Abstract
Objective: Chronic painful knee osteoarthritis (OA) is a disabling physical health condition. Alterations in the cortical function may explain persistent pain in knee OA. This study investigated source localised, resting-state, full-band electroencephalography (EEG) features and evaluated the relationship between EEG and pain and physical function in people with knee OA, compared to matched healthy control (HC).
Methods: Adults aged 44–85 years with knee OA (n = 37) and healthy controls (n = 39) completed pain and physical function questionnaires. Resting-state EEG data (10 minutes, eyes closed) were collected, preprocessed, and analysed across frequency bands. Current source density of cortical regions’ bilateral somatosensory cortices (SSC), dorsal anterior cingulate cortex (dACC), and pregenual anterior cingulate cortex (pgACC) was computed. Whole-brain mapping and correlations between CSD and outcomes were also analysed.
Results: Whole-brain analysis showed increased Gamma activity in the right insula (RIns) in the OA group (p = 0.01). The Mann-Whitney U-test revealed decreased (p < 0.0001) Infraslow activity at pgACC and increased Theta, Alpha, Beta, and Gamma activity at dACC, pgACC, SSC, and RIns. Infraslow activity at dACC was positively correlated with neuropathic pain, physical function, and sensitivity to physical activity measures, while RIns activity in Theta, Alpha, and Beta bands negatively correlated with pain.
Conclusion: Aberrations in cortical activities at sensory-discriminative, motivational-affective, and descending inhibitory cortical regions were demonstrated. Moreover, EEG cortical activities were correlated with pain experience, physical function and performance. The study highlights the cortical aberrations in people with knee OA and informs potential cortical targets for non-invasive, neuromodulatory interventions for managing pain experience.