To control for the possibility of the regression being driven by between-group differences in IHTT and/or the diffusion measures, the Group × FA and Group × Mode interaction terms were added to the model. Adding these interaction terms did not significantly increase the amount of variance accounted for by the model, indicating that the relationship between IHTT and FA/Mode was comparable between the patient and control groups. Consistent with this finding, the regression model was similar and remained statistically significant when the HCs were considered alone: IHTT(P9/P10)=−277∗FA+107∗Mode+72,R2=.383,F2,15=4.032p=0.043.
