Microscope field size and the neuropathologic criteria for Alzheimer's disease

A diagnosis of definite Alzheimer's disease (AD) can only be made by histopathologic examination of the brain, in conjunction with clinical information. Neuropathologic criteria for diagnosing AD require quantitation of senile plaques in the neocortex by microscopic examination of specially stained sections. The Khatchaturian criteria require a minimum of 2 to 15 senile plaques per 200 times field depending on the age at death.1 The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) developed criteria utilizing a series of three illustrations representing sparse, moderate, and frequent senile plaques per 100 times field.2 New National Institute on Aging(NIA)-Reagan Institute Criteria, which are similar to the CERAD criteria but include semiquantitation of neurofibrillary tangles, are scheduled to be published in Neurobiology of Aging (Markesbery, 1997, personal communication). The precise application of these published criteria is especially important …