Investigation of Total Cerebellar and Flocculonodular Lobe Volume in Parkinson's Disease and Healthy Individuals: A Brain Segmentation Study

Abstract

Background Parkinson's disease (PD) is a neurodegenerative disorder with an unexplored link to the cerebellum. In the pathophysiology of balance disorders in PD, the role of the flocculonodular lobe (FL) is linked to the impairment of the dopaminergic system. Dopamine deficiency can also lead to changes in cerebellum functions, disrupting balance control. This study compares cerebellar and FL volumes between healthy controls (HC) and PD patients, analyzing their correlation with clinical outcomes. Methods We used magnetic resonance images of 23 PD patients (14 male, 9 female) and 24 HC (9 male, 15 female). Intracranial (ICV), total cerebellar, FL, and cerebellar gray matter volumes were measured using VolBrain. Clinical outcomes in PD patients were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS-III) to evaluate motor function, with scores correlated to volumetric data. Results The cerebellar and gray matter volumes in HC were 115.53 +/- 10.44 cm(3) and 84.83 +/- 7.76 cm(3), respectively, compared to 126.83 +/- 13.47 cm(3) and 92.37 +/- 9.45 cm(3) in PD patients, indicating significantly larger volumes in PD patients (p < 0.05). The flocculonodular lobe gray matter volume was 1.14 +/- 0.19 cm(3) in PD patients and 1.02 +/- 0.13 cm(3) in HC, but there was a significant increase in gray matter volume in PD patients between the groups (p < 0.05). In PD patients, significant negative correlations were observed between FL volume and the UPDRS-III scores (r = - 0.467, p = 0.033) and between UPDRS-III scores and both total (r = - 0.453, p = 0.039) and normalized (r = - 0.468, p = 0.032) gray matter volumes of the FL. Conclusion Although total gray matter volumes were larger in PD patients, the volumes of FL did not differ between groups. In Parkinson's disease, increased cerebellar volume may regulate fine motor movements rather than balance.