HYPOTHALAMIC DYSFUNCTION IN DEMENTIA

In 40 patients with Alzheimer's disease (AD) 56 patients with senile d ementia of Alzheimer type (SDAT) and 45 patients with vascular dementi a (VAD) degree of dementia was rated into mild, moderate and severe ac cording to DSM-III-R and an the GBS scale. Basal cortisol levels were determined and a dexamethasone test (DST) performed. Basal cortisol le vels were high in all the dementia groups. Forty percent of AD patient s, 54% of SDAT patients and 49% of VAD patients were non suppressors. Significant correlations between post DST cortisol levels and rated va riables were seen mainly in the VAD group. The pathological DST could hardly be explained by presence of depression. In dementia, especially those with white matter disturbances, disconnections between cortical areas (hippocampus) and hypothalamus can be assumed explaining a redu ced inhibitory tone on hypothalamus. When characterizing VAD patients with pathological DST these patients were significantly more intellect ually impaired, showed higher degree of anxiety, restlessness and fear -panic than VAD patients with normal DST. Some behaviourial disturbanc es in dementia disorders may be a consequence of HPA over activity rat her than a consequence of the dementia process itself.