LYON, FRANCE—Antonio Giorgio, MD, from the University of Siena in Italy, and colleagues reported that in relapsing-remitting MS, MRI metrics of tissue damage such as baseline brain volume and 10-year changes in T1 lesion volume and brain volume proved to be good predictors of long-term disability change. When the 10-year relapse number was included in the model, the predictive value was even stronger. “This adds long-term evidence to previous short-term data suggesting that combined measures of MRI parameters and clinical relapses are the best predictors of disability progression in patients with relapsing MS,” Dr. Giorgio said.
To assess the long-term relationship of disability change with MRI measures of brain structural damage in patients with relapsing-remitting MS, the researchers acquired conventional brain MRI scans in 57 patients with relapsing-remitting MS at baseline and after 10 years. The Expanded Disability Status Scale (EDSS) was assessed on each patient at the time of both MRI examinations. The number of relapses was recorded throughout the study period. T2 and T1 brain lesion volumes were computed with a semiautomated segmentation technique based on user-supervised local thresholding. The baseline normalized brain volume and the percent brain volume change (PBVC) between the two MRI time points were computed on MRI images using the SIENAx/SIENA software.
After 10 years, patient EDSS increased from 1.8 to 2.6. The number of 10-year relapses was 3.9. Over 10 years, mean T2 and T1 lesion volume changes were 2.5 cm3 and 2 cm3, respectively, while PBVC was -5.3%. Univariate analysis showed that 10-year EDSS changes correlated with baseline measures of normalized brain volume and lesion volume. Changes in MRI measures over 10 years also correlated with 10-year EDSS changes. Over 10 years, EDSS changes were also associated with the relapse number. Multivariate analysis showed that baseline normalized brain volume, PBVC, and T1 lesion volume changes over 10 years survived as significant MRI predictors of 10-year disability changes, correlating closely with 10-year EDSS changes. This correlation was stronger when the relapse number was added to the MRI model.
—Glenn S. Williams