Functional Reorganization of the Default Mode Network across Chronic Pain Conditions

Chronic pain reorganizes the brain's default mode network (DMN). Using resting-state functional magnetic resonance imaging, patients with chronic back pain, complex regional pain syndrome, and knee osteoarthritis all showed reduced connectivity between the medial prefrontal cortex and posterior DMN regions, alongside increased connectivity to the insular cortex proportional to pain intensity. Multiple DMN regions, especially the medial prefrontal cortex, exhibited increased high-frequency oscillations and decreased phase locking with parietal attention-processing regions. Both phase and frequency changes correlated with pain duration in osteoarthritis and chronic back pain patients. These findings suggest chronic pain reflects maladaptive neural dynamics across different pain types.

Study at a glance

Abstract

Chronic pain is associated with neuronal plasticity. Here we use resting-state functional magnetic resonance imaging to investigate functional changes in patients suffering from chronic back pain (CBP), complex regional pain syndrome (CRPS) and knee osteoarthritis (OA). We isolated five meaningful resting-state networks across the groups, of which only the default mode network (DMN) exhibited deviations from healthy controls. All patient groups showed decreased connectivity of medial prefrontal cortex (MPFC) to the posterior constituents of the DMN, and increased connectivity to the insular cortex in proportion to the intensity of pain. Multiple DMN regions, especially the MPFC, exhibited increased high frequency oscillations, conjoined with decreased phase locking with parietal regions involved in processing attention. Both phase and frequency changes correlated to pain duration in OA and CBP patients. Thus chronic pain seems to reorganize the dynamics of the DMN and as such reflect the maladaptive physiology of different types of chronic pain.