Abstract: P529

Type: Poster

Abstract Category: Pathology and pathogenesis of MS - Imaging

Objective: We studied differences in diffusion tensor imaging metrics (DTI-metrics) of white matter structural integrity among cohorts of subjects with multiple sclerosis (MS) classified according to progression and their relation to verbal memory.

Methods: We prospectively studied consecutive patients with radiologically or clinically isolated syndrome (n=23; 18 female; age 35±9.1 years), primary or secondary progressive (PP/PS) MS (n=35; 19 female; age 53.5±7.2 years), relapsing-remitting (RR) (n=24; 16 female; mean age 43.9±11.3 years) MS, and 30 healthy controls (18 female; age 41.4±10.9 years) on a 1.5T scanner. Imaging included DTI with 16 diffusion-sensitized gradients applied along 15 noncollinear directions with b-value of 1000s/mm² and anatomic T1 turbo-field echo sequence. We used Olea Sphere 3.0 to map axial diffusivity (AD), radial diffusivity (RD), mean diffusivity, and fractional anisotropy (FA); FSL tools to normalize images; and Juelich"s Atlas to identify white matter tracts. We calculated total white and grey matter volumes. We estimated verbal memory by the Long Term Storage (LTS) Selective Reminding Test (SRT) subtests. We used analysis of variance to assess differences in SRT among groups and analysis of covariance (ANCOVA) including variables associated with cognitive scores (p< 0.01) to analyze relations between DTI-metrics and SRT among groups. To avoid confounding by age or schooling on SRT, ANCOVA used unstandardized residual values of the regression between SRT and these variables.

Results: Groups differed on SRT-LTS (p< 0.001). The best ANCOVA model to explain SRT-LTS scores among groups (p=0.002) included right acoustic radiation AD (p=0.001), corpus callosum AD (p=0.004) and RD (p=0.005), left corticospinal tract AD and RD (both p=0.001), right corticospinal tract RD (p=0.006), left fornix FA (p=0.004), right optical radiation RD (p=0.028), right superior longitudinal fascicle RD (p=0.006), and total grey matter volume (p=0.006).

Conclusion: Our preliminary results suggest structural white matter integrity measured by DTI is associated with verbal memory scores in MS according to progression.

Disclosure:

Ll. Ramió-Torrentà has received speaking honoraria and travel expenses for scientific meetings and has participated in advisory boards in the past years with Bayer Schering Pharma, Biogen, EMD Merck Serono, Sanofi Genzyme, Novartis, Sanofi-Aventis, Teva Phramaceuticals, Almirall and Roche.

G. Blasco: nothing to disclose

C. Biarnés: nothing to disclose

J. Gich has received consulting fees from Novartis and speaking honoraria from Bayer Schering Pharma, Biogen, EMD Merck Serono, Novartis, Teva Phramaceuticals, Almirall.

M. Rivero: nothing to disclose

J. Salavedra: nothing to disclose

P. Danius i Estadella: nothing to disclose

S. Pedraza: nothing to disclose

J. Puig: nothing to disclose

Funding: Novartis