Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.
Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.
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DOI：
10.1093/brain/awr325
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
M. L. Lambon Ralph;Sheeba Ehsan;G. Baker;T. Rogers
中科院分区：
文献类型：
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作者：
M. L. Lambon Ralph;Sheeba Ehsan;G. Baker;T. Rogers
当代临床和基础神经科学研究越来越多地涉及前颞叶区域，双边，在形成连贯的概念。在双侧前颞叶损伤（例如语义性痴呆）患者、功能性神经成像和重复经颅磁刺激研究中发现了越来越多的证据表明前颞叶在语义记忆中的重要性。如果这一提议是正确的，那么人们可能会认为因长期颞叶癫痫而接受前颞叶切除术的患者会出现语义受损。然而，这些患者在临床上并不表现出明显的理解缺陷，而是表现出健忘症和可变的命名障碍，这导致一些人得出结论，颞叶癫痫切除术中的语义记忆是完整的，从而对语义痴呆和相关的基础神经科学研究得出的结论产生了怀疑。虽然有相当多的神经心理学文献颞叶癫痫，很少有研究直接探讨语义记忆，结果好坏参半，没有进行相同类型的语义处理的系统研究，已与其他患者群体进行。因此，在这项研究中，我们调查了20例慢性颞叶癫痫切除术患者的语义表现，并进行了完整的语义评估，包括更敏感的语义处理措施。本研究结果为颞叶癫痫切除术的临床观察与语义性痴呆和其他神经科学发现的预期之间提供了一座桥梁。具体来说，我们发现，在简单的语义任务中，患者的准确性落在正常范围内，除了一些因颞叶癫痫而接受左侧切除术的患者有可测量的命名障碍。一旦语义评估变得更具挑战性，通过探测特定级别的概念，较低的频率/更抽象的项目或测量语义任务的反应时间与那些困难匹配的非语义评估，语义障碍的证据被发现在所有个人。最后，我们描述了一个统一的，计算启发的框架，捕捉不同程度的语义障碍，发现在不同的患者群体（语义痴呆，颞叶癫痫，神经胶质瘤和中风），以及语义处理在神经系统完整的参与者。
Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants.