Department of Neurology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
Epilepsia. 2012 Aug;53(8):1371-8. doi: 10.1111/j.1528-1167.2012.03544.x. Epub 2012 Jun 18.
Previous neuroimaging studies provide growing evidence that patients with juvenile myoclonic epilepsy (JME) have both structural and functional abnormalities of the thalamus and frontal lobe gray matter. However, limited data are available regarding the issue of white matter (WM) involvement, making the microstructural WM changes in JME largely unknown. In the present study we investigated changes of WM integrity in patients with JME, and their relationships with cognitive functions and epilepsy-specific clinical factors.
We performed diffusion tensor imaging (DTI) and neuropsychological assessment in 25 patients with JME and 30 control subjects matched for age, gender, and education level. Between-group comparisons of fractional anisotropy (FA) and mean diffusivity (MD) were carried out in a whole-brain voxel-wise manner by using tract-based spatial statistics (TBSS). In addition, both FA and MD were correlated with cognitive performance and epilepsy-specific clinical variables to investigate the influence of these clinical and cognitive factors on WM integrity changes.
Neuropsychological evaluation revealed that patients with JME had poorer performance than control subjects on most of the frontal function tests. TBSS demonstrated that, compared to controls, patients with JME had significantly reduced FA and increased MD in bilateral anterior and superior corona radiata, genu and body of corpus callosum, and multiple frontal WM tracts. Disease severity, as assessed by the number of generalized tonic-clonic seizures in given years, was negatively correlated with FA and positively correlated with MD extracted from regions of significant differences between patients and controls in TBSS.
Our findings of widespread disturbance of microstructural WM integrity in the frontal lobe and corpus callosum that interconnects frontal cortices could further support the pathophysiologic hypothesis of thalamofrontal network abnormality in JME. These WM abnormalities may implicate frontal cognitive dysfunctions and disease progression in JME.
先前的神经影像学研究提供了越来越多的证据，表明青少年肌阵挛癫痫（JME）患者的丘脑和额叶灰质存在结构和功能异常。然而，关于白质（WM）受累问题的数据有限，使得 JME 的微观 WM 变化在很大程度上尚不清楚。在本研究中，我们研究了 JME 患者 WM 完整性的变化及其与认知功能和癫痫特异性临床因素的关系。
我们对 25 名 JME 患者和 30 名年龄、性别和教育程度匹配的对照组进行了弥散张量成像（DTI）和神经心理学评估。通过基于束的空间统计学（TBSS），在全脑体素水平上进行了组间各向异性分数（FA）和平均弥散度（MD）的比较。此外，还将 FA 和 MD 与认知表现和癫痫特异性临床变量相关联，以研究这些临床和认知因素对 WM 完整性变化的影响。
神经心理学评估显示，与对照组相比，JME 患者在大多数额叶功能测试中表现较差。TBSS 显示，与对照组相比，JME 患者双侧前、上放射冠、胼胝体膝部和体部以及多个额叶 WM 束的 FA 降低，MD 升高。疾病严重程度，以每年发生的全面强直阵挛性发作次数评估，与从 TBSS 中患者与对照组的差异显著区域提取的 FA 呈负相关，与 MD 呈正相关。
我们在额叶和胼胝体中发现了广泛的微观 WM 完整性紊乱，这些结构连接了额叶皮质，可以进一步支持 JME 中丘脑-额叶网络异常的病理生理假说。这些 WM 异常可能与额叶认知功能障碍和 JME 疾病进展有关。
