Brain perfusion imaging in Parkinson's disease and Alzheimer's disease demonstrated by three-dimensional surface display with 123I-iodoamphetamine.

We reconstructed three-dimensional (3D) surface images from data from single-photon emission computed tomography (SPECT) with N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 29 patients with Parkinson's disease, 16 patients with Alzheimer's disease and 11 normal control subjects. In patients with nondementing Parkinson's disease, perfusion defects were frequently found in the parietal cortical region at a threshold value of 65%. In demented Parkinson's disease patients, perfusion defects were frequently noted at threshold of 45-65%, and were more marked in the bilateral temporal and parietal cortices. In Alzheimer's disease, perfusion defects were similar to those found in dementing Parkinson's disease. These results suggest that dementia in Parkinson's disease is related to the perfusion reduction of the temporoparietal cortex, and may support the view that Parkinson's disease and Alzheimer's disease overlap in some patients. A 3D display of an 123I-IMP brain tomogram may be useful for detecting cortical lesions in patients with dementia or cognitive impairment.