Screening of neuropathic pain components in patients with chronic back pain associated with nerve root compression: a prospective observational pilot study (MIPORT)

Abstract

Objective: Chronic back pain is characterized by a combination of neuropathic and nociceptive mechanisms of pain generation. The prevalence of the neuropathic pain component is unknown. Thus, in the context of an explorative study, we aimed to determine the prevalence of signs and symptoms indicating neuropathic pain in adult patients treated by orthopaedists. We also aimed to assess the usefulness of handheld computers (PDAs) in data collection. Methods: Prospective epidemiological study in 18 orthopaedic practices or centres throughout Germany. Physician and patient questionnaires (paper/pencil or on handheld computers, PDAs) for patients with back pain of at least 3 months in duration were applied, as well as the von Korff score to assess pain intensity (visual analogue scale, VAS; 0 = no pain, 10 = worst possible pain) and pain characteristics, the Hannover Functional Ability Questionnaire (FFbH-R), and if patients agreed to provide information, the short-form Patient Health Questionnaire (PHQ-D) for depression. Results: For 717 patients, both patient and physician questionnaires were available. Mean patient age was 56 years; pain was predominantly located in the low back (87%). Median current pain intensity on the VAS was 5.0. Confirmed key signs and symptoms indicated neuropathic pain was frequent, e.g. radicular pain radiating beyond the knee towards the foot (40.0%), positive Lasegue sign (18.4%), or absent patellar reflex (17.3%). A third of all patients (33.5%) had ≥ 3 characteristic signs for neuropathic pain. Patient functionality was severely reduced (median 43.3%). There were no relevant differences in outcomes between patients using the paper/pencil method (47%) versus those preferring PDAs (53%). Conclusion: Screening for neuropathic pain in this setting is feasible with simple questionnaires and scales on PDAs. Neuropathic pain is a major contributor to chronic back pain and a frequent component in patients seen by orthopaedists. At least one third of all patients should undergo additional diagnostic measures to confirm the cause of neuropathic pain.