Altered resting-state functional connectivity within corticostriatal and subcortical-striatal circuits in chronic pain

Figure 1. NAcc-MPFC functional connectivity in patients with fibromyalgia vs. healthy controls. (A) Location of the right NAcc ROI (top) and bilateral MPFC VOI (bottom). (B) Right NAcc ROI (top)—Bilateral MPFC VOI (bottom). (C) NAcc-MPFC connectivity in patients with fibromyalgia vs. healthy controls. Effect size refers the average difference in Fisher-transformed correlation coefficients. Error bars indicate the 95% confidence interval. (D) Correlations between NAcc-MPFC connectivity and STAI-Trait within the fibromyalgia group. ROI, region of interest, i.e., brain region defined; VOI, volume of interest, i.e., sphere at specific coordinates; NAcc, nucleus accumbens; MPFC, medial prefrontal cortex.

Figure 2. Mesolimbic volumes of interest. Location of 12 VOIs within mesolimbic circuits as defined in Liu et al.23 for exploratory analyses. Each of the volumes of interest were a fixed size of 10-mm diameter spheres which were centered at the left hippocampus (− 30, − 20, − 18), right amygdala (24, − 2, − 16), left and right caudate (− 8, 14, 2; 8, 20, 2), left putamen (− 16, 4, − 10), left and right insula (− 32, 20, − 4; 36, 20, − 6), left and right thalamus (− 6, − 16, 8; 4, − 14, 8), left ventral pallidum (− 10, 8, − 4), and right and central anterior cingulate cortex (2, 44, 20; 0, 44, 10). “ACC” in the figure refers to the central anterior cingulate cortex with x coordinate at 0. VOI, volume of interest; NAcc, nucleus accumbens; ACC, anterior cingulate cortex.

Figure 3. Resting-state functional connectivity between the right NAcc and 12 brain regions within mesolimbic circuits. (A) For the group difference, the contrast used was Fibromyalgia > Healthy Controls (e.g., reduced left putamen—right NAcc connectivity in patients with fibromyalgia compared to healthy controls). Line color indicates the magnitude of the effect for ROI-to-VOI connectivity. Blue—light blue color lines indicate negative connectivity. Results are thresholded for significance at p < 0.05 (exploratory analysis, uncorrected for multiple comparisons). (B) Group comparison (Fibromyalgia > Healthy Controls) of the average difference in Fisher-transformed correlation coefficients (i.e., effect sizes) for all 12 mesolimbic circuit brain regions. Error bars indicate the 95% confidence interval (uncorrected p-values). ROI, region of interest; VOI, volume of interest; NAcc, nucleus accumbens; ACC, anterior cingulate cortex.