Network topology and metabolic alterations in early- and mid-stage Parkinson's disease: insights from fluorodeoxyglucose PET imaging.

Objectives: Parkinson's disease (PD) is a neurodegenerative disorder with distinct metabolic alterations in the brain, which are detectable via 18F-FDG PET. This study aims to delineate glucose metabolism patterns and network topology changes across early- and mid-stage PD patients.

Methods: A total of 80 PD patients (Hoehn-Yahr stages 1-3) were retrospectively analyzed, including 40 early-stage and 40 mid-stage cases, along with 40 age-matched healthy controls. All participants underwent 18F-FDG PET imaging. The brain metabolic activity was quantified, and network topology was assessed using graph theory metrics. Statistical comparisons between PD stages and control groups were performed to identify significant differences in metabolic patterns and network alterations.

Results: Early-stage PD patients exhibited hypermetabolism in regions such as the pons and thalamus, with significant differences in metabolic activity compared with controls. Mid-stage PD patients showed more extensive hypermetabolism in the pons, right cerebellum, and putamen, alongside hypometabolism in the cuneus and calcarine regions. Hub node connectivity analysis revealed decreased connectivity in temporal and occipital lobes for both stages, while the limbic and frontal lobes showed enhanced connectivity. Compared with early-stage PD, mid-stage PD had reduced connectivity in the limbic system but increased in the frontal and occipital lobes.

Conclusions: 18F-FDG PET imaging reveals progressive metabolic disruptions and network changes in PD, offering potential biomarkers for disease staging and therapeutic targeting, while also aiding in the understanding of disease progression and guiding therapeutic interventions.