Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology , Ilmenau , Germany.
Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA ; Department of Newborn Medicine, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA.
Front Hum Neurosci. 2014 Mar 26;8:175. doi: 10.3389/fnhum.2014.00175. eCollection 2014.
Tuberous sclerosis complex (TSC) is a rare disorder of tissue growth and differentiation, characterized by benign hamartomas in the brain and other organs. Up to 90% of TSC patients develop epilepsy and 50% become medically intractable requiring resective surgery. The surgical outcome of TSC patients depends on the accurate identification of the epileptogenic zone consisting of tubers and the surrounding epileptogenic tissue. There is conflicting evidence whether the epileptogenic zone is in the tuber itself or in abnormally developed surrounding cortex. Here, we report the localization of the epileptiform activity among the many cortical tubers in a 4-year-old patient with TSC-related refractory epilepsy undergoing magnetoencephalography (MEG), electroencephalography (EEG), and diffusion tensor imaging (DTI). For MEG, we used a prototype system that offers higher spatial resolution and sensitivity compared to the conventional adult systems. The generators of interictal activity were localized using both EEG and MEG with equivalent current dipole (ECD) and minimum norm estimation (MNE) methods according to the current clinical standards. For DTI, we calculated four diffusion scalar parameters for the fibers passing through four ROIs defined: (i) at a large cortical tuber identified at the right quadrant, (ii) at the normal appearing tissue contralateral to the tuber, (iii) at the cluster formed by ECDs fitted at the peak of interictal spikes, and (iv) at the normal appearing tissue contralateral to the cluster. ECDs were consistently clustered at the vicinity of the large calcified cortical tuber. MNE and ECDs indicated epileptiform activity in the same areas. DTI analysis showed differences between the scalar values of the tracks passing through the tuber and the ECD cluster. In this illustrative case, we provide evidence from different neuroimaging modalities, which support the view that epileptiform activity may derive from abnormally developed tissue surrounding the tuber rather than the tuber itself.
结节性硬化症（TSC）是一种罕见的组织生长和分化障碍，其特征是脑和其他器官中有良性错构瘤。高达 90%的 TSC 患者会出现癫痫，其中 50%的患者需要进行抗药性癫痫的手术治疗。TSC 患者的手术结果取决于准确识别由结节和周围致痫组织组成的致痫区。关于致痫区是位于结节本身还是位于异常发育的周围皮质，目前存在相互矛盾的证据。在这里，我们报告了一名 4 岁 TSC 相关耐药性癫痫患者在进行磁共振脑磁图（MEG）、脑电图（EEG）和弥散张量成像（DTI）检查时，多个皮质结节中的癫痫样活动的定位情况。对于 MEG，我们使用了一种原型系统，与传统的成人系统相比，该系统具有更高的空间分辨率和灵敏度。根据当前的临床标准，我们使用脑电图和 MEG 等效电流偶极子（ECD）和最小范数估计（MNE）方法来定位间歇性活动的发生器。对于 DTI，我们计算了通过四个 ROI 定义的纤维的四个扩散标量参数：（i）在右象限识别出的大型皮质结节处，（ii）在结节对侧的正常组织处，（iii）在拟合在间歇性棘波峰值的 ECD 簇处，以及（iv）在 ECD 簇对侧的正常组织处。ECD 始终聚集在大型钙化皮质结节附近。MNE 和 ECD 都表明了相同区域的癫痫样活动。DTI 分析显示，通过结节和 ECD 簇的轨迹的标量值存在差异。在这个说明性的病例中，我们提供了来自不同神经影像学模式的证据，支持了这样一种观点，即癫痫样活动可能源自结节周围异常发育的组织，而不是结节本身。
