Perioperative anesthesia can affect postoperative cognitive function. In our previous study, intraoperative dexmedetomidine (Dex) infusion reduced the incidence of delirium within the first 5 days after brain tumor. However, the mechanism is still unclear. With the development of neuroimaging, multimodal neuroimaging technology provide a new method to explore the underlying mechanism. Therefore, the purpose of this study is to analyze the alterations of brain network under sedation and anesthesia by different anesthetics in patients with supratentorial glioma and their association with cognition.

Inclusion Criteria:

• Diagnosed as unilateral supratentorial glioma by MRI
• Selective operation
• Age over 18 years old
• ASA I-II
• Right handedness

Exclusion Criteria:

• History of cerebrovascular disease, brain trauma, chemotherapy and radiotherapy, or psychotropic drugs
• History of intracranial surgery
• Drug and/or alcohol abuse
• History of dementia or mental illness
• Pregnant or lactating women
• Contraindications for MRI
• Severe bradycardia (heart rate less than 40 beats per minute), sick sinus syndrome or second-to-third degree atrioventricular block
• Severe hepatic or renal dysfunction

The population will be selected from patients who schedule to receive elective surgery in Beijing Tiantan Hospital.