John Jones wrote:The point here is that the abnormality is not an abnormality of tissue, but an abnormality of behaviour, and that is always a social consideration. The tissue doesn't tell you what is abnormal, you baptize it as being abnormal by a social judgement.
In the later stages, deterioration of musculature and mobility, leading to bedfastness, inability to feed oneself, and incontinence, will be seen if death from some external cause (e.g. heart attack or pneumonia) does not intervene. Source:
Wikipedia article
Alzheimer's can't be definitively diagnosed without an autopsy because the abnormal tissues can only be examined post-mortem, but by definition, the tissue abnormality, and not behavioral abnormality, is what constitutes Alzheimer's as distinct from other diseases that lead to the inablility to take care of oneself.