Hippocampal functional connectivity in patients with intractable temporal lobe epilepsy: a resting state functional MRI study

Abstract

Objective To explore the alterations of hippocampal functional connectivity in patients with intractable temporal lobe epilepsy (ITLE) with resting state functional magnetic resonance imaging (rs-fMRI).Methods Eighteen patients with ITLE,admitted to our hospital from August 2013 to May 2014,and 18 healthy controls were chosen in our study; the fMRI data of the two groups were obtained; analysis of the resting state brain functional connectivity was performed by choosing the left and right hippocampus as the regions of interest (ROIs),and then,the differences of hippocampal functional connectivity were compared between ITLE group and healthy control group.Results When the left hippocampus was selected as ROI,significantly enhanced functional connectivity in the ITLE group was observed in the right cuneus,significantly weakened functional connectivity in the ITLE group was observed in the bilateral caudate nucleus,bilateral septal area and right gyrus rectus,as compared with those in the healthy control group (P＜0.05); when the right hippocampus was selected as ROI,significantly enhanced functional connectivity in the ITLE group was observed in the bilateral cuneus,bilateral lingual gyrus,and left calcarine,significantly weakened functional connectivity in the ITLE group was observed in the bilateral superior temporal gyrus,right middle temporal gyrus,left supramarginal gyrus,left precentral gyrus and left postcentral gyrus,as compared with those in the healthy control group (P＜0.05).Conclusion Hippocampal dysfunction of patients with ITLE could be found based on rs-fMRI,which prompts that the hippocampus plays an important role in the epilepsy network of patients with ITLE. Key words: Temporal lobe epilepsy; Functional magnetic resonance imaging; Functional connectivity; Hippocampus