RESUMEN
Objective To observe the abnormality of gray matter volume and density in patients undergoing postoperative delirium (POD).Methods Forty-seven cases of aged patients, 26 males and 21 females, aged 60-75 years, ASA physical status Ⅱ or Ⅲ, were selected.On the third day after operation, cognitive function estimation was performed.The patients were assigned into group POD and group C according to whether POD occurred and brain magnetic resonance imaging (MRI) scanning was implemented.The discrepancy in gray matter volume and density between the two groups were compared using voxel-based morphometry method (VBM).Correlation analysis was performed between the corresponding parameters in the regions where notable differences between the two groups existed and minimum mental state examination (MMSE) score were found.Results Global gray matter volume of group POD was notably lower than that of group C (P<0.01).Cerebrospinal fluid volume of group POD was significantly higher than that of group C (P<0.01).Gray matter volume of bilateral frontal gyrus and right parahippocampus was remarkably reduced in group POD (P<0.001).Gray matter density of bilateral hippocampus and right parahippocampus decreased significantly (P<0.001).Right parahippocampal gray matter volume was positively correlated with MMSE score in POD patients (P<0.05).Conclusion Structural abnormality in frontal regions, hippocampus and parahippocampus may play an important role in pathogenetic and developing process of POD.Gray matter volume in the right parahippocampus may be one of reference index for POD severity.