Ultrasound can be routinely used in the diagnosis of the carpal tunnel syndrome?: Electrophysiological and ultrasonographic study of the of carpal tunnel

Abstract

Purpose: To determine electrophysiological and ultrasonographic features of the carpal tunnel during flexion and extension of the wrist. Methods: This study included 35 right-handed healthy volunteers, of whom 24 were females and 11 males. The mean age of females and males were 37,5 ± 2.4 and 42 ± 1,9 years respectively. All subjects gave oral informed consent. Anterio-posterior and medio-laterally diameters of the carpal tunnel were measured on ultrasonography during flexion and extension of the wrist. Electrophysiological features of the median nerve sensorimotor conduction in the first digit of the right hand were determined during flexion and extension of the hand. Data from ultrasonographic and electrophysiological measurements were analyzed with SPSS 10.0 package program and the data were compared with ANOVA and Tukey tests. Results: There was a decrease in median n. motor amplitude on flexion and extension of the wrist (p<0.0001), while median n. motor conduction speed decreased only on extension of the wrist (p<0.005). Median n. sensory conduction decreased (p<0.0001) and distal latency lengthened (p<0.0001) on flexion of the wrist. On ultrasonography, the medio-laterally diameter of the carpal tunnel increased on flexion and extension of the wrist (p<0.0001), wile there was a considerable decrease in anterioposterior diameter of the tunnel on flexion of the wrist (p<0.0001). Conclusions: The diagnosis of carpal tunnel syndrome (CTS) is usually based on clinical and electrophysiological findings and then an appropriate treatment alternative is determined accordingly. Incorporation of ultrasonography (US), computed tomography (CT) and/or magnetic resonance imaging (MRI) into diagnostic efforts will help determine both etiopathogenesis and the most apropriate treatment alternative.