Hidden Neuropathic Pain in Chronic Low Back Pain: Prevalence, Pattern, and Impact on Quality of Life

Abstract

Objective: A patient with Neuropathic Pain (NP) may suffer from pure NP or may have mixed nociceptive and neuropathic pain. No previous study has investigated NP among Thai patients with Chronic Low Back Pain (CLBP). This study aimed to investigate the prevalence and clinical presentation of NP, and the impact of NP on Quality of Life (QoL) in Thai Chronic Low Back Pain (CLBP) patients. Materials and Methods: Adult patients with CLBP longer than 3 months were included. NP was detected by painDETECT questionnaire, and NP was defined as a score 19. Demographic data, pain characteristics, treatment, Oswestry Disability Index (ODI), and quality of life score (Short Form 36, SF-36) were recorded. Results: 371 CLBP patients were enrolled. The overall prevalence of neuropathic pain was 50.1% (95% CI: 44.955.3%). The prevalence of NP in patients with axial low back pain, back pain with pain radiating above the knee, and back pain with pain radiating below the knee was 28.3%, 58.21%, and 59.5%, respectively. Only 48.9% of patients with NP received neuropathic pain medication. Multivariate analysis showed only older age to be associated with NP (OR: 1.017, 95% CI: 1.002-1.033). NP patients had a significantly higher ODI score. There is no difference in most dimension of SF-36 scores, except marginally higher general health and vitality dimension scores. Conclusion: Prevalence of NP in Thai CLBP patients is high. Additionally, it is undertreated and associated with higher disability especially among patients with radiating pain above the knee. Older age is an independent predictor of NP.