comparison of ultrasonic and electrophysiological pre and postoperative evaluation for carpal tunnel syndrome

Abstract

Purpose: The aim of this prospective study was to compare high definition ultrasonography vs. electrophysiological testing in order to evaluate their diagnostic value for Carpal Tunnel Syndrome (CTS). Methods: In this prospective study forty patients with carpal tunnel syndrome were studied preoperatively and 1, 3, 6 and 12 months postoperatively. The electrophysiological testing included the distal motor latency and the sensory conduction velocity. The crosssectional area of the median nerve at the carpal tunnel inlet (Level 1) and at the middle of carpal tunnel (Level 2) was measured with ultrasonography. The intensity of preand postoperative pain was also documented with pain scales and correlated with the electrophysiological and ultrasonic findings. Results: A postoperative statistical significant alteration was observed for the distal motor latency and the sensory conduction velocity. At Level 1 and at Level 2 no statistical significant change of the cross-sectional area of the median nerve was observed postoperatively. The cross-sectional area of the median nerve of the operated and non-operated hand at Level 2 showed preoperatively a statistic significant difference which was not detectable 12 months postoperatively Discussion: The electrophysiological testing as a clinically established method for diagnosing CTS also allows a postoperative monitoring of the level of regeneration and function of the median nerve. High definition ultrasound is a versatile method to diagnose CTS, but it is necessary to analyze both hands in order to identify a difference of the cross-sectional area of both median nerves. For the postoperative follow up of median nerve recovery electrophysiological testing has to be preferred.