AXONAL DYSFUNCTION AND DISABILITY IN A RELAPSE OF MULTIPLE-SCLEROSIS - LONGITUDINAL-STUDY OF A PATIENT

In a 6-year longitudinal study of a patient with relapsing progressive multiple sclerosis (MS), we used proton magnetic resonance spectrosco py to assess N-acetylaspartate (NAA) from a large central brain volume to evaluate the relationship between this marker of neuronal integrit y and clinical disability. During the follow-up period, there was one major relapse and its subsequent partial remission. Changes in the bra in NAA to creatine ratio correlated strongly with clinical disability (Spearman rank coefficient = -0.73, p < 0.001). We interpret this as e vidence that axonal dysfunction or loss contributes to functional impa irment of patients with MS. Because the NAA signal in the large volume of interest originated predominantly from white matter that appeared normal on conventional MRI, these results also suggest that some degre e of axonal dysfunction may be widespread in acute, severe relapses.