Diffusion tensor imaging and memory impairment in patients with temporal lobe epilepsy

Objective Using diffusion tensor imaging(DTI)to explore the pathological changes in brain and the related to memory impairment of temporal lobe epilepsy(TLE),and to discuss the possible mechanism.Methods 15 TLE cases and 15 healthy individuals were randomly selected and included into the DTI study.The Wechsler memory scale(WMS)were adopted to assess the memory of all the subjects.Results Compared with control in voxel-based analysis(VBA),the patients had less activation of frontal lobe,apical lobe、occipital,with increased diffusivity found in those regions.A decreased diffusivity was found in the temporal lobe,limbic lobe and insular lobe.A significant increase in ADC was found in the temporal lobe,frontal lobe,apical lobe and occipital lobe.The MQ of patients(90.73±19.72)was significantly dropped compared with control group(P0.01).FA activation result regressed against MQ,in the control group,left insular lobe and left tempore lobe were positively correlated with MQ.Right frontal lobe,apical lobe,occipital lobe and left apical lobe were positively correlated with MQ in the TLE patients.Left tempore lobe showed negative correlation in the TLE group.In the control group,there were ADC activation result positive correlation with MQ in left limbic lobe.Left apical lobe,parahippocampal gyrus and right tempore lobe were negatively correlated with MQ.In the TLE group,there were ADC activation result positively correlated with MQ in left and right tempore lobe.Conclusions This study showed that diffusion abnormalities are not restricted to the temporal lobe but involves a larger network.This pattern may indirectly reflect the epileptogenic network and may be interpreted as a cause or a consequence of epilepsy.There are positive correlation between DTI of whole brain and MQ,implying the relationship between memory impairment and structural change of brain.