Krueger C E, Bird A C, Growdon M E, Jang J Y, Miller B L, Kramer J H
Memory and Aging Center, UCSF Department of Neurology, San Francisco, CA, USA.
Neurology. 2009 Aug 4;73(5):349-55. doi: 10.1212/WNL.0b013e3181b04b24.
Despite the extensive frontal atrophy and behavioral disinhibition that characterizes behavioral variant frontotemporal dementia (bvFTD), many studies of early bvFTD suggest normal executive functioning (EF). The current study examined cognitive control in patients with bvFTD who otherwise seemed cognitively normal.
Subjects included 7 patients with bvFTD with normal neuropsychological test scores, 7 patients with bvFTD matched for Mini-Mental State Examination score but with impaired neuropsychological test scores, and 14 normal controls. A flanker paradigm and other measures of EF were administered to participants. A semiautomated parcellation program was used to analyze structural MRI scans.
On the flanker task, multivariate analysis of variance revealed a significant condition X diagnosis interaction. Both bvFTD groups showed a larger congruency effect than normal controls, i.e., they displayed disproportionately reduced speed and accuracy on incongruent trials relative to congruent trials. Imaging data illustrated significant orbitofrontal atrophy in patients with early bvFTD as compared with controls.
Patients with behavioral variant frontotemporal dementia (bvFTD) who performed within normal limits on clinical tests of executive functioning demonstrated a select impairment on an experimental test of cognitive control, suggesting a subtle impairment in inhibiting attention or response to the irrelevant stimuli. Measures of neuropsychological functioning sensitive to the ventromedial prefrontal cortex may be useful in early diagnosis of patients with bvFTD. Our understanding of this syndrome may be increased by considering the efficiency of selective inhibition, a fundamental component of executive cognitive control.
尽管行为变异型额颞叶痴呆（bvFTD）具有广泛的额叶萎缩和行为抑制解除的特征，但许多关于早期bvFTD的研究表明其执行功能（EF）正常。本研究考察了在其他方面认知看似正常的bvFTD患者的认知控制情况。
研究对象包括7名神经心理测试得分正常的bvFTD患者、7名简易精神状态检查表得分匹配但神经心理测试得分受损的bvFTD患者以及14名正常对照者。对参与者实施了侧翼范式及其他EF测量方法。使用半自动分割程序分析结构磁共振成像扫描结果。
在侧翼任务中，多变量方差分析显示出显著的条件×诊断交互作用。两个bvFTD组均显示出比正常对照者更大的一致性效应，即相对于一致试验，他们在不一致试验中表现出速度和准确性的不成比例下降。成像数据表明，与对照组相比，早期bvFTD患者存在显著的眶额萎缩。
在执行功能临床测试中表现正常的行为变异型额颞叶痴呆（bvFTD）患者在认知控制的实验测试中表现出选择性损伤，提示在抑制对无关刺激的注意力或反应方面存在细微损伤。对腹内侧前额叶皮质敏感的神经心理功能测量方法可能有助于bvFTD患者的早期诊断。考虑选择性抑制的效率这一执行认知控制的基本组成部分，可能会增进我们对该综合征的理解。
