Anneleen Malfliet1, Robby De Pauw2, Jeroen Kregel3, Iris Coppieters4, Mira Meeus5, Nathalie Roussel, Lieven Danneels6, Barbara Cagnie6, Jo Nijs7. 1. Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; Department of Physiotherapy, Physiology and Anatomy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; "Pain in Motion" international research group, www.paininmotion.be. 2. Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Belgium. 3. Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Belgium; Pain in Motion international research group, www.paininmotion.be; Department of Physiotherapy, Human Physiology and Anatomy (KIMA), Free University Brussels, Belgium. 4. Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University. 5. Univeristy of Antwerp, Faculty of medicine and health sciences, Department of Rehabilitation Sciences and Physiotherapy, Antwerp, Belgium. 6. Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium. 7. Pain in Motion Research Group (www.paininmotion.be); Department of Human Physiology and Physiotherapy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; Department of Physical Medicine and Physiotherapy, University Hospital Brussels, Brussels, Belgium.
Abstract
BACKGROUND: Although the association of gray matter morphology alterations and pain-related psychosocial characteristics with pain intensity and chronification in people with chronic spinal pain is evident, research on their mutual interaction is scarce and does not account for possible gender differences. Gender-based differences are, however, of utmost importance to consider when examining pain neurobiology. OBJECTIVES: To look for gender differences in the association between magnetic resonance imaging- (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 characteristics were examined in women and men with nonspecific chronic spinal pain. Statistical analyses were performed in SPSS and R to identify differences between men and women regarding brain gray matter, self-reported psychosocial characteristics, as well as gender differences in the association between those outcome measures. RESULTS: A total of 94 people with chronic spinal pain were studied, including 32 men (15 suffering from neck pain, 17 suffering from low back pain; demographics [mean ± SD] age: 45.00 ± 12.02 years; pain duration: 128.37 ± 110.45 months), and 62 women (36 suffering from neck pain, 26 suffering 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), emotional representations (P < 0.001), chronicity (P < 0.001), and pain catastrophizing (P< 0.001). Men showed larger (both positive and negative) associations of the precuneus cortex, the precentral gyrus, and the insula 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 sufficient power. Another limitation is the observational study design, which hampers the possibility to look for causal or temporal interactions. CONCLUSIONS: Gray matter morphology relates differently to psychosocial characteristics in women and men. These explorative findings provide ideas for further research to investigate if targeting perceived negative consequences of the illness, perceived emotional representations, perceived chronicity, and pain catastrophizing in women, and perceived personal control of the illness and kinesiophobia in men, could contribute to the normalization of brain alterations in people with nonspecific chronic spinal pain. KEY WORDS: Gray matter, brain morphology, central nervous system, illness perceptions, central sensitization.
BACKGROUND: Although the association of gray matter morphology alterations and pain-related psychosocial characteristics with pain intensity and chronification in people with chronic spinal pain is evident, research on their mutual interaction is scarce and does not account for possible gender differences. Gender-based differences are, however, of utmost importance to consider when examining pain neurobiology. OBJECTIVES: To look for gender differences in the association between magnetic resonance imaging- (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 characteristics were examined in women and men with nonspecific chronic spinal pain. Statistical analyses were performed in SPSS and R to identify differences between men and women regarding brain gray matter, self-reported psychosocial characteristics, as well as gender differences in the association between those outcome measures. RESULTS: A total of 94 people with chronic spinal pain were studied, including 32 men (15 suffering from neck pain, 17 suffering from low back pain; demographics [mean ± SD] age: 45.00 ± 12.02 years; pain duration: 128.37 ± 110.45 months), and 62 women (36 suffering from neck pain, 26 suffering 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), emotional representations (P < 0.001), chronicity (P < 0.001), and pain catastrophizing (P< 0.001). Men showed larger (both positive and negative) associations of the precuneus cortex, the precentral gyrus, and the insula 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 sufficient power. Another limitation is the observational study design, which hampers the possibility to look for causal or temporal interactions. CONCLUSIONS: Gray matter morphology relates differently to psychosocial characteristics in women and men. These explorative findings provide ideas for further research to investigate if targeting perceived negative consequences of the illness, perceived emotional representations, perceived chronicity, and pain catastrophizing in women, and perceived personal control of the illness and kinesiophobia in men, could contribute to the normalization of brain alterations in people with nonspecific chronic spinal pain. KEY WORDS: Gray matter, brain morphology, central nervous system, illness perceptions, central sensitization.