Interhemispheric Functional and Structural Alterations in Unilateral Temporal Lobe Epilepsy / 中国医学影像学杂志

ABSTRACT

Purpose To investigate the alterations of homotopic functional connectivity and interhemispheric structural connectivity in patients with unilateral temporal lobe epilepsy (unilateral TLE).Materials and Methods Resting-state functional MR imaging data were acquired from patients in the first affliated hospital of Guang Zhou Medical University who were enrolled from Oct.2013 to Oct.2015 with unilateral temporal lobe epilepsy (n=43) [21 left TLE(LTLE) and 22 right TLE(RTLE)] and normal controls (NC) (n=24).We mainly concerned about the functional connectivity between any pair of symmetric interhemispheric voxels which were measured by voxel-mirrored homotopic connectivity (VMHC).Structural magnetic resonance images were acquired in 10 LTLE patients,16 RTLE patients and 20 NCs.Homotopic regions showing abnormal functional connectivity in patients were adopted as regions of interest for DTI.The FA values were compared between groups.Two-sample t test were used.Results Compared with NC group,the LTLE patients showed increased interhemispheric functional connectivity among the bilateral angular gyri,occipital gyri and superior parietal gyri,and decreased functional connectivity between the bilateral supplementary motor areas,middle temporal gyri,medial frontal gyri and inferior parietal lobules.Compared with control subjects,RTLE patients exhibited increased interhemispheric functional connectivity among bilateral inferior occipital gyri,parahippocampa gyri,cerebellum,as well as decreased functional connectivity among the bilateral middle temporal gyri,precentral gyri and inferi or frontalgyri.Statistical results indicated that the FA value of the commissural fiber bundles connecting the bilateral hippocampal gyri was smaller in RTLE patients than NC patients (t=10.55,P＜0.01).The FA value of the association fibers connecting the bilateral hippocampal gyrus had no significant difference between the LTLE group and NC group.Conclusion The increase or decrease of VMHC value in some brain regions in TLE suggested that there were changes in the functional synchronization and coordination in the two hemispheres in patients with unilateral TLE.In the RTLE patients,some brain regions which had abnormal interhemispheric functional connectivity also had structural damage.