Ultrasonography of the Median Nerve in the Carpal Tunnel Syndrome Diagnosis

The purpose of this paper is to highlight the possibility of using ultrasonography for diagnosing the carpal tunnel syndrome (CTS).Our study is based on 100 patients, 75 women and 25 men. We performed the ultrasound examination, measuring the nerve diameter (longitudinal and transverse) at entrance and exit out of the carpal tunnel and proposing the calculation of an ultrasonographic index. Results: The investigation can reveal the morphology of the carpal tunnel and damaged nerve -differentiation of nerve fibers, clepsydra-shaped compression in the carpal tunnel ischemic area. The results were compared with the results in the healthy hand. The following mean values were determined: G1= 2.93 ± 0.54 mm, L = 6.02 ± 1.42 mm, G2 at CT level =1.46 ± 0.62 mm and G2 distal to CT = 1.52 ± 0.69 mm.The median nerve sonographic index at the level of the carpal tunnel is a valuable and practical indicator which can be used in the diagnosis of CTS. It may be of help in determining the severity of lesion by having a higher value compared to the flattening ratio (sensibility 4,49%, specificity 97,95%) and to the cross-sectional area (sensibility 88,76%, specificity 32,08%).