Relationship between cervical spondylotic radiculopathy and carpal tunnel syndrome

Objective To explore the relationship between cervical spondylotic radiculopathy (CSR) and carpal tunnel syndrome (CTS) by investigating their electrophysiological characteristics and the incidence of CSR root injury and root injury complicating with CTS. Methods One hundred and twenty-four cases of CSR diagnosed in Peking Union Medical College Hospital from September 2013 to February 2014 by electromyography (EMG) were recruited. According to the results of EMG, patients were divided into root injury and root injury complicating with CTS groups. The distal motor latency (DML), motor nerve conduction velocity (MCV), sensory nerve conduction velocity (SCV), sensory nerve action potential (SNAP), compound muscle action potential (CMAP) and spontaneous potential (SP) were compared between the two groups. Results There were 81 (65.3%) cases with root injury, 11 cases with double sides injury and 29 cases with normal EMG among these 124 patients. The CMAP, DML, MCV, SCV and SNAP were normal in 76 cases, CMAP lowered 5%-12% in 3 cases, DML extended 3% and 9% in 2 cases. There were 14 cases (11.3%) with concomitant CTS (female 10 cases and male 4 cases, double sides CTS 10 cases). Among the 14 cases with concomitant CTS, there were 9 cases with simply sensory nerve conduction abnormality, SCV slowing down 26%-47%, SNAP reducing 58%-86% or normal, while other 5 cases with motor conduction abnormality as well as sensory nerve conduction abnormality, CMAP reducing 21%-78%, DML extending 27%-39% in 3 cases, MCV slowing down 32% and 40% in 2 cases. Five cases had spontaneous electricity position movement in the abductor pollicis brevis. The incidence of root injury complicating with CTS in C6 (27.4%, 9/33), C7 (26.9%, 7/26) and C8 (5/7) showed statistically significant difference (χ2=5.96, P<0.01). Conclusions There is a high incidence of root injury and CTS in CSR patients, indicating a possible double crush between CSR and CTS. Key words: Radiculopathy; Spinal osteophytosis; Cervical vertebrae; Carpal tunnel syndrome; Electromyography; Nerve compression syndromes