Powell H W Robert, Richardson Mark P, Symms Mark R, Boulby Philip A, Thompson Pam J, Duncan John S, Koepp Matthias J
Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, Queen Square, London, UK.
Epilepsia. 2007 Aug;48(8):1512-25. doi: 10.1111/j.1528-1167.2007.01053.x. Epub 2007 Mar 13.
Patients with temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) often suffer from material-specific memory impairments. The purpose of this study was to use functional magnetic resonance imaging (fMRI) to study the organization of specific memory functions in these patients.
We report 14 patients with unilateral TLE and HS, and 10 controls, performing an fMRI memory paradigm of word, picture, and face encoding.
Compared with controls, patients with left TLE demonstrated less left MTL and greater right MTL activation and patients with right TLE demonstrated less right MTL and greater left MTL activation. Correlations between fMRI activation and memory performance revealed greater activation in the damaged left hippocampus to be correlated with better verbal memory performance in left TLE patients and greater right hippocampal activation to be correlated with better nonverbal memory in right TLE patients. Conversely, greater fMRI activation in the contralateral hippocampus correlated with worse memory performance.
Our findings suggest that memory function in unilateral TLE is better when it is sustained by activation within the damaged hippocampus and that reorganization to the undamaged MTL is an inefficient process, incapable of preserving memory function.
因海马硬化（HS）导致的颞叶癫痫（TLE）患者常存在特定材料记忆障碍。本研究旨在利用功能磁共振成像（fMRI）研究这些患者特定记忆功能的组织情况。
我们报告了14例单侧TLE和HS患者以及10名对照者，他们进行了一项关于单词、图片和面部编码的fMRI记忆范式实验。
与对照者相比，左侧TLE患者左侧内侧颞叶（MTL）激活较少，右侧MTL激活较多；右侧TLE患者右侧MTL激活较少，左侧MTL激活较多。fMRI激活与记忆表现之间的相关性显示，左侧TLE患者受损左侧海马体中更大的激活与更好的言语记忆表现相关，右侧TLE患者右侧海马体更大的激活与更好的非言语记忆相关。相反，对侧海马体中更大的fMRI激活与更差的记忆表现相关。
我们的研究结果表明，单侧TLE患者的记忆功能在由受损海马体内的激活维持时更好，并且向未受损MTL的重组是一个低效的过程，无法保留记忆功能。
