ABSTRACT
In 1907, Alois Alzheimer described changes in the brain of a 56-year-old woman, dying of progressive dementia. Using a newly developed histologic staining technique Alzheimer demonstrated the presence of neurofibrillary tangles and ‘miliary foci’ in the post-mortem brain tissue. Senile plaques (SPs) are spherical lesions, measuring up to 200 µm in diameter. Neurofibrillary tangles (NFTs) are intracellular collections of abnormal filaments that displace the normal cytoplasmic organelles. Although SPs and NFTs are considered to be the characteristic pathologic changes of AD, they are not specific. Autopsy examination of non-demented individuals discloses at least some plaques and tangles in the majority, over the age of 60 years. Post-mortem neuropathologic examination of demented individuals frequently demonstrates AD in combination with other pathologic changes that could potentially have contributed to dementia. The most common coexisting conditions are cerebrovascular disease (CVD), Lewy body disease (LBD), or both.
