Cortical thickness alterations in Parkinson's disease related anxiety: A cross-sectional 7 T MRI study

BackgroundAnxiety is a common non-motor symptom in Parkinson's disease (PD) and has previously been associated with changes in cortical thickness of various brain regions.ObjectiveTo identify changes in cortical thickness in PD-related anxiety.Methods148 patients from an ongoing cohort study were included: 30 PD patients with anxiety, 73 PD patients without anxiety and 45 healthy controls. Anxiety was measured with the Parkinson Anxiety Scale (PAS). A 7 T structural MRI scan was performed and used to compare cortical thickness between these groups. Region of interest (ROI) as well as whole-brain analyses were performed to identify differences.ResultsROI analyses revealed a strong negative association between the cortical thickness of the left lingual gyrus and the severity of anxiety in PD patients (R = -0.71; p = 0.006). Additional significant strong negative associations with the severity of anxiety in PD patients were observed in the frontal and cingulate regions (R between -0.56 and -0.65). Whole-brain analysis revealed a significant cluster of cortical thinning in the left anterior cortex and the dorsolateral prefrontal cortex weakly associated with PAS total score across all groups (R = -0.25, p = 0.00201).ConclusionsThis study is the first to report a strong negative association between left lingual gyrus thickness and anxiety severity in PD. Additionally, anxiety in early PD is associated with cortical thinning in the fronto-cingulate region, mainly affecting left sided structures. Future studies should examine whether these cortical changes can predict the anxiety progression patterns or the treatment response in PD patients.