Neurophysiological Evidence of Methylmercury Neurotoxicity

Details

• Personal Author:
  Dakeishi M ; Grandjean P ; Murata, Kiyoshi
• Description:
  Background: A variety of neurophysiological measures are useful in hospital settings for diagnostic and other clinical purposes. Previously, abnormal changes in various sensory evoked potentials (EPs), and heart rate variability (HRV) were observed in patients with acquired and fetal Minamata disease (MD; methylmercury poisoning). In recent years, some of these methods have been used for the risk assessment of low-level methylmercury exposure in asymptomatic children. The objectives of this article were to present an overview of neurophysiological findings involved in methylmercury neurotoxicity and to examine the usefulness of those measures. Methods: The reports addressing both neurophysiological measures and methylmercury exposure in humans were identified and evaluated. Results: The neurological signs and symptoms of MD included paresthesias, constriction of visual fields, impairment of hearing and speech, mental disturbances, excessive sweating, and hypersalivation. Neuropathological lesions involved visual, auditory, and post- and pre-central cortex areas. Neurophysiological changes involved in methylmercury, as assessed by EPs and HRV, were found to be in accordance with both clinical and neuropathological observations in patients with MD. Conclusions: EPs and HRV appear to be useful and objective methods for assessing methylmercury neurotoxicity. However, subtle changes due to low-level methylmercury exposure may not necessarily be of clinical relevance, and interpretation of small deviations from expectations must be cautious. [Description provided by NIOSH]
• Subjects:
  Cardiovascular System Chemistry Environmental Exposure Eye Hazardous Substances Hearing Loss Mental Disorders Mental Health Nervous System Occupational Health Poisoning Pregnancy Risk Assessment Risk Factors Safety Sense Organs Vision Disorders

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• Keywords:
  Author Keywords: Methylmercury Chemical Properties Chemicals Children Drugs Environmental Exposure Exposure Levels Health Effects Health Hazards Hearing Disorders Heart Rate Humans Mental Disorders Neuropathology Neurophysiological Effects Neurophysiological Measures Neurotoxicity Poisons Prenatal Exposure Review Risk Assessment Risk Factors Speech Disorders Vision Disorders

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• ISSN:
  0271-3586
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  50
• Issue:
  10
• NIOSHTIC Number:
  nn:20058639
• Citation:
  Am J Ind Med 2007 Oct; 50(10):765-771
• Contact Point Address:
  Katsuyuki Murata, Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
• Email:
  winestem@med.akita-u.ac.jp
• CAS Registry Number:
  Methylmercury(1+) (CAS RN 22967-92-6)
• Federal Fiscal Year:
  2008
• Performing Organization:
  Harvard School of Public Health
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  American Journal of Industrial Medicine
• End Date:
  20280630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:371ab6ab102a070258e02f3c645e0ff3f89daffc3586385de744bad665af5ad1516fdd1399317a60336f5c5b0af65f732d92e48472fbb70dbe2b9d396714fc9f
• Download URL:
  https://stacks.cdc.gov/view/cdc/221681/cdc_221681_DS1.pdf
• File Type:
  [PDF - 85.08 KB ]