Visual evoked potentials in children prenatally exposed to methylmercury

Takashi Yorifuji, Katsuyuki Murata, Kristian S. Bjerve, Anna L. Choi, Pal Weihe, Philippe Grandjean

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Prenatal exposure to methylmercury can cause both neurobehavioral deficits and neurophysiological changes. However, evidence of neurotoxic effects within the visual nervous system is inconsistent, possibly due to incomplete statistical adjustment for beneficial nutritional factors. We evaluated the effect of prenatal methylmercury exposure on visual evoked potential (VEP) latencies in Faroese children with elevated prenatal methylmercury exposure. A cohort of 182 singleton term births was assembled in the Faroe Islands during 1994-1995. At age 7 years, VEP tracings were obtained from 139 cohort subjects after exclusion of subjects with abnormal vision conditions. We used multiple regression analysis to evaluate the association of mercury concentrations in cord blood and maternal hair at parturition with VEP latencies after adjustment for potential confounders that included the cord-serum phospholipid concentration of n-3 polyunsaturated fatty acids (PUFAs) and the duration of breastfeeding. Unadjusted correlations between mercury exposure and VEP latencies were equivocal. Multiple regression models showed that increased mercury concentrations, especially in maternal hair, were associated with delayed latencies for VEP peak N145. After covariate adjustment, a delay of 2.22. ms (p= 0.02) was seen for each doubling of the mercury concentration in maternal hair. In agreement with neuropsychological findings, the present study suggests that prenatal methylmercury exposure may have an adverse effect on VEP findings despite the absence of clinical toxicity to the visual system. However, this association was apparent only after adjustment for n-3 PUFA status.

Original languageEnglish
Pages (from-to)15-18
Number of pages4
JournalNeuroToxicology
Volume37
DOIs
Publication statusPublished - Jul 2013

Fingerprint

Visual Evoked Potentials
Bioelectric potentials
Mercury
Hair
Mothers
Omega-3 Fatty Acids
Term Birth
Social Adjustment
Denmark
Breast Feeding
Fetal Blood
Neurology
Nervous System
Phospholipids
Regression analysis
Toxicity
Regression Analysis
Parturition
Blood
Serum

Keywords

  • Evoked potentials
  • Food contamination
  • Methylmercury compounds
  • Neurophysiological measures
  • Omega-3 fatty acids
  • Prenatal exposure delayed effects

ASJC Scopus subject areas

  • Neuroscience(all)
  • Toxicology

Cite this

Visual evoked potentials in children prenatally exposed to methylmercury. / Yorifuji, Takashi; Murata, Katsuyuki; Bjerve, Kristian S.; Choi, Anna L.; Weihe, Pal; Grandjean, Philippe.

In: NeuroToxicology, Vol. 37, 07.2013, p. 15-18.

Research output: Contribution to journalArticle

Yorifuji, Takashi ; Murata, Katsuyuki ; Bjerve, Kristian S. ; Choi, Anna L. ; Weihe, Pal ; Grandjean, Philippe. / Visual evoked potentials in children prenatally exposed to methylmercury. In: NeuroToxicology. 2013 ; Vol. 37. pp. 15-18.
@article{34168ca88c3f4b219db080db2dfa3ee2,
title = "Visual evoked potentials in children prenatally exposed to methylmercury",
abstract = "Prenatal exposure to methylmercury can cause both neurobehavioral deficits and neurophysiological changes. However, evidence of neurotoxic effects within the visual nervous system is inconsistent, possibly due to incomplete statistical adjustment for beneficial nutritional factors. We evaluated the effect of prenatal methylmercury exposure on visual evoked potential (VEP) latencies in Faroese children with elevated prenatal methylmercury exposure. A cohort of 182 singleton term births was assembled in the Faroe Islands during 1994-1995. At age 7 years, VEP tracings were obtained from 139 cohort subjects after exclusion of subjects with abnormal vision conditions. We used multiple regression analysis to evaluate the association of mercury concentrations in cord blood and maternal hair at parturition with VEP latencies after adjustment for potential confounders that included the cord-serum phospholipid concentration of n-3 polyunsaturated fatty acids (PUFAs) and the duration of breastfeeding. Unadjusted correlations between mercury exposure and VEP latencies were equivocal. Multiple regression models showed that increased mercury concentrations, especially in maternal hair, were associated with delayed latencies for VEP peak N145. After covariate adjustment, a delay of 2.22. ms (p= 0.02) was seen for each doubling of the mercury concentration in maternal hair. In agreement with neuropsychological findings, the present study suggests that prenatal methylmercury exposure may have an adverse effect on VEP findings despite the absence of clinical toxicity to the visual system. However, this association was apparent only after adjustment for n-3 PUFA status.",
keywords = "Evoked potentials, Food contamination, Methylmercury compounds, Neurophysiological measures, Omega-3 fatty acids, Prenatal exposure delayed effects",
author = "Takashi Yorifuji and Katsuyuki Murata and Bjerve, {Kristian S.} and Choi, {Anna L.} and Pal Weihe and Philippe Grandjean",
year = "2013",
month = "7",
doi = "10.1016/j.neuro.2013.03.009",
language = "English",
volume = "37",
pages = "15--18",
journal = "NeuroToxicology",
issn = "0161-813X",
publisher = "Elsevier",

