Cerebellar atrophy in different subtypes of Parkinson's disease

Background: To investigate, using Magnetic Resonance Imaging (MRI) and voxel-based morphometry (VBM), morphometric changes of cerebellum in Parkinson's disease with different motor and affective subtypes. Methods: Fifty-four patients with idiopathic Parkinson's disease (PD) were classified into tremor-predominant-PD (PDT) (n = 37) and akinetic/rigidity-predominant-PD (PDAR) (n = 17). Moreover, PD groups were divided into four affective subtypes, including depressive but not anxious PD (dPD, n = 5), anxious but not depressive PD (aPD, n = 8), comorbid depressive and anxious PD (coPD, n = 8), and PD patients without depressive or anxious symptoms (nPD, n = 33). They were additionally compared at a group level with thirty-nine normal controls (NCs). An analysis of covariance followed by post hoc tests was performed to examine the alterations of cerebellar grey matter volume (GMV) in different groups of PD. Results: Compared with NCs, PD showed grey matter (GM) atrophy in the right Crus II, pyramis, culmen, the right lobules IV, and V, and the left lobule VI. PDT, PDAR and NCs did not differ in the volume of the cerebellum. Relative to nPD group, dPD group exhibited GMV reduction in the left Crus I, while aPD group showed GMV reduction in the tonsil and the right lobule VIII. The GM atrophy was also found in the coPD group compared to NCs, including the tonsil, the left lobule VIII, the right lobule VI, the left Crus I, and vermis IV, and V. There was a significant negative correlation between the Hamilton Rating Scale for Depression (HAMD) score and the right lobule IX volume, and a significant negative correlation between the Hamilton Rating Scale for Anxiety (HAMA) score and the right lobule VIII volume. Conclusions: These findings suggest that cerebellar changes are involved in PD. It also supports a possible role of the cerebellum in the depressive and anxious symptoms in PD.