Prevalence and Location of Neuropathic Pain in Lumbar Spinal Disorders: Analysis of 1804 Consecutive Patients With Primary Lower Back Pain.

STUDY DESIGN A cross-sectional study of 1804 consecutive patients. OBJECTIVE The aim of this study was to investigate the prevalence of pathological pain and its distribution features in patients with chronic lumbar spinal disorders. SUMMARY OF BACKGROUND DATA Clinical spinal disorders can involve pathological neuropathic pain (NeP) as well as physiological nociceptive pain (NocP), as they have varied pathology, including spinal cord injury, stenosis, and compression. A study conducted by the Japanese Society for Spine Surgery and Related Research (JSSR) has determined a prevalence of 29.4% for NeP in patients with lumbar spinal disorder. However, the data did not include information on pain location. METHODS Patients aged 20 to 79 years with chronic lower back pain (≥3 months, visual analog scale score ≥30) were recruited from 137 JSSR-related institutions. Patient data included an NeP screening questionnaire score and pain location (lower back, buttock, and legs). The association between the pain pathology and its location was analyzed statistically using the unpaired t test and Chi-square test followed by Fisher test. P < 0.05 was considered significant. RESULTS Low back pain subjects showed 31.9% of NeP prevalence, and the pain distribution showed [NocP(%)/NeP(%)] low back pain only cases: 44/22, while low back pain with leg pain cases showed a prevalence of 56/78. This indicates that low back pain alone can significantly induce NocP rather than NeP (P < 0.01). Buttock pain was revealed to significantly induce both lower back pain and leg pain with NeP properties (P < 0.01). Leg pain was revealed to be predominantly neuropathic, especially when it included peripheral pain (P < 0.01). CONCLUSION Low back pain with no buttock pain induces NocP rather than NeP. Buttock pain is significantly associated with NeP prevalence whether or not leg pain exists. Leg pain can increase the prevalence of NeP, especially when it contains a peripheral element. LEVEL OF EVIDENCE 3.