Prevalence and associations of neuropathic pain in a cohort of multi-ethnic Asian low back pain patients.

The prevalence of neuropathic low back pain differs in different ethnic populations. The aims of the study are to determine its frequency and associations in a multi-ethnic cohort of Asian low back pain patients. This was a cross-sectional study of low back patients seen at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia. Neuropathic low back pain patients were identified using the painDETECT questionnaire and compared with non-neuropathic (unclear or nociceptive) low back pain patients, in terms of socio-demographic and clinical factors, pain severity (numerical pain rating scale, NPRS), disability (Roland Morris Disability Questionnaire, RMDQ), as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS). Of 210 patients, 26 (12.4%) have neuropathic low back pain. Neuropathic pain is associated with non-Chinese ethnicity, higher body mass index and pain radiation below the knee. Patients with neuropathic pain have significantly higher NPRS and RMDQ scores, and there are more subjects with anxiety on HADS. However, there are no differences between the groups in age, gender, pain duration or underlying diagnosis of low back pain. The prevalence of neuropathic low back pain in a multi-ethnic Malaysian cohort is lower than previously reported in other populations with possible differences between ethnic groups. It is associated with greater pain severity, disability and anxiety.