颞叶癫痫患者磁共振弥散张量成像及记忆损害的研究

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

目的利用磁共振弥散张量成像技术(DTI)研究颞叶癫痫(TLE)患者脑内微观改变及记忆损害的相关脑区。方法对颞叶癫痫患者15例和健康对照者15例,进行DTI检查,利用韦氏记忆量表检测记忆功能。结果 TLE患者部分各向异性弥散(FA)值降低激活区域有颞叶、边缘叶、扣带回和岛叶,升高区有:额叶、顶叶、枕叶,表观系数(ADC)值升高激活区域在颞叶、额叶、枕叶、顶叶;无ADC值降低区域。与健康者相比,颞叶癫痫患者的记忆商数(MQ)(90.73±19.72)显著下降,P<0.01。对照组FA值在左岛叶、颞叶与MQ值正相关;患者组FA值在右额、顶、枕叶、左顶叶与MQ值正相关,在左颞叶与MQ值负相关。对照组ADC与MQ正相关区域在左边缘叶,与MQ成负相关区域在左顶叶、患者组正相关区域在左、右颞叶。结论初步证实TLE患者的脑内结构变化不局限于颞叶,还包括颞叶外网络结构;TLE患者全脑DTI与MQ存在着相关激活脑区,表明记忆功能损害与脑内相关结构改变有关。

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（P〈0.01）.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.