eMedicine Specialties > Neurology > Neurotoxicology

Mercury: Follow-up

Author: David A Olson, MD, Clinical Neurologist, Dekalb Neurology Associates, Decatur, Georgia
Contributor Information and Disclosures

Updated: Sep 21, 2009

Follow-up

Further Outpatient Care

  • Determine follow-up care on a case-by-case basis. Obtain laboratory measurements of toxicity in patients with possible continued sources of exposure.

Inpatient & Outpatient Medications

  • Chelation treatment may be administered in the outpatient setting with an oral chelator, such as DMSA.
  • Little information is available about the treatment of mercury-induced tremulousness, but initiation of empiric treatment for patients who are functionally impaired with this complication would be reasonable.
  • Patients with cognitive and emotional sequelae may require psychotropic medications.

Transfer

  • Serious clinical manifestations due to exposure should be managed in a tertiary care facility by physicians experienced with toxicological emergencies.

Deterrence/Prevention

  • Unfortunately, a clinician can do little to prevent mercury toxicity. Public education can raise awareness about the risks associated with easily preventable sources of toxicity, such as contaminated herbal preparations or mercury thermometers.
  • Workplace hygiene and careful monitoring and disposal of industrial waste are equally important.
  • Publicizing the amount of mercury contained in frequently eaten fish can help reduce toxicity on a local level.

Prognosis

  • Recovery from mercury poisoning is variable. While the cognitive and emotional sequelae, at least in adults, may diminish with time, tremors and neuropathic changes have been reported to persist for decades after inorganic mercury exposure. For example, among 104 workers examined 30 years following inorganic mercury exposure, the presence of resting tremors correlated significantly with prior cumulative mercury exposure.51

Patient Education

Miscellaneous

Medicolegal Pitfalls

  • The American Dental Association has reported that 34 of 38 lawsuits alleging amalgam-induced mercury toxicity have been dismissed since 2002.
  • The recent book Evidence of Harm outlines the litigious efforts of parents of autistic children who claim that thimerosal-containing vaccines caused their children's neurologic dysfunction. At least one described lawsuit alleged that the vaccinating pediatrician was liable.52
  • Because of the potential for extensive litigation, exercise extreme care in documenting the route and circumstances of the exposure along with the presenting symptoms and physical findings.
  • Supportive documentation with carefully processed laboratory measures of exposure is also essential.
  • Reserve neuroimaging and electrophysiological testing for selected cases.

Special Concerns

  • Notify state and local health officials to clarify the mechanism of exposure and to institute appropriate decontamination measures should these be necessary.
 


More on Mercury

Overview: Mercury
Differential Diagnoses & Workup: Mercury
Treatment & Medication: Mercury
Follow-up: Mercury
References
[ CLOSE WINDOW ]

References

  1. Charcot JM. Clinical lectures of diseases of the nervous system. The Landmark Library of Neurology and Neurosurgery. 1994;186.

  2. Wilson SAK. Neurology. The Landmark Library of Neurology and Neurosurgery. 1994;739-740.

  3. Harada M. Minamata disease: methylmercury poisoning in Japan caused by environmental pollution. Crit Rev Toxicol. 1995;25(1):1-24. [Medline].

  4. Takeuchi T, Eto K, Kinjo Y, Tokunaga H. Human brain disturbance by methylmercury poisoning, focusing on the long-term effect on brain weight. Neurotoxicology. Spring 1996;17(1):187-90. [Medline].

  5. Vahter ME, Mottet NK, Friberg LT, Lind SB, Charleston JS, Burbacher TM. Demethylation of methyl mercury in different brain sites of Macaca fascicularis monkeys during long-term subclinical methyl mercury exposure. Toxicol Appl Pharmacol. Oct 1995;134(2):273-84. [Medline].

  6. Carvalho CM, Chew EH, Hashemy SI, Lu J, Holmgren A. Inhibition of the human thioredoxin system. A molecular mechanism of mercury toxicity. J Biol Chem. May 2 2008;283(18):11913-23. [Medline].

  7. Basu N, Scheuhammer AM, Rouvinen-Watt K, Evans RD, Grochowina N, Chan LH. The effects of mercury on muscarinic cholinergic receptor subtypes (M1 and M2) in captive mink. Neurotoxicology. Mar 2008;29(2):328-34. [Medline].

  8. Huang CF, Hsu CJ, Liu SH, Lin-Shiau SY. Neurotoxicological mechanism of methylmercury induced by low-dose and long-term exposure in mice: oxidative stress and down-regulated Na+/K(+)-ATPase involved. Toxicol Lett. Feb 15 2008;176(3):188-97. [Medline].

