Manganese neurotoxicity: A review of clinical features, imaging and pathology

Manganese intoxication can result in a syndrome of parkinsonism and dystoni a. If these extrapyramidal findings are present, they are likely to be irre versible and even progress after termination of the exposure to manganese. Clinical features are usually sufficient to distinguish these patients from those with Parkinson's disease. The neurological syndrome does not respond to levodopa. Imaging of the brain may reveal MRI signal changes in the glo bus pallidus, striatum, and midbrain. Positron emission tomography reveals normal presynaptic and postsynaptic nigrostriatal dopaminergic function. Th e primary site of neurological damage has been shown by pathological studie s to be the globus pallidus. The mechanism of toxicity is not clear. (C) 19 99 Inter Press, Inc.