Differential Effects of Propofol on Scalp and Intracranial EEG

• Conditions: General Anesthesia
• Interventions: Other: differences between surface and intracerebral EEG

• Registration Number: NCT02995447
• Lead Sponsor: University Hospital, Bonn

Brief Summary

The anesthetic propofol has a dose-depending effect on the EEG, which differs in comparison between scalp and intracerebral electrodes

Detailed Description

The electrical activity of the brain (electroencephalogram EEG) is usually assessed from the surface of the head, which is approximately 1-2 cm above the cerebral cortex. Thus, the spatial resolution of the EEG is low, and the electrical activity recorded originates from a multitude of neurons.

Deep brain structures such as the hippocampus also generate electrical activity which cannot be assessed from the surface of the head. However, in some patients electrodes are implanted into the brain to look for the origin of epileptic seizures. Along the way, these intracerebral electrodes enable to record the EEG from intracerebral structures which are generated from few neurons only. Once the origin of epilepsy has been identified, the intracerebral electrodes are removed under general anesthesia.

Anesthetics such as propofol characteristically modify the EEG in a dose-dependant manner. More over, the propofol effect on the EEG recorded from the surface is likely to be different from the intracerebral EEG, however little is known so far. Therefore we aim to investigate the differential effect of propofol on the superficial versus intracerebral recorded EEG.

Study Timeline

• Study Start: 2012-11
• Study First Submitted: 2014-10-03
• Study First Submitted QC: 2016-12-13
• Study First Posted: 2016-12-16
• Status Verified: 2017-12
• Last Update Submitted: 2017-12-04
• Last Update Posted: 2017-12-05
• Primary Completion: 2018-10
• Study Completion: 2018-12

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 15

Inclusion Criteria

• Patients with implanted intracerebral EEG electrodes

Exclusion Criteria

• Pregnancy

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
epilepsy patients	differences between surface and intracerebral EEG	The group consists of patients with therapy refractory epilepsy, in which intracerebral electrodes were implanted to locate the seizure origin and to determine whether the patients are eligible for epilepsy surgery. In an observational study, differences between surface and intracerebral EEG are recorded.

Primary Outcome Measures

Name	Time	Method
EEG amplitude	up to two hours of EEG recording	EEG amplitude in comparison between scalp and intracranial recordings
EEG frequency spectrum	up to two hours of EEG recording	EEG frequency spectrum in comparison between scalp and intracranial recordings

Secondary Outcome Measures

Name	Time	Method
EEG Burst Suppression Ratio	up to two hours of EEG recording	EEG Burst Suppression Ratio in comparison between scalp and intracranial recordings

Trial Locations

Locations (1)

Dept. of Anaesthesiology and Intensive Care Medicine, University of Bonn; 🇩🇪 Bonn, Germany