Cerebellar Volume and Executive Function in Parkinson Disease with and without Freezing of Gait.

BACKGROUND: Freezing of gait (FOG) affects approximately 50% of people with Parkinson Disease (PD), impacting quality of life and placing financial and emotional strain on the individual and caregivers. People with PD and FOG have similar deficits in motor adaptation and cognition as individuals with cerebellar lesions, indicating the cerebellum may play a role in FOG.

OBJECTIVE: To examine potential differences in cerebellar volumes and their relationships with cognition between PD with (FOG+) and without FOG (FOG-).

METHODS: Sixty-three participants were divided into two groups, FOG+ (n = 25) and FOG- (n = 38), based on the New Freezing of Gait Questionnaire. Cognitive assessment included Trail Making, Stroop, Verbal Fluency, and Go-NoGo executive function tasks. All participants completed structural T1- and T2-weighted MRI scans. Imaging data were processed with FreeSurfer and the Spatially Unbiased Infratentorial toolbox to segment the cerebellum into individual lobules.

RESULTS: FOG+ performed significantly worse on phonemic verbal fluency (F(1, 22)  =  7.06, p = 0.01) as well as the Go-NoGo task (F(1, 22)  =  9.00, p = 0.004). We found no differences in cerebellar volumes between groups (F(4, 55)  = 1.42, p = 0.24), but there were significant relationships between verbal fluency measures and lobule volumes in FOG-.

CONCLUSIONS: These findings underscore the need for longitudinal studies to better characterize potential changes in cerebellar volume, cognitive function, and functional connectivity between people with PD with and without FOG.