Anterior pituitary response to thyrotrophin releasing hormone in senile dementia (Alzheimer type) and elderly normals

Sixteen patients with senile dementia of the Alzheimer type (SDAT) were compared with 11 age-matched normal subjects with respect to their responses of thyrotrophin (TSH) and prolactin (PRL) to thyrotrophin releasing hormone (TRH) challenge. Both groups showed a continuing rise in TSH response at 60 min, and no difference was found between the groups. A significantly exaggerated PRL response at 20 min was found in the SDAT group. There was no difference between sexes with respect to either the TSH or PRL response. These findings, albeit preliminary, may have implications for dopaminergic impairment in SDAT.