Investigations on the brain connectivity patterns in progression of Alzheimer's disease using functional MR imaging and graph theoretical measures

摘要

Alzheimer's disease (AD) is a progressive brain disorder which has a long preclinical phase. The beta-amyloid plaques and tangles in the brain are considered as the main pathological causes. Functional connectivity is typically examined in capturing brain network dynamics in AD. A definitive underconnectivity is observed in patients through the progressive stages of AD. Graph theoretic modeling approaches have been effective in understanding the brain dynamics. In this work, the brain connectivity patterns and the functional topology in default mode network regions through the progression of Alzheimer's disease are analysed using resting state fMRI. The altered network topology analysed by graph theoretical measures explains cognitive deficits caused by the progression of this disease. Results show that the functional topology is disrupted in the default mode network regions as the disease progress in AD patients. Further, it is observed that there is a lack of left lateralization involving default mode network regions as the severity in AD increases.