Abstract Details

Title Differences in Functional Connectivity Assessed by Graph Measures in Primary and Secondary Progressive Multiple Sclerosis Patients

Topic Multiple Sclerosis

Presentation(s) P1 - Poster Session 1 (12:00 PM-1:00 PM)

Poster/Presentation
Number 9-021

Objective

Background

Functional connectivity (FC) in patients with progressive multiple sclerosis (MS) has received limited attention so far, with previous discordant results. Network-based methodologies have been recently applied to MS but on samples including mainly patients with relapsing-remitting MS. We investigated alterations in FC, using a network-based approach, in primary and secondary progressive MS patients (PP-MS and SP-MS, respectively).

Design/Methods Nineteen patients with PP-MS, 14 with SP-MS and 25 healthy subjects (HS) were included. Functional ROIs were generated using the Schaefer atlas, with 100 parcels and connectivity matrices were obtained estimating the coactivations between regions after thresholding the normalized fMRI signal, using the 80% quantile as threshold. The following network properties (NP) were derived for each subject: nodal strength, eigenvector centrality, clustering coefficient, local network efficiency and betweenness centrality. Differences of NP z-scores among the three groups and their relationship with measures of cognitive status were assessed using a multivariate linear regression model.

Results

PP-MS patients, compared to HS, showed higher values in the NP at the level of insular and prefrontal regions, but lower NP values at the level of the bilateral temporal areas and precuneus while SP-MS showed lower values at the level of parietal regions and insula, the latter surviving after multiple comparison correction (p<.001). NP values at the level of the insular regions and the betweenness centrality of the precuneus positively correlated with symbol digit modalities test in SP-MS and PP-MS patients, respectively (p=0.02 and p<0.001, respectively).

Conclusions

Although PP-MS and SP-MS patients are often pooled together in studies on FC, they present with a different pattern in terms of altered functional network properties which also correlates to cognitive measures. Further efforts in distinguishing the functional alterations in two clinical phenotypes could shed light in the understanding of the underlying pathophysiological process and in properly addressing the cognitive rehabilitation strategies.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
Maria Petracca, PhD (University of Rome Sapienza)	Dr. Petracca has nothing to disclose.
	No disclosure on file
	No disclosure on file
Matilde Inglese, MD, PhD (University of Genoa)	Dr. Inglese has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for SANOFI GENZYME. Dr. Inglese has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for BIOGEN. Dr. Inglese has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for NOVARTIS. Dr. Inglese has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for MERCK-SERONO. Dr. Inglese has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for ROCHE. Dr. Inglese has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for MS Journal.
	No disclosure on file