Ultrasonographic Measurement of the Median to Ulnar Nerve Cross-Sectional Area Difference and Ratio as a Diagnostic Technique in the Carpal Tunnel Syndrome: A Diagnostic Tool

Carpal tunnel syndrome (CTS) is a prevalent type of neuropathy among the general population. The median nerve is compressed at the wrist level. To determine if the variation in the cross-sectional areas of the ulnar (u-CSA) and median (m-CSA) nerves at the plane of the pisiform bone, as evaluated by ultrasonography, is a useful diagnostic tool for CTS. Thirty individuals with CTS symptoms were compared to thirty healthy participants who served as the control group. Both groups underwent a comprehensive clinical evaluation. The Boston Carpal Tunnel Questionnaire (BCTQ) was completed by the patient group and ultrasonographic measurements of the cross-sectional area of the median nerve (m-CSA) and cross-sectional area of the ulnar nerve (u-CSA). All subjects had their median-ulnar difference (MUD) and median-ulnar ratio (MUR) evaluated at the carpal tunnel’s entrance. The BCTQ evaluating the degree of CTS in the patient group revealed that 6 patients (20%) had minimal CTS, 11 patients (36.7%) had mild CTS, 10 patients (33.3%) had moderate CTS, and 3 patients (10%) had severe CTS. Ultrasonographic measurements revealed that CTS patients had a significantly higher m-CSA (14.53 ± 4.04) than the control group (9.04 ± 1.23) (P 0.001). The CTS group had significantly higher MUR and MUD (4.02 ± 1.17) and (10.88 ± 3.94) than the control group (2.68 ± 0.36) and (5.61 ± 1.02), respectively (P 0.001). CTS diagnosis can be accomplished using the MUD and MUR methods, and their increased use in both clinical and research settings is strongly encouraged.