Vibratory detection thresholds following a digital nerve lesion.

Vibratory detection thresholds were measured at a number of frequencies between 5 and 320 Hz following a lesion of the lateral digital nerve innervating the terminal phalanx of the left index finger. Thresholds measurements began approximately 4 weeks after the nerve was repaired. A staircase method was used to determine thresholds on both the injured fingerpad and the intact fingerpad of the opposite hand. There was a large increase in thresholds on the injured fingerpad in the lower range of frequencies (5-40 Hz) while at higher frequencies (80-250 Hz) there was no significant difference between the thresholds on the injured fingerpad and those on the intact fingerpad. It is suggested that the differential effect of the nerve lesion on vibratory thresholds reflects the spread of the vibratory stimulus through the skin and the spatial characteristics of functionally intact receptor/afferent groups innervating neighbouring skin.