Application of iodine-123-labeled isopropylamphetamine imaging to the study of dementia.

Forty-seven patients diagnosed as clinically demented were imaged with 123I isopropylamphetamine (IMP). All of these patients also had a nuclear magnetic resonance (NMR) study. In those patients diagnosed as having senile dementia of the Alzheimer type a bilateral reduction in IMP uptake in the temporo-parieto-occipital region was always seen. The NMR appearances were normal in 64% of these sites. The IMP images of patients with multi-infarct dementia varied from normal to marked focal deficits. There was, however, a much closer agreement between the abnormalities seen on the IMP and NMR images. In alcoholic dementia no focal areas of reduced IMP uptake were seen, although the uptake was generally irregular. In both Korsakoff's psychosis and Huntington's chorea the IMP uptake pattern and the NMR study were normal.