Analysis Of Mechanism Of Cognitive Impairment After Traumatic Brain Injury:Resting-State Functional Magnetic Resonance Imaging

Part ? Analysis of DMN on cognitive impairment after TBI:Resting-state functional magnetic resonance imaging studyObjective To investigate the changes of the DMN in the cognitive disorders after TBI using resting-state fMRI and independent component analysis(ICA).Methods Forty TBI patients with cognitive impairment were as traumatic brain injury group(TBIs)and Thirty healthy person were as the normal control group(NCs).General cognition was assessed by MMSE and MoCA.Resting-state fMRI and T1-weighted imaging were performed in all subjects.Then the maps of DMN were obtained from resting-state fMRI by ICA.Finally,two-sample t-test was performed in the map between two groups.Results Comparing to healthy controls,the TBI group showed significantly decreased connectivity of aDMN in the left lateral prefrontal cortex(BA6?44),PC-R(BA7?18),left fusiform(BA36),and pDMN in right dorsolateral superior frontal gyrus(BA9),right middle Cingulum(BA32),PC-R(BA5),left inferior parietal(BA40).The significantly increased connectivity of the TBI group was the aDMN in MPFC-L(BA45?47),ACC-R(BA32)?right middle temporal gyrus(BA21?37),right hippocampal(BA27?30);pDMN in MPFC(BA10?47),left Middle Occipital Gyrus(BA19).Conclusions It was the significantly decreased connectivity of the DMN in PCC/PC,dorsolateral prefrontal cortex,fusiform gyrus,inferior parietal lobule,that may illustrate the central mechanism of cognitive impairment after TBI.The study also found that the increased connectivity of MPFC,ACC,middle temporal gyrus,hippocampal,middle occipital gyrus may be a compensatory mechanism.Part ? Analysis of central mechanism of HBOT on cognitive impairment after TBI:Resting-state functional magnetic resonance imaging studyObjective A large number of clinical and basic research found that HBOT can improve cognitive function in patients with TBI.However,the central mechanism of the effect of HBOT is unclear.Firstly,our study proved the HBOT can improve cognitive function in TBI patients with cognitive disorder.Secondly,we used the resting-state fMRI to investigate the differences of the connectivity in DMN.Methods Patients with cognitive disorder after TBI were randomized to the HBO group and NHBO group.The patients of HBO group receive the HBOT combined with conventional surgical treatment and cognitive training.Meanwhile,the patients of NHBO group receive only conventional surgical treatment and cognitive training.All participants received MMSE,MoCA and rs-fMRI before and after 4 weeks with treatment.Then,the paired-sample t-test was respectively performed in the maps of DMN in the two groups.Results Compared with per-treatment,the scale scores of the HBO group and the NHBO group were both increased(P<0.05).And the scores of the HBO group showed the better effect(P<0.05).In the HBO group,compared with per-treatment,the significantly increased connectivity of the DMN was the left medial frontal gyrus(BA10),right middle temporal gyrus(BA21/22),PCC-L(BA23),right insular cortex(BA47),lingual gyrus(BA17?18),and the significantly decreased connectivity of the DMN was the superior frontal cortex(BA10),the supper orbit gyus(BA11),right fusiform(BA19),right inferior parietal lobule(BA39),left Occipital gyrus(BA18/37),right s supplementary motor area(BA6).Conclusions 1.HBOT can improve cognitive function in patients with TBI.HBOT combined with cognitive training is the ideal scheme for the cognitive impairment after TBI.2.Increased connectivity of the PC/PCC,frontal lobe,temporal gyus may be the nerve mechanism of cognitive recovery after HBOT.