Clinical characteristics and functional determinants of central sensitization in chronic neck myofascial pain syndrome

BackgroundCentral sensitization (CS) is a key mechanism in chronic pain, but its relationship with cervical muscle pressure pain thresholds (PPT) and disability in myofascial pain syndrome (MPS) remains unclear.ObjectiveTo investigate the clinical characteristics and functional determinants of CS in patients with chronic neck MPS.MethodsThis prospective cross-sectional study included 98 patients with chronic neck MPS. Participants were categorized into High CSI $(n=58)$ and Low CSI $(n=40)$ groups using a Central Sensitization Inventory (CSI) cutoff score of 40. Disability (NDI), neuropathic pain (painDETECT), quality of life (SF-12), and PPTs of the upper trapezius, levator scapulae (LSP), and splenius cervicis (SC) were assessed. Multivariate linear regression was performed.ResultsA high CSI score $(\ge 40)$, reflecting prominent symptoms associated with central sensitivity, was identified in 59.2% of the participants. The High CSI group was significantly older and had higher BMI, NDI, and painDETECT scores (p < 0.05). Mean LSP PPT was significantly lower in the High CSI group (p = 0.003, rank-biserial correlation = 0.350), while splenius cervicis (SC) showed high sensitivity in both groups. The regression model explained 40% of the variance in CSI scores (R² = 0.40). NDI score (β = 0.48, p < 0.001) and age (β = 0.23, p = 0.01) were the only independent predictors.ConclusionsClinicians evaluating chronic neck MPS should routinely screen for CS using the CSI. Identifying a High CSI phenotype early enables the integration of multimodal, centrally-targeted therapies to mitigate severe functional disability, rather than relying solely on peripheral structural interventions.