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IC‐P2‐131: Brain perfusion spect: Characterization and prognostic evaluation of mild cognitive impairment
Author(s) -
Santana Isabel J.,
Caldas Joana,
Cavaco Ana,
Cunha MJoâo,
Isidoro J.,
Santiago Beatriz,
Rodrigues Ana,
Ribeiro Helena,
Dourado António,
Lima J.M. Pedroso
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.2586
Subject(s) - posterior cingulate , cerebral blood flow , medicine , entorhinal cortex , cardiology , neuropsychology , alzheimer's disease , perfusion , nuclear medicine , psychology , cognition , neuroscience , disease , hippocampus
Background: Mild Cognitive Impairment (MCI) is recognized as a clinical entity with a high risk to develop Alzheimer’s disease (AD). There is actually a great interest in MCI characterization and the proposal of clinical variables that predict the conversion to AD. Our aim is to characterize MCI and to look for predictors of future development of AD, using regional cerebral blood flow (rCBF) as measured by single photon emission computed tomography (SPECT) and other AD diagnostic variables. Methods: Seventy-three subjects (38 MCI e 35 mild AD) matched for age, gender and education, where submitted to a clinical/neuropsychological comprehensive evaluation and Apolipoprotein E genotype was also obtained for both groups of patients. rCBF was measured using Tc-99m hexamethylpropyleneamine oxime (HMPAO) and quantitative analysis normalized to cerebellum were measured in 20 zones and 90 areas (Broadmann areas) using NeuroGam software. Elementary statistical analysis, t-Student test, and VisRed software, where used to analyze rCBF data. Results: MCI group presented a significant hypo-perfusion (more than 1.5 SD) comparatively to an internal-software control group, in posterior cingulate cortex (A23 e A24) and left entorhinal cortex (A28). As a group, mild AD subjects had more extensive areas of hypo-perfusion in neocortex comparatively to MCI, with significant differences (p 0,02) in internal temporal areas, Wernicke’s area, parietal lobes, pre-frontal and cingulate córtex. However, cluster analysis using VisRed Software demonstrated that MCI and AD patients were incompletely segregated as two separated groups. Considering predictor variables, we observed that .ApoE 4 MCI carriers showed significant hypo-perfusion comparatively to MCI ApoE 4 noncarriers (p 0,05) in frontal and pre frontal areas (A11, A25, A47). Conclusions: As a diagnostic tool, SPECT is not able to classify individual patients between MCI and mild AD. MCI-group and especially ApoE 4 carriers present hypo-perfusion in cingulate cortex, medial temporal and pre-frontal regions, the typical profile of preclinical histological AD.