Amyloid-Beta Deposition is Associated with Increased Medial Temporal Lobe Activation during Memory Encoding in the Cognitively Normal Elderly.
Am J Geriatr Psychiatry
; 25(5): 551-560, 2017 May.
Article
em En
| MEDLINE
| ID: mdl-28161156
ABSTRACT
BACKGROUND:
Much is unknown about changes that occur in the brain in the years preceding the cognitive and functional impairment associated with Alzheimer disease (AD). This period before mild cognitive impairment is present has been referred to as preclinical AD, and is thought to begin with amyloid-beta deposition and then progress to neurodegeneration and functional brain circuit alterations. Prior studies have shown that there is increased medial temporal lobe activation on functional magnetic resonance imaging (fMRI) early in the course of mild cognitive impairment. It is unknown, however, whether this altered fMRI activity precedes cognitive impairment. The purpose of this study is to address this question using Pittsburgh Compound-B (PiB) imaging and fMRI in a sample of cognitively normal older adults.METHODS:
Forty-four cognitively normal older adults underwent both PiB imaging and fMRI with a face-name memory task 21 were classified as PiB(+) and 23 were PiB(-). Additionally, thorough cognitive and neuropsychological test batteries were administered outside the scanner. The main outcome measure in this study is fMRI activation in the medial temporal lobe during a face-name memory-encoding task.RESULTS:
PiB(+) subjects showed higher fMRI activation during the memory task in the hippocampus relative to PiB(-) participants.CONCLUSIONS:
The increased medial temporal lobe activation in preclinical AD, observed in this study, may serve as an early biomarker of neurodegeneration. Future studies are needed to clarify whether this functional biomarker can stratify AD risk among PiB(+) older adults.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
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Peptídeos beta-Amiloides
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Cognição
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Hipocampo
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Memória
Tipo de estudo:
Observational_studies
/
Risk_factors_studies
Limite:
Aged
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Female
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Humans
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Male
Idioma:
En
Revista:
Am J Geriatr Psychiatry
Assunto da revista:
GERIATRIA
/
PSIQUIATRIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Panamá