Central Sensitization in Patients with Chronic Pain Secondary to Carpal Tunnel Syndrome and Determinants

Abstract

Beibei Feng,1– 4,* Chen Gong,1,3,4,* Longfei You,1,3,4,* Yangyang Lin,1,3,4 Yafei Wang,1,3,4 Wing Yuk Ip,2 Yuling Wang1,3,4 1Department of Rehabilitation Medicine, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China; 2Department of Orthopaedics & Traumatology, the University of Hong Kong, Hong Kong, Special Administrative Regions, People’s Republic of China; 3Guangdong Provincial Clinical Research Center for Rehabilitation Medicine, Guangzhou, People’s Republic of China; 4Biomedical Innovation Center, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yuling Wang, Department of Rehabilitation Medicine, the Sixth Affiliated Hospital, Sun Yat-sen University, No. 26, Yuancun 2nd Cross Road, Guangzhou, 510655, People’s Republic of China, Tel + 86-20-38476737, Fax [phone], Email [email protected] Wing Yuk Ip, Department of Orthopaedics & Traumatology, the University of Hong Kong, Hong Kong, Special Administrative Regions, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected]: Central sensitization (CS) is commonly seen in chronic pain disorders, including neuropathic pain. However, there exist inconsistencies concerning the presence of CS in chronic pain secondary to carpal tunnel syndrome (CTS). CS and neuropathic pain manifestations in CTS remain not well established. Therefore, this study aims to investigate the CS and pain profiles in patients with CTS and to explore the potential determinants associated with CS.Patients and Methods: Patients with suspected CTS symptoms lasting 3 months or above and healthy controls were enrolled. History, physical examinations, and nerve conduction studies were employed to confirm the diagnosis and severity of median nerve dysfunction. The central sensitization inventory (CSI) was used to screen CS. Other outcomes included neuropathic pain, CTS-specific symptom severity and functions, emotion, and health-related quality of life. Between-group comparisons were conducted in terms of the CS presence. Logistic regression analysis was performed to identify determinants associated with CS.Results: Over 60% of participants with CTS were found with clinical CS, significantly higher than that in the control group. More than 70% of the CTS participants were identified to have possible or very likely neuropathic pain components. In addition, one-fourth of CTS cases had depression or anxiety. Anxiety was associated with an increased risk of developing CS in CTS (adjusted OR=1.31, 95% CI 1.08– 1.59), whereas higher self-perceived general health rating was negatively associated with the presence of CS (adjusted OR=0.92, 95% CI 0.88– 0.97) in the multivariate adjusted regression model.Conclusion: CS is prevalent in patients with CTS. Predominant neuropathic pain characteristics were uncovered in CTS patients as well as comorbid psychological distress. Significant association was found between anxiety and CS presence. Self-perceived general health was inversely related to CS. Further research is warranted to explore the mechanisms of anxiety and central pain processing in painful entrapment neuropathy.Keywords: central sensitization, chronic pain, carpal tunnel syndrome, determinants

Keywords

• central sensitization
• chronic pain
• carpal tunnel syndrome
• determinants