MRI Signal Intensity and Parkinsonism in Manganese-Exposed Workers.

OBJECTIVE T1-weighted brain magnetic resonance imaging (MRI) of the basal ganglia provides a non-invasive measure of manganese (Mn) exposure, and may also represent a biomarker for clinical neurotoxicity. METHODS We acquired T1-weighted MRI scans in 27 Mn-exposed welders, 12 other Mn-exposed workers, and 29 non-exposed participants. T1-weighted intensity indices were calculated for four basal ganglia regions. Cumulative Mn exposure was estimated from work history data. Participants were examined using the Unified Parkinson's Disease Rating Scale motor subsection 3 (UPDRS3). RESULTS We observed a positive dose-response association between cumulative Mn exposure and the pallidal index (PI) (β = 2.33; 95% confidence interval [CI] 0.93, 3.74). There was a positive relationship between the PI and UPDRS3 (β = 0.15; 95% CI 0.03, 0.27). CONCLUSION The T1-weighted pallidal signal is associated with occupational Mn exposure and severity of parkinsonism.

[1]  Xuemei Huang,et al.  Manganese promotes the aggregation and prion-like cell-to-cell exosomal transmission of α-synuclein , 2019, Science Signaling.

[2]  Mechelle M Lewis,et al.  Magnetic resonance T1w/T2w ratio: A parsimonious marker for Parkinson disease , 2018, Annals of neurology.

[3]  L. Sheppard,et al.  Selective D2 receptor PET in manganese-exposed workers , 2018, Neurology.

[4]  L. Sheppard,et al.  [18F]FDOPA positron emission tomography in manganese‐exposed workers , 2017, Neurotoxicology.

[5]  Lianne Sheppard,et al.  Dose-dependent progression of parkinsonism in manganese-exposed welders , 2017, Neurology.

[6]  R. Mailman,et al.  T1 Relaxation Rate (R1) Indicates Nonlinear Mn Accumulation in Brain Tissue of Welders With Low-Level Exposure. , 2015, Toxicological sciences : an official journal of the Society of Toxicology.

[7]  L. Sheppard,et al.  Neurological outcomes associated with low-level manganese exposure in an inception cohort of asymptomatic welding trainees. , 2015, Scandinavian journal of work, environment & health.

[8]  N. Seixas,et al.  Quantitative neuropathology associated with chronic manganese exposure in South African mine workers. , 2014, Neurotoxicology.

[9]  F. Wang,et al.  Pallidal Index as Biomarker of Manganese Brain Accumulation and Associated with Manganese Levels in Blood: A Meta-Analysis , 2014, PloS one.

[10]  L. Sheppard,et al.  Blood Manganese as an Exposure Biomarker: State of the Evidence , 2014, Journal of occupational and environmental hygiene.

[11]  L. Sheppard,et al.  Increased risk of parkinsonism associated with welding exposure. , 2012, Neurotoxicology.

[12]  J. Perlmutter,et al.  Basal ganglia intensity indices and diffusion weighted imaging in manganese-exposed welders , 2011, Occupational and Environmental Medicine.

[13]  T. Videen,et al.  Reduced uptake of [18F]FDOPA PET in asymptomatic welders with occupational manganese exposure , 2011, Neurology.

[14]  N. Seixas,et al.  Estimation of particulate mass and manganese exposure levels among welders. , 2011, The Annals of occupational hygiene.

[15]  Joo-Hyun Kim,et al.  Altered working memory process in the manganese-exposed brain , 2010, NeuroImage.

[16]  V. Preedy,et al.  Unified Parkinson's Disease Rating Scale , 2010 .

[17]  M. Aschner,et al.  Manganese (Mn) and Iron (Fe): Interdependency of Transport and Regulation , 2010, Neurotoxicity Research.

[18]  R. Park,et al.  Exposure-Response Relationship and Risk Assessment for Cognitive Deficits in Early Welding-Induced Manganism , 2009, Journal of occupational and environmental medicine.

[19]  Yongmin Chang,et al.  High signal intensity on magnetic resonance imaging is a better predictor of neurobehavioral performances than blood manganese in asymptomatic welders. , 2009, Neurotoxicology.

[20]  Michael Aschner,et al.  A model for the analysis of competitive relaxation effects of manganese and iron in vivo , 2009, NMR in biomedicine.

[21]  N. Seixas,et al.  Validity and Reliability of an Occupational Exposure Questionnaire for Parkinsonism in Welders , 2009, Journal of occupational and environmental hygiene.

[22]  Maryse Bouchard,et al.  Sequelae of fume exposure in confined space welding: a neurological and neuropsychological case series. , 2007, Neurotoxicology.

[23]  H. Cheong,et al.  Evaluation of MR signal index for the assessment of occupational manganese exposure of welders by measurement of local proton T1 relaxation time. , 2007, Neurotoxicology.

[24]  D. Dorman,et al.  Tissue manganese concentrations in young male rhesus monkeys following subchronic manganese sulfate inhalation. , 2006, Toxicological sciences : an official journal of the Society of Toxicology.

[25]  Jean Lambert,et al.  Bioaccumulation and locomotor effects of manganese sulfate in Sprague-Dawley rats following subchronic (90 days) inhalation exposure. , 2006, Toxicology and applied pharmacology.

[26]  Yangho Kim,et al.  High signal intensities on T1-weighted MRI as a biomarker of exposure to manganese. , 2004, Industrial health.

[27]  Erik Stålberg,et al.  Effects of manganese oxide on monkeys as revealed by a combined neurochemical, histological and neurophysiological evaluation , 2004, Archives of Toxicology.

[28]  O. Jansen,et al.  Results of magnetic resonance imaging in long-term manganese dioxide-exposed workers. , 2001, Environmental research.

[29]  A. Bonnet,et al.  [The Unified Parkinson's Disease Rating Scale]. , 2000, Revue neurologique.

[30]  J. W. Kim,et al.  Increase in signal intensities on T1-weighted magnetic resonance images in asymptomatic manganese-exposed workers. , 1999, Neurotoxicology.

[31]  N. Chu,et al.  Long-term progression in chronic manganism , 1998, Neurology.

[32]  S. Greenland,et al.  Simulation study of confounder-selection strategies. , 1993, American journal of epidemiology.

[33]  C. Angle,et al.  Manganese encephalopathy: utility of early magnetic resonance imaging. , 1993, British journal of industrial medicine.

[34]  J RODIER,et al.  Manganese Poisoning in Moroccan Miners , 1955, British journal of industrial medicine.