Figure 4.

CAG-repeat length related to rate of cortical and striatal atrophy. (A) A brain surface projection and (B) parameter ± SD that indicates whether individual CAG-repeat length predicts regional rate of atrophy. Participants with higher CAG-repeat length showed an increased rate of atrophy, especially in posterior cortical and striatal areas. White indicates nonsignificant CAG effects. Only significant regions are shown in bar plot. Analysis from Bayesian model average accounted for effects of age, gender, and confounds (see Methods and Materials). (B) Proportion of total variance of volume in caudate/putamen/white matter explained (i.e., R²) by CAG-repeat length. We show R² over all time points 6 years before to 5 years after diagnosis. x-axis: disease progression time in years relative to individual motor diagnosis.