Acute hypercalcemia in hemodialysis patients: distinction from 'dialysis dementia'

The clinical, laboratory and EEG findings of 4 uremic patients on hemodialysis who accidently developed acute hypercalcemia were reviewed. An acute central nervous system syndrome developed, associated with the clinical changes of disorientation, dysarthria, seizures, myoclonic jerks, hallucinations, irritability, confusion, memory and judgment defects plus bizarre behavior. The EEG findings demonstrated diffusely severe slow background activity in all tracings. In addition, the EEG abnormalities as well as the clinical findings disappeared when serum calcium returned to normal. Hypercalcemia, a reversible condition, seems to have been the cause of this clinical syndrome which should be differentiated from dialysis dementia, a condition known to be irreversible and fatal.