Comparison of Modulations of Motor Brain Activity and SedLine After Median Nerve Stimulation in General Anesthesia

NCT ID: NCT07267403

Last Updated: 2025-12-05

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 48 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-10-27
• Study Completion Date: 2026-12-31

Brief Summary

To this date, no monitoring device can reliably detect episodes of accidental awakening during general anesthesia. One promising approach is the use of electroencephalography (EEG) to detect movement attempts via a brain-computer interface (BCI). Previous work has shown that combining a BCI with painless median nerve stimulation can detect cerebral motor activity under light propofol sedation. However, clinical data are still lacking regarding the persistence or otherwise of a cerebral motor response (neural synchronization, or ERS) induced by this stimulation during general anesthesia.

In this new study, the aim is to simultaneously record the EEG centered on the motor cortex and the signal from the SedLine Patient State Index (PSI) to better characterize the evolution of cerebral motor activity before, during general anesthesia, and up to awakening. This approach will allow us to explore the complementarity of the two signals for future automated detection of residual states of consciousness during surgery.

Preliminary data from a previous protocol (STIM-MOTANA) allowed to develop an EEG classification algorithm based on Riemannian geometry, capable of inferring a patient's state of consciousness from cortical responses induced by median nerve stimulation.

The objective of this new study is also to compare the sensitivity of this algorithm with that of PSI, in order to assess its potential as a complementary - or even alternative - indicator of the level of consciousness under general anesthesia.

Investigators hypothesize that it is possible to detect, using EEG, specific brain signatures related to median nerve stimulation, including during propofol-induced general anesthesia. Specifically, neuronal desynchronization and resynchronization phases (ERD/ERS), well characterized in wakefulness or light sedation, could partially persist at higher propofol concentrations. Parallel PSI recording will allow analyzing to what extent these EEG modulations are related to classically measured levels of consciousness, and to validate the relevance of the new algorithm based on Riemannian geometry as a tool for detecting intra-operative arousals.

Conditions

Accidental Awareness During General Anesthesia

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Sedation by intravenous anesthesia with propofol concentration target.

Any patient undergoing surgery requiring the use of sedation by intravenous anesthesia with propofol concentration target.

Group Type: EXPERIMENTAL

EEG Headset

Intervention Type: DEVICE

64-electrode device (including 16 on the motor cortex), placed on the scalp. The EEG measurement is performed using OpenViBE software, in conjunction with an Eego amplifier (64 electrodes, ANT Neuro), both CE certified.

SD LTM STIM (Micromed)

Intervention Type: DEVICE

Median nerve stimulation: applied to the right forearm using two ECG electrodes positioned at the wrist (palmar side), allowing painless transcutaneous stimulation (intensity 3 to 14 mA; pulse duration: 0.1 ms; frequency: 5 Hz). The stimulator used is a SD LTM STIM model (Micromed), CE certified.

SedLine®

Intervention Type: DEVICE

Anesthetic depth monitoring: Performed using the SedLine® Brain Function Monitoring device (Masimo Corporation, model RDS7A, CE certified), using four forehead electrodes to record EEG activity. The Patient State Index (PSi), calculated in real time, is interpreted within a target range of 25 to 50 to ensure adequate general anesthesia. The device complies with international standards for electrical safety (IEC 60601) and hospital use.

Interventions

EEG Headset

64-electrode device (including 16 on the motor cortex), placed on the scalp. The EEG measurement is performed using OpenViBE software, in conjunction with an Eego amplifier (64 electrodes, ANT Neuro), both CE certified.

Intervention Type: DEVICE

SD LTM STIM (Micromed)

Median nerve stimulation: applied to the right forearm using two ECG electrodes positioned at the wrist (palmar side), allowing painless transcutaneous stimulation (intensity 3 to 14 mA; pulse duration: 0.1 ms; frequency: 5 Hz). The stimulator used is a SD LTM STIM model (Micromed), CE certified.

Intervention Type: DEVICE

SedLine®

Anesthetic depth monitoring: Performed using the SedLine® Brain Function Monitoring device (Masimo Corporation, model RDS7A, CE certified), using four forehead electrodes to record EEG activity. The Patient State Index (PSi), calculated in real time, is interpreted within a target range of 25 to 50 to ensure adequate general anesthesia. The device complies with international standards for electrical safety (IEC 60601) and hospital use.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Right-handed patient
• Scheduled for surgery using intravenous anesthesia with propofol concentration

Exclusion Criteria

• Allergy to propofol, soy, or peanuts.
• BMI < 20 or > 30
• Pregnant or breastfeeding women
• Medical or surgical history that may interfere with median nerve stimulation or EEG signal acquisition (e.g., diabetes, polyneuropathy, central neurodegenerative disease, epilepsy, brain surgery)
• History of right median nerve injury
• Right upper limb amputation
• Upper limb surgery
• Unable to wear an EEG headset (prone position, head and neck surgery)
• Drug abuse

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 81 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Brugmann University Hospital

OTHER

Sponsor Role: lead

Responsible Party

Tatiana Besse-Hammer

Head of clinical research unit

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Seyed Javad Bidgoli, MD

Role: PRINCIPAL_INVESTIGATOR

CHU Brugmann

Locations

CHU Brugmann

Brussels, , Belgium

Site Status: RECRUITING

Countries

Belgium

Central Contacts

Seyed Javad Bidgoli, MD

Role: CONTACT

seyedjavad.bidgoli@chu-brugmann.be@chu-brugmann.be

02 477 21 79

Facility Contacts

Seyed Javad Bidgoli, MD

Role: primary

SEYEDJAVAD.BIDGOLI@chu-brugmann.be

003224772179

Other Identifiers

STIM-PSI

Identifier Type: -

Identifier Source: org_study_id