POS1389 IDIOPATHIC, RHEUMATOID ARTHRITIS AND DIABETES MELLITUS ASSOCIATED CARPAL TUNNEL SYNDROME: EVALUATION OF THE DEPTH OF THE CARPAL TUNNEL BY ULTRASONOGRAPHY
Authors: A. Elsaman, Y. Alzahrani, H. Alzahrani, A. Radwan
Journal: Annals of the Rheumatic Diseases (2021)

Background: The depth of the carpal tunnel is a relatively new sonographic parameter for evaluation of carpal tunnel syndrome (CTS). It showed a sensitivity and specificity comparable to cross-sectional area measurement. So far it is not clear how the depth can changes with different types of CTS [1, 2]. Objectives: is to assess the depth in 3 different types of CTS including idiopathic, rheumatoid arthritis, and diabetes mellitus associated CTS and to compare it with other sonographic and electro-physiologic scales. Methods: We included a total number of 360 participants; including 289 with CTS (60 idiopathic, 106 diabetes associated, and 123 rheumatoid arthritis associated CTS), all fulfilled the criteria for electro-physiologic diagnosis according to the American Association of Electro Diagnostic Medicine; along with 71 non-CTS cases (20 healthy controls, 20 RA and 31 diabetic patients). Median nerve cross-sectional area (CSA); flattening ratio (FR); and depth of the carpal tunnel (DCT) were measured for all participants. Results: We found the mean age 35.6±9.48 years. The female-to-male ratio was 47:13. The sensitivities for CSA, FR and DCT were 74.7%, 68.9%, and 75.1%; respectively, and the specificities were 91.6%, 63.4% and 87.3%; respectively. DCT was the best sonographic parameter with rheumatoid arthritis associated CTS (giving an accuracy of 88.6%) and CSA was the best in the other two types (giving an accuracy of 87.5% for idiopathic CTS and 83.4% for diabetes associated CTS). Table 1 summarizes the sensitivity statistics among each of the three groups and all over the study participants. Conclusion: The depth of the CTS showed the best accuracy in rheumatoid arthritis associated CTS followed by idiopathic CTS and finally diabetes mellitus associated CTS. References: [1]Elsaman AM, Thabit MN, Radwan AR, Ohrndorf S. Idiopathic Carpal Tunnel Syndrome: Evaluation of the Depth of the Carpal Tunnel by Ultrasonography. Ultrasound in medicine &amp; biology 2015; 41: 2827-35. [2]AM E, Hamed A, Borai A, Radwan A. Carpal tunnel syndrome in rheumatoid arthritis patients: evaluation of the depth by ultrasonography. [3]Elsaman AM, Thabit MN, Radwan AR, Ohrndorf S. Idiopathic Carpal Tunnel Syndrome: Evaluation of the Depth of the Carpal Tunnel by Ultrasonography. Ultrasound in medicine &amp; biology 2015; 41: 2827-35. Table 1. Sensitivity statistics for different US measures for CTS Idiopathic RA Diabetic All Number of the CTS cases 60 123 106 289 Number of the controls 20 20 31 71 CSA Sensitivity 80% 70.7% 76.4% 74.7% Specificity 95% 90% 90.3% 91.6% Accuracy 87.5% 80.4% 83.4% 83.1% FR Sensitivity 75% 61.8% 73.6% 68.9% Specificity 60% 65% 64.5% 63.4% Accuracy 67.5% 63.4% 69.1% 66.1% DCT Sensitivity 75% 82.1% 67% 75.1% Specificity 85% 95% 83.9% 87.3% Accuracy 80% 88.6% 75.4% 81.2% CSA: cross sectional area, FR: flattening ratio, DCT: Depth of the carpal tunnel Disclosure of Interests: None declared