Measurements of regional cerebral blood flow and cognitive performance in Alzheimer's disease.

Abstract

Single photon emission computed tomography (SPECT) with 99mTc-HMPAO was used to image 26 patients with dementia of the Alzheimer type (DAT) and 10 healthy controls. Regional cerebral blood flow (rCBF) data indicated a relative sparing of the occipital regions in DAT. Normalisation to occipital flow illustrated highly significant CBF deficits in a number of cortical regions, particularly in the left and right posterior-temporal cortex in DAT compared to controls. The cognitive performance of DAT patients was measured using a clinical cognitive assessment procedure (CAMCOG) and numerous correlations between these scores and rCBF were obtained. The implications and value of this investigative technique are discussed.

Reduction of Regional Cerebral Blood Flow and Cognitive Impairment in Patients with Alzheimer's Disease: Evaluation of an Observer-Independent Analytic Approach

“…In Alzheimer's disease (AD) the measurement of re gional cerebral blood flow (rCBF) by single-photon emis sion computed tomography (SPECT) reveals a decreased relative cortical perfusion which is typically predominant in temporal and parietal cortex [1,2], This pattern matches the metabolic abnormalities which can be dem onstrated in AD patients by the more sensitive method of positron emission computed tomography [3][4][5], The re gion-specific reductions in CBF determined by SPECT are associated with latcralizcd cognitive functions such as language and praxis [6][7][8]. The ability of rCBF measure ment by SPECT to reflect in vivo the typical topography of morphological changes in AD seen at neuropathological examination [9] is a valuable aid in the early recogni tion of AD and in its differentiation from other dement ing disorders.…”

Volume Reduction in Cerebral Blood Flow in Patients with Alzheimer’s Disease: A Sonographic Study

“…The growing literature concerning cerebral blood flow (CBF) in Alzheimer's disease (AD) raises new issues regarding CBF decline which is typical of the disease [1][2][3][4][5][6][7][8][9][10][11]. Mechanisms of decline of CBF in AD are still under debate, some authors arguing for a decrease in cerebral metabolic demands as the principal cause [12], others proposing a decline in CBF due to age-related accumulations of the deleterious effects of various disease processes affecting the blood supply of the brain and secondarily reducing its metabolism [13][14][15].…”

Age at Onset and SPECT Imaging in Alzheimer's Disease

“…Although recently criticized [ 17] for the long interval necessary' to complete the scintigraphic examination, we did not find a high refu sal rate by the patients. A further ratio was obtained in accordance to that previously described [9].…”

“…For many years one of the more promising agents for Accepted: April 3. 1993 demonstrating regional cerebral blood flow were the l23I-labeld amine derivatives and in the past two years the " mTcHM-PAO [10][11][12][13][14], Furthermore SPECT has proved to be potentially useful in detecting AD by demonstrating patterns of reduced cerebral blood flow in temporoparie tal association cortex [13,[15][16][17] comparable to those obtained with a more sophisticated procedure, such as positron emission tomography (PET) [ 18,19], Returning to the main question of this report, the rela tionship of age at onset of AD and its clinical severity, Jagust et al [9] reported a relative left frontal hypoperfu sion in presenile but not in senile-onset patients using SPECT imaging. They concluded that available data pro vide evidence for an involvement of left-frontal hemi sphere in patients with early onset Alzheimer's disease.…”