Yuxia Li, Xiaoni Wang, Yongqiu Li, Yu Sun, Can Sheng, Hongyan Li, Xuanyu Li, Yang Yu1, Guanqun Chen, Bing Jing,Defeng Wang, Kuncheng Li, MingruiXia*,Ying Han*
Yox, Abnormal Resting-State Functional Connectivity Strength in Mild Cognitive Impairment and its Conversion to Alzheimers Disease(1970)SDRP Journal Of Information Science and Technology 1(1)
Background: Individuals diagnosed with mild cognitive impairment (MCI) are at high risk of transition to Alzheimer’s disease (AD). However, little is known about functional characteristics of the conversion from MCI to AD. Methods: Resting-state functional magnetic resonance imaging was performed in 25 AD patients, 31 MCI patients and 42 well-matched normal controls at baseline. Twenty one of the 31 MCI patients converted to AD according to the approximately 24 months follow up. Functional connectivity strength (FCS) and seed-based functional connectivity analyses were used to assess the functional differences among the three groups and especially between MCI-converters (MCI-c) and MCI-nonconverters (MCI-nc) at baseline. Relationships between FCS and clinical variables were further investigated in the patients group. Results: Compared to controls, subjects with MCI and AD showed decreased FCS in the default-mode network and the occipital cortex. Importantly, the FCS of the left angular gyrus and middle occipital gyrus was significantly lower in MCI-c as compared with MCI-nc. Significantly decreased functional connectivity was found between the left angular gyrus and other brain regions including bilateral inferior parietal lobules, dorsolateral prefrontal and lateral temporal cortices, and between the left middle occipital gyrus and other brain regions including right precentral, right postcentral and right middle occipital gyri. Additionally, the FCS of the left angular gyrus was positively correlated with mini-mental state examination scores. Conclusions: We demonstrated gradual but progressive functional changes during a median 2-year interval inpatients converting from MCI to AD, which might serve as early indicators for the dysfunction and progression in the early stage of AD.