Resting-State Functional Magnetic Resonance Imaging Research On Coma Patients Default Network

[Objects] To explore differences of regional brain spontaneous activity and functional connectivity in resting state between coma patients and healthy participants with functional magnetic resonance imaging(fMRI). and investigate the baseline characteristics of coma patients on associated with physiological changes or affect disorder.[Methods] Twelve coma patients diagnosed by Glasgow test and clinic criteria were included and 12 subjects with normal cognitive function were recruited as control group. All subjects were scanned with resting-state fMRI by a 3.0T MR scanner. Image data preprocessing and statistical analysis were completed with REST/DPARSF sofeware (which developed by Beijing Normal University National Key Laboratory of Cognitive Neuroscience and Learning) and SPM5. Regional homogeneity and functional connectivity in the resting state between coma patients and healthy participants were compared with posterior cingulate cortex selected as the region of interest.[Results] Compared with control group, coma patients showed significant decrease of ReHo in some regions of cerebellum, temporal lobe, frontal lobe, inferior parietal lobule, posterior cingulate cortex and precuneus (P<0.01). Default-mode functional connection brain regions with the PCC in coma patients are right temporal lobe, frontal lobe, precuneus and cingulate gyrus. Compared with control group, decompensated connection areas are cerebellum, precuneus, left middle temporal gyrus, right fusiform gyrus, superior frontal gyrus, left middle frontal gyrus, right medial frontal gyrus, the left parahippocampal gyrus, left angular gyrus and left parietal cingulated compensatory connection brain areas are cerebellar lobe, lingual gyrus, occipital Sub_Gyral area, temporal lobe Sub_Gyral area, inferior frontal gyrus, left inferior parietal lobule, the right parietal lobe and left insula Sub_Gyral area and right cingulate gyrus (P<0.01).[Conclusion] Coma patients showed significant decrease of ReHo in multiple brain regions in the resting state, which suggested that the physiological mechanisms of unconscious is associated with abnormal brain function network, coma is a behave of brain function loss of connection.The reduction of coma patients’default mode functional connection with PCC is potentially a cause of cognitive impairment, while increased functional connection may be a compensatory mechanism for the cognitive impairment. Resting-state fMRI plays an important role in comatose study.