Examining associations between psychophysical functioning and pain in young women with endometriosis and chronic pelvic pain: a pilot study

OBJECTIVES: This study aims to explore the relationships between preoperative psychosocial factors in relation to postoperative chronic pelvic pain (CPP) in adolescents and young women with endometriosis, which is a significant public health concern. As a pilot sample, there is large need to present preliminary data exploring the biopsychosocial correlates and possible predictors of central sensitization and CPP, which remains non-existent in the realm of adolescents and young adults with CPP secondary to endometriosis. \nMETHODS: Eligible candidates included patients 12-22 years old who were diagnosed with CPP after laparoscopic confirmation of endometriosis. 25 successfully enrolled subjects had pre-surgical information obtained from baseline surveys and underwent a postoperative sensory protocol to assess mechanical allodynia, pressure pain sensitivity, central sensitization, and a self-report measure of pain sensitivity. Correlation calculations were conducted between pre-surgical factors (pain intensity, pain catastrophizing (PCS), and quality-of-life (from SF-36)) and post-surgical factors (pain and sensitivity thresholds as measured by QST and the PSQ) in the subject population as a whole, and in two population subgroups: those exhibiting central sensitization and those who are not. One-way ANOVA calculations and one sample t-tests were conducted to compare differences between cohorts and between abdominal and control sites for various study parameters. \nRESULTS: 6 of 25 (24%) subjects experienced a wind-up phenomenon during the temporal summation for pain test, serving as a surrogate for central sensitization. The differences in study parameters that this group (+CS) exhibited in comparison to the –CS group, failed to reach significance in all study parameters. Both cohorts exhibited positive correlations between pre-operative disability due to bodily pain (SF-36) and sensitivity of the abdomen, as well as negative correlations between disability due to bodily pain and pressure pain thresholds of the abdomen. The +CS cohort also exhibited a negative correlation between disability due to bodily pain and pinprick pain scores, a positive correlation between role limitations due to physical health (SF-36) and sensitivity of the abdomen, and a positive correlation between pain catastrophizing and sensitivity of the abdomen. As a whole, the subject population had significantly higher levels of catastrophizing than published means. In all cohorts, pressure pain thresholds of the abdomen were significantly lower than the control values, and PSQ-minor scores were significantly higher than published means. \nCONCLUSIONS: Results suggest the importance of pre-operative pain and psychosocial functioning on pain outcomes, particularly when considering subjects presenting with central sensitization, in young women with CPP secondary to endometriosis. The results indicate the need for a larger sample as well as established control values to further explore the relationships between these variables.