With the application and development of neuroimaging, neuronavigation, and intraoperative neurophysiologic monitoring techniques in the clinic in recent years, neurosurgery has been transformed from the traditional anatomical model to the modern anatomical-functional model, which greatly improves the quality of surgery and surgical outcomes. Neuroimaging techniques related to neurosurgery that have emerged in recent years, such as blood oxygen level-dependent magnetic resonance functional imaging, magnetic resonance diffusion tensor imaging, and magnetoencephalography, are helpful in the preoperative evaluation of the relationship between the lesion and the functional area of the brain and the surgical effect. Intraoperative determination of the cortex of the functional brain area and its subcortical nerve fibers is the most important part of neurosurgery to protect brain function and avoid postoperative dysfunction. Clinical observation shows that the traditional anatomical localization resection cannot effectively protect the brain function due to the deformation and displacement of the anatomical structure of the important functional areas caused by individual variation and the occupying effect of the lesion. Intraoperative electrophysiological localization of cortical functional areas is currently the only method that can reliably determine the functional areas of the brain. For lesions located in or adjacent to functional brain areas such as speech, movement, and corticospinal tract conduction pathways such as the radial crown, internal capsule, and thalamus, intraoperative cortical evoked potentials or cortical stimulation localization should be implemented to monitor cortical and subcortical functional areas. Intraoperative electrical stimulation in the wake state is an effective method to remove as many lesions as possible from functional brain areas while protecting brain function. Direct intraoperative electrical stimulation to determine the functional areas of the brain during general anesthesia requires a high level of intraoperative arousal technology, which requires adequate analgesia in the process of opening and closing the skull so that the patient can tolerate the surgery, requires a smooth transition between anesthesia and wakefulness, so that the patient is awake enough to cooperate with the neurological function test during intraoperative electrical stimulation of the cortex, and requires an effective control of the airway during the operation, so that respiratory depression does not occur, and at the same time ensures that the patient is comfortable without aspiration, limb and torso movement. The patient should be comfortable without aspiration, limb and trunk movement. Current anesthesia methods include intravenous general anesthesia or conscious sedation, local anesthesia for complex surgical incisions, or regional nerve block anesthesia. In recent years, anesthesia has undergone epochal changes due to the renewed understanding of pharmacokinetic and pharmacodynamic principles; the increasing number of new anesthetics, such as rapid-acting and ultra-short-acting intravenous anesthetics, and long-acting and safe local anesthetics; as well as new intravenous anesthesia delivery methods and techniques. Wake-up anesthesia methods are also becoming more and more mature, and ultimately meet the clinical requirements of removing the lesions in the functional brain area as much as possible while protecting the brain function. Intraoperative awakening Indications 1. Occupation of functional brain area Occupation of functional brain area mainly includes glioma, arteriovenous malformation and so on. Glioma is the most common neurological tumor in neurosurgery, and surgery is still the most important and basic treatment method in current clinical practice. Removing as much diseased tissue as possible and obtaining maximum therapeutic effect with minimum medical trauma have always been the basic principles to be followed in the surgical treatment of glioma. Intraoperative determination of cortical and subcortical nerve fibers in the functional areas of the brain is an important part of glioma surgery to protect brain function and avoid postoperative dysfunction. Intraoperative electrophysiological cortical functional area localization is currently the only method that can reliably determine the functional area of the brain. For gliomas growing in functional brain areas such as language, movement or their adjacent cortex and corticospinal tract conduction pathways such as the radial crown, internal capsule, thalamus, etc., intraoperative cortical evoked potentials or cortical stimulation localization should be used to determine the functional areas cortical and subcortical functional fibers during tumor resection. Neurological functions such as speech and movement were monitored during the resection process. During the resection process, intraoperative electrical stimulation should be applied to monitor the neurological functions such as language and movement in real time, so as to protect the brain function while removing gliomas in the functional areas of the brain as much as possible. Surgery is the most effective way to treat intractable epilepsy. Functional area intractable epilepsy surgery should take into account both effective epilepsy control and maximum preservation of the normal function of the cortex in the functional area, otherwise the epileptogenic foci will cause serious neurological dysfunction after resection, affecting the efficacy of the surgery For drug-refractory restrictive epilepsy with epileptic foci located in the main functional areas of the brain (e.g., anterior central, posterior gyrus, language area, Wernick’s area, angular gyrus, and supramarginal gyrus), the use of intraoperative cortical EEG to monitor the exact location and extent of the epileptogenic foci. All current anesthetic drugs inhibit intraoperative cortical EEG monitoring results to varying degrees, and the use of intraoperative arousal technique is the safest and most effective anesthetic method. Localization of deep brain nuclei and conduction bundles Stereotactic disfiguring surgery or deep brain stimulation (DBS) implantation for treatment of refractory motor dysfunction such as Parkinson’s disease and dystonia requires precise localization of nuclei. Even if the preoperative image localization is very accurate, intraoperative brain displacement due to positional changes, cerebrospinal fluid leakage and other factors may cause the target position to be shifted, so intraoperative electrophysiological confirmation of the target point is very important. Wake-up technique is the most effective anesthesia method to ensure the accurate positioning of electrophysiological target point during operation. 4.Surgical treatment of refractory central pain Central pain refers to the pain caused by diseases originating in the central nervous system, the main part involved is the spinal cord – thalamus pathway or the medial thalamus system of the posterior cord, the onset of often delayed triggering factors caused by the most typical central pain is the thalamic pain or thalamus syndrome. When central pain cannot be effectively analgesized by psychological, physical and pharmacological treatments, and when pain becomes a major intolerable symptom and seriously affects the patient’s quality of life, surgical treatment may be considered. Intraoperative awakening anesthesia is also needed to complete the surgery. Contraindications to anesthesia 1. Absolute contraindications: (1) Preoperative severe intracranial hypertension and brain herniation; (2) Preoperative conscious and cognitive disorders; (3) Preoperative communication disorders and severe aphasia, including naming, motor, and conductive aphasia, which may cause communication disorders between patients and doctors and make it difficult to complete the intraoperative functional monitoring; (4) Patients who have not strictly fasted on water and stomach fullness before surgery, which may result in the reflux and aspiration of gastric contents; (5) Patients who have not strictly fasted on water and stomach fullness before surgery. (5) Combined serious respiratory diseases and long-term heavy smoking; (6) Suboccipital posterior cranial recess approach requires prone position; (7) Inexperienced surgeons and anesthesiologists. Relative contraindications: (1) Those who are extremely anxious and fearful of the surgery, and do not cooperate during the surgery; (2) Those who take sedative drugs for a long time, or those who have become addicted to sedative drugs; (3) Those who are pathologically obese, with BMI>35K/O, and combined with obesity-type hypoventilation syndrome; (4) Those who are combined with obstructive sleep apnea syndrome; (5) Those whose tumors have obvious adherence to dura mater, and whose surgical operation can cause obvious dural pain and stimulation; (6) Patients who cannot tolerate prolonged fixed position, such as patients with spondylitis and arthritis; (7) Patients with systemic or vital organ infections; (8) Serious damage to the function of vital organs, such as serious hepatic and renal insufficiency.