Experimental pain phenotyping in community-dwelling individuals with knee osteoarthritis

Abstract

Pain among individuals with knee osteoarthritis (OA) is associated with significant disability in older adults, and recent evidence demonstrates enhanced experimental pain sensitivity. Although previous research showed considerable heterogeneity in the OA clinical pain presentation, less is known regarding the variability in responses to experimental pain. The present study included individuals with knee OA (n = 292) who participated in the Understanding Pain and Limitations in Osteoarthritic Disease study and completed demographic and psychological questionnaires followed by a multimodal quantitative sensory testing (QST) session. Quantitative sensory testing measures were subjected to variable reduction procedures to derive pain sensitivity index scores, which in turn were entered into a cluster analysis. Five clusters were significantly different across all pain sensitivity index variables (P < 0.001) and were characterized by: (1) low pain sensitivity to pressure pain (N = 39); (2) average pain sensitivity across most modalities (N = 88); (3) high temporal summation of punctate pain (N = 38); (4) high cold pain sensitivity (N = 80); and (5) high sensitivity to heat pain and temporal summation of heat pain (N = 41). Clusters differed significantly by race, gender, somatic reactivity, and catastrophizing (P < 0.05). Our findings support the notion that there are distinct subgroups or phenotypes based on experimental pain sensitivity in community-dwelling older adults with knee OA, expanding previous findings of similar cluster characterizations in healthy adults. Future research is needed to further understand the pathophysiological mechanisms underlying pain within these subgroups, which may be of added value in tailoring effective treatments for people with OA.

Pain Susceptibility Phenotypes in Those Free of Knee Pain With or at Risk of Knee Osteoarthritis: The Multicenter Osteoarthritis Study

“…The group with the highest proportion of pressure pain sensitivity at both the knee and the wrist (indicating more sensitization both locally and centrally) had a 2‐fold increased risk of developing PKP over a 2‐year period. This work lends further support for the importance of sensitization in the knee pain experience of people with symptomatic knee OA and provides new insights into the influence of preexisting sensitization on the transition from intermittent to PKP among those who were free of persistent pain initially. Interestingly, subjects in the group with primarily predominant evidence of central sensitization with facilitated TS at either the wrist or the knee were not at increased risk of developing PKP in this sample.…”

“…In contrast to previous phenotyping studies of people with symptomatic knee OA that have concentrated on QST measures or psychological factors , we employed a multifactorial approach similar to that recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials . This work represents an initial step in helping to more clearly understand symptom persistence and the transition from intermittent to persistent pain.…”

Physical performance and movement-evoked pain profiles in community-dwelling individuals at risk for knee osteoarthritis

“…Indeed, movement-evoked pain is associated with sensitization of peripheral Aδ and C-fiber afferents (Brucini et al 1981; Hendiani et al 2003), while spontaneous pain or pain at rest is related to sensitization at the dorsal horn and spinal cord (Schaible et al, 2002). Also, increased heat temporal summation implicates centrally-mediated mechanisms, and evidence suggests that in some individuals, peripheral and central nervous system mechanisms significantly contribute to knee OA pain (Murphy et al 2011; Arendt-Nielsen et al 2010; Frey-Law et al 2016; Cardoso et al 2016). Future mechanism-based research is needed incorporating measures of temporal summation of movement-evoked pain and their associations with physical function and intervention outcomes.…”

“…Recent evidence demonstrates considerable inter-individual heterogeneity among people with knee pain across a number of clinical, experimental and psychological variables (Cruz-Almeida et al 2013; Cardoso et al 2016; Frey-Law et al 2016). There is likely similar heterogeneity in physical functional performance among individuals with knee pain that accounts for distinct functional trajectories (i.e., get worse or recover over time) (van Dijk et al 2006).…”

Women Undergoing Third Line Overactive Bladder Treatment Demonstrate Elevated Thermal Temporal Summation

“…the suprapubic area) follows a widely used and validated approach that has successfully demonstrated elevated TS in various chronic pain conditions relative to controls when tested well outside of the location of the clinical pain. 19 However, further study is needed to examine the impact of segmental changes in afferent processing in women with OAB.…”