[Acute psychosis--an unusual clinical manifestation of primary hyperparathyroidism].

In 1942, the Norwegian psychiatrist Eitinger drew attention to the fact that acute psychosis may be the presenting and major symptom of primary hyperparathyroidism. A case of this variety is reported. In the course of two months a 77-year old woman developed an acute psychosis characterized by apathy, amnesia, somatic delusions and hallucinations. Initially, the case was misinterpreted as senile dementia. The serum calcium level was 4.3 mmol/l. After parathyroidectomy her mental symptoms were completely relieved.