Heavy metal intoxication

1. Symptoms:
   1. children typically become anorexic, less playful, less alert, and more irritable with intermittent vomiting, vague abdominal pain, clumsiness, and ataxia; full blown encephalopathy may develop with more ingestion of lead; brain may become extremely swollen and CSF is under high pressure
   2. adults typically have colic, anemia, and peripheral neuropathy (bilateral wrist drop); encephalopathy is very rare; a black lead line may develop along the gingiva
2. Lead lines become present in the growth plates of the long bones (in children) and basophilic stippling of red cells and bone marrow blastocytic cells are increased; massive brain edema may develop
3. Impairment of heme synthesis results in increased excretion of urinary coproporphyrin and aminolevulinic acid
4. Treatment: establish urinary flow with IV fluids; chelation therapy with demercaptopropanol (BAL) and EDTA followed by oral penicillamine
5. Aluminum toxicity
   1. most common in patients undergoing chronic hemodialysis
   2. symptoms: encephalopathy with dysarthria and apraxia, myoclonus, gait disturbance, focal seizures and dementia
   3. neuritic plaques in Alzheimer’s patients show trace amounts of aluminum (significance is unknown)