Correlation between the current age, onset age, SARA score, CAG repeat number, and MRS measurements for control, SCA2, SCA3, and SCA6, respectively.

R-NAA, V-NAA, and L-NAA = right, vermis, and left hemispheric N-acetyl aspartate/creatine ratio; MRS, magnetic resonance spectroscopy; ND = not derived; NA = not assessed; SARA, scale for the assessment and rating of ataxia; SCA, spinocerebellar ataxia.Data are shown with Pearson correlation coefficients (r). aSpearman correlation was applied, owing to the fact that L-NAA in the control group was not normally distributed.*P**P***P