Increased response of serum prolactin to metoclopramide in senile dementia of Alzheimer type

The investigation studied the effect of intravenous administration of a dopamine blocking agent (metoclopramide) on serum prolactin levels in patients with senile dementia of Alzheimer type (SDAT) and in non-demented elderly controls. The response to metoclopramide was greater in the demented patients than in the controls, suggesting that dementia is associated with dysfunction in the tubero-infundibular pathway which controls prolactin secretion. This finding adds to the evidence that dopaminergic systems may be affected in dementia, in the absence of clinical evidence of extrapyramidal disorder.