NAA/Cr ratio from MRS correlates with EDSS

A statistically significant correlation was found between disability (measured by Expanded Disability Scale Score) and N-Acetyl Aspartate (NAA/Cr ratio) levels in normal appearing white matter in 31 patients using Magnetic Resonance Spectroscopy. No correlation was found between the NAA/Cr ratio and disability measured by any of the other disability assessment scales. It would be great to see something like this become a standard measure of disease progression so that drugs getting approval would have to slow disability rather than just reduce relapse rates and lesion load (which do not correlate with disability).