Alternation of the Rich-Club Organization of Individual Brain Metabolic Networks in Parkinson's Disease

Objective The diagnosis of Parkinson's disease (PD) remains challenging. Although F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography (PET) has revealed the metabolic abnormalities associated with PD at systemic levels, the underlying rich-club organization of the metabolic connectome in these patients remains largely unknown. Materials and Methods The data of 49 PD patients and 49 well-matched healthy controls (HCs) were retrieved and assessed. An individual metabolic connectome based on the standard uptake value (SUV) was built using the Jensen-Shannon Divergence Similarity Estimation (JSSE) method to compare the rich-club properties between PD patients and HC. Results Our results showed the rich-club organization of metabolic networks (normalized rich-club coefficients > 1) in the PD and HC group were within a range of thresholds. Further, patients with PD demonstrated lower strength and degree in rich-club connections compared with HCs (strength: HCs = 55.70 +/- 8.52, PDs = 52.03 +/- 10.49, p = 0.028; degree: HCs = 56.55 +/- 8.60, PDs = 52.85 +/- 10.62, p = 0.029), but difference between their feeder and local connections was not significant. Conclusion Individual metabolic networks combined with rich club analysis indicated that PD patients had decreased rich club connections but similar feeder and local connections compared with HCs, indicating rich club connections as a promising marker for early diagnosis of PD.