ABSTRACT
Objective To explore the functional properties of the brain's resting state networks in neonates with hypoxic ischemic encephalopathy.Methods Use the methods of functional MRI probabilistic tractography and graph theory to compare the global and local functional properties of the brain's resting state network between 12 cases of children with mild HIE and 14 cases of children with moderate/severe HIE.Results In terms of global topological properties,both the mild and moderate/severe group showed small-world properties.The γ and λ in the mild group were 2.450± 1.642 and 1.542±0.564 and in the moderate/severe group were 2.331± 1.554 and 1.353±0.672,respectively,which were in line with the characteristics of small-world properties (γ＞ 1 and λ ≈ 1).As far as local topological properties were concerned,the distribution of hub regions in the functional networks had smaller number of nodes in the moderate/severe group (8 nodes) than the mild group (14 nodes).The comparison of nodal efficiencies showed that the moderate/severe group had significantly reduced nodal efficiency in the left insula opercula,left supramarginal gyrus,left and right temporal pole and right middle temporal gyrus(the nodal efficiencies of the moderate/severe group:0.4089±0.0865,0.3377±0.1223,0.3842±0.0898,0.3508±0.1295,0.3564±0.0843;the nodal efficiencies of the mild group:0.4801±0.0762,0.4465±0.0898,0.4655 ±0.0812,0.4640±0.0690,0.4271±0.0636,all P＜0.05).Conclusion The topological structure of resting state functional network in children with moderate and severe hypoxic-ischemic encephalopathy is obviously backward than that in children with mild hypoxic-ischemic encephalopathy,which may be related to abnormal language,movement and cognitive function in the late stage.