Carey Catherine L, Kramer Joel H, Josephson S Andrew, Mungas Dan, Reed Bruce R, Schuff Norbert, Weiner Michael W, Chui Helena C
Department of Psychiatry, University of California, San Diego, 150 W. Washington, 2nd Floor San Diego, CA 92103, USA.
Stroke. 2008 Feb;39(2):397-402. doi: 10.1161/STROKEAHA.107.491795. Epub 2007 Dec 20.
The relationship between subcortical ischemic vascular disease (SIVD) and cognition in normal elderly is unclear, in part because of methodological inconsistencies across studies. To clarify this relationship, the current study investigated a well characterized cognitively normal elderly sample (>or=55 years) with quantitative MRI and psychometrically robust neuropsychological measures within a multivariate model. Converging evidence suggests that SIVD selectively impairs frontal-executive tasks by disrupting frontal-subcortical circuits. We therefore hypothesized that MRI markers of SIVD would be selectively associated with worse executive functioning.
We studied 94 participants who were cognitively and functionally normal. Volumetric measures of white matter signal hyperintensity (WMH), subcortical lacunes, hippocampal volume, and cortical gray matter were obtained to predict performance on composite measures of executive functioning and episodic memory.
Hierarchical regression demonstrated that after controlling for demographic variables, MMSE, and total intracranial volume, the total number of subcortical lacunes was the only significant predictor, with a greater number of lacunes associated with poorer executive performance. Hippocampal volume best predicted episodic memory performance.
Results suggest that SIVD in the form of silent lacunes corresponds to poorer executive functioning even in otherwise normal elderly, which is consistent with the hypothesis that SIVD preferentially disrupts frontal-subcortical circuits. The clinical importance of these findings is highlighted by the fact that 33% of the normal elderly participants in this study had lacunar infarcts.
皮质下缺血性血管疾病（SIVD）与正常老年人认知之间的关系尚不清楚，部分原因是各研究方法存在不一致性。为了阐明这种关系，本研究在多变量模型中，采用定量磁共振成像（MRI）和心理测量学上可靠的神经心理学测量方法，对一组特征明确的认知正常的老年人样本（年龄≥55岁）进行了调查。越来越多的证据表明，SIVD通过破坏额叶 - 皮质下回路，选择性地损害额叶执行任务。因此，我们假设SIVD的MRI标志物将与较差的执行功能选择性相关。
我们研究了94名认知和功能正常的参与者。获取了白质信号高亮度（WMH）、皮质下腔隙、海马体积和皮质灰质的体积测量值，以预测执行功能和情景记忆综合测量的表现。
分层回归表明，在控制了人口统计学变量、简易精神状态检查表（MMSE）和总颅内体积后，皮质下腔隙的总数是唯一显著的预测因子，腔隙数量越多，执行表现越差。海马体积最能预测情景记忆表现。
结果表明，即使在其他方面正常的老年人中，无症状腔隙形式的SIVD也与较差的执行功能相对应，这与SIVD优先破坏额叶 - 皮质下回路的假设一致。本研究中33%的正常老年参与者有腔隙性梗死这一事实突出了这些发现的临床重要性。
