Chronic manganese poisoning. Clinical picture and manganese turnover.

SINCE COWPER’S FIRST DESCRIPTION,^ human chronic manganese poisoning has been the subject of many reports and several reviews.2-6 The aim of most publications seems to have been the definition of the clinical picture of this disease in relation to various environmental factors. The clinical picture has consisted of both psychiatric and neurological manifestations, the most crippling of which have been related to the extrapyramidal system.6 The environmental factors investigated have included the physical characteristics of dusts inhaled by manganese miners as well as some chemical properties of ores which have induced the disease in high incidence.? Consequently, chelating agents have been introduced in the management of this disease.8 The present study was undertaken after consideration of some disease states in which abnormal metabolism of metals is correlated with chronic disturbances of the brain. Such correlations are particularly striking in lead encephalopathy and Wilson’s disease. In both diseases the respective presence of high tissue concentrations of leadQJ0 and of copperll seems essential to the induction and, perhaps, to the progression of the symptomatology. It seemed reasonable to investigate chronic manganese poisoning with these precedents in mind. The present publication is the initial report of studies on this problem. It develops arguments in favor of the thesis that chronic manganese poisoning may diverge significantly from the aforementioned diseases. If further substantiated by analytical evidence, these