Current perception threshold screening for carpal tunnel syndrome.

Screening for the onset of carpal tunnel syndrome (CTS), which is associated with excess ergonomic stresses of the wrist and hand, is a major concern in occupational medicine. CTS questionnaires, physical examinations, and quantitative sensory function determination through neuroselective current perception threshold (CPT) measurements were obtained from the median digital nerves of 16 assembly line workers who were symptomatic with hand pain. Median nerve evaluations by CPT detected sensory abnormalities in 75% of the workers, and abnormalities in 50% of the workers were detected by clinical evaluations (p less than .05, df = 22). CPT abnormalities were characterized as "hypoesthetic" in 25% and hyperesthesic in 42% of the workers. The noninvasive, nonaversive CPT technique provided sensitive and easily obtained quantitative measures. Regular use of this procedure in the occupational setting may assist in preventing the development of advanced CTS for it provides early detection of median nerve abnormalities.