Central Sensitization and Neuropathic Pain in Hemiplegic Shoulder Pain: A Cross-Sectional Study.

Objective: Hemiplegic shoulder pain (HSP) is a common complication that can significantly impair motor recovery, functional independence, and quality of life in stroke survivors. Although the condition has traditionally been attributed to musculoskeletal factors, recent evidence highlights the roles of neuropathic pain and central sensitization in its pathogenesis. This study aimed to investigate the relationship between central sensitization, neuropathic pain, and functional independence in patients with and without post-stroke shoulder pain. Methods: This cross-sectional study included 97 chronic stroke patients (mean age: 55.55±12.51 years; 30 females, 67 males) who were divided into two groups based on the presence of shoulder pain. The probability of neuropathic pain was assessed using the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and central sensitization was measured using the Central Sensitization Inventory (CSI). Motor recovery was evaluated with Brunnstrom staging, and functional independence with the Barthel Index. Group comparisons, correlation analyses, and multivariate logistic regression analyses were performed. Results: Shoulder pain was present in 58.8% of participants. Patients with shoulder pain had significantly higher LANSS (14.49±8.23 vs. 2.45±3.83, p<0.001) and CSI scores (53.36±18.16 vs. 27.70±8.55, p<0.001), and lower Barthel Index scores (55.70±28.08 vs. 81.50±16.33, p<0.001). Strong positive correlations were found between CSI and LANSS (r=0.861, p <0.001), while both measures were strongly negatively correlated with the Barthel Index (r=-0.850, p<0.001). Logistic regression identified female gender [odds ratio (OR)=106.48, 95% CI: 13.24-855.00, p<0.001], a higher CSI score [OR=1.21, 95% Confidence interval (CI): 1.10-1.33, p<0.001], and a lower Barthel Index (OR=0.91, 95% CI: 0.87-0.95, p<0.001) as independent predictors of shoulder pain. Conclusions: Among chronic stroke patients, HSP was strongly associated with greater central sensitization, neuropathic pain, and reduced functional independence. Screening with CSI and S-LANSS may help identify patients with a higher symptom burden and inform more individualized rehabilitation approaches that address both peripheral and central pain mechanisms.