Study of Carpal Tunnel Syndrome Using Electroneurography and Ultrasound in a Spanish Cohort

Abstract

Introduction: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. Its diagnosis is clinically supported by the electroneurography (ENG). The use of ultrasound (US) has increased in recent years. Our objectives are: to describe the ENG and US findings in patients with suspected CTS, based on age, sex and anthropometric data; and to study the correlation of both tests based on the severity of CTS. Material and methods: prospective study of patients with suspected CTS who undergo ENG and US. ENG examination: antidromic sensory median at 3rd and 4th finger; distal motor of median. US: crosssectional area (CSA) prior to or within the tunnel (higher values). Inclusion criteria: patients aged 18 to 85 years. Exclusion criteria: previous trauma or previous surgery for CTS or forearm, carpus or hand. Statistical study with the SPSS 29.0 program. Results: 400 nerves from 266 patients (52.59 ± 12.09 years) were studied, 183 women and 83 men. According to the ENG, 129 did not have CTS, 61 were incipient, 113 mild, 19 moderate and 75 severe. The mean CSA was 8.37 ± 1.21 mm2 in non-CTS, 10.09 ± 1.45 mm2 in early, 11.33 ± 1.87 mm2 in mild, 14.63 ± 1.92 mm2 in moderate and 15.46 ± 3.33 mm2 in severe CTS, with a significance of p<0.01 (95% CI) in the ANOVA test. The highest and inverse correlation appears between the conduction velocities (CV) at the 4th finger with CSA (-0.816) and CV at the 3rd finger with CSA (-0.800), which coincides with the most sensitive ENG values for the diagnosis of CTS. Discussion: CSA is an appropriate test as a complement to ENG in the diagnosis of CTS. However, it has limitations when establishing the cut-off point between normality and neuropathy, as well as when classifying based on severity.