Environmental, biochemical and molecular factors regulating manganese-induced neurological injury

Abstract

Manganese intoxication is most often regarded as an occupational disorder in which abnormally high atmospheric concentrations prevail, such as in welding and mining. The syndrome known as manganism is characterized by cognitive, behavioral, intellectual and minor neurological disturbances in the initial stages of the disorder and by more prominent and irreversible extrapyramidal dysfunction resembling Parkinson's disease upon prolonged exposure. Recent evidence further reveals that individuals with liver dysfunction and those receiving parenteral nutrition exhibit many of the same symptoms as occupationally exposed workers. Common homeostatic processes are normally capable of preventing Mn overload for a typical dietary intake but in environmental settings in which occupational exposures are both chronic and excessive, these regulatory processes are inadequate to maintain tolerable levels of the metal, as demonstrated by significant increases in both blood and brain levels of Mn. Based on T1-weighted MRI ...