Thalamocortical dysconnectivity in knee osteoarthritis

Abstract

Previous studies have suggested abnormal morphology and function of the thalamus and cortex in KOA. However, it is not known whether the thalamocortical network is differentially affected in this disorder. In this study, we examined functional and effective connectivity between thalamus and the major divisions of the cortex in 27 healthy controls and 27 KOA participants using functional magnetic resonance imaging. We also explored the topological features of the whole brain based on graph theory analysis. The results suggested that patients with KOA had significantly reduced resting-state functional connectivity (rsFC) of the thalamo-sensorimotor pathway, enhanced rsFC of the thalamo-medial/lateral frontal cortex (mFC/LFC), parietal, lateral temporal and occipital pathways, decreased effective connectivity of the left sensorimotor-to-thalamus pathway and enhanced effective connectivity of the right thalamus-to-sensorimotor pathway as compared with of healthy controls. The functional connectivity of the thalamo-sensorimotor and thalamo-mFC pathways was enhanced when performing multi-source interference task. Moreover, patients with KOA showed changed nodal properties associated with thalamo-cortical circuits including the medial and dorsal superior/middle frontal gyrus, inferior parietal gyrus, left thalamus, etc. as compared with healthy controls. Correlation analysis suggested significant negative correlation between thalamo-mFC’s rsFC and pain intensity, between thalamo-sensorimotor task-related connectivity and disease duration/depression scores, as well as positive correlation between right frontal nodal properties and pain intensity in KOA. Taken together, these findings establish abnormal and differential alterations of the thalamocortical network associated with pain characteristics in KOA, which extends our understanding of its’ role in the pathophysiology of KOA.