The predictors for altered central pain modulation in individuals with nonspecific chronic low back pain: A systematic review

Background: Research suggests that the prognosis of chronic nonspecific low back pain is poor when there is an alteration in the central pain processing pathway. This alteration creates a cascade of events, leading to poor outcomes. An overview of the predictors which increase this heightened pain perception is needed. Objectives: To review the studies identifying predictors for altered central main modulation in individuals with nonspecific chronic low back pain. Design: This is a systematic review. Methods: PubMed, Cochrane Library, Science Direct, Scopus, Ovid, Embase, Web of Science, and CINAHL were searched from inception to 25th May 2021. Titles, abstracts, and full text were searched for eligible articles, which met the set criteria. Research articles that have employed outcome measure specific to altered central pain modulation and assessed at least one predictor were included. Results: Six studies (n = 1389) were included in this review. The following five groups of predictors were identified: (1) psychological, (2) psychosocial (education, employment status, pain catastrophizing, and kinesiophobia), (3) sensory profile, (4) gender, and (5) others (illness and cognitive factors). Positive evidence of association was found for psychological predisposition and psychosocial (pain catastrophizing and employment and education status), whereas no evidence of association was found for kinesiophobia and cognitive factors. Conclusion: This review identified the predictors for altered central pain modulation in chronic nonspecific low back pain. This alteration could be responsible for the suspected poor outcomes even post treatment. Furthermore, the knowledge of predictors could potentially aid the therapist in planning a treatment regime when poor outcomes are suspected.