Cortical Localization in Temporal Lobe Epilepsy

描述（由申请人提供）：众所周知，颞叶在语言中介中起着关键作用。然而，颞叶区域内语言的功能解剖组织尚未得到很好的理解。对于选择手术治疗控制癫痫发作的颞叶癫痫患者来说，这是一个值得关注的问题，因为这种手术切除了颞叶皮层的很大一部分。为了保持语言能力，大脑皮层语言映射通常用来识别“必要的”语言皮层，避免这些区域被切除。然而，尽管有这样的定位，许多患者的术后功能还是下降了，主要是在单词发现方面。尽管大多数手术项目依赖于视觉物体命名来识别“基本”语言皮层，但听觉命名的增加揭示了前颞叶皮层中一个独特的区域，在那里刺激会损害听觉而不是视觉命名。初步的后续测试表明，保留这些听觉命名部位可以保留单词识别能力，而切除这些部位则会导致能力下降（不影响癫痫发作的结果）。有趣的是，尽管只有“纯听觉”部位被切除，而所有视觉命名部位都被保留，但许多患者在听觉和视觉命名方面都有所下降。在本研究中，我们将在颞叶切除前后使用心理语言任务来研究前颞叶皮层在词语及其意义获取中的作用。在映射过程中，将使用类似的任务，在其他方法无法达到的分析级别上描述与语言相关的结构-功能关系。持续的术后随访将评估初步结果的可靠性，并确定缺陷是否持续存在。癫痫发作的结果也将被监测。主要目标是：1)确定去除听觉命名部位导致单词识别能力下降的频率，以及在哪些患者中；2)确定单词选择和获取词义的过程在多大程度上在解剖学上是不同的，以及这些过程在神经解剖学上是如何表现的；3)确定为什么切除似乎支持特定模式（听觉）命名的皮层会导致一般的单词发现能力下降；4)确定保留听觉命名部位切除是否会影响癫痫发作的结果。研究结果有望对语言的神经功能组织有更深入的了解，不仅对癫痫手术患者，而且对其他基于神经系统的语言障碍患者，都有可能提供更好的治疗和语言技能的保存。

DESCRIPTION (provided by applicant): It is well established that the temporal lobe plays a critical role in language mediation. Yet, the functional-anatomical organization of language within the temporal lobe region is not well understood. This is a significant concern for temporal lobe epilepsy patients who elect surgical treatment for seizure control, because a substantial portion of temporal cortex is removed with this procedure. To preserve verbal abilities, cortical language mapping is often performed to identify "essential" language cortex and spare these areas from resection. Nonetheless, many patients decline post-operatively despite such mapping, primarily with respect to word finding. Although most surgery programs rely on visual object naming to identify 'essential' language cortex, the addition of auditory naming revealed a distinct region in anterior temporal cortex where stimulation impaired auditory but not visual naming. Preliminary follow-up testing suggests that sparing these auditory naming sites preserves word finding whereas resecting these sites results in decline (without affecting seizure outcome). Interestingly, a number of patients declined on both auditory and visual naming, despite the fact that only "pure auditory" sites were resected, and that all visual naming sites were spared. In the proposed studies, psycholinguistic tasks will be used before and after temporal lobe resection to study the role of anterior temporal cortex in the access of words and their meaning. Similar tasks will be used during mapping to delineate language-related structure-function relations at a level of analysis that is not attainable with other methods. Continued post-operative follow-up will assess the reliability of the preliminary findings, and determine whether deficits persist. Seizure outcome will be monitored as well. Primary goals are: 1) To determine how often, and in which patients, removing auditory naming sites results in word finding decline; 2) To determine the extent to which processes involved in word selection and access to word meaning are anatomically distinct, and where these process are represented neuroanatomically, 3) Determine why resection of cortex that appears to support modality-specific (auditory) naming can result in general word finding decline; 4) Determine whether sparing auditory naming sites from resection affects seizure outcome. Results promise deeper understanding of the neuro-functional organization of language, potentially offering improved treatment and preservation of language skills, not only to epilepsy surgery patients, but also to individuals with other neurologically based language disorders.