A Research Of Correlation Between Resting State FMRI And Memory Function In Mesial Temporal Lobe Epilepsy

ObjectObserve the alterations in resting state brain network of unilateral mesialtemporal lobe epilepsy (MTLE) during interictal period,and analysis the relationshipbetween resting state brain functional connection (FC) and memory function toexplore the pathogenesis of MTLE.MethodsResting state functional magnetic resonance imaging (rs-fMRI) data wereacquired from13patients with left and11patients with right MTLE. Rs-fMRI data of13healthy volunters matched for age,sex,and level of education were selected ascontrols. The altered functional connectivity pattern in MTLE patients was valuatedby comparing to normal controls.Then a correlation analysis was performed betweenthe strength of FC and the clinical memory scale scores in patients with MTLE.Results1. The scores of memory quotient, point to memory, associative learning, theimage free recall, recognition of nonsense figure, portrait characteristic Contactrecalls in patients with MTLE were significantly lower than that in the normal controlgroup. The scores of point to memory in patients with L-MTLE were significantlylower than R-MTLE (p=0.045), while the scores of recognition of nonsense figure inpatients with R-MTLE were significantly lower than L-MTLE (p=0.018).2. Compared with the control group,the patients with L-MTLE showed FCincrease between the left hippocampus (LH) and several brain regions,including theright superior frontal gyrus,the right middle frontal gyrus,the right superior temporalgyrus,the right inferior temporal gyrus,the right precuneus.There were also someregions that showed decreased FC,which included the right olfactory,the leftthalamus,the right middle frontal gyrus,the right/left superior temporal gyrus,the leftprecentral gyrus,the left premotor cortex.3. Compared with the control group,the patients with R-MTLE showed FCincrease between the right hippocampus (RH) and several brain regions, including theright/left fusifotm,the right inferior frontal gyrus,the left calcarine,the rightcaudate,the left putamen,the right/left middle frontal gyrus,the right premotorcortex,the left inferior parietal cortex,the right precuneus,the left/right brain stem,theleft cerebellum.4. In the L-MTLE patients, the FC between LH and left postcentral gyrus wasnegatively correlated with the scores of associative learning. The FC between RH andleft hippocampus/amygdala was positively correlated with the scores of point tomemory and memory quotient.5. In the R-MTLE patients, the FC between LH and right middle ocipitalgyrus was negatively correlated with the scores of point to memory and memoryquotient. The FC between LH and left middle temporal gyrus was positively correlated with the scores of point to memory and associative learning. The FCbetween LH and left inferior frontal gyrus was positively correlated with the scores ofthe image free recall, recognition of nonsense figure and memory quotient. The FCbetween RH and right middle frontal gyrus was positively correlated with the scoresof the image free recall.Conclusions1. The memory function of patients with MTLE are impaired.The L-MTLEpatients had the lowest scores on pure verbal memory test and the R-MTLE patientsshowed the worst performance on pure visual memory test.2. The distribution pattern of epileptic network may be related to the spread ofepileptic activity.3. Strengthening the connectivity to contralateral hippocampal is one importantcompensation mechanism to improve the memory function in unilateral MTLE.