Gee James, Ding Lijun, Xie Zhiyong, Lin Michael, DeVita Christian, Grossman Murray
Department of Radiology, University of Pennsylvania, 3600 Market Street, Suite 370, Philadelphia, PA 19104-2644, USA.
Acad Radiol. 2003 Dec;10(12):1392-401. doi: 10.1016/s1076-6332(03)00543-9.
The purpose of this study was to test the hypothesis that distinct patterns of gray matter atrophy are responsible for unique interruptions of the naming process in Alzheimer's disease (AD) and frontotemporal dementia (FTD).
Voxel-based morphometry (VBM) was performed to characterize at the voxel level the neuroanatomic changes that occur in AD and FTD based on high-resolution T1-weighted three-dimensional (3D) spoiled-gradient echo images of patients (AD, n = 12; FTD, n = 29) and healthy control subjects (n = 12). The cortical atrophy measurements were correlated with performance on behavioral measures of naming and related processes to identify brain regions that may contribute to this language function.
Both AD and FTD have significant naming difficulty, and this difficulty in naming correlates with a measure of lexical retrieval in both patient groups as well. However, only FTD patients showed a correlation with semantic memory. Areas of cortical atrophy common to AD and FTD were found in the anterior temporal, posterolateral temporal, and dorsolateral prefrontal regions of the left hemisphere. Correlation with naming in both AD and FTD was seen in the left anterior temporal cortex, suggesting that this area may play a role in the lexical retrieval component of naming. We also observed several unique areas of cortical atrophy in temporal and frontal cortices of these patients. Right anterior temporal and left posterolateral temporal regions of atrophy correlated with naming difficulty in FTD, suggesting that these areas may contribute to the semantic memory component of naming. Cortical areas correlating with naming that are not atrophic may represent regions that play an optional role in naming.
VBM provides an important first step in analyzing brain-behavior relations in vivo in patients with neurodegenerative diseases. More refined analyses of brain morphology via high-dimensional normalization methods that are capable of modeling local as well as global variability in neuroanatomical structure promise to be even more informative.
本研究旨在验证以下假设，即不同模式的灰质萎缩是导致阿尔茨海默病（AD）和额颞叶痴呆（FTD）命名过程出现独特中断的原因。
基于患者（AD，n = 12；FTD，n = 29）及健康对照者（n = 12）的高分辨率T1加权三维（3D）扰相梯度回波图像，采用基于体素的形态测量法（VBM）在体素水平表征AD和FTD中发生的神经解剖学变化。将皮质萎缩测量结果与命名及相关过程的行为测量表现进行关联，以确定可能对这种语言功能有贡献的脑区。
AD和FTD患者均存在显著的命名困难，且两组患者的这种命名困难均与词汇检索指标相关。然而，只有FTD患者的命名困难与语义记忆相关。AD和FTD共有的皮质萎缩区域位于左半球的颞前、颞后外侧和额背外侧区域。AD和FTD患者的命名与左颞前皮质均存在相关性，提示该区域可能在命名的词汇检索成分中发挥作用。我们还在这些患者的颞叶和额叶皮质中观察到几个独特的皮质萎缩区域。右侧颞前和左侧颞后外侧区域的萎缩与FTD患者的命名困难相关，提示这些区域可能对命名的语义记忆成分有贡献。与命名相关但未萎缩的皮质区域可能代表在命名中起辅助作用的区域。
VBM为分析神经退行性疾病患者体内脑-行为关系提供了重要的第一步。通过能够对神经解剖结构的局部和整体变异性进行建模的高维归一化方法对脑形态进行更精细的分析，有望提供更多信息。
