Idiopathic, Rheumatoid Arthritis And Diabetes Mellitus Associated Carpal Tunnel Syndrome: Evaluation Of The Depth Of The Carpal Tunnel By Ultrasonography

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 & 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 & biology 2015; 41: 2827-35.Table 1.Sensitivity statistics for different US measures for CTSIdiopathicRADiabeticAllNumber of the CTS cases60123106289Number of the controls20203171CSASensitivity80%70.7%76.4%74.7%Specificity95%90%90.3%91.6%Accuracy87.5%80.4%83.4%83.1%FRSensitivity75%61.8%73.6%68.9%Specificity60%65%64.5%63.4%Accuracy67.5%63.4%69.1%66.1%DCTSensitivity75%82.1%67%75.1%Specificity85%95%83.9%87.3%Accuracy80%88.6%75.4%81.2%CSA: cross sectional area, FR: flattening ratio, DCT: Depth of the carpal tunnelDisclosure of Interests:None declared