Efficacy of vibration, electric current and thermal perception tests in diagnosis of hand-arm vibration syndrome.

Vibration perception test is usually proposed as a useful tool for quantitative assessment of neurological disturbances induced by hand-arm vibration syndrome (HAVS). The increased mean vibration perception threshold (VPT) is an early manifestation of this syndrome. However, we have identified a group of exposed subjects with normal VPT who showed electric current and/or thermal sensitivity impairment. The use of three tests instead of a single vibration test increased by 27% the number of persons with detected quantitative skin sensory disorders. The intensity of quantitative disorders of vibration and electric current sensitivity was closely related to the duration of vibration exposure. The thermal perception was diminished in subjects working for a longer period of time, but there was no relationship between intensity of disorders and the duration of exposure. In an early stage of hand-arm vibration syndrome (prevention of HAVS) the use of three tests helps to identify a larger number of workers at risk who should undergo thorough diagnostic examinations. In our study the proportion of identified workers increased from 27% (32 subjects with vibration sensory impairment) to 45% (53 persons with disorders detected in one, two or even three tests).