Symptom descriptors and patterns in lumbar radicular pain caused by disc herniation: a 1-year longitudinal cohort study

Objective The objective of the present study was to explore the diversity, quality, severity and distribution of symptoms in patients with radicular pain and a lumbar disc herniation. Design Longitudinal cohort study. Setting Hospital-based back clinic. Participants Ninety patients referred to secondary healthcare with (a) low back-related leg pain, (b) age between 18 and 65 years and (c) MRI confirmed lumbar disc herniation at a relevant side and level. Outcome measures Neuropathic pain symptoms were assessed using the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) and the painDETECT Questionnaire. In a subsample classified with neuropathic pain, in-depth interviews were performed, and symptomatic areas were drawn on standardised body charts. Results At baseline, the most frequently used painDETECT symptom descriptor was numbness sensation, reported by 94%, followed by sudden pain attacks and tingling or prickling. The mean (SD) SF-MPQ-2 score (0–10) for aching pain was 5.9 (2.8); numbness 4.3 (3.3); tingling 4.0 (3.4); burning 2.6 (3.1); pain caused by light touch 1.5 (2.6). Leg pain was rated as extremely bothersome by 73%, numbness and tingling by 38%, weakness by 24% and back pain by 17%. In the subsample (n=52), deep-lying pain and non-painful abnormal sensations were frequent, at 71% and 85%. Drawings demonstrated substantial overlap between symptoms from compromised L5 and the S1 nerve roots. Painful and non-painful symptoms improved at approximately the same rate. At the 1-year follow-up, 45% (14/31) of patients who had received disc surgery, and 34% (18/53) of those who had received conservative treatment reported no bothersome back pain, leg pain, numbness/tingling or weakness. Conclusion Patients reported several highly bothersome symptoms, but not all are described as painful. The overall symptom profile of lumbar disc-related radicular pain differs from other neuropathic pain conditions with limited allodynia and thermal hyperalgesia. Symptomatic areas for the L5 and S1 nerve roots have a large overlap.