Abstract
AIMS: The aim of this study was to investigate the whole-brain asymmetry changes in spinocerebellar ataxia type 3 (SCA3) and their association with movement disorders. METHODS: Voxel-based morphometry (VBM) was used to assess asymmetry in gray matter (GM) volume in 83 genetically confirmed SCA3 patients and 83 sex- and age-matched healthy controls (HCs). The asymmetry index (AI) was analyzed for partial correlation with disease severity, as measured by the Scale for Assessment and Rating of Ataxia (SARA) and International Cooperative Ataxia Rating Scale (ICARS). Age, sex, and total intracranial volume (TIV) were included as covariates in the analysis. RESULTS: Asymmetry in GM analysis with SCA3 patients showed decreased leftward asymmetry in cerebellar lobules VIII and IX, the visual cortex, and the putamen, as well as decreased rightward asymmetry in the ventral lateral thalamus, as analyzed by VBM. The AI in the cerebellum, the visual cortex, and the putamen was positively correlated with SARA and ICARS scores, whereas the AI in the thalamus was negatively correlated with these scales. CONCLUSION: SCA3 patients exhibit distinct patterns of asymmetrical changes in GM volume, which correlates with motor dysfunction. These changes in asymmetry may serve as potential biomarkers for early intervention in SCA3. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR): 1800019901, 2000039434.