Preliminary Study Of BOLD-fMRI For Memory Cognition Of Patients With Temporal Lobe Epilepsy

ObjectiveThe study aims to explore the neural basis of WM in TLE patients,and toprovide imaging evidence for the study of plasticity and reorganization of WMcognition, with BOLD-fMRI technique and digit2-back WM target task in15TLEpatients,and with normal subjects as a comparison.Materials and Methods1. The data of15TLE patients and15normal subjects were acquired withBOLD-fMRI by performing a digit2-back task and a0-back task as contro1.2. The experiment adopted a block-design with memory task and control taskperformed alternatively.Behavioral performance(i.e. reaction time and score)wasrecorded.Preprocessing，statistical analysis and result display of functional data wereperformed using SPM5,and activated brain areas were obtained.Then the LIswere calculated from number of activated voxels in the whole hemispheres.Thereaction time and score,the number of activated voxels and the average T value ofactivated voxels of the ROI in bilateral IFG(Broca area),bilateral IPL,and temporallobe between the two groups were all compared with independent student’s t-test.Results1. The performance of TLE for N-back WM task was lower than that of normalsubjects,and the mean response time was delayed and the score declinedaccordingly.2. All normal subjects and Most TLE patients indicated left hemispherelateralization. The left hemisphere lateralization degree of TLE patients was lessthan the former.3. The frontal lobe and the parietal lobe were mainly activated brain areas in thetwo groups, but the range of WM task activated area,the number of activated voxelsand the average T value of activated voxels of the ROI in IFG(Broca area),IPL, andtemporal lobe were less than the normal subjects.The difference was statistically significant.Conclusion1. The WM needs the coordination of multiple brain regions to accomplishdigital WM information processing successfully and the frontal lobes play a leadingrole.2. The neural basis of the parametric digit N-back WM task is a distributednetwork including cortex，subcortical structures and cerebella areas.The normaloperation of the network is important to ensure the correct implementation of theWM task.3. The results reflect impairment of advanced cognitive abilities to some extentin TLE patients, and probably suggest the physiopathologic mechanism of cognitivefunction change relevant to WM in TLE patients.4. The BOLD-fMRI can provide imaging evidence for the hypothesis thatnormal sides of brain regions have the capability to compensate for and reorganizethe relevant important cognitive functions of the lesion side, such as WM cognitivefunction.