PARADOXICAL HIPPOCAMPUS PERFUSION IN MILD-TO-MODERATE ALZHEIMERS-DISEASE

The purpose of this study was to clarify the changes in hippocampal pe rfusion in mild-to-moderate Alzheimer's disease using PET and O-15-lab eled water. Methods: Sixteen patients with probable mild-to-moderate A lzheimer's disease (age: 68.1 +/- 11.3 yr; MMSE: 21.1 +/- 4.5) and 10 normal volunteers (age: 65.1 +/- 8.2 yr) were studied. Regional cerebr al blood flow (CBF) and cerebral blood volume (CBV) were measured usin g (15)0-labeled water autoradiographic method, (CO)-O-15-gas inhalatio n technique and PET. Results: Although the mean CBF in the parietotemp oral region was significantly lower in the patient group than in the c ontrol group, the mean CBF in the hippocampus did not show significant reduction between the two groups, both in absolute and relative value s. There was no significant regional CBV difference between the two gr oups. Parietotemporal perfusion correlated well with cognitive scores, both in absolute and relative values, in Alzheimer's disease, but hip pocampal perfusion did not correlate well. Conclusion: Hippocampal per fusion was preserved in mild-to-moderate Alzheimer's disease.