Data from: Cognitive correlates of cerebellar resting-state functional connectivity in Parkinson disease.

Objective: The purpose of this cross-sectional study was to investigate
the contributions of altered cerebellar resting-state functional
connectivity (FC) to cognitive impairment in Parkinson disease (PD).
Methods: We conducted morphometric and resting-state functional
connectivity MRI (FC-MRI) analyses contrasting 81 PD and 43 age-matched
healthy controls using rigorous quality assurance measures. To investigate
the relationship of cerebellar FC to cognitive status, we compared PD
participants without cognitive impairment (Clinical Dementia Rating scale,
CDR=0; n=47) to PD participants with impaired cognition (CDR≥0.5; n=34).
Comprehensive measures of cognition across the five cognitive domains were
assessed for behavioral correlations. Results: The PD participants had
significantly weaker FC between the vermis and peristriate visual
association cortex compared to controls, and the strength of this FC
correlated with visuospatial function and global cognition. In contrast,
weaker FC between vermis and dorsolateral prefrontal cortex was found in
the cognitively impaired PD group compared to PD participants without
cognitive impairment. This effect correlated with deficits in attention,
executive functions and global cognition. No group differences in
cerebellar lobular volumes or regional cortical thickness of the
significant cortical clusters were observed. Conclusion: These results
demonstrate a correlation between cerebellar vermal FC and cognitive
impairment in PD. The absence of significant atrophy in cerebellum or
relevant cortical areas suggests this could be related to local
pathophysiology such as neurotransmitter dysfunction.