Disrupted morphological brain network organization in subjective cognitive decline and mild cognitive impairment

Abstract

Abstract We aim to investigate the underlying neuropathological mechanisms of alternations in gray matter for subjective cognitive decline (SCD) and mild cognitive impairment (MCI) from the perspective of the human connectome. High-resolution T1-weighted images were acquired from 54 SCD patients, 95 MCI, and 65 healthy controls (HC). Morphological brain networks (MBN) were constructed using similarities in the distribution of grey matter volumes between regions. Structural connectivity strength and topographic metrics were compared, and the relationship to disease severity was assessed. We found significantly decreased structural connectivity strength of MBN between the SMN and VAN subnetworks was observed for SCD. The graph-theoretic analysis illustrated disruptions in the whole network organization, where the normalized shortest path increased and the global efficiency decreased in the MCI group compared to the SCD group. In addition, Montreal Cognitive Assessment scores of SCD patients had a significantly negative correlation with global efficiency. In summary, the SCD and MCI groups showed different patterns of disruptions in the morphological grey matter network. The present study could provide new sight into the mechanism of AD in terms of MBN.