Cortical Localization in Temporal Lobe Epilepsy

描述(申请人提供)：颞叶切除术为患有难治性颞叶癫痫的患者提供了最大的治愈希望。不幸的是，这种手术往往伴随着命名能力的损失，而命名能力通常在手术前就已经受到了影响。在手术前识别命名缺陷可以提供有价值的信息，可以确定癫痫发作的侧向。此外，保留通过刺激映射识别的命名皮质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以识别基本语言皮质的唯一方法。然而，视觉命名未能可靠地识别真实的命名缺陷，也未能始终如一地保护术后命名。最近添加的听觉描述命名增强了我们对与致痫皮质相关的皮质功能障碍进行定侧和定位的能力。在刺激映射中，听觉命名通过识别临床上相关的语言皮质而提高了映射效率，否则这些皮质将保持不被检测到。尽管取得了这些长足的进步，但有两个问题依然存在。首先，一些患者术后仍表现出命名能力下降，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分部分中处理：成人地图和儿童命名。关于成人映射，初步研究提出了命名下降的两个新的潜在来源：1)海马区的移除(海马体通常被认为是没有语言参与的记忆结构，但最近的手术和成像数据表明它与命名下降有关)和2)支持命名相关语言功能的外侧颞区的外科破坏(初步映射结果揭示了在解剖学上不同的参与语义和语音通达的位置，这两者都是命名所必需的)。为了解决这两种可能性，将在直接刺激海马区和外侧颞区的过程中测试包括命名的语言过程，以确定这些脑区在命名中的作用和临床相关性。成人图的项目目标是确定：a)命名的哪些方面是由海马体调节的，b)非命名的侧位是否参与关键的命名子过程，以及c)命名衰退的性质和严重程度是否与手术破坏的命名部位的位置、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合年龄的命名措施的问题。该项目这一部分的项目目标是：a)通过规范研究和患者测试，开发和标准化成人听觉和视觉命名测试的儿科模拟版本，以及b)确定听觉命名能力是否预测偏侧性癫痫儿童发作的半球偏侧化，就像在成人中一样。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。 公共卫生相关性：这项工作将有助于更好地理解颞叶语言组织，这将提高我们在需要进行颞叶癫痫手术的个体中保存语言能力的能力。这项工作也将为评估和理解儿童的找词能力提供一种手段。

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. PUBLIC HEALTH RELEVANCE: This work will lead to better understanding of temporal lobe language organization, which will improve our ability to preserve language abilities in individuals who require temporal lobe epilepsy surgery. This work will also provide a means for assessing and understanding word finding ability in children.