Abstract
Extensive literature from the past 40 years accuses brain amyloid as one of the causal factors of senile dementia. Amyloid is considered, together with intracellular inclusions of tau-protein, as the originator for a specific Alzheimer's disease.
After being dependent for many decades on amyloid detection only in autopsy specimens, the application of radioactive ligands using positron emission tomography (PET) currently achieves highly informative in vivo findings. The recognition of relations between mental acuity and the intensity of amyloid deposits has thus obtained a new dimension.
We are providing a review of methods and their conclusions which shed light onto the mechanisms of brain ageing: histological properties of amyloid, techniques and the yield of its detection in PET, relation of amyloid density to that of neurofibrillary tangles, its relation to tissue metabolism and atrophy, dynamics of amyloid presence according to age and cor relative studies between amyloid and mental effectivity. The given interpretation puts doubt on the causal role of amyloid in the psychic deterioration of seniors and thus also on one of the pillars of the so-called Alzheimer's disease.