Structural abnormalities of the cerebellar gray matter and cerebellar peduncles in cervical dystonia patients

Background: Cerebellar abnormalities involved in cervical dystonia (CD) have gained increasing attention, but a consistent pattern of structural changes in the cerebellar lobules and peduncles has not been fully identified. Associations between cerebellar abnormalities and the phenotypic characteristics of CD patients have not been established. Method: Ninety CD patients and 52 healthy controls (HC) were selected from our database, including 52 with head tremor (trCD) and 38 without head tremor (ntrCD). Between-group differences in gray matter volumes of cerebellar subregions and fiber morphometric properties of the cerebellar peduncles (CP) were investigated using voxel-based, region of interest-based and fixel-based analysis, respectively. The significant structural changes were correlated with clinical data, including disease duration and the first section of TWSTRS. Results: Compared to HC, reduced fiber cross-section (FC) was found in the right inferior CP of CD patients. Furthermore, not only decreased gray matter volume in vermis Crus II, vermis VIIIa, vermis VIIIb, vermis IX, left Crus I and Crus II was detected, but also lesser FC in the left superior CP was observed in ntrCD patients. However, only reduced FC in the right inferior CP was shown in trCD patients. Notably, lower gray matter volume in the left Crus I was associated with a higher TWSTRS 1 score in patients with ntrCD (p = 0.007). Conclusion: Our study provided potential evidence that structural cerebellar changes in CD patients, manifested as gray matter loss or CP atrophy, and structural changes may vary in patients with different phenotypic characteristics.