The NAWM of patients with RR-MS shows decreased perfusion compared with that of controls.

The correlation between brain atrophy and EDSS score was better in patients with secondary progressive MS than in those with relapsing-remitting MS.

A majority of mildly brain injured patients, as well as those more severely injured, showed diminished NAA/creatine (Cr) levels in the splenium compared with normal control volunteers. The patients displaying lowered NAA/Cr in the splenium were also likely to exhibit lowered NAA/Cr in lobar white matter. Also, the levels of NAA/Cr in the splenium of normal volunteers were higher compared with those found in lobar white matter. Decreases in NAA/Cr levels in the splenium may be a marker for diffuse injury. A proton MRS examination may be particularly useful in evaluating mildly injured patients with unexplained neurological and cognitive deficits. It is concluded that MRS is a sensitive tool in detecting axonal injury.

The age-dependent decrease of whole brain N-acetylaspartate (WBNAA) in the patients suggests that progressive neuronal cell loss is a cardinal feature of this disease. WBNAA offers a quick, highly reproducible measure of disease progression and may be an important marker of treatment efficacy in MS as well as other neurodegenerative diseases.

Purpose:To investigate the feasibility of diffusion tensor imaging (DTI) assessment of microscopic fiber tract injury in the corpus callosum (CC) and other normal-appearing white matter (NAWM) in patients with early multiple sclerosis (MS). Materials and Methods:DTI was performed in 12 healthy volunteers and 15 patients who have relatively short disease duration (mean ϭ 2.7 years). Both fractional anisotropy (FA) and mean diffusivity (MD) were obtained in different regions of normal-appearing CC (NACC) and NAWM in frontal and occipital regions. Results:The data showed significantly lower FA (P Ͻ 0.001) and higher MD (P Ͻ 0.04) for NACC regions, but not for frontal and occipital NAWM regions, in patients than in those in healthy volunteers after Bonferroni adjustment. The increase of MD in the entire NACC regions was correlated with the total cerebral lesion volume (r ϭ 0.75, P ϭ 0.001) in patients. Conclusion:The water diffusion changes indicate that in the early phase of disease there is a preferential occult injury of CC, which is likely due to the Wallerian degeneration from distant lesions.