Pain Distribution and its Association With Neuropathic Pain Features and Assumed Central Sensitization in Acute Whiplash-Associated Disorders: A Cross-Sectional Study.

Abstract

Objectives: This study aimed to evaluate pain distribution in people with acute whiplash associated disorders (WAD) and explore its association with neuropathic pain and assumed central sensitization features. Although widespread pain is common after a whiplash injury, the relationship between pain extent (the area of the body perceived as painful) and underlying pain-related mechanisms in acute WAD remains poorly understood.

Methods: In this cross-sectional study, 124 individuals (mean age: 39.7±11.2 y; 67 females) with acute WAD grade II (7-30 d post-injury) completed questionnaires assessing neck pain intensity, disability, neuropathic pain (S-LANSS), and assumed central sensitization (CSI). Pain drawings were analyzed with a validated image-processing algorithm to quantify pain extent. Correlation and multiple linear regression analyses were performed to identify predictors of pain extent.

Results: Bivariate correlations showed that pain extent was significantly associated with all clinical variables, with the strongest correlation observed between pain extent and S-LANSS (ρ=0.816, P<.001). In the multiple regression model, only S-LANSS was a significant predictor of PE (β=0.705, P<.001), explaining 64% of the variance. A moderate correlation (ρ=0.437) was found between CSI and pain extent, but the CSI did not independently predict pain extent. No sex differences were observed for any clinical variable.

Discussion: This is the first study to show a strong association between neuropathic pain features and widespread pain in people with acute WAD. These findings highlight the potential utility of assessing pain extent and neuropathic pain features to identify pain phenotypes early after injury which may support more individualized treatment approaches.