Category: Parkinson's Disease: Non-Motor Symptoms
Objective: We aimed to identify clinical and imaging biomarkers of visual system injury associated with the presence of Visual hallucinations (VH) in Parkinson’s disease (PD).
Background: VH are present in up to 75% of PD patients. In addition, it is well established that patients with PD have early structural and functional alterations in the visual system, from the retina to higher-order visual brain areas. However, no detailed analysis of the relationship between damage to the visual system and the presence of VH in PD has been performed.
Method: Seventy-four participants, including 12 PD with VH (PDVH), 35 PD without VH (PDnoVH) and 27 controls underwent a comprehensive battery of primary visual function and visual cognition tests, retinal optical coherence tomography (OCT) and structural and resting-state functional brain MRI. We quantified cortical thickness with Freesurfer and functional connectivity (FC) of Visual (VIS), Fronto-Parietal (FP), Ventral Attention (VAN) and Dorsal Attention (DAN) networks with CONN toolbox. Group comparisons were performed with MANCOVA. Area Under the Curve (AUC) was computed to assess the ability of clinical and imaging parameters to differentiate PDVH from PDnoVH.
Results: Compared to PDnoVH and HC, PDVH showed significantly reduced performance on contrast sensitivity, neuropsychological visuoperception and visuospatial tests, increased photoreceptor layer thickness of the retina, reduced cortical thickness mostly in right visual associative occipital areas, decreased between-network connectivity for VIS-VAN and VAN-DAN and increased within-network connectivity for DAN. The combination of clinical and imaging variables that best discriminated PDVH from PDnoVH were within-network DAN FC, photoreceptor layer thickness and cube analysis test from Visual Object and Space Perception Battery (AUC = 0.818).
Conclusion: Compared to PDnoVH, PDVH have specific functional and structural abnormalities within the visual system, which can be quantified non-invasively and could potentially constitute biomarkers for VH in PD.
To cite this abstract in AMA style:
M. Diez-Cirarda, A. Cabrera, A. Murueta-Goyena, A. Strafella, R. Del Pino, MA. Acera, O. Lucas-Jiménez, N. Ibarretxe-Bilbao, B. Tijero, JC. Gomez-Esteban, I. Gabilondo. Visual system abnormalities and visual hallucinations in Parkinson’s disease [abstract]. Mov Disord. 2022; 37 (suppl 2). https://www.mdsabstracts.org/abstract/visual-system-abnormalities-and-visual-hallucinations-in-parkinsons-disease/. Accessed June 14, 2025.« Back to 2022 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/visual-system-abnormalities-and-visual-hallucinations-in-parkinsons-disease/