  9. Yamashita T, Ando Y, Sakashita N, et al. Role of nitric oxide in the cerebellar degeneration during methylmercury intoxication. Biochim Biophys Acta. Mar 15 1997;1334(2-3):303-11. [Medline].

  10. Nierenberg DW, Nordgren RE, Chang MB, et al. Delayed cerebellar disease and death after accidental exposure to dimethylmercury. N Engl J Med. Jun 4 1998;338(23):1672-6. [Medline].

  11. Albers JW, Kallenbach LR, Fine LJ, et al. Neurological abnormalities associated with remote occupational elemental mercury exposure. Ann Neurol. Nov 1988;24(5):651-9. [Medline].

  12. Myers GJ, Davidson PW. Prenatal methylmercury exposure and children: neurologic, developmental, and behavioral research. Environ Health Perspect. Jun 1998;106 Suppl 3:841-7. [Medline].

  13. Stern AH, Jacobson JL, Ryan L, Burke TA. Do recent data from the Seychelles Islands alter the conclusions of the NRC Report on the toxicological effects of methylmercury?. Environ Health. Jan 30 2004;3(1):2. [Medline].

  14. Davis LE, Kornfeld M, Mooney HS, et al. Methylmercury poisoning: long-term clinical, radiological, toxicological, and pathological studies of an affected family. Ann Neurol. Jun 1994;35(6):680-8. [Medline].

  15. Jao-Tan C, Pope E. Cutaneous poisoning syndromes in children: a review. Curr Opin Pediatr. Aug 2006;18(4):410-6. [Medline].

  16. Takaoka S, Kawakami Y, Fujino T, Oh-ishi F, Motokura F, Kumagai Y. Somatosensory disturbance by methylmercury exposure. Environ Res. May 2008;107(1):6-19. [Medline].

  17. Haut MW, Morrow LA, Pool D, Callahan TS, Haut JS, Franzen MD. Neurobehavioral effects of acute exposure to inorganic mercury vapor. Appl Neuropsychol. 1999;6(4):193-200. [Medline].

  18. Yokoo EM, Valente JG, Grattan L, Schmidt SL, Platt I, Silbergeld EK. Low level methylmercury exposure affects neuropsychological function in adults. Environ Health. Jun 4 2003;2(1):8. [Medline].

  19. Weil M, Bressler J, Parsons P, Bolla K, Glass T, Schwartz B. Blood mercury levels and neurobehavioral function. JAMA. Apr 20 2005;293(15):1875-82. [Medline].

  20. Chang JW, Pai MC, Chen HL, Guo HR, Su HJ, Lee CC. Cognitive function and blood methylmercury in adults living near a deserted chloralkali factory. Environ Res. Nov 2008;108(3):334-9. [Medline].

  21. Echeverria D, Woods JS, Heyer NJ, Rohlman D, Farin FM, Li T, et al. The association between a genetic polymorphism of coproporphyrinogen oxidase, dental mercury exposure and neurobehavioral response in humans. Neurotoxicol Teratol. Jan-Feb 2006;28(1):39-48. [Medline].

  22. Boyd AS, Seger D, Vannucci S, Langley M, Abraham JL, King LE Jr. Mercury exposure and cutaneous disease. J Am Acad Dermatol. Jul 2000;43(1 Pt 1):81-90. [Medline].

  23. Dantzig PI. A new cutaneous sign of mercury poisoning?. J Am Acad Dermatol. Dec 2003;49(6):1109-11. [Medline].

  24. Tang HL, Chu KH, Mak YF, Lee W, Cheuk A, Yim KF. Minimal change disease following exposure to mercury-containing skin lightening cream. Hong Kong Med J. Aug 2006;12(4):316-8. [Medline].

  25. Espinoza EO, Mann MJ, Bleasdell B. Arsenic and mercury in traditional Chinese herbal balls. N Engl J Med. Sep 21 1995;333(12):803-4. [Medline].

  26. Sallon S, Namdul T, Dolma S, et al. Mercury in traditional Tibetan medicine - panacea or problem?. Hum Exp Toxicol. Jul 2006;25(7):405-12. [Medline].

  27. Garetano G, Stern AH, Robson M, Gochfeld M. Mercury vapor in residential building common areas in communities where mercury is used for cultural purposes versus a reference community. Sci Total Environ. Jul 1 2008;397(1-3):131-9. [Medline].

