1295 Assessing the Correlation Between Freezing of Gait and Visual Disorders in Parkinson’s Disease: A Study of Associated Brain Networks

INTRODUCTION: Gait and visual disorders are recognized as debilitating symptoms in individuals with Parkinson’s disease (PD). METHODS: 11 PD subjects with FOG and 29 PD subjects with no gait disorder (NGD) were recruited. VD were identified, and each group was divided into two subgroups based on VD presence: FOG+VD, FOG-VD, NGD+VD, and NGD-VD. Resting-state fMRI was performed using a 3T Siemens scanner with 64 channels head and neck coil. Inter-subject hemisphere dominance was uniformed by flipping the MRI to align the disease-dominant hemisphere. ROI-to-ROI analysis was performed using Conn toolbox. Group-based analysis was then performed between each pair of the two groups. The voxel threshold p-value was set at <0.05, with Bonferroni correction applied for multiple comparisons (0.05/170=0.00029). Network analysis was controlled for disease and dopaminergic therapy duration as confounding variables. RESULTS: Visual disorders, longer disease duration, and extended dopaminergic therapy were correlated with the presence of FOG in subjects with PD. After conducting ROI-to-ROI network analysis between subjects with FOG+VD and FOG-VD, the salience network demonstrated increased functional connectivity (FC) with regions from the language network. When comparing subjects with NGD+VD to NGD-VD, four pairs of networks demonstrated increased FC and one pair showed decreased FC. CONCLUSIONS: Disrupted FC in the salience and default mode networks is a significant factor in emergence of visual and gait disorders. Alterations in FC, especially in the salience network, are correlated with both manifestations in PD subjects.