Tracking Median Nerve Conduction as a Method of Early Detection of Carpal Tunnel Syndrome

Abstract

Cumulative trauma disorders in general, and carpal tunnel syndrome (CTS), in particular, have been an increasingly costly problem for both the afflicted individual and the company that employs that individual. This research involved a longitudinal study of cumulative trauma in six poultry processing plants. The primary objective of this research was to evaluate the potential of a procedure that tracks changes in motor median nerve latencies as a method of early detection of carpal tunnel syndrome. Although there was a statistically significant difference between the average latencies of the non-symptomatic group and the symptomatic group, the use of motor median nerve latencies for predictive diagnostic purposes is definitely questionable. There was no systematic shift in latencies observed as a function of the time that the person had been performing processing tasks which are generally considered to be associated with CTS. A second important result was that the incidence rate of objectively evaluated CTS appears to be far lower than that generally reported in both the popular media and the research literature. Probably the most important conclusion of the study, however, was that the variation within people, over time, independent of exposure, can lead to serious misdiagnosis of CTS. These results and conclusions are very important for both assessing the magnitude of the problem of CTS, as well as questioning the efficacy of one of the most widely used criteria to justify CTS surgery.