Assessment of Carpal Tunnel Syndrome Severity by Ultrasound and Electrodiagnosis Study

Abstract

Carpal tunnel syndrome (CTS) is the upper limb neuropathic entrapment. Electrodiagnostic study (EDX) is the gold standard for diagnosis. However, EDX is not always abnormal in CTS beside its relatively high cost which requires the search for alternative modalities. Objectives: To investigate ultrasound (US) has a function in the evalution of CTS as well as determination disease severity. Subjects and Methods: A case-control experiment which involve 50 CTS patients (65 wrists) and 30 healthy subjects (30 wrists). Electrodiagnostic study involve nerve coduction test (NCS) were performed for all included wrists, with ultrasound measure the cross-sectional area (CSA) of the median nerve. Results: The result of 65 affected wrists with CTS is classified for 40 (61.15%) wrist mild disease, 19 wrists (29.23%) demonstrated a moderate disease and 6 wrists (9.23%) had severe disease. The mean in mild, moderate, and severe cases, median nerve CSA was determined 11.21±1.22 mm2, 15.09±0.1.14 mm2 and 17.88±0.2.1 mm2, respectively with highly significant differences between the three categories. Furthermore, all three categories had higher CSA than control (8.73±0.45 mm2) with highly significant differences. In patients, CSA demonstrated a significant linked with median distal sensory latency (r = 0.71 8, p <0.001), median motor distal latency (r = 0.818, p < 0.001) and age (r = 0.316, p = 0.0 1) and a negative significant with median nerve conduction velocity (r= -0.837, p < 0.001). US demonstrated excellent diagnostic values. The sensitivity and specificity of US in the context of discriminate patients and controls at cut off value of CSA = 10 mm2 were 92% and 100%, respectively. Furthermore, US can effectively discriminate between mild, moderate and severe cases CTS with sensitivity levels ranging from 83%- 100% and 94%-100% specificity. The optimal cut off values ranges between 13.2-16.2 mm2. Conclusions: The CSA of the median nerve is increased and the degree of enlargement significantly correlates with the parameters of disease severity. However, the CSA of the nerve does not associate with the gender of patients or the side of the affected wrist. Ultrasound of CST of median nerve has an excellent diagnostic value in the disinguish between patients and controls, with 92 percent sensitivity and 99 percent specificity, respectively. The optimum cut off value is 10 mm2. Also, US can effectively distinguish mild, moderate and severe cases CTS with Sensitivity levels ranging from 83%- 100% and 94%-100% Specificity. The optimal values cut off ranges between 13.2-16.2 mm2.