Ultrasound therapy facilitates the recovery of acute pressure-induced conduction block of the median nerve in rabbits.

Though the use of ultrasound for the treatment of carpal tunnel syndrome (CTS) or compression neuropathy has been described, its effect remains controversial. A test model of acute CTS was developed using rabbits. Acute median nerve compression was induced by the infusion of saline into the carpal tunnel under general anesthesia to elevate the intracarpal pressure. A reduction in the compound muscle action potential (CMAP) amplitude of the abductor pollicis was noted after intracarpal pressure increased. To investigate the efficacy of ultrasound in acute CTS, rabbits with acute median nerve compression were divided into 3 groups (10 each) and ultrasound was applied at different intensities to each group as follows: 1.5 W/cm(2) to group 1; 0.2 W/cm(2) to group 2; 0.0 W/cm(2) (sham) to group 3. A total of 10 treatment sessions were given over a period of 2 weeks. Following ultrasound application, the CMAP amplitudes showed significant improvement in group 1 compared to the other two groups (P < 0.05), indicating facilitated recovery from acute CTS in this pressure-induced median nerve compression rabbit model. The benefits of ultrasound application in a clinical setting must be verified by further clinical trials. Copyright 2002 Wiley Periodicals, Inc.