| Purpose:To obtain an accurate diagnosis and prognosis for brain injured patients with disorders of consciousness is still a challenge for clinicians.By combination of structural magnetic resonance imaging,resting-state functional magnetic resonance imaging(rs-fMRI)and Diffusion tensor imaging(DTI),we analyzed the relationship between the lesion locations,the interhemispheric functional disconnectivity,functional connectivity of brain networks and the severity of consciousness disorder.We aimed to provide a neuroimaging biomarker for evaluation of consciousness disorders and its prognosis in patients with brain injury.Methods:Part I:During 2013 and 2016,19 brain injured patients with disorders of consciousness(DOC)(5 with traumatic brain injury(TBI);8 with cerebrovascular disease;4 with spontaneous intracerebral hemorrhage;2 with infection)were retrospectively reviewed in Department of Neurosurgery,Nanjing Drum Tower Hospital.Fourteen age and sex matched normal subjects were enrolled as controls.All subjects underwent multi-mode MRI exams including structural MRI,rs-MRI and DTI according to level of consciousness and tolerability(The statistics of patients were collected between 9 to 20 days after brain injury).The locations of brain injury and corpus callosum(CC)lesions were assessed based on structural MRI.Then fractional anisotropy(FA),mean diffusivity(MD),length and numbers of fiber bundles in CC were compared between patients and controls according to DTI results.The alternation of symmetry of two brain hemisphere in patients with corpus callosum injury were analyzed using functional connectivity from rs-fMRI.Part II:During 2013 and 2016,14 brain injured patients with disorders of consciousness(5 with TBI;4 with cerebrovascular disease;3 with spontaneous intracerebral hemorrhage;2 with infection)were enrolled in Department of Neurosurgery,Nanjing Drum Tower Hospital.Fourteen age and sex matched normal subjects were recruited as controls.All subjects underwent rs-MRI,while Glasgow coma scale(GCS)score of brain injured patients were obtained at baseline and three months later.We then evaluated the alternation of functional connectivity in executive control network(ECN)and default mode network(DMN)and anticorrelation between the two networks in brain injured patients.Then we analyzed the relationship between the extent of network disruption and GCS scores.Results:Part I:In 19 brain injured patients with DOC,we observed a significantly higher lesions incidence in CC,the medial prefrontal cortex(MPFC)and brainstem as compared to other brain regions.The number and FA of CC were significantly lower in patients with DOC(n=13)when compared to normal subjects(n=14).In 8 patients with corpus callosum injury,their lesions were mostly located in III and IV region,while the FA and symmetry were significantly lower in those fibers which project to CC.Part II:We observed significantly decreased functional connectivity in DMN,including posterior cingulate,bilateral inferior parietal lobule and MPFC.Moreover,the connectivity of precuneus was significantly correlated with patients' outcome.We also found decreased connectivity in ECN,including frontoparietal cortex and bilateral posterior parietal cortex,while the functional connectivity of left inferior temporal and parietal cortex were significantly correlated with the level of conscious.The anticorrelation of DMN and ECN were decreased in most patients with DOC.Conclusion:l.Our results suggested that in the brain injured patients with DOC,the lesions more likely located in ? and ? regions of CC,MPFC and brainstem.The white matter microstructure was damaged and more severe in CC as indicated by our DTI results,while its corresponding cortical symmetry was decreased.2.The connectivity of DMN and ECN were decreased in in the brain injured patients with DOC.The network impairment in DMN could reflect the level of conscious,while the extent of network impairment could potentially serve as an indicator for prognosis.The anticorrelation of DMN and ECN could be used as a complementary biomarker to reflect the level of conscious. |
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