Alzheimer patients: preamyloid deposits are more widely distributed than senile plaques throughout the central nervous system.

In Alzheimer's disease, anti-beta-protein antisera label not only amyloid deposits accompanied by degenerating neurites (neuritic and mature plaques) and amyloid deposits without degenerating neurites, but also preamyloid deposits lacking the optical properties of amyloid fibrils. We have carried out a study of the brains of 13 patients with Alzheimer's disease (one with the familial and 12 with the sporadic form), using anti-beta-protein and anti-paired helical filament antisera, thioflavine S, Congo red and Gallyas' silver impregnation, in order to determine whether the distribution of preamyloid deposits and amyloid deposits without degenerating neurites differs from that of amyloid deposits with degenerating neurites. Preamyloid deposits and amyloid deposits with or without degenerating neurites were present in cortex, neostriatum, medial geniculate body and thalamic (anterior and extralaminar) nuclei, whereas preamyloid deposits and amyloid deposits without degenerating neurites, but not amyloid deposits with degenerating neurites, were present in other thalamic nuclei, in the globus pallidus, brainstem, cerebellar cortex and upper spinal cord. These results support the view that preamyloid deposits evolve to senile (neuritic and mature) plaques only in specific brain regions, where neurites vulnerable to amyloid fibrils are widely distributed.