FUNCTIONAL MRI OF MEMORY IN TEMPORAL LOBE EPILEPSY

本研究项目将应用功能磁共振成像（fMRI）的新兴技术所面临的临床问题，并在内侧颞叶癫痫（MTLE）患者提出的理论问题。 会聚线的证据表明，内侧颞叶（MTL）是具体的材料，占主导地位的MTL是专门为口头记忆和非主导MTL是专门为视觉空间记忆。MTLE患者经常表现出与致痫灶偏侧性相关的细微的内容特异性记忆缺陷，但通常保持良好的整体记忆功能。 这意味着内侧颞叶硬化症患者将正常偏侧的记忆功能重新组织到对侧的MTL。本研究将检验以下假设：（1）当记忆系统参与内容特异性任务时，正常人可观察到左右MTL的离散、偏侧特异性激活;（2）颞叶癫痫患者根据其致痫灶的位置对颞叶的记忆激活区域进行特定重组。为了验证假设，我们将开发能够选择性激活健康志愿者的优势或非优势MTL的语言和非语言任务。 然后，这些范例将适用于癫痫患者，当他们执行特定的记忆处理任务时，他们将被成像。 将在颞叶切除术前后对患者进行研究，并将其与基线记忆缺陷、颈动脉内杏仁核测试和术后结局进行相关性研究。功能重组将被定义为与正常人中观察到的预期偏侧性的偏差。 这项工作的成功完成将完成双重目标的培训候选人在新的领域fMRI的一个重要的新的方面，她的研究技能和进一步了解MTLE患者的神经心理变化。

This research project will apply the emerging technology of functional magnetic resonance imaging (fMRI) to clinical problems faced by, and theoretical questions raised in, patients with mesial temporal lobe epilepsy (MTLE). Converging lines of evidence suggest that the mesial temporal lobe (MTL) is material specific; the dominant MTL is specialized for verbal memory and the non-dominant MTL is specialized for visuo-spatial memory. Patients with MTLE frequently exhibit subtle content-specific memory deficits related to the laterality of the epileptogenic focus, but generally maintain good overall memory function. This implies that patients with mesial temporal sclerosis reorganize normally lateralized memory functions to the contralateral MTL. This study will test the hypotheses that: (1) discrete, laterality-specific, activation of the left and right MTL may be seen in normals when engaging memory systems with content- specific tasks and (2) patients with temporal lobe epilepsy have particular reorganization of memory-activated regions of the temporal lobe based on the location of their epileptogenic foci. To test the hypotheses, we will develop verbal and non-verbal tasks that are able to selectively activate the dominant or non- dominant MTL in healthy volunteers. These paradigms will then be adapted for use in epilepsy patients who will be imaged as they perform the specific memory processing tasks. Patients will be studied both before and after temporal lobectomy, and correlation will be made to baseline memory deficits, intracarotid amytal testing, and post-operative outcome. Functional reorganization will be defined as a deviation from the expected laterality as observed in normals. The successful completion of this work will accomplish the dual goals of training the candidate in the new area of fMRI-an important new dimension to her research skills-and of furthering understanding of neuropsychological changes patients with MTLE.