Present-day professional lead polyneuropathy — chronic demyelinating disease of peripheral nervous system

Relatively high positive correlation between lead content in biologic environment and indices of porphyrinic exchange in patients with neurogenic form of chronic polyneuropathy has been determined. In risk group such correlation was absent. Clinical symptoms, change in electric neuromyography, indices of porphyrinic exchange and lead content in biologic environment has been studied in 92 workers engaged in making lead and exposed to small average concentrations of it close to the limiting permissible concentration during the working day. Progression of chronic lead intoxication, the initial form of which clinically reveals in 12—4 years by vegetosensoric polyneuropathy of upper and lower extremities and intrinsic changes in electric neuromyography indices has been determined. Isolated symptoms of polyneuropathy and lowering of the indicated parameters of electric neuromyography by 5—10% are revealed in preclinical stage (risk signs). The nature of electric neuromyography changes points to segmental myelinopathy.