Cover Story：The structural connectivity is the material basis of functional connectivity. The functional connectivity in default mode network (DMN) has reported in previous studies about childhood absence epilepsy. In order to explore the structural change in DMN, 11 childhood absence epilepsy patients and 12 healthy controls were recruited, and the fiber bundles among regions of DMN were built by diffusion tensor imaging (DTI) fiber tractography. Three fiber bundles were identified in all subjects, including the fiber bundles linking posterior cingulate cortex/precuneus to medial prefrontal cortex, and linking posterior cingulate cortex/precuneus to bilateral medial temporal lobe. Furthermore, the significantly decreased fractional anisotropic(FA) and connection strength, and increased mean diffusivity(MD) in fiber bundles linking posterior cingulated cortex/precuneus to medial prefrontal cortex were found in patients compared with controls. Predominantly, the decreased fractional anisotropic values were negatively related to the epilepsy duration. These findings may reflect the structural basis of the altered functional connectivity in DMN in absence epilepsy. Together with functional connectivity abnormality in our previous study, the findings implicated that the abnormality in connection from posterior cingulated cortex/precuneus to medial prefrontal cortex may play an important role in childhood absence epilepsy.
