Correlation of Apparent Diffusion Coefficient to cognitive impairment in Relapsing remittent multiple sclerosis (plaque, peri-plaque and Normal appearing white matter)

Abstract

The purpose of this study was to determine diffusion coefficient (ADC) in plaque, peri-plaque and normal-appearing white matter (NAWM) in multiple sclerosis (MS), compare them with the control and correlate findings with cognitive state. Subjects and methods Sixty-five participants were included and categorized into MS patients with normal cognition (n = 25); MS with mild cognitive impairment (n = 20) and control group (no MS and normal cognition; n = 20). The Montreal Cognitive Assessment was used to determine cognitive state. Mean ADC was measured in plaque, peri-plaques and NAWM, compared with ADC from corresponding white matter in control and correlated with cognitive scores. Chi Square and Pearson correlation coefficient were used. Results The mean ADC of peri-plaque and NAWM in MS group with cognitive impairment was significantly higher than MS group with normal cognition (p < 0.001) and control group (p < 0.05) respectively. In MS patients with impaired cognition, the mean ADC in peri-plaque and NAWM demonstrated inverse correlations with cognitive state (r = −0.64, p < 0.001) and (r = −0.56, p = 0.01) respectively. Conclusions ADC values in peri-plaque and NAWM have an inverse correlation with cognition in MS. The ADC is useful for detecting subtle abnormalities in white matter and can be used as a predictor of cognitive state.