}

TY - JOUR

T1 - Visual evoked potentials in children prenatally exposed to methylmercury

AU - Yorifuji, Takashi

AU - Murata, Katsuyuki

AU - Bjerve, Kristian S.

AU - Choi, Anna L.

AU - Weihe, Pal

AU - Grandjean, Philippe

PY - 2013/7

Y1 - 2013/7

N2 - Prenatal exposure to methylmercury can cause both neurobehavioral deficits and neurophysiological changes. However, evidence of neurotoxic effects within the visual nervous system is inconsistent, possibly due to incomplete statistical adjustment for beneficial nutritional factors. We evaluated the effect of prenatal methylmercury exposure on visual evoked potential (VEP) latencies in Faroese children with elevated prenatal methylmercury exposure. A cohort of 182 singleton term births was assembled in the Faroe Islands during 1994-1995. At age 7 years, VEP tracings were obtained from 139 cohort subjects after exclusion of subjects with abnormal vision conditions. We used multiple regression analysis to evaluate the association of mercury concentrations in cord blood and maternal hair at parturition with VEP latencies after adjustment for potential confounders that included the cord-serum phospholipid concentration of n-3 polyunsaturated fatty acids (PUFAs) and the duration of breastfeeding. Unadjusted correlations between mercury exposure and VEP latencies were equivocal. Multiple regression models showed that increased mercury concentrations, especially in maternal hair, were associated with delayed latencies for VEP peak N145. After covariate adjustment, a delay of 2.22. ms (p= 0.02) was seen for each doubling of the mercury concentration in maternal hair. In agreement with neuropsychological findings, the present study suggests that prenatal methylmercury exposure may have an adverse effect on VEP findings despite the absence of clinical toxicity to the visual system. However, this association was apparent only after adjustment for n-3 PUFA status.

AB - Prenatal exposure to methylmercury can cause both neurobehavioral deficits and neurophysiological changes. However, evidence of neurotoxic effects within the visual nervous system is inconsistent, possibly due to incomplete statistical adjustment for beneficial nutritional factors. We evaluated the effect of prenatal methylmercury exposure on visual evoked potential (VEP) latencies in Faroese children with elevated prenatal methylmercury exposure. A cohort of 182 singleton term births was assembled in the Faroe Islands during 1994-1995. At age 7 years, VEP tracings were obtained from 139 cohort subjects after exclusion of subjects with abnormal vision conditions. We used multiple regression analysis to evaluate the association of mercury concentrations in cord blood and maternal hair at parturition with VEP latencies after adjustment for potential confounders that included the cord-serum phospholipid concentration of n-3 polyunsaturated fatty acids (PUFAs) and the duration of breastfeeding. Unadjusted correlations between mercury exposure and VEP latencies were equivocal. Multiple regression models showed that increased mercury concentrations, especially in maternal hair, were associated with delayed latencies for VEP peak N145. After covariate adjustment, a delay of 2.22. ms (p= 0.02) was seen for each doubling of the mercury concentration in maternal hair. In agreement with neuropsychological findings, the present study suggests that prenatal methylmercury exposure may have an adverse effect on VEP findings despite the absence of clinical toxicity to the visual system. However, this association was apparent only after adjustment for n-3 PUFA status.

KW - Evoked potentials

KW - Food contamination

KW - Methylmercury compounds

KW - Neurophysiological measures

KW - Omega-3 fatty acids

KW - Prenatal exposure delayed effects

UR - http://www.scopus.com/inward/record.url?scp=84876725290&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84876725290&partnerID=8YFLogxK

U2 - 10.1016/j.neuro.2013.03.009

DO - 10.1016/j.neuro.2013.03.009

M3 - Article

C2 - 23548974

AN - SCOPUS:84876725290

VL - 37

SP - 15

EP - 18

JO - NeuroToxicology

JF - NeuroToxicology

SN - 0161-813X

ER -