Baseline Characteristics of the Median Nerve on Ultrasound Examination. (September 2016)

• Record Type: Journal Article
• Authors: Pan, Tiffany J.; White, Richard J.; Zhang, Caiyan; Hagberg, William C.; Imbriglia, Joseph E.; Fowler, John R.
• Is Part Of: Hand. Volume 11:Number 3(2016)
• Page Start: 353
• Page End: 356
• Publication Date: 2016-09
• Subjects: carpal tunnel syndrome -- ultrasound -- sonography -- diagnosis -- median nerve; Hand -- Surgery -- Periodicals; Hand -- Surgery; Periodicals; 617.57005
• DOI: 10.1177/1558944715620799
• Languages: English
• ISSNs: 1558-9447

Abstract

Background: Previous studies using ultrasound for diagnosis of carpal tunnel syndrome have reported on relatively small series of patients, leading to large standard deviations and/or confidence intervals for the mean cross-sectional area of the median nerve. The purpose of this study is to define the CSA of the median nerve in a large cohort of patients.Methods: Patients (n = 175) without history of carpal tunnel release were recruited. All participants were evaluated using the Carpal Tunnel Syndrome-6 questionnaire, a validated clinical diagnostic tool, with a score of 12 or greater considered positive for CTS. Ultrasound examination was performed on both wrists of all participants using a 13-6 MHz linear array transducer.Results: The mean median nerve CSA was significantly larger (P < .001) for patients with a positive (mean = 11.16, SD = 2.51) versus negative CTS-6 result (mean = 6.91, SD = 2.06). There was a significant correlation (.527, P < .001, n = 349) between CSA and CTS-6 score. Logistic regression analysis determined that a CSA of 10 mm2 optimized sensitivity and specificity at 80% and 88%, respectively. Accuracy was 87.9%.Conclusions: A significant difference in mean CSA was found between patients with and without CTS. Median nerve CSA showed a statistically significant positive correlation with CTS-6. Similar to prior studies, a CSA of 10 mm2 was determined to be the optimal cutoff. In this large series of patients, ultrasound was a sensitive, specific, and accurate test for confirmation of a clinical diagnosis of CTS.