Work

Microstructural alterations of the thalamo-striatal system in parkinson’s disease with dementia: a diffusion tensor imaging study

Year: 2026

Type: article

Abstract: Background Cognitive impairment is a common non-motor manifestation of Parkinson’s disease (PD) and may progress to dementia. Increasing evidence suggests that disruption of subcortical networks, particularly the thalamo-striatal system, may contribute to cognitive decline in PD. Diffusion tensor imaging (DTI) provides a non-invasive method to detect microstructural alterations in these structures that may not be visible on conventional MRI. This study aimed to assess microstructural alterations of the thalamo-striatal system using DTI, comparing normally cognitive PD (NC-PD) and PD with cognitive impairment (PD-CI). Methods Patients were recruited between 2023 and 2024 and underwent comprehensive clinical assessment including motor and cognitive evaluations. DTI was performed on a 1.5 T MRI scanner, and FA and ADC were measured within regions of interest (ROIs) encompassing the putamen, caudate nucleus and thalamus, representing the thalamo-striatal system. Results Bilateral putaminal ADC was higher in the PD-CI group compared to NC-PD, though this did not survive correction for multiple comparisons. Significant negative correlations were found between putaminal ADC and cognitive scores. Caudate FA showed significant negative correlations with motor scales. No significant differences were found in caudate or thalamic DTI measures between groups. Conclusions Elevated bilateral putaminal ADC was significantly associated with cognitive decline in PD-CI, suggesting potential involvement of the putaminal network in PD-related cognitive impairment. While these exploratory findings do not confirm thalamo-striatal involvement, they highlight the need for further investigation of this pathway using advanced connectivity methods in larger, adequately powered cohorts.

Source: The Egyptian Journal of Radiology and Nuclear Medicine

DOI: 10.1186/s43055-026-01792-2