P4‐272: Neurostructural Predictors Of Conversion To Alzheimer's Disease: A Meta‐analysis Of Vbm Studies
Year: 2009
Type: article
Study designs: Systematic Review, Meta-Analysis
Abstract: The early diagnosis of Alzheimer's disease (AD) is very important due to disease modifying drugs. However, the clinical diagnosis of AD at pre-dementia stages has limited specificity. The identification of biological correlates of the neurodegenerative process at early stages contributes to diagnostic accuracy. Structural MRI is a promising tool to improve such accuracy but, in spite of recent developments, results of neurostructural studies on predicting conversion to AD are not uniform. A widely employed method to reliably analyze whole brain imaging data is voxel-based morphometry (VBM). To conduct a systematic review and meta-analysis of VBM studies about the neurostructural predictors of conversion to AD. Medline, ISI Web of Science, PsycInfo, Embase and Scopus databases were searched in April 16, 2009 for longitudinal studies on the conversion of mild cognitive impairment (MCI) or normal subjects to AD. We selected studies that used whole brain VBM methods to compare converters and non-converters according to baseline brain MRI. VBM coordinates were retrieved in order to perform meta-analysis, which was based on the activation likelihood estimation and used the Ginger Ale 1.1 software. Seven studies met inclusion criteria and comprised a total of 336 subjects from which 117 converted to AD. They reported regional atrophy in baseline MRI of subjects who progressed to AD. Most of these regions were located in the temporal lobe and in the left hemisphere. No study reported deficits in cognitively stable subjects compared to subjects who developed AD. We meta-analyzed a total of 16 coordinates from 4 studies that enrolled subjects with amnestic MCI (aMCI) at baseline, yielding two significant clusters of volumetric reduction in aMCI patients who converted to AD as compared to non-converters: one in left middle temporal gyrus and another in left inferior temporal gyrus. Atrophy in the left temporal lobe is the most frequent finding in subjects that eventually develop AD. Meta-analysis showed that atrophy in the left middle and inferior temporal gyri is the most consistent neurostructural biomarker to predict conversion from aMCI to AD.
Source: Alzheimer s & Dementia
Institution: Universidade de São Paulo
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1994186816