AGE VS AGING IN THE PATHOGENESIS OF SENILE DEMENTIA OF THE ALZHEIMER-TYPE - ELECTROPHYSIOLOGICAL EVIDENCE

Is senile dementia of the Alzheimer type (SDAT) the end result of agin g of the brain (serial or aging-related model) or the result of some o ther mechanism that runs in parallel to normal aging (parallel or age- related model)? This question can be answered by comparing variables t hat measure biological aging (aging-dependent variables, ADVs) of norm al individuals and of SDAT patients. If the serial model applies, the values of the ADVs of SDAT patients should be at the upper end of the normal ADV curves. In control individuals the power of the alpha band in the 2-Hz flash-stimulated EEG at the posterior head regions increas ed with age, while the power of the delta band in the resting EEG at t he anterior head regions decreased. In SDAT patients the ADVs were sig nificantly different from normal and opposite to the trend of normal a ging, supporting the parallel model and suggesting that the pathogenes is of SDAT is different from normal aging.