[The relationship between the course of bismuth encephalopathy and the amount of bismuth in blood and urine].

Study of the course of bismuth encephalopathy following the ingestion of a bismuth salt in relation to blood and urinary bismuth levels indicates a close parallel between the improvement in the clinical picture and the decrease in the degree of toxic impregnation of the body. This confirms the direct responsibility of bismuth for the disorder. Regression of myocolonic movements goes with the fall in blood bismuth levels, whilst improvement in the confusional syndrome is aomewhat delayed. There is a significant correlation between bismuth levels in the blood and urine. The excretion of bismuth is slow, and the persistence of blood and urinary bismuth levels higher than normal for several weeks after the acute phases and the interruption of the ingestion of bismuth salts reflects the existence of stable bonds between the metal and cellular constituents. The authors have observed a non-negligeable solubility of bismuth sub-nitrate in certain drinking waters, which brings up the hypothesis of a possible role of the hydrosobulity of bismuth in the pathogenesis of the intoxication.