Neural Correlates of Cognitive Alterations and Minor and Structured Hallucinations in Parkinson's Disease
medRxiv July 10, 2026 Lada Kohoutová, Jevita Potheegadoo, Léa F Duong Phan Thanh et al.
Hallucinations in Parkinson's disease, from minor to structured, are linked to changes in brain connectivity and cognitive decline. Non-demented patients with minor or structured hallucinations share a common pattern of resting-state functional connectivity that is absent in patients without hallucinations. This pattern involves connections between subcortical areas and visual, attention, and default mode networks, as well as within-cerebellar and within-subcortical connectivity. The pattern is equally expressed in both hallucination groups and is associated with impairments in attention and executive function, as well as increased sensitivity to an experimental procedure that induces presence hallucinations. The findings suggest that altered subcortical-cortical connectivity underlies hallucinations even in their early, minor forms.