AUTHOR=Li Duan , Puglia Mike P. , Lapointe Andrew P. , Ip Ka I , Zierau Mackenzie , McKinney Amy , Vlisides Phillip E. 

TITLE=Age-Related Changes in Cortical Connectivity During Surgical Anesthesia

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 11 - 2019

YEAR=2020

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2019.00371

DOI=10.3389/fnagi.2019.00371

ISSN=1663-4365

ABSTRACT=An advanced understanding of the neurophysiologic changes that occur with aging may help improve perioperative care for older, vulnerable patients. The objective of this study was to determine age-related changes in cortical connectivity patterns during surgical anesthesia. This was a substudy analysis of a prospective, observational study characterizing cortical connectivity during surgical anesthesia in adult patients (n=45) via whole-scalp (16-channel) electroencephalography. Functional connectivity was estimated using weighted phase lag index, which was classified into a discrete set of states through k-means analysis. Temporal dynamics were quantified by occurrence rate and state transition probabilities. The mean global, connectivity state transition probability (13.4% [±8.1]) was not correlated with age (ρ = 0.100, P=0.513). Increasing age was inversely correlated with prefrontal-frontal alpha-beta connectivity (ρ = -0.446, P=0.002) and positively correlated with frontal-parietal theta connectivity (ρ = 0.414, P=0.005). After adjusting for anesthetic-related confounders, prefrontal-frontal alpha-beta connectivity remained significantly associated with age (β = -0.625, 95% CI -0.99 to -0.26; P=0.001), while frontal-parietal theta connectivity was no longer significant (β = 0.436, 95% CI -0.03 to 0.90; P=0.066). Specific transition states were also examined. Between frontal-parietal connectivity states, transitioning from theta-alpha to theta-dominated connectivity positively correlated with age (ρ = 0.545, P=0.001). Exploratory analysis in subsets of relatively young and old patients also demonstrated an increased propensity for frontal-parietal theta connectivity with older age and reduced prefrontal-frontal alpha-beta connectivity. Dynamic connectivity states during surgical anesthesia, particularly involving alpha and theta bandwidths, may be an informative measure to assess neurophysiologic changes that occur with aging.