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. 2016 May 5;139(7):1958–1970. doi: 10.1093/brain/aww100

Figure 3.

Figure 3

Amygdala and hippocampus volumes are risk factors for chronic pain. (A and B) Subcortical structures were segmented, corresponding volumes summed across hemispheres, and compared between groups as a function of time (Supplementary Tables 4 and 5). Heat maps display overlap of automated segmentation across SBPp, SBPr, and healthy controls at week 0. (C and D) Repeated measure ANCOVAs (group and time effects; covariate for age, gender, and grey matter volume) revealed that SBPp showed smaller amygdala [F(2,63) = 7.94; P < 0.001] and hippocampus [F(2,70) = 6.35; P = 0.003], but no main effect of time (P-values > 0.69) or group by time interaction (P-values > 0.23). Bar graphs illustrate group differences at 3 years. Scatterplots show volume reproducibility over 3 years across all SBP. *P < 0.05 SBPp versus SBPr, and SBPp versus healthy controls. (E and F) Age-matched chronic back pain patients showed significant smaller amygdala [t(1,42) = 2.71; P = 0.009 two-sided unpaired t-tests] and hippocampus [t(1,43) = 1.99; P = 0.05 two-sided unpaired t-tests] than SBPr, matching the volumes observed in SBPp. Similarly, osteoarthritis patients displayed at least marginally smaller amygdala [t(1,52) = 2.21; P = 0.03 two-sided unpaired t-tests] and hippocampus [t(1,52) = 1.95; P = 0.057 two-sided unpaired t-tests] when compared to age matched healthy controls. *P < 0.05, &P < 0.06. (G) Vertex-wise shape analyses of the amygdala and the hippocampus indicated that SBPp had thinner right amygdala across all visits. Number of subjects is shown in parentheses. Error bars indicate SEM.