  28. Saper RB, Kales SN, Paquin J, et al. Heavy metal content of ayurvedic herbal medicine products. JAMA. Dec 15 2004;292(23):2868-73. [Medline].

  29. Kingman A, Albers JW, Arezzo JC, Garabrant DH, Michalek JE. Amalgam exposure and neurological function. Neurotoxicology. Mar 2005;26(2):241-55. [Medline].

  30. [Best Evidence] Bellinger DC, Trachtenberg F, Barregard L, et al. Neuropsychological and renal effects of dental amalgam in children: a randomized clinical trial. JAMA. Apr 19 2006;295(15):1775-83. [Medline].

  31. [Best Evidence] DeRouen TA, Martin MD, Leroux BG, et al. Neurobehavioral effects of dental amalgam in children: a randomized clinical trial. JAMA. Apr 19 2006;295(15):1784-92. [Medline].

  32. Triunfante P, Soares ME, Santos A, Tavares S, Carmo H, Bastos Mde L. Mercury fatal intoxication: two case reports. Forensic Sci Int. Jan 30 2009;184(1-3):e1-6. [Medline].

  33. Deschamps F, Strady C, Deslee G, Menciere-Faroy B, Deschamps S. Five years of follow-up after elemental mercury self-poisoning. Am J Forensic Med Pathol. Jun 2002;23(2):170-2. [Medline].

  34. Bigham M, Copes R. Thiomersal in vaccines: balancing the risk of adverse effects with the risk of vaccine-preventable disease. Drug Saf. 2005;28(2):89-101. [Medline].

  35. Risher JF, Amler SN. Mercury exposure: evaluation and intervention the inappropriate use of chelating agents in the diagnosis and treatment of putative mercury poisoning. Neurotoxicology. Aug 2005;26(4):691-9. [Medline].

  36. Li YF, Chen C, Li B, et al. Scalp hair as a biomarker in environmental and occupational mercury exposed populations: suitable or not?. Environ Res. May 2008;107(1):39-44. [Medline].

  37. Guallar E, Sanz-Gallardo MI, van't Veer P, et al. Mercury, fish oils, and the risk of myocardial infarction. N Engl J Med. Nov 28 2002;347(22):1747-54. [Medline].

  38. Rees JR, Sturup S, Chen C, Folt C, Karagas MR. Toenail mercury and dietary fish consumption. J Expo Sci Environ Epidemiol. Jan 2007;17(1):25-30. [Medline].

  39. Sallsten G, Barregard L, Wikkelso C, Schutz A. Mercury and proteins in cerebrospinal fluid in subjects exposed to mercury vapor. Environ Res. May 1994;65(2):195-206. [Medline].

  40. Urban P, Lukas E, Benicky L, Moscovicova E. Neurological and electrophysiological examination on workers exposed to mercury vapors. Neurotoxicology. Spring 1996;17(1):191-6. [Medline].

  41. Korogi Y, Takahashi M, Hirai T, et al. Representation of the visual field in the striate cortex: comparison of MR findings with visual field deficits in organic mercury poisoning (Minamata disease). AJNR Am J Neuroradiol. Jun-Jul 1997;18(6):1127-30. [Medline].

  42. White RF, Feldman RG, Moss MB, Proctor SP. Magnetic resonance imaging (MRI), neurobehavioral testing, and toxic encephalopathy: two cases. Environ Res. Apr 1993;61(1):117-23. [Medline].

  43. O'Carroll RE, Masterton G, Dougall N, Ebmeier KP, Goodwin GM. The neuropsychiatric sequelae of mercury poisoning. The Mad Hatter's disease revisited. Br J Psychiatry. Jul 1995;167(1):95-8. [Medline].

  44. Murata K, Weihe P, Budtz-Jorgensen E, Jorgensen PJ, Grandjean P. Delayed brainstem auditory evoked potential latencies in 14-year-old children exposed to methylmercury. J Pediatr. Feb 2004;144(2):177-83. [Medline].

  45. Chu CC, Huang CC, Ryu SJ, Wu TN. Chronic inorganic mercury induced peripheral neuropathy. Acta Neurol Scand. Dec 1998;98(6):461-5. [Medline].

  46. Miyakawa T, Murayama E, Sumiyoshi S, Deshimaru M, Fujimoto T. Late changes in human sural nerves in Minamata disease and in nerves of rats with experimental organic mercury poisoning. Acta Neuropathol. Jun 15 1976;35(2):131-8. [Medline].

