Aldenkamp A P, Boon P A, Deblaere K, Achten E, Backes W H, Boon P, Hofman P, Troost J, Vandemaele P, Vermeulen J, Vonck K, Wilmink J
Epilepsy Centre 'Kempenhaeghe', Ghent University Hospital, Belgium.
Acta Neurol Scand. 2003 Sep;108(3):147-52. doi: 10.1034/j.1600-0404.2003.00116.x.
Several procedures for testing language lateralization and memory function exist during the intracarotid amobarbital test (IAT). The use of functional magnetic resonance imaging (fMRI) gives the opportunity to assess the validity of some of these procedures, or at least to inspect the neuronal correlates. A comprehensive fMRI protocol was tested, aimed at addressing aspects of lateralization of language, as well as testing memory in relation to activation of mesiotemporal regions. Here we report observations with possible consequences for the current IAT procedures.
The protocol consisted of three language tasks (overt naming, semantic decision and silent word generation) and two memory tasks (encoding and retrieving visual scenes). The paradigms used a block-related procedure in nine right-handed normal volunteers. During the procedure dynamic weighted full brain images were acquired which are sensitive to the blood oxygenation activation effect.
Encoding showed symmetrical bilateral activation in the mesiotemporal regions, specifically the hippocampus, parahippocampal gyrus and fusiform gyrus. With a retrieval task activation of the mesiotemporal areas was restricted to the posterior hippocampal area. Overt object naming showed results, similar to encoding tasks with bilateral activation of hippocampal areas. Silent word generation showed much stronger ability to lateralize than the other two language-related tasks and especially object naming.
Activation revealed by fMRI activation shows that IAT procedures, using active semantic language processing or comprehensive procedures with multiple language tasks have the highest guarantee for individual activation lateralization. Simple object naming does not guarantee a lateralized language fMRI activation pattern. Of the different memory procedures during IAT, the procedures (Interview and the Montreal) demanding encoding processing will be related to larger areas of bilateral hippocampal activation than procedures (Seattle) exclusively requiring retrieval. Moreover, tasks using recognition of previously presented language items (naming objects) are equally effective for assessing hippocampal activation compared with presenting separate memory items.
在颈动脉内注射异戊巴比妥试验（IAT）期间，存在几种测试语言侧化和记忆功能的程序。功能磁共振成像（fMRI）的应用为评估其中一些程序的有效性提供了机会，或者至少可以检查神经元相关性。我们测试了一个全面的fMRI方案，旨在解决语言侧化方面的问题，并测试与颞叶内侧区域激活相关的记忆。在此，我们报告一些观察结果，这些结果可能会对当前的IAT程序产生影响。
该方案包括三个语言任务（公开命名、语义判断和默读词生成）和两个记忆任务（视觉场景编码和检索）。这些范式在九名右利手正常志愿者中采用了与块相关的程序。在该过程中，采集了对血氧合激活效应敏感的动态加权全脑图像。
编码显示颞叶内侧区域双侧对称激活，特别是海马体、海马旁回和梭状回。在检索任务中，颞叶内侧区域的激活仅限于海马体后部区域。公开物体命名的结果与海马体区域双侧激活的编码任务相似。默读词生成比其他两个与语言相关的任务，尤其是物体命名，具有更强的侧化能力。
fMRI激活显示，使用主动语义语言处理或包含多个语言任务的综合程序进行IAT程序，对个体激活侧化具有最高的保证。简单的物体命名不能保证fMRI语言激活模式的侧化。在IAT期间的不同记忆程序中，需要编码处理的程序（访谈和蒙特利尔）将比仅需要检索的程序（西雅图）与双侧海马体更大区域的激活相关。此外，与呈现单独的记忆项目相比，使用识别先前呈现的语言项目（命名物体）的任务在评估海马体激活方面同样有效。
