THE ENIGMA OF PARKINSONISM IN CHRONIC BORDERLINE MERCURY INTOXICATION, RESOLVED BY CHALLENGE WITH PENICILLAMINE

A 47 year old female dentist suffered from hemiparkinsonism which had started eighteen months earlier and was manifested mainly by resting t remor and cogwheel rigidity. A baseline quantitative urinary mercury e xcretion was 46 mu g/day. The patient was treated with chelating agent d-penicillamine for a week. Chelation therapy resulted in clinical im provement of parkinsonism and in dynamic changes in daily urinary merc ury excretion with a prompt increase to 79 mu g/day, a subsequent decl ine followed by increase in the mercury urinary excretion. After a wee k chelation therapy was stopped. During a follow-up period of five yea rs, the neurological status remained unchanged after the initial penic illamine-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 s igns of chronic mercurialism. (C) 1996 Inter Press, Inc.