How anesthesia changes deep brain signals and consciousness

The Electroencephalographic Mechanisms of Anesthesia and Human Consciousness

This trial will test how the anesthetic dexmedetomidine changes deep brain electrical signals in patients with drug‑resistant epilepsy who are having SEEG electrodes placed, to see what brain activity looks like when consciousness is lost and when it returns.

Quick facts

• Phase: PHASE4
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 3 Years to 65 Years
• Sex: All
• Sponsor: Guangzhou General Hospital of Guangzhou Military Command (other)
• Locations: 1 site (Guangzhou, Guangdong)
• Trial ID: NCT07145697 on ClinicalTrials.gov

What this trial studies

Researchers will record stereo‑electroencephalography (SEEG) from deep brain structures in patients with drug‑refractory epilepsy who require clinically indicated SEEG electrode implantation while administering dexmedetomidine to induce sedation and recovery. Continuous intracranial recordings will capture electrical activity before, during, and after drug‑induced loss of consciousness to identify neural patterns associated with transitions in awareness. The study leverages dexmedetomidine because it provides sedation with minimal respiratory depression and is commonly used in clinical practice. Results aim to link specific deep‑brain signal changes to loss and return of consciousness.

Who should consider this trial

Good fit: Ideal participants are patients aged 1–65 with drug‑resistant epilepsy scheduled for SEEG electrode implantation, with BMI 18.5–25 kg/m², ASA physical status I–III, and who provide informed consent.

Not a fit: Patients with severe arrhythmia or other major cardiac disease, obstructive sleep apnea, significant hepatic or renal dysfunction, active cancer or autoimmune disease, or those not undergoing SEEG implantation are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this work could identify brain‑signal signatures of consciousness that improve anesthesia monitoring and patient safety.

How similar studies have performed: Surface EEG studies have repeatedly shown anesthetic‑related changes in brain oscillations and dexmedetomidine's effects are documented, but applying SEEG to map deep‑brain mechanisms of consciousness in humans is relatively novel.

Eligibility criteria

Inclusion Criteria:

1. Age range: 1 - 65 years old
2. BMI: 18.5 - 25.0 kg/m²
3. ASA physical status classification: I - III
4. Patients diagnosed with drug - refractory epilepsy who, after long - term monitoring of epileptic seizures, require stereo-electroencephalography (SEEG) electrode implantation based on the clinical need for monitoring their epilepsy.
5. Patients voluntarily participate in this study and sign a written informed consent form.

Exclusion Criteria:

1. Patients with severe arrhythmia or other organic heart diseases;
2. Patients with comorbid obstructive sleep apnea-hypopnea syndrome (OSAHS);
3. Patients with hepatic or renal dysfunction; those with a history of immunodeficiency diseases , or a history of cancer/malignant tumors, or a history of autoimmune diseases, or severe cardiovascular and cerebrovascular diseases, or other diseases that may significantly reduce life expectancy;
4. Patients with any history of diseases that may affect protocol compliance (such as severe mental disorders, disturbance of consciousness; cognitive dysfunction, drug abuse or addiction, etc.);
5. Pregnant or lactating women, or those of childbearing potential who are unwilling/unable to take effective contraceptive measures;
6. Patients with known allergies to the ingredients contained in the drugs used in this study;
7. Patients who have participated in any drug clinical trial within 6 months before the screening examination;
8. Patients who are deemed unsuitable to participate in this study by the researcher.

Where this trial is running

Guangzhou, Guangdong

• General hospital of southern theater command, PLA — Guangzhou, Guangdong, China (RECRUITING)

Conditions: Consciousness, Level Altered