows faster, infiltrates and destroys brain tissue, and the surrounding brain edema is also significant, so the local symptoms are more obvious and develop faster. Tumors in the intracerebroventricular region or tumors located in the quiet zone may have no local symptoms in the early stage. In contrast, tumors in the brainstem and other important functional areas show local symptoms at an early stage, and it takes a long time before the symptoms of increased intracranial pressure appear. In some tumors that develop slowly, the symptoms of increased intracranial pressure often do not appear until the late stage due to compensatory effects. The US NCCN guidelines for the surgical treatment of neurological tumors include maximizing resection of malignant neurological tumors, minimizing surgical complications, and providing accurate pathological diagnosis of surgical specimens. Chinese consensus on the principles of surgical treatment for glioma: 1. Preferred treatment strategy for malignant glioma: surgical resection. 2. 2. Basic principle: maximum safe resection of the tumor, i.e., maximum resection of the tumor lesion with maximum preservation of normal neurological function (highly recommended). 3. For those who cannot perform maximum safe resection of tumor, partial resection of tumor, open biopsy or stereotactic (or under navigation) puncture biopsy will be used as appropriate to clarify the histopathological diagnosis of tumor. At present, the treatment of glioma at home and abroad is generally surgery, radiotherapy, chemotherapy, X-knife, gamma knife, etc. Surgery Chinese consensus on the principles of chemotherapy for glioma: (1) newly diagnosed malignant glioma (2) recurrent malignant glioma. The following five aspects: (1) clear pathological diagnosis; (2) reduce tumor volume to lower the number of tumor cells; (3) improve symptoms to relieve high cranial pressure symptoms; (4) prolong life and create time for other subsequent comprehensive treatment; (5) obtain tumor cell kinetic information to provide a basis for finding effective treatment. Radiation therapy Radiation therapy is the routine treatment for almost all types of glioma, but the efficacy is evaluated differently. Except for medulloblastoma, which is highly sensitive to radiation therapy, and ventricular meningioma, which is moderately sensitive, all other types are insensitive to radiation therapy, and it has been observed that the prognosis is the same for those treated with radiation therapy and those not treated with radiation therapy. In addition, the effect of radiation-induced radionecrosis on brain function should not be underestimated. X-knife, gamma-knife – all belong to the category of radiation therapy, due to the location of the tumor, the size of the tumor (generally limited to less than 3 cm) and the sensitivity of the tumor to radiation, the scope of treatment is limited, at present, gliomas, especially malignant nature of astrocytic grade III-IV or glioblastoma are not suitable for R-knife treatment. However, as gamma knife doctors continue to explore the treatment of gliomas, the treatment of large gliomas with a tumor diameter of more than 3 cm has achieved good results in clinical practice. Chemotherapy In principle, chemotherapy is used for malignant tumors, but the efficacy of chemotherapeutic drugs is not yet certain because they are limited to the blood-brain barrier and the toxic side effects of drugs, and the efficiency of commonly used BCNU, CCNU, VM-26, etc. is less than 30%.