The enigma of parkinsonism in chronic borderline mercury intoxication, resolved by challenge with penicillamine

Neurotoxicology. 1996 Spring;17(1):291-5.


A 47 year old female dentist suffered from hemiparkinsonism which had started eighteen months earlier and was manifested mainly by resting tremor and cogwheel rigidity. A baseline quantitative urinary mercury excretion was 46 micrograms/day. The patient was treated with chelating agent d-penicillamine for a week. Chelation therapy resulted in clinical improvement of parkinsonism and in dynamic changes in daily urinary mercury excretion with a prompt increase to 79 micrograms/day, a subsequent decline followed by increase in the mercury urinary excretion. After a week chelation therapy was stopped. During a follow-up period of five years, the neurological status remained unchanged after the initial penicillamine-induced improvement. This case may be evidence, therefore, of a rare clinical variant of elemental mercury intoxication associated with parkinsonism, in the absence of most classical neuropsychiatric signs of chronic mercurialism.

Publication types

  • Case Reports

MeSH terms

  • Chelating Agents / therapeutic use*
  • Dentists
  • Female
  • Humans
  • Mercury / adverse effects
  • Mercury / urine
  • Mercury Poisoning / drug therapy*
  • Mercury Poisoning / urine
  • Middle Aged
  • Occupational Diseases / chemically induced
  • Occupational Diseases / drug therapy*
  • Parkinson Disease, Secondary / chemically induced
  • Parkinson Disease, Secondary / drug therapy*
  • Penicillamine / therapeutic use*


  • Chelating Agents
  • Mercury
  • Penicillamine