Search

Background: Carpal tunnel syndrome (CTS) is a prevalent condition during gestation. The recent ability of ultrasound to provide comparable results with electrodiagnostic tests (EDx) has opened the door for investigating new parameters. The objective of this investigation is to explore the clinical importance of a new anthropometric independent parameter called the nerve/tendon ratio (NTR) when compared to EDx and to determine whether it has the utility to be used in clinical practice. Methods: In this prospective case-control study conducted between April 2023 and September 2023, 160 pregnant women displaying clinical symptoms of CTS who presented to the outpatient clinic underwent evaluation employing the Boston Carpal Tunnel Questionnaire, Visual Analog Scale, and provocative tests (Phalen and Tinnel). The pregnant women with clinical symptoms were divided into two groups: those with positive CTS in the EDx results (mild/moderate/severe) and those without EDx findings (control group). All pregnant women participating in the study had their median nerve cross-sectional area (MN-CSA), flexor carpi radialis (FCR), and MN-CSA/FCR ratio (expressed as a percentage called NTR) values examined. The sonographers were unaware of the clinical and EDx results. Subsequently, the data were examined utilizing logistic regression models, with a significance threshold established at p < 0.05. Results: In pregnant women with CTS, the MN-CSA values were observed to surpass those in the control cohort (10.03 ± 3.28 vs. 7.80 ± 2.50) (p < 0.001). The NTR values in the pregnant women with CTS were also higher than those in the control group (0.94 ± 0.39 vs. 0.81 ± 0.28) (p = 0.045). The best cut-off for MN-CSA values was calculated to be >8.5 mm2. The best cut-off point for MN-CSA/FCR values was found to be >0.82%. A receiver operating characteristic curve was generated, and the NTR cut-off point of 0.82% showed a sensitivity of 51.9% and a specificity of 67.9%. The positive predictive value and the negative predictive value were 61.2% and 59.1%, respectively, with the mentioned point as the diagnostic threshold (area under the curve 0.592 (95% confidence interval [CI]: 0.503–0.680)). Among ultrasound-related factors, patients with symptoms of CTS exhibited an association with MN-CSA (odds ratio [OR] of 6.396, 95% CI: 2.981–13.722). NTR was not identified as a risk factor for CTS (p > 0.05). Conclusions: Ultrasonography of the wrist may serve as an alternative diagnostic tool for CTS in pregnant women due to its rapid, non-invasive, and reproducible characteristics. Further research should focus on investigating the response to treatment. Clinical Trial Registration: the study was registered at https://clinicaltrials.gov (registration number NCT05839769).