  47. Forman J, Moline J, Cernichiari E, et al. A cluster of pediatric metallic mercury exposure cases treated with meso-2,3-dimercaptosuccinic acid (DMSA). Environ Health Perspect. Jun 2000;108(6):575-7. [Medline].

  48. Grandjean P, Guldager B, Larsen IB, Jorgensen PJ, Holmstrup P. Placebo response in environmental disease. Chelation therapy of patients with symptoms attributed to amalgam fillings. J Occup Environ Med. Aug 1997;39(8):707-14. [Medline].

  49. Cantor MO. Mercury lost in the gastrointestinal tract; report of an unusual case. J Am Med Assoc. Jun 9 1951;146(6):560-1. [Medline].

  50. Ragothaman M, Kulkarni G, Ashraf VV, Pal PK, Chickabasavaiah Y, Shankar SK. Elemental mercury poisoning probably causes cortical myoclonus. Mov Disord. Oct 15 2007;22(13):1964-8. [Medline].

  51. Letz R, Gerr F, Cragle D, Green RC, Watkins J, Fidler AT. Residual neurologic deficits 30 years after occupational exposure to elemental mercury. Neurotoxicology. Aug 2000;21(4):459-74. [Medline].

  52. Kirby D. Evidence of Harm. Mercury in Vaccine and the Autism Epidemic: A Medical Controversy. New York: Saint Martin's Press; 2005.

  53. Andersen A, Ellingsen DG, Morland T, Kjuus H. A neurological and neurophysiological study of chloralkali workers previously exposed to mercury vapour. Acta Neurol Scand. Dec 1993;88(6):427-33. [Medline].

  54. Ballatori N. Transport of toxic metals by molecular mimicry. Environ Health Perspect. Oct 2002;110 Suppl 5:689-94. [Medline].

  55. Bellanger TM, Caesar EM, Trachtman L. Blood mercury levels and fish consumption in Louisiana. J La State Med Soc. Feb 2000;152(2):64-73. [Medline].

  56. Bender MT, Williams JM. A real plan of action on mercury. Public Health Rep. Sep-Oct 1999;114(5):416-20. [Medline].

  57. Bluhm RE, Bobbitt RG, Welch LW, et al. Elemental mercury vapour toxicity, treatment, and prognosis after acute, intensive exposure in chloralkali plant workers. Part I: History, neuropsychological findings and chelator effects. Hum Exp Toxicol. May 1992;11(3):201-10. [Medline].

  58. Centers for Disease Control and Prevention. Mercury exposure among residents of a building formerly used for industrial purposes--New Jersey, 1995. MMWR Morb Mortal Wkly Rep. May 24 1996;45(20):422-4. [Medline].

  59. Centers for Disease Control and Prevention. Mercury poisoning associated with beauty cream--Texas, New Mexico, and California, 1995-1996. MMWR Morb Mortal Wkly Rep. May 17 1996;45(19):400-3. [Medline].

  60. Centers for Disease Control and Prevention. Update: expanded availability of thimerosal preservative-free hepatitis B vaccine. MMWR Morb Mortal Wkly Rep. Jul 21 2000;49(28):642, 651. [Medline].

  61. Cernichiari E, Myers GM, Clarkson TW, Weiss B. Did Andrew Jackson have mercury poisoning?. JAMA. Jan 12 2000;283(2):200-1. [Medline].

  62. Deleu D, Hanssens Y, al-Salmy HS, Hastie I. Peripheral polyneuropathy due to chronic use of topical ammoniated mercury. J Toxicol Clin Toxicol. 1998;36(3):233-7. [Medline].

  63. Dodes JE. The amalgam controversy. An evidence-based analysis. J Am Dent Assoc. Mar 2001;132(3):348-56. [Medline].

  64. Echeverria D, Aposhian HV, Woods JS, et al. Neurobehavioral effects from exposure to dental amalgam Hg(o): new distinctions between recent exposure and Hg body burden. FASEB J. Aug 1998;12(11):971-80. [Medline].

  65. Eto K, Takizawa Y, Akagi H, et al. Differential diagnosis between organic and inorganic mercury poisoning in human cases--the pathologic point of view. Toxicol Pathol. Nov-Dec 1999;27(6):664-71. [Medline].

  66. Eto K, Yasutake A, Kuwana T, et al. Methylmercury poisoning in common marmosets--a study of selective vulnerability within the cerebral cortex. Toxicol Pathol. Sep-Oct 2001;29(5):565-73. [Medline].

