Abstract Details

Title Longitudinal in Vivo Imaging Study of Watershed Brain Lesions due to Multiple Sclerosis

Topic Multiple Sclerosis

Presentation(s) P8 - Poster Session 8 (11:45 AM-12:45 PM)

Poster/Presentation
Number 19-009

Objective To compare the longitudinal changes in WMLs volume and degree of microstructural injury among ws, non-watershed (nws), and mixed (m) regions of the brain over one-year duration.

Background

Watershed (ws) white matter (WM) regions of the brain are more vulnerable to lesion formation in multiple sclerosis (MS). However, the longitudinal evolution of WM lesions (WMLs) located in different vascular territories has not been assessed.

Design/Methods

Methods
In this prospective study, 31 treatment-naïve subjects with early clinical and pre-clinical MS underwent a baseline and year-one magnetic resonance imaging (MRI) inclusive of T₂-weighted fluid attenuated inversion recovery (FLAIR), T₁-weighted turbo spin echo, selective inversion recovery quantitative magnetization transfer (SIR-qMT) and multi-compartment diffusion with spherical mean technique (SMT). Changes in SIR-qMT-derived pool size ratio (PSR) and SMT-derived volume axonal fraction (V_ax) were assessed using generalized linear mixed model (β). Spearman's correlation coefficients (r) were calculated to assess the relationships between baseline MRI metrics (volume, PSR, V_ax) and neurocognitive outcomes at year-one.

Results No differences were observed in WMLs volume changes among the groups. However, PSR (β= -11.58; 95%CI= -22.37- -1.27; p=0.029) and V_ax (β= -5.10; 95%CI= -9.95- -0.23; p=0.041) percentage changes were lower in ws-WMLs than in nws-WMLs, with no differences between ws- and m-ones which is consistent with lower improvement in myelin and axonal integrity of the tissue. Ws-WMLs V_ax at baseline was correlated with nine-hole peg test of the dominant (r=-0.478, p=0.012) and non-dominant hand (r=-0.513, p=0.010), and California verbal learning test (r=0.508, p=0.044) at year-one while Ws-WMLs volume was correlated with timed 25-foot walk test (r=-0.800, p=0.010). No correlations were found between nws-WMLs metrics and neurocognitive outcomes.

Conclusions WMLs in ws-areas show a smaller degree of myelin and axonal repair, relative to those located in nws-zones. Our data underscores that the arterial vascularization of the brain may impact tissue recovery in MS.

Authors/Disclosures
Ahmad A. Toubasi, MD (Vanderbilt University Medical Center) PRESENTER	Dr. Toubasi has nothing to disclose.
Marc Graham	Mr. Graham has nothing to disclose.
Eric Brian, BS/BA	Mr. Brian has received research support from National MS Society.
Victoria Lim	Miss Lim has nothing to disclose.
Caroline Gheen	Ms. Gheen has nothing to disclose.
Taegan V. Vinarsky	Miss Vinarsky has nothing to disclose.
Chaoyang Jin, PhD	Dr. Jin has nothing to disclose.
Stephanie Taylor, MD (Vanderbilt University Medical Center)	Dr. Taylor has nothing to disclose.
James E. Eaton III, MD (Vanderbilt University)	Dr. Eaton has received personal compensation in the range of $0-$499 for serving as a Consultant for Uniqure. Dr. Eaton has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Law Practices. Dr. Eaton has received personal compensation in the range of $0-$499 for serving as a Speaker with Can Do MS.
Richard D. Dortch, PhD	Dr. Dortch has nothing to disclose.
Manus Donahue, PhD	Prof. Donahue has nothing to disclose.
Junzhong Xu, PhD	Dr. Xu has received personal compensation for serving as an employee of Vanderbilt University Medical Center.
Francesca Bagnato, MD (Vanderbilt University Medical Center)	Dr. Bagnato has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Sanofi. Dr. Bagnato has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi-Genzyne. Dr. Bagnato has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Bagnato has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Jenseen. Dr. Bagnato has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merk-Serono.

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