A study on electrophysiological characteristic of carpal tunnel syndrome in 88 patients and the correlation with BMI

Objective:To discuss the electrophysiological characteristic of carpal tunnel syndrome (CTS) in 88 patients and ex-press the value of electromyography in the diagnosis of CTS. Method:Subsection motor nerve conduction velocity(MCV) and sensory nerve conduction velocity (SCV) of Ⅰ、Ⅴ、Ⅳ digits of one side or both side of median nerve and ulnar nerve and needle electromyography of short abductor of pollicis brevis were performed in 88 patients with CTS. Body mass index (BMI) and sensory nerve action potential (SNAP) amplitude ratio of Ⅳ digit median nerve and ulnar nerve were calculated in all patients. Result:The percentage of patients with lengthened latency of SNAP of median nerve of Ⅰ、 Ⅳ digits, were 59.1% and 65.9% respectively. In patients with reduced amplitude of compound muscle action potential (CMAP) 87.2% EMGs of short abductor of pollicis brevis were abnormal. In the patients with normal SNAP parameters, amplitude ratios of SNAPs of median nerve and ulnar nerve of Ⅳ digit were abnormal in 8 patients(72.7%). BMI had no sig-nificant difference in the abnormal patients. Conclusion:Neuroelectrophysiology examination is a optimal measure in diagnosing CTS.