Temporal relationships between pain, functioning, and human assumed central sensitization in patients with chronic low back pain; a single-case design

Anne Nel Bennema; Henrica Rosalien Schiphorst Preuper; Leonie Adriana Krops; Hans Timmerman; Michiel Felix Reneman

doi:10.1016/j.msksp.2024.102966

Temporal relationships between pain, functioning, and human assumed central sensitization in patients with chronic low back pain; a single-case design

Musculoskelet Sci Pract. 2024 May 3:72:102966. doi: 10.1016/j.msksp.2024.102966. Online ahead of print.

Authors

Anne Nel Bennema¹, Henrica Rosalien Schiphorst Preuper¹, Leonie Adriana Krops¹, Hans Timmerman², Michiel Felix Reneman³

Affiliations

¹ University of Groningen, University Medical Center Groningen, Department of Rehabilitation Medicine, Groningen, the Netherlands.
² University of Groningen, University Medical Center Groningen, Department of Anesthesiology Pain Center, Groningen, the Netherlands.
³ University of Groningen, University Medical Center Groningen, Department of Rehabilitation Medicine, Groningen, the Netherlands. Electronic address: m.f.reneman@umcg.nl.

PMID: 38714148
DOI: 10.1016/j.msksp.2024.102966

Abstract

Background: Interdisciplinary pain rehabilitation (IPR) aims to improve functioning in people with chronic low back pain (CLBP), and is not primary aimed at pain reduction. Many patients however also report a decrease in pain. An explanation could be that IPR results in a decrease in Central Sensitization (CS). As CS is not directly assessable in humans the term Human Assumed Central Sensitization (HACS) is used in this study. It is unknown whether a decrease in HACS precedes a decrease in pain and improved functioning or vice versa.

Objectives: This study aimed to gain understanding into the temporal relationships between changes in pain, functioning, and HACS in patients with CLBP during IPR.

Design: Longitudinal observational small-N-study.

Method: Twelve patients filled in frequently repeated self-reports 1 week before, during the 12-week IPR program, and 2 weeks after IPR. Pain was assessed by Visual Analogue Scale for pain (daily), functioning by Pain Disability Index (weekly) and Work Ability Score (daily), and HACS by Central Sensitization Inventory part A (bi-weekly). Analyses were performed by visual inspection and time series cross-correlation analyses.

Results: Visual inspection showed large fluctuations within and between individual participants in patterns over time. Cross-correlation analyses showed that in most participants, relationships between pain, functioning, and HACS were strongest when analyzed at the same time (55% of comparisons). Strength and direction of (strongest) correlations showed high interindividual variability (neg: 0.33-0.97; pos: 0.22-0.99).

Conclusion: Overall, relationships between pain, functioning, and HACS did not show consistent temporality in patients with CLBP.

Keywords: Chronic low back pain; Functioning; Human assumed central sensitization; Interdisciplinary pain rehabilitation.