Cortical Localization in Temporal Lobe Epilepsy

描述（申请人提供）：颞叶切除为难治性颞叶癫痫患者提供了治愈的最大希望。不幸的是，这种手术往往要付出命名能力的代价，而命名能力通常在手术前就已经受损。在手术前识别命名缺陷提供了有价值的信息，可以侧化癫痫发作。此外，通过刺激映射识别的命名皮层的保留有助于防止术后命名能力下降。从历史上看，视觉对象命名一直是评估命名和刺激映射识别基本语言皮层的唯一方法。然而，视觉命名不能可靠地识别真正的命名缺陷，也不能始终如一地保护术后命名。最近增加的听觉描述命名增强了我们侧化和定位与癫痫相关的皮质功能障碍的能力。在刺激映射中，听觉命名通过识别临床相关的语言皮层而提高了映射效率，否则这些语言皮层将无法被发现。尽管取得了这些重大进展，但仍存在两个问题。首先，部分患者术后仍有命名能力下降的现象；其次，听觉命名的工作尚未扩展到儿童。这两个问题将在拟议项目的两个子组件中解决：成人映射和儿童命名。关于成人地图，初步研究提出了两个新的潜在的命名下降来源：1)海马体切除（海马体通常被认为是一种没有语言参与的记忆结构，但最近的术后和成像数据表明它与命名能力下降有关）；2)手术破坏支持命名相关语言功能的外侧颞区（初步测绘结果显示，解剖学上不同的部位介导语义和语音通路，这两者都是命名所必需的）。为了解决这两种可能性，将在直接刺激海马和颞外侧部位时测试包含命名的语言过程，以确定这些大脑区域在命名中的作用和临床相关性。成人地图的项目目标是确定：a)海马介导命名的哪些方面，b)“非命名”颞外侧位点是否介导关键的命名子过程，以及c)命名能力下降的性质和严重程度是否与手术破坏的命名位点的位置、类型或数量有关。在儿童命名方面，我们将解决癫痫儿童缺乏适龄命名措施的问题。该项目的这一部分的项目目标是：a)通过规范性研究和患者测试，开发和标准化成人听觉和视觉命名测试的类似儿科版本；b)确定听觉命名表现是否能预测患有侧侧性癫痫的儿童癫痫发作的半球偏侧性，就像它在成人中所做的那样。整个项目的结果有望为语言的颞叶组织提供新的见解，更好地预测和预防术后缺陷，并改善儿童癫痫的护理。

DESCRIPTION (provided by applicant): Temporal lobe resection offers the best hope of cure for patients who suffer from refractory temporal lobe epilepsy. Unfortunately, this surgery often comes with a cost to naming ability, which is typically already compromised before surgery. Identification of naming deficits prior to surgery provides valuable information that can lateralize seizure onset. Furthermore, sparing of naming cortex identified via stimulation mapping helps prevent naming decline postoperatively. Historically, visual object naming has been the sole method both for assessing naming and for stimulation mapping to identify essential language cortex. However, visual naming has failed to reliably identify true naming deficits and has failed to consistently protect postoperative naming. The recent addition of auditory description naming has enhanced our ability to lateralize and localize cortical dysfunction associated with epileptogenic cortex. In stimulation mapping, auditory naming has improved mapping efficacy by identifying clinically relevant language cortex that otherwise would have remained undetected. Despite these considerable advances, two problems persist. First, some patients still exhibit postoperative naming decline and second, the work in auditory naming has not been extended to children. These two issues will be addressed in the two subcomponents of the proposed project: Adult Mapping and Child Naming. Regarding Adult Mapping, preliminary studies suggest two new potential sources of naming decline: 1) Hippocampal removal (the hippocampus is generally considered a memory structure without language involvement, but recent postoperative and imaging data implicate it in naming decline) and 2) Surgical disruption of lateral temporal areas that support naming-related linguistic functions (pilot mapping results reveal anatomically distinct sites that mediate semantic and phonological access, both of which are necessary for naming). To address these two possibilities, the linguistic processes that comprise naming will be tested during direct stimulation of hippocampal and lateral temporal sites to establish the role and clinical relevance of these brain areas in naming. Project goals for Adult Mapping are to determine: a) Which aspects of naming are mediated by the hippocampus, b) Whether "non-naming" lateral temporal sites mediate critical naming sub-processes, and c) Whether the nature and severity of naming decline are related to the location, type, or number of naming sites disrupted by surgery. Regarding Child Naming, we will address the absence of age appropriate naming measures for children with epilepsy. Project goals for this component of the project are to: a) Develop and standardize analogous pediatric versions of the adult auditory and visual naming tests via normative study and patient testing, and b) Determine whether auditory naming performance predicts hemispheric lateralization of seizure onset in children with lateralized epilepsy, as it does in adults. Results from the overall project promise new insights into temporal lobe organization of language, better prediction and prevention of postoperative deficits, and improvements in pediatric epilepsy care.