Digital nerve conduction velocity for evaluation of peripheral nerve impairments in vibration syndrome.

In order to evaluate peripheral nerve impairments in vibration syndrome, sensory nerve conduction velocity (SCV) in the digital segment of the median nerve was measured by applying electrical stimulation to the wrist and recording from two pairs of electrodes attached to the middle finger. Fractionated SCVs were also measured in the palm-to-finger, wrist-to-palm, and elbow-to-wrist segments of the median nerve. Subjects were 65 patients with vibration syndrome and 48 healthy controls of similar age. SCVs in the digital nerve segment were significantly slower in the patients than in the controls. Significant slowing was also found in the wrist-to-palm segment. SCVs in the palm-to-finger and elbow-to-wrist segments did not differ between the two groups. Slowed SCVs were most frequently encountered in the digital segment (38% of the patients). The slowing in the wrist-to-palm segment was found in 20% of the patients. Present findings indicate that the digital segment is most frequently affected in vibration-induced neuropathy, and measurement of SCVs in the digital segment would serve to evaluate the peripheral neuropathy in vibration syndrome.