[Esthesiometric thresholds in workers exposed to neuropathogenic chemical and physical agents]

Two-point discrimination (TPD) and depth sense perception (DSP) were measured by means of two aesthesiometers in the fingertips of 65 forestry workers exposed to chain saw vibrations and 46 shoe industry workers exposed to neurotoxic solvents (n-hexane). Two control groups, consisting of 31 and 46 healthy subjects, were also examined. The compound means of the TPD and DSP threshold values for the 2nd, 3rd and 4th digits of the right and left hands were significantly higher in the chain saw workers suffering from peripheral sensorineural disorders than in the asymptomatic chain saw workers and the controls (p less than 0.001). Among the forestry workers, a significant relationship was found between loss of tactile perception and vibration dose expressed in terms of four-hour energy-equivalent frequency-weighted acceleration (ISO 5349). The shoe workers, who were asymptomatic, had higher DSP threshold values than the controls (p less than 0.01). No differences in the mean values of TPD thresholds were observed between the exposed and control subjects. These results indicate that DSP is more sensitive than TPD in detecting "sub-clinical neuropathy". On the basis of our previous investigations, the specificity of aesthesiometric threshold testing was high, ranging from 93 to 100%. The sensitivity of the aesthesiometric method was lower than the specificity, varying from 52-56% for TPD to 67-72% for DSP. These findings suggest that aesthesiometry may be considered as a useful testing method to differentiate on a group basis between healthy subjects and workers exposed to physical and chemical agents affecting the peripheral nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)