Panel A: A region of the left posterior insula where we observed decreases in GMV showed decreased evoked-pain connectivity to DMN structures (right inferior parietal lobule and middle/medial frontal gyrus) between PGB and PBO treatments (analysis 4). Panel B: Additionally, a region of the right posterior insular where we observed decreases in GMV showed concomitant decreases in evoked-pain connectivity to the left anterior insula and the cuneus (analysis 4). Panel C: Reductions in left posterior insula to middle/medial frontal gyrus evoked-pain connectivity during the PGB period are associated with reductions in MPQ total and sensory pain scores. Right/left posterior insular seeds were obtained from VBM results.
Black lines with filled in circles indicate individual PGB subject changes in evoked-pain connectivity. Black lines with empty circles indicate evoked-pain connectivity changes during PBO. Red lines indicate group means. Abbreviations: GMV= Gray Matter Volume; MPQ= McGill Pain Questionnaire; PGB= Pregabalin; PBO= Placebo.