NEUROPATHOLOGY OF PRECLINICAL AND CLINICAL LATE-ONSET ALZHEIMERS-DISEASE

We report on the neuropathological examinations of a 74-year-old woman with Alzheimer's disease (AD) and of her 47-year-old nondemented daug hter. The brain of the mother showed fully developed pathological chan ges of AD. By contrast, the brain of the daughter revealed only perine uronal deposition of diffuse amyloid in cerebral cortex and striking a bnormalities of the endosomal-lysosomal system, without neurofibrillar y, glial, or microglial changes. These observations suggest that amylo id deposition and endosomal-lysosomal changes are early events in late -onset AD and that they may precede the onset of dementia by several d ecades.