Background: Neglect-like symptoms (NLS) describe the experience of perceiving a limb as foreign and could be detected in chronic pain disorders as well as after knee joint replacement. The aim of the present study was to find out whether patients with and without NLS after surgery of the upper extremities differ with respect to pain intensity and psychosocial variables and if NLS are associated with chronic postoperative pain (CPSP).
Methods: In this study 241 patients were interviewed using a validated questionnaire preoperatively as well as 1 day, 4 weeks, 3 months and 6 months postoperatively. Patients with and without NLS were compared using the χ2-test or Mann-Whitney U‑test. The level of significance was adjusted for multiple testing.
Results: The NLS could be found to a slight extent throughout the entire study period. Patients with NLS showed significantly higher maximum pain scores at every measurement time point: average difference (∆ = 3, adjusted p < 0.005), a higher impairment due to pain (∆ = 15, adjusted p < 0.005), more anxiety (∆ = 3, adjusted p < 0.005), depression (∆ = 3, average adjusted p < 0.003) and kinesiophobia (∆ = 4, preoperative not significant, average postoperative adjusted p = 0.004). Preoperatively, more stressful life events (p = 0.002) and higher stress values (p < 0.001) were reported. In patients with CPSP, NLS occurred significantly more often (74%) than in patients without clinically relevant pain (17.5%. p < 0.001).
Conclusion: The occurrence of NLS is associated with higher pain scores, more impairment due to pain and a higher psychosocial burden and they are more frequent in patients with CPSP. Further investigations are needed to show if NLS are an independent risk factor for the chronification of pain and if NLS play an independent role in the pathogenesis of pain.
Keywords: Neglect-like symptoms; Pain chronification; Postoperative pain.