Investigating the mechanism of sedation induced by dexmedetomidine with LORETA

Abstract

PURPOSE: Dexmedetomidine (DEX) is a sedative, the use of which has been increasing in clinical practice. It acts as an agonist to pre-synaptic α2-adrenergic receptors with little effect on respiratory functions. Although consciousness impairment is closely related to disturbances of brain function at different frequency bands, time-varying DEX effects on cortical activity at specific frequency bands has not yet been studied.

METHODS: We analyzed the differences in activity of the cerebral cortex between awake and sedated status induced by DEX at specific frequency bands. Differences in standardized low resolution electromagnetic tomography(sLORETA) obtained means were examined. sLORETA localizes multiple channel scalp recordings of cerebral electric activity to specific brain regions.

RESULTS: We have found an increased activity in the cuneus at delta band frequencies and the posterior cingulate cortex at theta frequencies, the cingulate gyrus at beta frequencies, the cuneus at gamma frequencies, and parts of the default mode network (DMN) and common midline core (CMC).

CONCLUSION: These results support the hypothesis that disinhibition of the DMN during sedation makes robust connections more prominent

from the perspective of information integration, the synchronized brain network impairs the efficiency of information processing.