Lyra Katarina P, Chaim Khallil T, Leite Claudia C, Park Eun J, Andrade Celi S, Passarelli Valmir, Valério Rosa M F, Jorge Carmen L, Castro Luiz H M, Otaduy Maria C G
Department of Radiology and Oncology, Clinics Hospital, School of Medicine, University of São Paulo, São Paulo, Brazil; LIM44-Laboratory of Magnetic Resonance in Neuroimaging, Clinics Hospital, School of Medicine, University of São Paulo, São Paulo, Brazil.
Department of Neurology, Clinics Hospital, School of Medicine, University of São Paulo, São Paulo, Brazil.
Epilepsy Res. 2017 Nov;137:112-118. doi: 10.1016/j.eplepsyres.2017.09.008. Epub 2017 Sep 20.
To detect by diffusion tensor imaging (DTI) the extent of microstructural integrity changes of the corpus callosum (CC) in patients with hippocampal sclerosis (HS) and to evaluate possible association with clinical characteristics.
Fourty-two patients with temporal lobe epilepsy (TLE) and HS and 30 control subjects were studied with DTI. We grouped patients according to lesion side (left or right) HS. Mean diffusivity (MD), fractional anisotropy (FA), radial (RD) and axial diffusivity (AD) were extracted from five segments in CC midsagittal section obtained by automatic segmentation. CC DTI findings were compared between groups. We also evaluated association of DTI changes and clinical characteristics.
HS patients displayed decreased FA and increased MD and RD in the anterior, mid-posterior and posterior CC segments, compared to controls. No differences were observed in AD. Patients reporting febrile seizure as the initial precipitating event presented more intense diffusion changes. No differences were seen comparing left and right HS. Age at epilepsy onset, disease duration and seizure frequency were not associated with DTI findings.
This is one of the largest series of TLE-HS patients evaluating CC white matter fiber integrity by DTI, which allowed us to study how some clinical characteristics, such as seizure frequency, disease duration and lesion side, are related to CC integrity. Occurrence of febrile seizure was the only factor that had significant impact on tract integrity. Diffusion changes were not restricted to the posterior part of the CC; we observed the same changes for the anterior part of the CC. Diffusion changes were characterized by an increase in RD, while the AD remained intact for all regions of the CC.
通过扩散张量成像（DTI）检测海马硬化（HS）患者胼胝体（CC）微观结构完整性变化的程度，并评估其与临床特征的可能关联。
对42例颞叶癫痫（TLE）合并HS患者和30例对照者进行DTI研究。我们根据HS的病变侧（左侧或右侧）对患者进行分组。从通过自动分割获得的CC矢状面中段的五个节段中提取平均扩散率（MD）、各向异性分数（FA）、径向扩散率（RD）和轴向扩散率（AD）。比较各组之间的CC DTI结果。我们还评估了DTI变化与临床特征的关联。
与对照组相比，HS患者在CC的前、中后和后段显示FA降低，MD和RD升高。AD未观察到差异。报告热性惊厥为初始诱发事件的患者表现出更强烈的扩散变化。比较左侧和右侧HS未见差异。癫痫发作起始年龄、病程和发作频率与DTI结果无关。
这是通过DTI评估CC白质纤维完整性的最大系列TLE-HS患者研究之一，这使我们能够研究一些临床特征，如发作频率、病程和病变侧，如何与CC完整性相关。热性惊厥的发生是对神经纤维束完整性有显著影响的唯一因素。扩散变化不仅限于CC的后部；我们在CC的前部也观察到了相同的变化。扩散变化的特征是RD增加，而CC所有区域的AD保持不变。
