Changes in anatomical and functional connectivity related to lower hippocampal volume

Resumen

Anatomical 3D T1 weighted images have been widely used to assess the volume of subcortical structures. It has been demonstrated that volume loss of hippocampi, entorhinal cortex and amygdala are early biomarkers for the diagnosis of cognitive impairments and AD1. In this work, we investigate AD biomarkers based on brain connectivity. SC-FC differences have been reported between controls and patients at risk for AD2. We will try to anticipate to MCI or AD diagnoses by differentiating in a sample of healthy subjects, i.e. with no cognitive impairment, other than related to ageing, using as criterion of separation the normalized hippocampal volume (NHV). The sample is formed by volunteers in the Valleca?s Initiative, a longitudinal study evaluating normal ageing in a cohort of more than 600 healthy elder people (70-85 years). The prevalence of AD in people older than 65 years is 13%3 suggesting that a certain number of those subjects will develop AD in the next years. The subjects with lower NHV are more prone to have AD than subjects with higher NHV. Thus they are more likely to manifest connectivity patterns that can be considered as AD biomarkers.