Functional MRI for Neurosurgical Planning in Epilepsy

描述(申请人提供)：癫痫患者 脑部病变的外科切除必须有某种形式的功能图谱 以确定是否可以移除病变而不创建功能性 赤字。目前在这些患者中映射语言的程序是 空间受限(例如，使用WADA测试的半球映射)或高度受限 侵入性(使用硬膜下电极的皮质刺激)。功能性MR 成像(FMRI)有可能取代或显著增强 目前神经外科计划中使用的方法。它是非侵入性的，并且已经 显示出能够定位大脑皮质活动。然而，标准的回声 基于大胆激活反应的平面成像FMR1方法存在以下问题 空间分辨率低，对静态Bo磁场敏感 导致图像失真和低信号强度的不均匀。这些 这些问题严重限制了fMRI定位大脑活动的能力 神经外科手术计划。这个项目有三个目标。首先，它的设计目的是 改进功能磁共振成像方法。我们早期的工作已经确定了开发 在功能磁共振成像研究中最大化统计能力的单次激发方法，因此 方法学的发展将集中在单次拍摄图像的方法上。 失真和信号损失，包括非对称自旋回波的研究 EPI和动态垫片。这一创新计划将允许高度稳健地 手术计划需要进行功能定位，但方法是 所开发的可应用于任何功能磁共振研究。第二，我们将继续我们的工作 通过与WADA测试的对比验证检测到的fMRI激活 和大脑皮层刺激。一组fMRI语言范例，与 磁力外行为研究，旨在解决特定的 在颞叶癫痫患者中获得的缺陷，这些将被应用 对于对照受试者和顽固性癫痫患者 做手术的候选人。患者将接受成像和行为测试 手术前和手术后。通过这样的研究，功能磁共振成像能够预测 将对手术结果进行评估。最后，我们将考察这一关系 在疾病状态(内侧颞叶硬化症、皮质畸形和 肿瘤)和语言重组(手术前后)和 通过将语言组织和绩效与之前的 手术，与癫痫发作的类型、位置和年龄有关。这样的研究将会 不仅提供语言重组的证据，而且提供具体的证据 重组的皮质区域，以及这种重组对 表现和手术结果。

Description (provided by applicant): Epilepsy patients who are candidates for surgical resection of a brain lesion must have some form of functional mapping to determine if the lesion can be removed without creating a functional deficit. The current procedures for mapping language in these patients are spatially limited (e.g. hemispheric mapping with Wada testing) or highly invasive (cortical stimulation using subdural electrodes). Functional MR imaging (fMRI) has the potential to replace, or significantly enhance, the current methods used in Neurosurgical planning. It is noninvasive and has been shown to be able to localize cortical activity. However, the standard echo planar imaging fMR1 methods, based on the BOLD activation response, suffer from low spatial resolution, and sensitivity to static Bo magnetic field inhomogeneities which lead to image distortions and low signal intensity. These problems severely limit the ability of fMRI to localize brain activity for Neurosurgical planning. This project has 3 aims. First, it is designed to improve fMRI methodology. Our earlier work has identified the need to develop single shot approaches to maximize statistical power in fMRI studies, and thus the methodology developments will focus on single shot approaches to image distortion and signal loss, including the investigation of asymmetric spin echo EPI and dynamic shimming. This innovative program will allow for highly robust functional localization required for surgical planning, but the methods to be developed may be applied to any fMRI study. Secondly, we will continue our work on validating the fMRI activation detected through comparison with Wada testing and cortical stimulation. A battery of fMRI language paradigms, parallel to out-of-magnet behavioral studies, have been designed to address the specific deficits obtained in temporal lobe epilepsy patients and these will be applied to both control subjects and patients with intractable epilepsy who are candidates for surgery. Patients will be imaged and tested behaviorally both pre and post- surgery. Through such studies the ability of fMRI to predict surgical outcome will be evaluated. Finally, we will examine the relationship between disease states (mesial temporal sclerosis, cortical malformations, and tumors) and language reorganization both acutely (pre- and post- surgery) and chronically by relating the language organization and performance prior to surgery, to the type, location, and age at onset of epilepsy. Such a study will provide evidence not only of language reorganization but also of the specific cortical regions that reorganize, and the impact this reorganization has on performance and surgical outcome.