Browsing by Author "Hochberg, B"

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    Late motor deficits of Chilean manganese miners: A blinded control study
    (1996) Hochberg, F; Miller, G; Valenzuela, R; McNelis, S; Crump, KS; Covington, T; Valdivia, G; Hochberg, B; Trustman, JW
    High-level chronic manganese (Mn) exposure produces dystonic rigidity and proximal tremor. The late effects of asymptomatic exposure are uncertain. To evaluate hand movements of asymptomatic Chilean miners, we utilized a manual tremormeter (EAP) and a digitizing tablet (MOVEMAP). In Andacollo, Chile, we examined 59 individuals aged >50 years (mean age, 64.4 years). Twenty-seven exposed miners had heavy Mn dust exposure in Mn mines for more than 5 years (mean duration, 20.25 years), ending at least 5 years previously. Thirty-two control miners had never worked in Mn mines or had short-term Mn employment. Tests of resting tremor (EAP Tremormeter, MOVEMAP Steady paradigm), action tremor (MOVEMAP Square paradigm), and repetitive hand movements (EAP Tapping Test and Ortho-kinesimeter) differentiated performance of exposed miners from that of controls. Chronic asymptomatic Mn exposure results in detectable late-life abnormalities of movement.