Biomarkers in cerebrospinal fluid of persistent neuropathic pain after lumbar stenosis surgery.

Abstract

To analyze which CSF biomarkers affect persisting neuropathic pain (NP) after surgery. CSF samples were gathered from patients who had a dural tear injury during surgery or who underwent myelography, from July 2022 to July 2023. Patients were evaluated for pain and NP using LANSS, PDQ, DN4, ODI, and NRS questionnaires preoperatively, and at 1 month, 3 months, and 1 year postoperatively, and divided into three groups based on the presence of NP. CSF samples were processed and analyzed using ELISA to measure various biomarkers, including IL-6, Her1, MCP1, P-NFH, Apolipoprotein A1, MBP, IL-8, TNF- α, and BDNF. Among 22 patients, 16 had preoperative pain; 8 resolved and 8 persisted postoperatively. Patients were categorized into Group A (no NP), Group B (resolved NP), and Group C (persistent NP). Comparisons revealed no significant differences according to preoperative NP presence. However, patients with persistent postoperative NP had significantly lower levels of Her1 (p = 0.019), IL-6 (p = 0.025), and MCP-1 (p = 0.039). Intergroup comparisons confirmed significantly lower IL-6 levels in group C compared to groups A and B. Her1 and MCP-1 levels showed marginal significance. Moderate correlation was found between IL-6 levels and NP improvement post-surgery (Spearman's rho: 0.56, p = 0.024; Kendall's tau: 0.48, p = 0.03), whereas IL-6 negatively correlated with persisting postoperative NP (r = -0.55, p = 0.008). IL-6 concentration was significantly lower in patients with persisting NP after the surgery as well as other biomarkers such as Her1 and MCP-1. It can be suggested that such biomarkers associated with NP primarily impact the acute phase, while persistent NP requires distinct consideration and treatment approaches.