Object
To this day, no parameter can really monitor the progression of multiple sclerosis (MS). In this study, an index the skewness
(S) derived from parameters calculated in diffusion tensor imaging (DTI) has been tested on MS patients for its ability to
monitor the disease course.
Materials and methods
Eighteen patients underwent two examinations within 3 months consisting of a clinical evaluation (EDSS) and DTI acquisitions
on a 1.5 T imager. Tensor was calculated thanks to“home-made” software. Mean diffusivity (MD) and fractional anisotropy (FA)
histograms were described for normal-appearing white matter (NAWM) and gray matter (GM) of patients with S and also with usually
indices peak position (pp) and peak height (ph) for the whole group of patients and for two separate groups according to their
clinical status (EDSS ≤ 3 and EDSS > 3 at month 0).
Results
Although no significant clinical evolution is observed over 3 months, S in GM showed a significant shift for both MD/FA histograms
towards abnormal values for the whole group of patients (p = 0.02/p = 0.04) and for the group with EDSS ≤ 3 (p = 0.04/p = 0.007), while ph and pp do not.
Conclusion
S in GM could be an alternative marker to monitor the disease course before the repercussion on the clinical score.
Keywords Diffusion tensor imaging - Multiple sclerosis - Skewness - Normal appearing white matter - Gray matter