Psychological characteristics, pain perception and voxel-based brain morphology of women with chronic pelvic pain in the presence and absence of endometriosis

Introduction Endometriosis is a chronic disease that may influence pain perception and brain neurobiology. It is unknown, whether these changes are caused by chronic pelvic pain (CPP) and/or comorbid mental disorders or endometriosis itself.

Materials & methods In this prospective study, we investigated psychological characteristics, thermal pain perception and brain gray matter volume (GMV) via MRI in women with CPP in the absence (n=21) and presence (n=23) of endometriosis in comparison to healthy controls (n=20). Whole brain GMV and regions of interest (ROI) were analyzed.

Results The groups were comparable with respect to demographics and thermal pain perception. Up to 70%, women with CPP with and without endometriosis reported on previous mental comorbidities. Compared to the CPP group, endometriosis patients had a trend towards increased GMV in several brain regions including inferior temporal and superior medial gyrus, mid- and anterior cingulate cortex (MCC & ACC), p<0.05, and significantly higher GMV in the frontal medial cortex and the cingulate gyrus (p<0.05) in the ROI analyses. Further, they demonstrated increased GMV in the supplementary motor cortex (p<0.05) in contrast to healthy controls. CPP patients without endometriosis had decreased GMV in the amygdala and thalamus (p<0.05) in comparison to the control group. Pain itself and pain perception as well as mental comorbidities were also associated with neurobiological changes.

Summary Women with endometriosis demonstrated GMV alterations associated with pain processing and executive functioning, potentially specific for endometriosis brain. However, pain and mental comorbidities are likely to be involved in shaping of those brain regions.

Publication History

Article published online:
11 October 2022