Transient epileptic amnesia: regional brain atrophy and its relationship to memory deficits
Transient epileptic amnesia: regional brain atrophy and its relationship to memory deficits
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DOI：
10.1093/brain/awn336
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发表时间：
2009-02-01
期刊：
影响因子：
14.5
通讯作者：
Zeman, A. Z.
中科院分区：
文献类型：
--
作者：
Butler, C. R.;Bhaduri, A.;Zeman, A. Z.
短暂性癫痫性遗忘症（TEA）是最近认识到的一种癫痫形式，其主要表现是反复发作的短暂孤立性记忆丧失。除了健忘发作，许多患者描述了显著的发作间期记忆困难。标准神经心理学测试的表现通常是正常的。然而，最近在TEA中证明了两种不寻常的记忆缺陷形式：（i）加速长期遗忘（ALF）：在几天或几周内新获得的记忆过度快速丢失;（ii）远程自传体记忆丧失：过去几十年中突出的个人经历事件的记忆丧失。TEA的神经解剖学基础及其相关的记忆缺陷尚不清楚。在这项研究中，我们首先评估了41例TEA患者的主观和客观记忆表现之间的关系。然后，我们分析了来自这些患者和20名匹配的健康对照的MRI数据，使用手动体积测定法和基于体素的形态测定法（VBM）将局部脑体积与临床和神经心理学数据相关联。主观记忆估计与标准神经心理测试的表现无关，但部分预测情绪，ALF和远程自传体记忆。手动容量测定法确定微妙的海马体积损失的患者组。手动容量测定和VBM均显示内侧颞叶萎缩与标准顺行记忆评分之间存在相关性，但萎缩与ALF或远程自传体记忆之间无相关性。这些结果增加了重量的假设，TEA是一个综合征的内侧颞叶癫痫。此外，他们认为，虽然标准的顺行性记忆测试的表现与内侧颞叶损伤的程度有关，但这对ALF和自传体遗忘症并不正确。这些不寻常的记忆缺陷可能有更广泛的生理基础，而不是离散的结构损伤的结果。
Transient epileptic amnesia (TEA) is a recently recognised form of epilepsy of which the principle manifestation is recurrent, transient episodes of isolated memory loss. In addition to the amnesic episodes, many patients describe significant interictal memory difficulties. Performance on standard neuropsychological tests is often normal. However, two unusual forms of memory deficit have recently been demonstrated in TEA: (i) accelerated long-term forgetting (ALF): the excessively rapid loss of newly acquired memories over a period of days or weeks and (ii) remote autobiographical memory loss: a loss of memories for salient, personally experienced events of the past few decades. The neuroanatomical bases of TEA and its associated memory deficits are unknown. In this study, we first assessed the relationship between subjective and objective memory performance in 41 patients with TEA. We then analysed MRI data from these patients and 20 matched healthy controls, using manual volumetry and voxel-based morphometry (VBM) to correlate regional brain volumes with clinical and neuropsychological data. Subjective memory estimates were unrelated to performance on standard neuropsychological tests but were partially predicted by mood, ALF and remote autobiographical memory. Manual volumetry identified subtle hippocampal volume loss in the patient group. Both manual volumetry and VBM revealed correlations between medial temporal lobe atrophy and standard anterograde memory scores, but no relation between atrophy and ALF or remote autobiographical memory. These results add weight to the hypothesis that TEA is a syndrome of mesial temporal lobe epilepsy. Furthermore, they suggest that although standard anterograde memory test performance is related to the degree of mesial temporal lobe damage, this is not true for ALF and autobiographical amnesia. It is possible that these unusual memory deficits have a more diffuse physiological basis rather than being a consequence of discrete structural damage.