Researchers of this PET–MRI study assessed cortical cholinergic integrity in Parkinson’s disease (PD) with the vesicular acetylcholine transporter tracer 18F- fluoroethoxybenzovesamicol (FEOBV) in 38 PD patients (13 visual hallucination [VH]+, 20 VH–, 5 excluded for remote VH) and 10 matched controls. All underwent 18F-FEOBV PET, T1 MRI, and standardized psychosis, cognition (Montreal Cognitive Assessment [MoCA], visuospatial), and motor assessments. Voxelwise and regions of interest analyses focused on the ventral visual stream (VIS), ventral/dorsal attention networks (VAN/DAN), and thalamic nuclei.
PD showed widespread reductions in 18F-FEOBV uptake versus controls, greatest in occipital cortex. Patients who were VH+ had lower cortical cholinergic signal than VH–, predominating in the 0 VIS (lingual/fusiform/inferior temporal) and superior temporal regions, with most VIS effects persisting after MoCA adjustment. VAN differences were present, while DAN effects attenuated with MoCA. Groups were otherwise similar demographically and cognitively, though VH+ had higher Hoehn-Yahr stage. Findings align with perception–attention deficit models, implicate cortical cholinergic loss—especially in left ventral visual pathways—in PD-VH, and support studying cholinomimetic strategies. Limitations include modest sample size, possible severity confounding, left lateralization, and lack of visual acuity data.
Reference: d’Angremont E, van der Zee S, Slingerland S, et al. Cholinergic deficiency in Parkinson’s disease patients with visual hallucinations. Brain. 2024;147(10):3370-3378. doi: 10.1093/brain/awae186.
