Differences between women with traumatic and idiopathic chronic neck pain and women without neck pain : interrelationships among disability, cognitive deficits, and central sensitization

Background. To date, a clear differentiation of disability, cognitive deficits, and central sensitization between chronic neck pain of a traumatic nature and that of a nontraumatic nature is lacking. Objective. This study aimed to examine differences in disability, cognitive deficits, and central sensitization between women with traumatic and idiopathic (nontraumatic) chronic neck pain and women who were healthy. In addition, interrelationships among these variables were investigated. Design. This was a case-control study. Methods. Ninety-five women (28 women who were healthy [controls], 35 women with chronic idiopathic neck pain [CINP], and 32 women with chronic whiplash-associated disorders [CWAD] [traumatic]) were enrolled in the study. First, all participants completed standardized questionnaires to investigate pain-related disability and health-related quality of life. Next, cognitive performance was assessed. Finally, pressure pain thresholds and conditioned pain modulation were examined to investigate central sensitization. Results. Pain-related disability, reduced health-related quality of life, and cognitive deficits were present in participants with CWAD and, to a significantly lesser extent, in participants with CINP. Local hyperalgesia was demonstrated in participants with CWAD and CINP but not in women who were healthy. However, distant hyperalgesia and decreased conditioned pain modulation efficacy were shown only in participants with CWAD; this result is indicative of the presence of central sensitization. Moderate to strong Spearman correlations (rho=.456-.701) among disability, cognitive deficits, and hyperalgesia (local and distant) were observed in participants with CWAD. In participants with CINP, only local hyperalgesia and subjective cognitive deficits were moderately (rho=.463) correlated. Limitations. No conclusions about the causality of the observed correlations can be drawn. Conclusions. This innovative research revealed important differences between women with CWAD and women with CINP and thus provided evidence of the clinical importance of distinguishing the assessment and rehabilitation approaches for both pain conditions.