Jäger Theodor, Szabo Kristina, Griebe Martin, Bäzner Hansjörg, Möller Johanna, Hennerici Michael G
Department of Neurology, Universitätsklinikum Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany.
Neuropsychologia. 2009 Jan;47(1):70-6. doi: 10.1016/j.neuropsychologia.2008.08.019. Epub 2008 Aug 22.
Transient global amnesia (TGA) is characterized by the abrupt onset of severe amnesia without concomitant focal neurological symptoms. Recent studies revealed that small and punctate MR-signal diffusion-weighted imaging (DWI) lesions can be found within the hippocampus of TGA patients during the post-acute phase. On the basis of dual-process models of recognition memory, the present study examined the hypothesis that hippocampal dysfunction as suggested by these DWI lesions disrupts hippocampus-mediated recollection in patients with TGA, whereas familiarity-based recognition memory that is assumed to be supported by extra-hippocampal brain regions should be unaffected. We administered a recognition memory task for faces and words to eleven TGA patients during the post-acute phase and to eleven matched controls. Receiver operating characteristics (ROCs) were obtained in order to derive estimates of familiarity and recollection by applying a formal dual-process model of recognition memory. Analyses of ROC curves revealed a disruption of recollection in TGA patients' memory for words [t(20)=2.70, p<.05], but no difference in familiarity-based recognition memory between patients and controls [t(20)=-1.10, p=.284]. Post hoc analyses indicated that the deficit in recollection is more pronounced in TGA patients who show visible hippocampal lesions on diffusion-weighted MR imaging compared to those without detectable hippocampal lesions. In conclusion, consistent with recent neuroanatomical dual-process models of recognition memory, hippocampal dysfunction in patients with TGA is associated with a selective effect on specific recognition memory subprocesses.
短暂性全面性遗忘症（TGA）的特征是突然发作严重遗忘，且无伴随的局灶性神经症状。最近的研究表明，在急性期过后，TGA患者海马体内可发现小而点状的磁共振信号扩散加权成像（DWI）病变。基于识别记忆的双过程模型，本研究检验了以下假设：这些DWI病变所提示的海马功能障碍会破坏TGA患者海马介导的回忆，而假定由海马外脑区支持的基于熟悉度的识别记忆应不受影响。我们在急性期过后对11名TGA患者和11名匹配的对照组进行了面孔和单词的识别记忆任务。通过应用正式的识别记忆双过程模型来获得接受者操作特征（ROC），以得出熟悉度和回忆的估计值。ROC曲线分析显示，TGA患者对单词的记忆中回忆受到破坏[t(20)=2.70, p<.05]，但患者与对照组之间基于熟悉度的识别记忆没有差异[t(20)=-1.10, p=.284]。事后分析表明，与没有可检测到海马病变的TGA患者相比，在扩散加权磁共振成像上显示可见海马病变的TGA患者回忆缺陷更明显。总之，与最近的识别记忆神经解剖学双过程模型一致，TGA患者的海马功能障碍与对特定识别记忆子过程的选择性影响有关。
