Manganese Poisoning In Clinical Studies

Studies on brain alterations at brain MRI and the levels of Mn,Mg,Zn,Fe,Ca and Cu in the blood in Mn-exposed workersObjective: To investigate the sub-clinical evidence in long-term manganese exposed workers at brain MRI and the levels of Mn, Zn, Cu, Fe, Ca and Mg in the blood among the Mn-exposed, manganism and control workers, which will provide the scientific basis on diagnosis, treatment and prevention of manganism clinically.Materials and Methods: Brain MRI examination and metal elements measurement were performed in 13 asymptomatic manganese-exposed workers and 4 manganism patients and 6 healthy volunteers.MR examination performed on a 1.5 T signa superconducting system (GE company, U.S.). Signal intensity in T₁-weighted imaging was measured on the globus pallidus (GP) and the frontal white matter (FW),respectively .The equation PI =SIGP/SIFW×100%.The concentration of metal elements were measured by ICP-AES. SPSS for 11.5 statistical software package was used to asses the difference of PI index and of six metal elements among three groups,studied the correlation between pallidal index and levels of six metal elements.Results: The Mn-exposed workers showed a symmetric pallidal hyperintensity in Tl-weighted MRI and a normal intensity in T₂,the differences in PI index among three groups are significantly. The concentration of Mn in total blood (MnB) of Mn-exposed workers is higher than the other two groups.Conclusion: Increased signal intensities in the globus pallidus on the T₁-weighed image and MnB may reflect recent exposure to manganese, but not necessarily manganism. PI index indicates Mn accumulation in centre nerve system. PI and MnB may be used as a early biomarker of Mn neurotoxicity.