[Chronic toxic encephalopathies]

The aim of this report is to present the clinical picture of some chronic occupational encephalopathies and evolution of neurological disturbances. Of 177 diagnosed encephalopathies, 103 were induced by heavy metals (Mn, Hg, Pb) and 48 by organic solvents. Of 200 persons exposed to vinyl chloride, neurological sings were found in 26 cases. In mangenose poisoning heavy encephalopathy with pyramidal and extrapyramidal disturbances proved to be progressive, in mercury chronic intoxication cerebellar symptoms and sensitive neuropathy were the most frequent. In some cases these neurological changes were either persistent or progressive or regressive. In chronic lead poisoning slight pyramidal and deliberative signs and sensitive polyneuropathy seemed to be the most typical. Chronic encephalopathy due to organic solvents was mostly subacute at the beginning, then a variety of clinical symptoms as well as partial or total regression were observed. Slight cerebellar signs and trigeminal sensitive neuropathy were the most frequent neurological findings in those exposed to vinyl chloride.