Evaluation of sensory nerve conduction velocity testing of the superficial radial nerve.

The purposes of this study were to evaluate the methods for examining the superficial radial nerve and to compare velocities and amplitudes of responses based on electrode shape and placement and site of stimulation. We selected 51 subjects with a mean age of 37 years from a healthy group. Twenty additional subjects with a mean age of 28 were also examined. Nerve conduction was done by stimulating over the dorsal forearm and lateral arm and recording from the superficial radial nerve where its branches cross the extensor pollicis longus tendon. The second group of subjects were stimulated at the same site and also at the elbow. Recording was done with a rectangular-shaped electrode placed in the area between the extensor pollicis longus and the extensor pollicis brevis tendons. We found a mean conduction velocity of 61 m/sec +/- 4.91 in the first group with a mean amplitude of response of 36.7 microV +/- 11.7 when we stimulated at the forearm site and 4.06 microV +/- 6.75 when we stimulated at the lateral arm site. In the second group of subjects, conduction velocity from lateral arm to forearm site was 63 m/sec +/- 4.50; from the lateral arm to elbow, 66 m/sec +/- 10.4; and from the elbow to the forearm site, 64 m/sec +/- 9.71. Amplitudes of response were 43.8 microV +/- 14.45 at the forearm stimulation site, 18.06 +/- microV +/- 7.37 at the elbow site, and 6.7 microV +/- 4.25 at the lateral arm site. We compared the mean velocities from the two methods and found no significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)