Abstract Details

Title Default and Saliency Network Functional Connectivity in Late-Life Depression: Task Free MRI Study

Topic Behavioral Neurology

Presentation(s) P05 - (-)

Poster/Presentation
Number 120

Objective

Background BACKGROUND: tfMRI is an emerging technique to study brain network dynamics in elderly subjects with mood disorders. Two networks, the default mode network (DMN) and the saliency network (SN) act in a reciprocal/anti-correlated manner whereby when one is activated, the other is deactivated. In common dementia syndromes such as Alzheimer dementia (AD) and frontotemporal dementia (FTD) there is evidence that as one network is disturbed the other is enhanced. Given the association of mood disorders with late life dementia we investigated the pattern of changes in these two networks in non-demented late-life depressed subjects.

Design/Methods DESIGN/METHODS: Weanalyzed tfMRI using a seed-whole brain voxel correlation approach with theposterior cingulate cortex (DMN) and the right, anterior insula (SN) in 47 depressed (68.72±6.99 years; Hamilton Depression Rating Scale 19.06±3.90) and 46 controls (72.89±7.9 years) matched by education and cognitive status. All results are uncorrected p<0.005. Analysis was performed using Conn (www.nitrc.org/projects/conn) toolbox.

Results RESULTS: There were minimal areas of increased connectivity in controls for either network. In depressed subjects increased PCC-DMN connectivity included: bilateral superior temporal gyrus, right insular cortex and bilateral somatosensory cortex- areas regularly disconnected with the DMN; whereas, in the SN there was a general increase in connectivity to areas regularly positively correlated: bilateral dorsolateral frontal cortex (left>right); the left insular cortex and left dorsal frontal cortex- indicating a possible enhancement.

Conclusions CONCLUSIONS: Exploring resting-state brain activity we found late-life depression to be associated with an increased connectivity in the SN- a network associated with emotional processing, affect regulation and executive function; and increased DMN connectivity to areas normally distinct from this network. This bares similarities to patterns identified in AD. Together this work supports existing data that late-life depression is a risk factor for AD.

Authors/Disclosures
Eric M. McDade, DO (Washington University At St. Louis School of Medicine) PRESENTER	Dr. McDade has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi. Dr. McDade has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Merck. Dr. McDade has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alector. Dr. McDade has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alzamend. Dr. McDade has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alnylam. Dr. McDade has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Ionis. Dr. McDade has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche-Genentech. The institution of Dr. McDade has received research support from NIA. The institution of Dr. McDade has received research support from Eli Lilly. The institution of Dr. McDade has received research support from Hoffman-La Roche. The institution of Dr. McDade has received research support from Eisai. The institution of Dr. McDade has received research support from Eisai. Dr. McDade has received intellectual property interests from a discovery or technology relating to health care. Dr. McDade has received personal compensation in the range of $500-$4,999 for serving as a Advisory Board Member with Fondation Alzheimer.
Zohar Argov, MD (Hadassah Hebrew University Medical Center)	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Oscar L. Lopez, MD, FAAN	Dr. Lopez has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Acumen.
Howard Aizenstein, MD, PhD	No disclosure on file

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