Laurie-Anne Dion1, Maryse F Bouchard2, Sébastien Sauvé3, Benoit Barbeau4, Alan Tucholka5, Philipe Major6, Guillaume Gilbert7, Donna Mergler8, Dave Saint-Amour9. 1. Department of Psychology, Université du Québec à Montréal, Québec, Canada; Sainte-Justine University Hospital Research Center, Montréal, Québec, Canada. 2. Sainte-Justine University Hospital Research Center, Montréal, Québec, Canada; Centre for Interdisciplinary Studies in Biology, Health, Society and Environment (CINBIOSE), Université du Québec à Montréal, Québec, Canada; Department of Environmental and Occupational Health, Université de Montréal, Montréal, Québec, Canada. Electronic address: maryse.bouchard@umontreal.ca. 3. Department of Chemistry, Université de Montréal, Québec, Canada. 4. Department of Civil, Geological and Mining Engineering, École Polytechnique de Montréal, Québec, Canada. 5. BarcelonaBeta Research Center, Pasqual Maragall Foundation, Barcelona, Spain; Department of Radiology, CHUM Notre-Dame Hospital, Montréal, Québec, Canada. 6. Sainte-Justine University Hospital Research Center, Montréal, Québec, Canada. 7. Department of Radiology, CHUM Notre-Dame Hospital, Montréal, Québec, Canada; MR Clinical Science, Philips Healthcare, Markham, Ontario, Canada. 8. Centre for Interdisciplinary Studies in Biology, Health, Society and Environment (CINBIOSE), Université du Québec à Montréal, Québec, Canada. 9. Department of Psychology, Université du Québec à Montréal, Québec, Canada; Sainte-Justine University Hospital Research Center, Montréal, Québec, Canada; Centre for Interdisciplinary Studies in Biology, Health, Society and Environment (CINBIOSE), Université du Québec à Montréal, Québec, Canada.
Abstract
BACKGROUND: Manganese (Mn) can have neurotoxic effects upon overexposure. We previously reported poorer cognitive and motor development in children exposed to Mn through drinking water, suggesting possible neurotoxic effects from Mn in water. Hyperintensity in the globus pallidus (GP) on T1-weighted magnetic resonance imaging (MRI) indicates excessive brain Mn accumulation. Previous studies have reported GP hyperintensity related to Mn exposure in occupationally exposed individuals. However, no study has used MRI in children exposed to Mn in drinking water and who show no sign of overt intoxication. OBJECTIVE: To examine MRI signal intensity in the GP in children exposed to contrasted levels of Mn in drinking water. METHODS: We enrolled 13 children exposed to low Mn concentration in water and 10 children (ages 9-15 years) with high concentration (median of 1 and 145μg/L, respectively). We calculated three MRI T1 indexes: (i) standard pallidal index (PI) using frontal white matter as reference; (ii) PI using pericranial muscles as reference; and (iii) T1 relaxation time. Each MRI index was compared between exposure groups, and with respect to the estimated Mn intake from water consumption. RESULTS: The standard PI did not differ between Mn-exposure groups. However, children in the group with high water-Mn concentration had significantly lower pericranial muscles PI than those with lower exposure and, accordingly, higher T1 relaxation time. Mn intake from water consumption was not correlated with the standard PI, but was significantly related to the pericranial muscles PI and T1 relaxation time. Motor performance was significantly lower in the high-exposure group. CONCLUSION: We observed lower signal intensity in the GP of children with higher exposure to Mn from drinking water. This result stands in contrast to previous MRI reports showing GP hyperintensity with greater Mn exposure. Differences in exposure pathways are discussed as a potential explanation for this discrepancy.
BACKGROUND:Manganese (Mn) can have neurotoxic effects upon overexposure. We previously reported poorer cognitive and motor development in children exposed to Mn through drinking water, suggesting possible neurotoxic effects from Mn in water. Hyperintensity in the globus pallidus (GP) on T1-weighted magnetic resonance imaging (MRI) indicates excessive brain Mn accumulation. Previous studies have reported GP hyperintensity related to Mn exposure in occupationally exposed individuals. However, no study has used MRI in children exposed to Mn in drinking water and who show no sign of overt intoxication. OBJECTIVE: To examine MRI signal intensity in the GP in children exposed to contrasted levels of Mn in drinking water. METHODS: We enrolled 13 children exposed to low Mn concentration in water and 10 children (ages 9-15 years) with high concentration (median of 1 and 145μg/L, respectively). We calculated three MRI T1 indexes: (i) standard pallidal index (PI) using frontal white matter as reference; (ii) PI using pericranial muscles as reference; and (iii) T1 relaxation time. Each MRI index was compared between exposure groups, and with respect to the estimated Mn intake from water consumption. RESULTS: The standard PI did not differ between Mn-exposure groups. However, children in the group with high water-Mn concentration had significantly lower pericranial muscles PI than those with lower exposure and, accordingly, higher T1 relaxation time. Mn intake from water consumption was not correlated with the standard PI, but was significantly related to the pericranial muscles PI and T1 relaxation time. Motor performance was significantly lower in the high-exposure group. CONCLUSION: We observed lower signal intensity in the GP of children with higher exposure to Mn from drinking water. This result stands in contrast to previous MRI reports showing GP hyperintensity with greater Mn exposure. Differences in exposure pathways are discussed as a potential explanation for this discrepancy.
Authors: Eun-Young Lee; Michael R Flynn; Mechelle M Lewis; Richard B Mailman; Xuemei Huang Journal: Neurotoxicology Date: 2017-06-23 Impact factor: 4.294
Authors: Erik de Water; Erika Proal; Victoria Wang; Sandra Martínez Medina; Lourdes Schnaas; Martha María Téllez-Rojo; Robert O Wright; Cheuk Y Tang; Megan K Horton Journal: Neurotoxicology Date: 2017-06-10 Impact factor: 4.398
Authors: Erik de Water; Demetrios M Papazaharias; Claudia Ambrosi; Lorella Mascaro; Emilia Iannilli; Roberto Gasparotti; Roberto G Lucchini; Christine Austin; Manish Arora; Cheuk Y Tang; Donald R Smith; Robert O Wright; Megan K Horton Journal: PLoS One Date: 2019-08-14 Impact factor: 3.752