Potential New Imaging Marker for Early Multiple Sclerosis

Ruth J Hickman, MD

Correlation between change in brain volume and a clinical measure of cognitive function could be potential marker for clinical progression of multiple sclerosis.

New Orleans, LA — October 13, 2013 — As part of a poster session Sunday at the Annual Meeting of the American Neurological Association, findings were presented on a new potential imaging marker associated with clinical progression in early multiple sclerosis (MS). The first author of the project is Amir-Hadi Maghzi, MD, Postdoctoral Scholar in the Neurology Department at the University of California-San Francisco School of Medicine.

Currently there are no approved neuroprotective agents for MS. One of the challenges in developing such agents is the lack of early imaging biomarkers for progression in the early stages of MS. Without clear imaging markers, it is difficult to evaluate the effectiveness of a given treatment, especially in the early stages of disease. With this in mind, Maghzi and colleagues aimed to find such early imaging markers and potentially correlate them with specific clinical deficits.

The forty-three patients in this study had relapsing-remitting MS and were seen within one year of their first symptoms. These patients began a regimen of intramuscular interferon-beta. Additionally, they were given the drug riluzole or a placebo. These patients were 72 percent female with an average age of 36.

The researchers obtained imaging using time domain optical coherence tomography (OCT) and magnetic resonance imaging (MRI) at baseline. They repeated these imaging tests at six months, one year, 18 months, two years, and three years. They assessed brain volume using Structural Imagine Evaluation using Normalization of Atrophy (SIENA and SIENAX). Using OCT, they also assessed peripapillary retinal nerve fiber layer thickness (RNFL) and radial macular volume (MV).

The clinicians also gave the subjects a variety of assessment tests at these same intervals. This included the symbol digit modality test (SDMT) and the expanded disability status score (EDSS). Patients also took the MS functional composite test (MSFC), including the timed 25-foot walk (T25FW), the 9-hole peg test (9HPT), and the paced auditory serial addition test (PASAT).

The researchers did not find a correlation between retinal nerve fiber layer changes and clinical outcomes as measured by these tests. They also did not find a correlation between radial macular volume changes and clinical testing. However, they did find a correlation between brain volume changes and changes in the symbol digit modality test. A decrease in one symbol digit modality test score represented a 0.06 decrease in brain volume (95%CI: 0.01-0.1, p =0.014).

Maghzi’s study was supported by the Multiple Sclerosis International Federation through a McDonald’s Fellowship and a research grant from the National MS Society.