Gliomas are the most common primary intracranial malignancy, and behavioral experiments in patients with supratentorial gliomas under sedation have shown potential neurological abnormalities; however, these behavioral experiments are susceptible to external influences. Therefore, more objective evidence is needed to support and extend the existing conclusions. The purpose of this study is to compare the EEG signatures (such as the EEG signal power) at various levels of anesthetics induced sedation in patients with supratentorial glioma in frontal lobe and in patients without intracranial-occupying lesion.

Inclusion Criteria:

1. Patients with supratentorial glioma in right frontal lobe, and patients requiring general anesthesia without intracranial-occupying lesion;
2. Aged 18-60 years;
3. ASA I to II;
4. All those who sign the informed consent form.

Exclusion Criteria:

1. Obese patients, BMI>30kg/m2;
2. Patients with Mallampati class III to IV airway anatomy;
3. Combined with other neurological or psychiatric diseases;
4. Combined with disturbance of consciousness;
5. Previous intracranial surgery;
6. Known or suspected cardiac dysfunction;
7. Allergic to intravenous general anesthetics;
8. Long-term history of analgesia, sedation and drug abuse.

Patients aged between 18 and 60 years with American Society of Anesthesiology status I or II who were scheduled to receive elective surgery under general anesthesia. Patients with supratentorial glioma in right frontal lobe diagnosed by magnetic resonance imaging were included in the glioma group while patients requiring general anesthesia without intracranial-occupying lesion were included in the control group.