The risk for developing chronic widespread pain (CWP) was found to be comparable in patients with regional pain with or without neuropathic pain (NP), according to study results published in Pain.
The Pain across the Adult Lifespan study was a prospective population-based cohort trial in which 1162 participants without CWP at baseline were enrolled. All individuals completed the Douleur Neuropathique 4 questionnaire (DN4; scores ≥3 indicate NP), and the Hospital Anxiety and Depression Scale (HADS), the Pittsburgh Sleep Quality Index and provided information regarding demographics and current pain medications. Based on these questionnaires, patients were categorized as having no pain, regional pain with NP symptoms (NP+), or regional pain without NP symptoms (NP−). After 1 year, the participants who had developed CWP were identified.
At baseline, 523 patients (45.0%), 562 patients (48.4%), and 77 patients (6.6%) were classified as having no pain, NP−, and NP+, respectively. At the 12-month follow-up, a total of 153 participants (13.2%) had CWP. Of those patients, 19 (3.6%) had no pain, 108 (19.2%) were classified as NP−, and 26 (33.8%) as NP+. A greater percentage of participants with vs without CWP at follow-up indicated experiencing NP symptoms on the initial DN4 (P <.001); were women vs men; and tended to have a greater number of baseline pain sites, higher medication use, higher HADS scores, and more sleep-related issues.
After adjusting for age and sex, the risk of developing CWP was 3 times higher in participants in the NP− vs no pain group at baseline (odds ration [OR], 2.9; 95% CI, 2.0-4.2), and four times higher in patients in the NP+ vs no pain group (OR, 3.9; 95% CI, 2.3-6.4).
Although after adjusting for age and sex, patients with NP+ vs NP− were found to be twice as likely to develop CWP at follow-up, this association was no longer present after adjusting for additional variables, including psychosocial and medication use.
Study strengths include the use of a large, unselected cohort without baseline CWP, the use of validated assessment tools, and the establishment of a temporal relationship between NP and CWP development.
Study limitations include the single follow-up at 12 months, a possible underestimation of CWP incidence and of the association between NP and CWP, and potential lack of suitability of screening tools to evaluate multi-site pain conditions.
“Neuropathic pain was relatively rare and predicted a small number of new-onset CWP cases. Using these estimates, treatments targeting NP would at best prevent 6% of CWP cases,” noted the authors.
Mcbeth J, Mulvey MR, Rashid A, Anderson J, Druce K. The relationship between regional pain with or without neuropathic symptoms and chronic widespread pain. Pain. 2019;160(8):1817-1823. doi:10.1097/j.pain.0000000000001568