Idiopathic parkinsonism with superimposed manganese exposure: Utility of positron emission tomography

It is difficult to distinguish manganism from idiopathic parkinsonism by cl inical signs only. Case history and examination: A 48-year-old welder for o ver 10 years complained of masked lace right side (arm and leg) resting tre mor, and bradykinesia for over one year. Magnetic resonance imaging (MRI) f indings showed symmetrical high signal intensities in the globus pallidus o n T1 weighted image. These intensities disappeared almost completely six mo nths after cessation of exposure. F-18-6-fluorodopa (F-18-dopa) positron em ission tomography (PET) findings showed reduced F-18-dopa uptake in the lef t putamen, findings which appear in idiopathic parkinsonism. A PET study is necessary to distinguish manganism from idiopathic parkinsonism, especiall y in a working environment with elevated Mn concentrations, such as welding . (C) 1999 Intox Press, Inc.