Explainable Graph Attention Network on Resting State fMRI Dynamic Functional Connectivity Reveals Cerebellar Hub Breakdown in Chronic Knee Osteoarthritis Pain
摘要
Chronic knee osteoarthritis (OA) pain involves widespread reorganization of brain network topology that often eludes conventional region-of‐interest analyses. Resting‐state fMRI connectivity offers a promising window into these alterations, yet methods that both capture signed (positive vs. negative) interactions and remain interpretable are lacking. We present DualEdge-GAT, an explainable graph neural network that constructs dynamic sliding-window partial-correlation graphs across 116 AAL regions and employs dual-stream graph attention (positive vs. negative edges) to separately weight positively and negatively signed functional connections. The architecture integrates Squeeze-Excitation channel reweighting and Self-Attention Graph Pooling to focus on the most informative nodes and edges before final classification. Evaluated on 56 chronic knee OA patients versus 20 healthy controls, DualEdge-GAT achieved a mean validation accuracy of 87 ± 4% and mean F1 score 92 ± 2%. Attention-based explanations consistently identified posterior cerebellar lobules as the most critical hubs. Graph-theoretic follow-up revealed that these regions exhibit significantly reduced nodal degree in OA patients, indicating a breakdown of richly interconnected local neighborhoods. Against a kernel SVM trained solely on handcrafted nodal degree features, DualEdge-GAT demonstrated superior discriminative performance and delivered mechanistic insight by pinpointing the specific cerebellar circuits underlying chronic pain. DualEdge-GAT not only achieves high accuracy in classifying chronic knee OA pain but also provides a transparent map of circuit-level dysfunction, uncovering cerebellar hub breakdown as a potential biomarker and therapeutic target.