Pain is prevalent in juvenile idiopathic arthritis (JIA). Unknowns regarding the biological drivers of pain complicate therapeutic targeting. We employed neuroimaging to define pain-related neurobiological features altered in JIA.
16 male and female JIA patients (12.7 ± 2.8 years of age) on active treatment were enrolled, together with age- and sex-matched controls. Patients were assessed using physical examination, clinical questionnaires, musculoskeletal MRI, and structural neuroimaging. In addition, functional magnetic resonance imaging (fMRI) data were collected during the resting-state, hand-motor task performance, and cold stimulation of the hand and knee.
Patients with and without pain and with and without inflammation (joint and systemic) were evaluated.  Pain severity was associated with more physical stress and poorer cognitive function. Corrected for multiple comparisons, morphological analysis revealed decreased cortical thickness within the insula cortex and a negative correlation between caudate nucleus volume and pain severity. Functional neuroimaging findings suggested alteration within neurocircuitry structures regulating emotional pain processing (anterior insula) in addition to the default-mode and sensorimotor networks.
Patients with JIA may exhibit changes in neurobiological circuits related to pain. These preliminary findings suggest mechanisms by which pain could potentially become dissociated from detectable joint pathology and persist independently of inflammation or treatment status.