Chronic manganese poisoning

Abstract

Clinical, laboratory, and isotopic studies are reported on groups of individuals representing a normal population, a population of "healthy" manganese miners, and patients suffering from chronic manganese poisoning. The "healthy" miners were selected among workers who had previously shown a significant incidence of the cogwheel phenomenon as an isolated finding. With this exception, there were no apparent psychiatric or neurological abnormalities among the two control groups. The patients with chronic manganese poisoning, on the other hand, displayed transitory psychiatric symptoms, followed by permanent neurological changes, including disorders of the extrapyramidal system. With the exception of low plasma protein concentrations encountered in both "healthy" miners and patients, the laboratory data showed no striking abnormalities among these subjects. Specifically, no hematological or significant hepatic disorder became evident. By contrast, determinations of the rate of loss of the radiois.otope 54Mn from the whole body following intravenous injection showed faster losses in the case of the "healthy" miners than in either the normal controls or the patients with chronic metal poisoning. This is interpreted as indicating the presence of large, actively exchanging stores of tissue manganese in the case of the healthy miners as contrasted to the patients suffering from chronic manganese poisoning. Consequently, chelation therapy was not practiced.