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Propofol Sedation Alters Perceptual and Cognitive Functions in Healthy Volunteers as Revealed by Functional Magnetic Resonance Imaging. Anesthesiology 2019 Aug;131(2):254-265

Date

07/18/2019

Pubmed ID

31314747

Pubmed Central ID

PMC6640651

DOI

10.1097/ALN.0000000000002669

Scopus ID

2-s2.0-85077347748   12 Citations

Abstract

BACKGROUND: Elucidating networks underlying conscious perception is important to understanding the mechanisms of anesthesia and consciousness. Previous studies have observed changes associated with loss of consciousness primarily using resting paradigms. The authors focused on the effects of sedation on specific cognitive systems using task-based functional magnetic resonance imaging. The authors hypothesized deepening sedation would degrade semantic more than perceptual discrimination.

METHODS: Discrimination of pure tones and familiar names were studied in 13 volunteers during wakefulness and propofol sedation targeted to light and deep sedation. Contrasts highlighted specific cognitive systems: auditory/motor (tones vs. fixation), phonology (unfamiliar names vs. tones), and semantics (familiar vs. unfamiliar names), and were performed across sedation conditions, followed by region of interest analysis on representative regions.

RESULTS: During light sedation, the spatial extent of auditory/motor activation was similar, becoming restricted to the superior temporal gyrus during deep sedation. Region of interest analysis revealed significant activation in the superior temporal gyrus during light (t [17] = 9.71, P < 0.001) and deep sedation (t [19] = 3.73, P = 0.001). Spatial extent of the phonologic contrast decreased progressively with sedation, with significant activation in the inferior frontal gyrus maintained during light sedation (t [35] = 5.17, P < 0.001), which didn't meet criteria for significance in deep sedation (t [38] = 2.57, P = 0.014). The semantic contrast showed a similar pattern, with activation in the angular gyrus during light sedation (t [16] = 4.76, P = 0.002), which disappeared in deep sedation (t [18] = 0.35, P = 0.731).

CONCLUSIONS: Results illustrate broad impairment in cognitive cortex during sedation, with activation in primary sensory cortex beyond loss of consciousness. These results agree with clinical experience: a dose-dependent reduction of higher cognitive functions during light sedation, despite partial preservation of sensory processes through deep sedation.

Author List

Gross WL, Lauer KK, Liu X, Roberts CJ, Liu S, Gollapudy S, Binder JR, Li SJ, Hudetz AG

Authors

Jeffrey R. Binder MD Professor in the Neurology department at Medical College of Wisconsin
Suneeta Gollapudy MD Associate Professor in the Anesthesiology department at Medical College of Wisconsin
William Gross MD, PhD Assistant Professor in the Anesthesiology department at Medical College of Wisconsin
Kathryn K. Lauer MD Vice Chair, Professor in the Anesthesiology department at Medical College of Wisconsin
Christopher J. Roberts MD, PhD Assistant Professor in the Anesthesiology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Adult
Brain
Cognition
Female
Humans
Hypnotics and Sedatives
Magnetic Resonance Imaging
Male
Propofol
Reference Values
Young Adult