Baseline MRI measures of lesion volume and brain atrophy predicted distinct long-term clinical changes in patients with early multiple sclerosis, reported authors of a small study published in Multiple Sclerosis and Related Disorders.
"We have identified several interesting putative biomarkers that are strongly associated with clinical worsening in early MS," wrote Dr. Amir-Hadi Maghzi of the University of California, San Francisco, and his associates.
The study included 43 patients with early MS, of whom 22 completed the 3-year assessment, the researchers said. MRI showed that T2 lesion volume significantly predicted longitudinal changes in the Paced Auditory Serial Addition Test (P = .004), they reported (Mult. Scler. Relat. Disord. 2014 July 23 [doi:10.1016/j.msard.2014.07.003]). The patients had participated in a randomized, double-blind, placebo-controlled trial at two centers that assessed the possible neuroprotective effects of riluzole in combination with intramuscular interferon beta-1a.
In addition, three baseline measures of atrophy – brain parenchymal volume and normal-appearing white and grey matter volumes – predicted longitudinal changes in the MS Functional Composite score and the Timed 25-Foot Walk (all P values less than .041), the researchers said. The different findings for lesion and brain volume could reflect distinct disease processes, the investigators added.
Dr. Maghzi and his colleagues calculated longitudinal changes in brain volume by using the SIENA (Structural Image Evaluation Using Normalization of Atrophy) analysis. They counted T2 and contrast-enhancing lesions by simultaneously visualizing T2 and T1 images before and after enhancement. Most MRI measures did not correlate with clinical outcomes at baseline, they noted.
In longitudinal analyses, every 1% decrease in brain volume was associated with a 1.14-point drop on the Symbol Digit Modalities Test (SDMT; P = .03). For MS patients, a 4- to 5-point decrease in SDMT is associated with job loss, according to the authors.
For every 1% decrease in brain volume, low-contrast letter acuity also declined by an average of nearly 1.5 letters, the investigators said.
The National MS Society and the Multiple Sclerosis International Federation funded the research. Three coauthors reported serving as committee members or receiving consulting fees, honoraria, or free study medication from Biogen Idec, Novartis, Mylan, Roche, Acorda, Bionure, CNS Imaging Consultant, Hoffman-LaRoche, Genzyme, Teva, Sanofi-Aventis, and Genentech.