Abstract

SUAREZ-REVELO, Ximena; OCHOA-GOMEZ, John Fredy; TOBON-QUINTERO, Carlos Andrés  and  DUQUE-GRAJALES, Jon Edinsón. Functional connectivity in senior adults from fMRI as a possible indicator for Alzheimer's Disease. Acta Neurol Colomb. [online]. 2014, vol.30, n.4, pp.273-281. ISSN 0120-8748.

Introduction: Alzheimer's disease is a neurodegenerative disease and the most common cause of dementia in the world. This disease is characterized by neuronal cell death leading to an overall loss of brain connectivity. Functional connectivity from magnetic resonance images can provide information about the interaction between brain regions and therefore may be an indicator of Alzheimer. Objective: assessing functional connectivity from functional magnetic resonance images at rest in elderly as a potential biomarker for Alzheimer's disease. Materials and methods: in a population of 35 elderly subjects (10 patients with Alzheimer 75 ± 2,87 years, 10 patients with mild cognitive impairment 74,9 ± 2,88 years and 15 healthy individuals 75,35 ± 2,91years), functional connectivity networks obtained through the temporal correlation of BOLD signal and elements of the graph theory were compared. Network indexes (cost and average degree) were calculated, and further correlated with the neuropsychological scales, ADNI-mem, and ADAS-Cog. Results: in Alzheimer patients there is a decrease in connectivity compared with healthy controls and patients with mild cognitive impairment. A significant correlation between the cost of networks in healthy subjects and neuropsychological scales was found. Conclusion: our graph-based algorithm was useful to confirm that both Alzheimer and mild cognitive impairment exhibit a significant loss of connectivity.

Keywords : Functional conectivity; Alzheimer's disease; FMRI; Graph Theory.

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