Background:
Few works studied the directed whole-brain interaction between different brain regions of
Alzheimer’s disease (AD). Here, we investigated the whole-brain effective connectivity and studied the graph metrics
associated with AD.
Method:
Large-scale Granger causality analysis was conducted to explore abnormal whole-brain effective connectivity of
patients with AD. Moreover, graph-theoretical metrics including small-worldness, assortativity, and hierarchy were
computed from the effective connectivity network. Statistical analysis identified the aberrant network properties of AD
subjects when compared against healthy controls.
Results:
Decreased small-worldness, and increased characteristic path length, disassortativity, and hierarchy were found in
AD subjects.
Conclusion:
This work sheds insight into the underlying neuropathological mechanism of the brain network of AD
individuals such as less efficient information transmission and reduced resilience to a random or targeted attack.
Assessment of Effective Connectivity in Alzheimer’s Disease Using Granger Causality