Current perception thresholds in vibration-induced neuropathy.

The authors evaluated the usefulness of current perception threshold testing for the assessment of vibration-induced neuropathy. The study population comprised 20 male controls and 59 males with hand-arm vibration syndrome. Current perception threshold at three test frequencies (i.e., 5 Hz, 250 Hz, and 2,000 Hz) was determined on the distal phalanges of the index and little fingers. Large myelinated fibers, small myelinated fibers, and unmyelinated fibers were evaluated selectively at 2,000-Hz, 250-Hz, and 5-Hz frequencies, respectively. The vibration-induced neuropathy groups had significantly increased current perception thresholds in both the index and little fingers. There was a significant increase in current perception threshold for the myelinated fibers, but not the unmyelinated fibers. The diagnostic sensitivity for vibration-induced neuropathy was relatively high. It appeared that current perception threshold evaluation was useful for the assessment of vibration-induced neuropathy.