Anesthesia, Drug Effects
Conditions
Keywords
EEG, fMRI, connectivity, sevoflurane
Brief summary
In imaging functional connectivity (FC) analyses of the resting brain, alterations of FC during unconsciousness have been reported. These results are in accordance to recent electroencephalographic studies observing impaired top-down processing during anesthesia. In this study, simultaneous records of functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) were performed to investigate the causality of neural mechanisms during sevoflurane anesthesia by correlating FC in fMRI and directional connectivity (DC) in electroencephalogram.
Interventions
DRUGSevoflurane
Sponsors
Technical University of Munich
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* ASA I * male * age \> 18y
Exclusion criteria
* drug abuse * history of psychiatric or neurologic diseases * amblyacousia, deafness * contradictions to the study drug (sevoflurane) * implants * piercings, tatoos
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes of information processing (entropy) in EEG and functional connectivity (BOLD ICA and small group network architecture) in fMRI during sevoflurane anesthesia at states awake, 2vol%, 3vol% and EEG endpoint burst suppression | 10 minutes for each condition | Changes of fMRI functional connectivity and of EEG information processing during different levels of sevoflurane anesthesia from wakefulness to deep anesthesia: At each anesthetic level at equilibrated states awake, 2vol%, 3vol% and EEG endpoint burst suppression, EEG and fMRI are recorded simultaneously for about 10 minutes. For each level EEG and fMRI connectivity analysis are performed using the recording length of 10 minutes. This results in one outcome parameter for EEG and fMRI connectivity. Furthermore, both modalities are combined resulting in one combined parameter for each level. For EEG analysis permutation entropy as a measure of information content in EEG, and symbolic transfer entropy as a measure of directed interaction in EEG are used. fMRI functional connectivity analysis is based on BOLD ICA and on network analysis of the BOLD time series. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Assessment of the brain network structure during recovery in EEG and fMRI | 10 minutes for each condition | Identical technical setup than main outcome |
Countries
Germany
Outcome results
None listed