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Can PET Data Differentiate Alzheimer's Disease from Vascular Dementia?
Author(s) -
NAGATA KEN,
MARUYA HIROSHI,
YUYA HIROMICHI,
TERASHI HIROO,
MITO YASUNORI,
KATO HARUHISA,
SATO MIKA,
SATOH YUICHI,
WATAHIKI YASUHITO,
HIRATA YUTAKA,
YOKOYAMA ERIKO,
HATAZAWA JUN
Publication year - 2000
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2000.tb06375.x
Subject(s) - vascular dementia , cerebral blood flow , dementia , medicine , positron emission tomography , alzheimer's disease , cardiology , perfusion , pathology , hemodynamics , disease , nuclear medicine
A bstract : The present study endeavored to differentiate Alzheimer's disease (AD) from vascular dementia (VaD) by comparing the metabolic and hemodynamic parameters. Positron emission tomographic (PET) studies were carried out in 13 patients with probable AD and 20 patients with VaD. PET findings were not included in the diagnostic criteria of AD or VaD. Using oxygen‐15 labeled compounds, cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO 2 ), oxygen extraction fraction (OEF), cerebral blood volume, and vascular transit time (VTT) were measured quantitatively during the resting state. To evaluate vascular reactivity (VR), CBF was also measured during 7% CO 2 inhalation. Regional CBF from the parietal cortex positively correlated with the neuropsychological scores in both AD and VaD groups. The typical parietotemporal pattern of hypoperfusion and hypometabolism was observed in the AD group, whereas the frontal lobe including the cingulate and superior frontal gyri were predominantly affected in the VaD group. The occipital cortex was preserved in both groups. A significant increase of the OEF was found in the parietotemporal areas in the AD group. No significant prolongation was seen with VTT. There was a marked difference in VR between the two groups: VR was depleted in the VaD group, whereas VR was normal in the AD group. The increased OEF with preserved vascular reserve seen in AD may implicate participation of a vascular factor in the pathogenesis of AD, possibly at the capillary level. Thus, PET provides important functional information in discriminating AD from VaD by comparing the patterns of hypoperfusion and/or hypometabolism, and in the understanding of the underlying hemodynamic pathophysiology.