The relationship between catastrophizing and altered pain sensitivity in patients with chronic low-back pain

Abstract

Changes in central pain processing have been shown in patients with chronic low-back pain (cLBP). We used quantitative sensory testing methods to identify differences in pain sensitization between patients with cLBP (N = 167) and healthy controls (N = 33). Results indicated that, compared with healthy pain-free controls, cLBP patients showed increased sensitivity and greater painful aftersensations for mechanical pressure and pin-prick stimuli and lower tactile spatial acuity in the 2-point discrimination task (ps < 0.05). Then, we examined the role of pain catastrophizing as a mediator of the group differences in pain sensitization. We found that catastrophizing partially accounted for group differences in pressure required to produce moderate pain. Finally, we examined the relationship between pain sensitization, catastrophizing, and clinical pain among patients with cLBP. We found that catastrophizing and deep-tissue pressure pain were associated with greater pain intensity in the past month, week, and at the visit as well as low-back pain bothersomeness. Furthermore, deep-tissue pressure pain mediated the associations between catastrophizing and both pain in the past month and low-back pain severity. Taken together, these results indicate that not only do patients with cLBP demonstrate increased pain sensitization and decreased sensitivity to innocuous stimuli, but these changes are also linked with increased catastrophizing. Furthermore, both catastrophizing and sensitization are associated with increased clinical pain among cLBP patients.

Figures

Figure 1.

Curatolo & Arendt-Nielsen (2015) model of path between peripheral injuries, central hypersensitivity, and clinical consequences.

Figure 2.

The mediating effect of catastrophizing in the relationship between back pain and P40 cuff inflation pressure. *p<.05; **p<.01

Figure 3.

The mediating effect of pain sensitization (as measured by P40 cuff inflation pressure and cuff aftersensations) in the relationship between catastrophizing and pain in the past month controlling for opioid use and depression. *p<0.05; **p<0.01

Figure 4.

The mediating effect of pain sensitization (as measured by P40 cuff inflation pressure) in the relationship between catastrophizing pain rating at time of visit controlling for opioid use and depression. *p<0.05; **p<0.01

Figure 5.

The mediating effect of pain sensitization (as measured by P40 cuff inflation pressure) in the relationship between catastrophizing and low back pain bothersomeness controlling for opioid use and depression. *p<0.05; **p<0.01