The clinical diagnosis of Alzheimer's disease without the use of head imaging studies. A cliniconeuropathological study.

Abstract

Although head imaging studies are frequently used in the work-up of dementia, published criteria for the clinical diagnosis of Alzheimer's disease (AD) do not require them. Since our brain bank contains cases in which physicians had specifically diagnosed AD without using a head imaging study, we thought it of interest to investigate the accuracy of their clinical diagnoses. We retrospectively reviewed 911 consecutive dementia cases for those clinically diagnosed as either AD or senile dementia (SD). Twenty-one were identified in which head imaging studies had not been used, each diagnosed as AD or SD by a different physician. In only three had the physician reported a reason why a study was not done. In all 21 cases the primary neuropathological cause of the dementia was AD. Neuropathology in addition to AD was also noted, including cortical Lewy bodies in three, infarcts on gross examination in three, multiple microscopic infarcts in four, and multiple cerebral metastases in one. Acknowledging a number of study limitations, it is remarkable that the judgment of the physicians was correct regarding AD in all 21 cases. It is questionable if a head CT or MRI scan at time of diagnosis would have benefited any of the patients.