Hernando Kathleen A, Szaflarski Jerzy P, Ver Hoef Lawrence W, Lee Seongtaek, Allendorfer Jane B
Department of Neurology, University of Alabama at Birmingham (UAB), Birmingham, AL, USA.
Department of Neurology, University of Alabama at Birmingham (UAB), Birmingham, AL, USA; UAB Epilepsy Center, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.
Epilepsy Behav. 2015 Apr;45:68-73. doi: 10.1016/j.yebeh.2015.02.022. Epub 2015 Apr 9.
The amygdala, hippocampus, and medial prefrontal cortex are limbic brain regions connected by the uncinate fasciculus (UF) and implicated in emotion regulation. The aim of this study was to assess the connectivity characteristics of the UF in patients with psychogenic nonepileptic seizures (PNES) and matched healthy controls. We hypothesized that white matter connectivity of the UF in patients with PNES would differ from that in healthy controls. Eight patients with PNES and eight age- and sex-matched healthy controls underwent 3T MRI and 32-direction diffusion tensor imaging (DTI). Computation of DTI indices including fractional anisotropy (FA) and diffusion tensor tractography was performed. Two regions of interest were defined to manually trace the UF in each hemisphere for each subject. Fractional anisotropy and the number of reconstructed streamlines for the left and right hemispheres of the UF and the degree of asymmetry for each measure were compared between groups. Correlations between UF measures and clinical variables were also performed. Patients with PNES exhibited a significantly greater number of UF streamlines in the right hemisphere tract than in the left hemisphere (p=0.031), with such difference not observed in controls (p=0.81). This was reflected in a significant group difference in the asymmetry index (AI) for the number of streamlines, with more rightward asymmetry in patients with PNES (p=0.021). Average FA of the UF was similar between groups and between hemispheres for each group (all p>0.05). Age at illness onset was correlated with the AI for FA (r=-0.87; p=0.0045). Previously observed differences in emotion processing between controls and patients with PNES may be related to the differences in the rightward asymmetry in the number of UF streamlines in patients with PNES. Age at PNES onset appears to also have a role in the FA asymmetry of the UF. This is the first study to investigate the structural connectivity in these regions involved in emotional regulation in patients with PNES; further research is necessary to clarify the complex relationships between clinical measures and DTI characteristics.
杏仁核、海马体和内侧前额叶皮质是边缘脑区，通过钩束（UF）相连，与情绪调节有关。本研究的目的是评估精神性非癫痫性发作（PNES）患者和匹配的健康对照者中钩束的连接特征。我们假设PNES患者中钩束的白质连接性与健康对照者不同。8例PNES患者和8例年龄及性别匹配的健康对照者接受了3T磁共振成像（MRI）和32方向扩散张量成像（DTI）检查。进行了包括分数各向异性（FA）和扩散张量纤维束成像在内的DTI指标计算。定义了两个感兴趣区域，以便为每个受试者手动追踪每个半球的钩束。比较了两组之间钩束左右半球的分数各向异性、重建纤维束数量以及每项测量的不对称程度。还进行了钩束测量与临床变量之间的相关性分析。PNES患者右侧半球纤维束的数量显著多于左侧半球（p = 0.031），而对照组未观察到这种差异（p = 0.81）。这反映在纤维束数量不对称指数（AI）上存在显著的组间差异，PNES患者右侧不对称性更高（p = 0.021）。两组之间以及每组半球之间钩束的平均FA相似（所有p>0.05）。发病年龄与FA的AI相关（r = -0.87；p = 0.0045）。先前观察到的对照组与PNES患者在情绪处理上的差异可能与PNES患者钩束纤维束数量右侧不对称性的差异有关。PNES发病年龄似乎也在钩束的FA不对称性中起作用。这是第一项研究PNES患者中这些参与情绪调节区域的结构连接性的研究；需要进一步研究以阐明临床测量与DTI特征之间的复杂关系。
