Sensorineural objective tests in the assessment of hand-arm vibration syndrome

Abstract

Assessment (staging) of workers exposed to vibration, based solely on a subjective history, has been shown to be unsatisfactory. The internationally agreed use of a sensorineural component in the Stockholm classification requires the use of sensory objective tests. Four hundred and twenty two subjects were assessed by a subjective history supplemented by multiple objective tests. These tests covered the vascular, sensorineural, musculoskeletal and dexterity aspects of hand-arm vibration syndrome. Tests to help with the differential diagnosis were also performed. Sensorineural tests are reported as are the associations between the subject's final Stockholm sensorineural staging and the subject's aesthesiometry, temperature threshold results, and grip strength. Scoring systems for these tests were evolved. Data showed that multiple sensory tests increased the accuracy of staging. Aesthesiometry, the temperature neutral zone tests, and grip strength were appropriate for the assessment of the sensory component, especially in separating sensorineural stages 0 and 1 from sensorineural stages 2 and 3. This is an important separation for an occupational physician monitoring subjects exposed to vibration. Analyses of the sensory tests clearly indicated that they need to be done on all digits. In this survey the sensorineural damage was greatest in the forefinger (second) and the little (fifth) fingers. No association was found between smoking and the final staging, aesthesiometry, temperature neutral zone thresholds, or grip strength.