The Damage Assessment And Prognostic In Severe Traumatic Brain Injury Coma Patients: A Resting-state FMRI Study

Objective: To investigate the change of the default-mode network(DMN) by using Amplitude of Low-Frequency Fluctuation(ALFF) and functional connectivity(FC)methods in acute phase patients after severe traumatic brain injury(s TBI)and to correlate these changes with The damage and prognostic in in severe traumatic brain injury coma patients,using resting-state functional magnetic resonance imaging(rs-f MRI)。Methods: 21 patients with severe traumatic brain injury and 21 age, education and gender matched healthy volunteers participated in this study. The raw data of the f MRI were processed with the software DPARSFA2.2. Selecting PCC for seed point, using single T test analyzed the PCC with all brain functional connective within the two groups respectively. We got two positive maps and then created a mask. Then using double T test analyzed the Amplitude of Low-Frequency Fluctuation within the mask between the two groups.And the same way to analyze the Amplitude of Low-Frequency Fluctuation and functional connectivity between revive patients and coma group.Results: Compared with the control subjects,the s TBI patients showed significantly decreased ALFF values in medial prefrontal cortex(MPFC), dorso-lateral prefrontal cortex, left temporal cortex,posterior cingulate cortex(PCC), precuneus(PC), anterior cingulate cortex(ACC),right middle Occipital gyrus, right inferior Occipital gyrus,right superior Parietal gyrus. Compared with the coma group,the revive patients showed significantly increased functional connectivity in superior frontal gyrus, left temporal cortex, posterior cingulate cortex(PCC), anterior cingulate cortex(ACC), Parietal gyrus.And increased ALFF values in right frontal gyrus, right temporal cortex, right inferior Parietal gyrus. Mean Amplitude of Low- Frequency Fluctuation values of the PCC was positively correlated with GCS scores in s TBI patients(r=0.798,P<0.0001).Conclusions: The default mode network may be existed in patients with severe traumatic brain injury during resting state, but the range was reduced. Compared with normal control group, patients with s TBI show significant decreased ALFF values in multiple brain regions in the resting state, which suggested that the mechanism of s TBI coma patients is not only a single abnormal spontaneous neuronal activity brain region, but also associated with a lot of brain regions. Compared with the coma group,the revive patients showed significantly increased functional connectivity and ALFF values in many brain regions, which suggested that these are closely related to prognostic. Mean Amplitude of Low-Frequency Fluctuation values of the PCC was positively correlated with GCS scores in s TBI patients,said that spontaneous neuronal activity of PCC was closely related to the extent of coma.