FIG. 5.

Positive correlations between imaging (fractional anisotropy [FA] value) and locomotor (Basso, Beattie, and Bresnahan [BBB] and middle swing foot position relative to hip) data. To assess for correlations between locomotor activity and diffusion tensor imaging findings, BBB scores (A,C) and middle swing foot position relative to hip measures (B,D) at 4 weeks post-injury were plotted versus corresponding FA values as a function of injury severity. Representative images at 200 μm caudal to the injury epicenter (A,B) and at the epicenter (C,D) are shown. Using linear regression, R² values were calculated at the injury epicenter and all rostral and caudal intervals. Corresponding Pearson correlation coefficient values (R) at all locations for BBB versus FA (E) and middle swing foot position relative to hip versus FA (F) were also plotted. Weaker correlations were observed at and immediately rostral to the injury epicenter while stronger correlations were measured in the caudal segment. These findings suggest that measuring FA values within the spinal cord distal to the site of injury may provide a non-invasive method to numerically assess relative spinal cord health as it pertains to locomotor activity. (At all locations, p<0.05)