MRI observation of changes of brain resting-state networks in patients with Alzheimer disease

Objective: To evaluate the difference of brain resting-state networks (RSNs) between Alzheimer disease (AD) patients and controls. Methods: Nineteen patients with AD and 20 controls were recruited in the study. Resting-state fMRI data and MPRAGE structure images were obtained using Simens Trio 3.0 Tesla MR scanner. Then the data were analyzed by SPM2 and GIFT 1.3b. Cerebra functional connectivity was revealed by independent component analysis (ICA) and compared between the two groups with SPM2. Results: Six RSNs were revealed in both AD and control group, in accordance with previous studies. Decreased functional connectivity was detected only in default mode networks (DMNs) and dorsal attention networks (DANs). Furthermore, in patients with AD, decreased activity in DMNs was demonstrated in bilateral cerebrum, superior temporal gyrus, middle temporal gyrus, inferior frontal gyrus and left superior frontal gyrus and right orbital gyrus. Increased activity in DMNs was demonstrated in bilateral medial frontal gyrus, inferior parietal lobule and right precuneus. On the other hand, decreased activity was also revealed in parts of the dorsal attention area, including bilateral cerebrum, medial frontal gyrus, left superior frontal gyrus and middle occipital gyrus. Conclusion: Significant deviation exists in RSNs deviation between AD and controls, providing a possible image methods to early diagnosis of AD.