Nineteen  SCA3 patients and 18 SCA10  patients were compared  to a control group of 37 patients. Demographic and clinical data (SARA), and expansions CAGn and ATTCTn were evaluated. The protocol of neuroimaging used a Siemens MAGNETOM Skyra scanner 3.0 T, and the software Freesurfer. Data were evaluated by descriptive statistics.  Variables were estimated by the correlation coefficient (r) (Student t test). The Chi-square test was  used in the comparative evaluation of the SCA x controls and SCA 10 x SCA 3. Statistical analysis of correlation used  the Spearman Rank Correlation software (v 1.0.3).

Nineteen SCA3 patients (mean age 46.04 ± 12.49 years-old) and 18 SCA10 patients (mean age 46.43 ± 8.04 years-old) were studied. There was positive correlation between disease duration and SARA score: SCA3 (ρ = 0.872; p < 0.001); SCA 10 (ρ = 0.590, p = 0.005. In SCA3,  volumetric reduction was seen in the cerebellum, basal ganglia, brain stem,  and diencephalon. Diminished cortical thickness occurred in caudal middle frontal, middle temporal, pars triangularis, and temporal pole. In SCA10,  volume reduction in  cerebellum and right pallidum was observed.  Reduced cortical thickness was restricted to  lingual, middle orbitofrontal, parahippocampal, rostral anterior cingulate, and frontal pole.

The volumetric changes were much more prevalent in the SCA3 than in SCA10 patients. This observation may reflect  the greater phenotypic presentation seen in SCA3 patients, in comparison with SCA10 patients.