Gender Differences in the Association of Brain Gray Matter and Pain-Related Psychosocial Characteristics

摘要

Background: Although the association of gray matter morphology alterations and pain-relatedpsychosocial characteristics with pain intensity and chronification in people with chronic spinalpain is evident, research on their mutual interaction is scarce and does not account for possiblegender differences. Gender-based differences are, however, of utmost importance to considerwhen examining pain neurobiology.Objectives: To look for gender differences in the association between magnetic resonanceimaging- (MRI) derived brain gray matter morphology and self-reported psychosocial characteristics.Study Design: An explorative, observational study.Setting: University Hospitals Ghent and Brussels, Belgium.Methods: Brain gray matter morphology (using MRI) and self-reported psychosocial characteristicswere examined in women and men with nonspecific chronic spinal pain. Statistical analyses wereperformed in SPSS and R to identify differences between men and women regarding brain graymatter, self-reported psychosocial characteristics, as well as gender differences in the associationbetween those outcome measures.Results: A total of 94 people with chronic spinal pain were studied, including 32 men (15 sufferingfrom neck pain, 17 suffering from low back pain; demographics [mean ± SD] age: 45.00 ± 12.02years; pain duration: 128.37 ± 110.45 months), and 62 women (36 suffering from neck pain, 26suffering from low back pain; demographics [mean ± SD] age: 38.78 ± 12.69 years; pain duration:114.27 ± 92.45 months). Woman showed larger (positive) associations of several central brain areas(paracentral, precentral, postcentral, etc.) with perceived consequences (P < 0.001), emotionalrepresentations (P < 0.001), chronicity (P < 0.001), and pain catastrophizing (P< 0.001). Men showedlarger (both positive and negative) associations of the precuneus cortex, the precentral gyrus, and theinsula with perceived personal control (P < 0.001) and kinesiophobia (P < 0.001).Limitations: Other factors, such as menstrual cycle and medication can have a certain influence,and were only partly taken into consideration in the present investigation to obtain sufficientpower. Another limitation is the observational study design, which hampers the possibility to lookfor causal or temporal interactions.Conclusions: Gray matter morphology relates differently to psychosocial characteristics inwomen and men. These explorative findings provide ideas for further research to investigate iftargeting perceived negative consequences of the illness, perceived emotional representations,perceived chronicity, and pain catastrophizing in women, and perceived personal control of theillness and kinesiophobia in men, could contribute to the normalization of brain alterations inpeople with nonspecific chronic spinal pain.