1. 2015;15;E889-E897Prevalence of Neuropathic Pain in Patients Scheduled for Lumbar Spine Surgery: Nationwide, Multicenter, Prospective Study
   Observational Study
   Yong Eun Cho, MD, PhD, Chang-Ju Hwang, MD, PhD, Seong-Hwan Moon, MD, and Kyung Hyun Kim, MD.

BACKGROUND: There is limited evidence about surgical outcomes after lumbar spinal surgery in patients with neuropathic pain (NP) or the prevalence of NP proportions among patients with degenerative lumbar diseases who are candidates for a surgical interventions.
OBJECTIVE: The objectives of this study were to investigate the prevalence of NP among patients scheduled for lumbar spinal surgery and the relationship between health-related quality of life (HRQoL) and NP. This study also aimed to identify the risk factors related to NP and compare the clinical outcomes after surgical treatment between patients with and without NP.
STUDY DESIGN: This study was a nationwide, multicenter, prospective, and observational study. It was conducted from September 2011 to May 2013, and included a total of 1,109 patients who were scheduled for lumbar spinal surgery from 44 spinal centers (both orthopedics and neurosurgeons).
SETTING: Multicenter study
METHODS: Patients were diagnosed of having NP if the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale was = 12 points. The patients were investigated to assess the differences in their clinical outcomes one week and 3 months after surgery and were followed-up with regards to pain and HRQoL to explore the risk factors affecting NP.
RESULTS: Of 1,109 recruited patients, 404 (36.4%) suffered from NP (mean age 62.06 years; 37.9% men) with mean LANSS score of 17.44 ± 4.06, while 705 (63.6%) had nociceptive pain with mean LANSS score of 6.03 ± 3.52. At baseline, patients with NP showed lower HRQoL and more severe pain compared to nociceptive pain patients. However, 3 months after surgical treatment, the NP group showed greater improvement in pain NRS (P = 0.087) and EQ-5D (P = 0.029) as compared to nociceptive pain group. Longer symptom duration was identified as a risk factor for NP (OR 1.003, respectively, P = 0.020).
CONCLUSION: There was a high prevalence of NP in Korean patients scheduled for lumbar spine surgery, and these patients suffered greater pain and lower HRQoL than nociceptive pain patients. The more remarkable improvement NP patients showed after treatment highlights the importance of appropriate diagnosis and treatment of NP.