  67. Fonfria E, Vilaro MT, Babot Z, Rodriguez-Farre E, Sunol C. Mercury compounds disrupt neuronal glutamate transport in cultured mouse cerebellar granule cells. J Neurosci Res. Feb 15 2005;79(4):545-53. [Medline].

  68. Hursh JB, Cherian MG, Clarkson TW, Vostal JJ, Mallie RV. Clearance of mercury (HG-197, HG-203) vapor inhaled by human subjects. Arch Environ Health. Nov-Dec 1976;31(6):302-9. [Medline].

  69. Juarez BI, Martinez ML, Montante M, et al. Methylmercury increases glutamate extracellular levels in frontal cortex of awake rats. Neurotoxicol Teratol. Nov-Dec 2002;24(6):767-71. [Medline].

  70. Juarez BI, Portillo-Salazar H, Gonzalez-Amaro R, Mandeville P, Aguirre JR, Jimenez ME. Participation of N-methyl-D-aspartate receptors on methylmercury-induced DNA damage in rat frontal cortex. Toxicology. Feb 14 2005;207(2):223-9. [Medline].

  71. Korogi Y, Takahashi M, Shinzato J, Okajima T. MR findings in seven patients with organic mercury poisoning (Minamata disease). AJNR Am J Neuroradiol. Sep 1994;15(8):1575-8. [Medline].

  72. Langworth S, Sallsten G, Barregard L, Cynkier I, Lind ML, Soderman E. Exposure to mercury vapor and impact on health in the dental profession in Sweden. J Dent Res. Jul 1997;76(7):1397-404. [Medline].

  73. Mahaffey KR. Recent advances in recognition of low-level methylmercury poisoning. Curr Opin Neurol. Dec 2000;13(6):699-707. [Medline].

  74. Ozuah PO. Mercury poisoning. Curr Probl Pediatr. Mar 2000;30(3):91-9. [Medline].

  75. Palmer C. House committee hears testimony on medical mercury use. American Dental Association News. Apr 30 2001.

  76. Pamphlett R, Waley P. Mercury in human spinal motor neurons. Acta Neuropathol. Nov 1998;96(5):515-9. [Medline].

  77. Tokuomi H, Okajima T, Kanai J, et al. Minamata disease. World Neurol. Jun 1961;2:536-45. [Medline].

  78. Yoshizawa K, Rimm EB, Morris JS, et al. Mercury and the risk of coronary heart disease in men. N Engl J Med. Nov 28 2002;347(22):1755-60. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

mad hatter's syndrome, metal fume fever, erethism, Minamata disease, methylmercury, methyl mercury, mercury poisoning, mercury toxicity, mercury-induced cognitive impairments, mercury intoxication, mercury exposure, prenatal mercury exposure

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

David A Olson, MD, Clinical Neurologist, Dekalb Neurology Associates, Decatur, Georgia
David A Olson, MD is a member of the following medical societies: American Academy of Neurology
Disclosure: Nothing to disclose.

Medical Editor

Joseph Quinn, MD, Assistant Professor, Department of Neurology, Portland VA Medical Center, Oregon Health Sciences University
Joseph Quinn, MD is a member of the following medical societies: American Academy of Neurology, Society for Neuroscience, and Society for Pediatric Radiology
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Richard J Caselli, MD, Professor, Department of Neurology, Mayo Medical School, Rochester, MN; Chair, Department of Neurology, Mayo Clinic of Scottsdale
Richard J Caselli, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine, American Medical Association, American Neurological Association, and Sigma Xi
Disclosure: Nothing to disclose.

CME Editor

,, Kathy Roarty Placeholder
Disclosure: Nothing to disclose.

Chief Editor

Tarakad S Ramachandran, MBBS, FRCP(C), FACP, Professor of Neurology, Clinical Professor of Medicine, Clinical Professor of Family Medicine, Clinical Professor of Neurosurgery, State University of New York Upstate Medical University; Chair, Department of Neurology, Crouse Irving Memorial Hospital
Tarakad S Ramachandran, MBBS, FRCP(C), FACP is a member of the following medical societies: American Academy of Neurology, American Academy of Pain Medicine, American College of Forensic Examiners, American College of International Physicians, American College of Managed Care Medicine, American College of Physicians, American Heart Association, American Stroke Association, Royal College of Physicians, Royal College of Physicians and Surgeons of Canada, Royal College of Surgeons of England, and Royal Society of Medicine
Disclosure: Abbott Labs  Honoraria Consulting; Teva Marion Honoraria Consulting; Boeringer-Ingelheim Honoraria Speaking and teaching

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.