Conditioned Pain Modulation, Central Sensitivity Syndromes and Psychological Characteristics in Individuals with Chronic Multi-Site Musculoskeletal Pain - A Pilot Investigation

R.Mani*¹, D. Adhia¹; S. Leong²; D. De Ridder^2
1Centre for Health, Activity and Rehabilitation Research, School of Physiotherapy
²Department of Surgical Sciences, Dunedin School of Medicine; University of Otago, Dunedin

 

Introduction and Aims: Chronic multi-site pain is a prevalent condition with a range of disabling physical and psychological symptoms. The research aims to explore the efficiency of descending pain inhibitory function in a sample of individuals with chronic multi-site joint/region pain and to characterize their features of psychological and central sensitivity measures.

Methods: Twenty five adults suffering from multi-site joint pain were recruited from the Dunedin community. All participants completed validated questionnaires relating to pain (Brief Pain Inventory- severity, interference, PainDETECT); psychological constructs (catastrophizing, hypervigilance, depression, anxiety and stress, coping strategies and pain acceptance, illness perceptions, and self-efficacy); and central sensitisation syndromes using the central sensitisation inventory (CSI). A standardised conditioned pain modulation (CPM) protocol (test stimulus- pressure pain detection threshold; conditioning stimulus- cold pressor task) was administrated. Descriptive statistics were computed for demographic, anthropometric and psychological variables. Paired student’s ‘T’ tests were used to assess the CPM effect. Standard error of measurement was calculated to interpret for a meaningful CPM effect. 

Results: Participants’ mean (SD) age and BMI were 64.3(8.6) years and 28.0(4.8) kg/m², respectively. Number of painful joints/body regions (median: 4). General health (67.6%,17.5); pain (4.1,1.9); interference (3.9,1.6); PainDETECT (12.3;7.4);  CSI (51.0;16.3, 17.5); catastrophizing and hypervigilance (13.2,10.6; 38,13.3); Depression (3.6,3.7); Anxiety (3.2,2.9) and Stress (6.5,4.1); Coping strategies (18.7,4.1); acceptance (29.3,5.5); Self efficacy (9.2, 1.7); Illness perception (39.8,10.2). CPM test stimuli mean scores (kilopascals): Pre- conditioning mean: 312.8 (217.3), and Post-conditioning mean: 353.9 (204.5). Mean differences between pre and post-conditioning scores indicates a CPM effect (p≤0.054); and the change (-41.1 (-83.1,0.8) is less than the SEM (42.2).

Conclusions: Positive CPM effect has been observed, however it does not have a meaningful effect. Among this sample, higher levels of confidence (self-efficacy) in functioning in the presence of pain were evident. Results must be interpreted with caution due to small sample size, introducing a sampling bias.

Acknowledgements: This research has been funded by the Jack Thomson Arthritis Grant (2016-17) - Otago Medical Research Foundation, and a collaborative research project being conducted by Pain@Otago Research Theme members. .