Use of neuropathic pain questionnaires in predicting persistent postoperative neuropathic pain following lumbar discectomy for radiculopathy.

Abstract

OBJECT Failed-back surgery syndrome has been historically used to describe extremity neuropathic pain in lumbar disease despite structurally corrective spinal surgery. It is unclear whether specific preoperative pain characteristics can help determine which patients may be susceptible to such postoperative disabling symptoms. METHODS This prospective study analyzed surgical microdiscectomy patients treated for lumbar, degenerative, painful radiculopathy. Clinical parameters included general demographics, preoperative and postoperative clinical examination status, self-reported pain and disability scores, and neuropathic pain scores. The screening tests for neuropathic pain were the Douleur Neuropathique 4 and Leeds Assessment of Neuropathic Symptoms and Signs, with correlation tested for ordinal score and screen positivity. Multiple logistic regression analysis was used to define predictors of postoperative symptomatology. RESULTS Twelve percent of the 250 patients with radiculopathy who underwent microdiscectomy experienced persistent postoperative neuropathic pain (PPNP) with only modest, if any, relief of leg pain. The condition was highly associated with abnormal preoperative screen results for neuropathic pain, but not sex, smoking status, or preoperative pain severity (α = 0.05). Good correlation was seen between the 2 screening tests used in this study for both absolute ordinal score (Spearman ρ = 0.84; p < 0.001) and the threshold for terming the patient as having neuropathic pain features (Spearman ρ = 0.48; p < 0.001). Younger age at treatment also correlated with a higher likelihood of developing PPNP (p = 0.03). CONCLUSIONS This population exhibited a low overall frequency of PPNP. Higher neuropathic pain screening scores correlated strongly with likelihood of significant postoperative leg pain. Further work is required to develop more accurate prognostication tools for radiculopathy patients undergoing structural spinal surgery.