Background: We have attempted to obtain normal values for vibration thresholds in children and to evaluate their application in polyneuropathies.
Methods: Vibration thresholds determinations were made by means of a handheld vibrameter (Fa Somedic AB Sweden): Within a constant frequency (100 Hz) and a calibrated pressure (450 g) the amplitude ranged variably from 0.01 to 399 microns. Measurements were made at three sites (carpal, tibial and tarsal). Vibration threshold (VT) was determined by the average of Vibration Perception Threshold (VPT) and Vibration Disappearance Threshold (VDT).
Results: Reference values obtained from 106 children and adolescents (control group), 5.5 to 19 years of age, correlated with age but not with sex. The amplitude of VT-values ranged from 0.4 microns (carpal at 6 years), to 1.10 microns (tarsal at 18 years). Patients with Friedreich's ataxia (n = 7) or hereditary motosensory neuropathy (n = 11) showed strongly increased thresholds at all sites up to a factor of 100.
Conclusions: The examination by means of a vibrameter took at least 10 min, the shorter examination by tuning fork however showed to be less sensitive and rather inexact. An examination with a vibrameter is, as rule, reliably possible in children older than 5 years.