Rajmohan Ravi, Anderson Ronald C, Fang Dan, Meyer Austin G, Laengvejkal Pavis, Julayanont Parunyou, Hannabas Greg, Linton Kitten, Culberson John, Khan Hafiz M R, De Toledo John, Reddy P Hemachandra, O'Boyle Michael
Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center Lubbock, TX, USA.
Department of Electrical and Computer Engineering, Texas Tech University Lubbock, TX, USA.
Front Aging Neurosci. 2017 Mar 1;9:37. doi: 10.3389/fnagi.2017.00037. eCollection 2017.
In Alzheimer Disease (AD), non-verbal skills often remain intact for far longer than verbally mediated processes. Four (1 female, 3 males) participants with early-stage Clinically Diagnosed Dementia of the Alzheimer Type (CDDAT) and eight neurotypicals (NTs; 4 females, 4 males) completed the emotional valence determination test (EVDT) while undergoing BOLD functional magnetic resonance imaging (fMRI). We expected CDDAT participants to perform just as well as NTs on the EVDT, and to display increased activity within the bilateral amygdala and right anterior cingulate cortex (r-ACC). We hypothesized that such activity would reflect an increased reliance on these structures to compensate for on-going neuronal loss in frontoparietal regions due to the disease. We used diffusion tensor imaging (DTI) to determine if white matter (WM) damage had occurred in frontoparietal regions as well. CDDAT participants had similar behavioral performance and no differences were observed in brain activity or connectivity patterns within the amygdalae or r-ACC. Decreased fractional anisotropy (FA) values were noted, however, for the bilateral superior longitudinal fasciculi and posterior cingulate cortex (PCC). We interpret these findings to suggest that emotional valence determination and non-verbal skill sets are largely intact at this stage of the disease, but signs foreshadowing future decline were revealed by possible WM deterioration. Understanding how non-verbal skill sets are altered, while remaining largely intact, offers new insights into how non-verbal communication may be more successfully implemented in the care of AD patients and highlights the potential role of DTI as a presymptomatic biomarker.
在阿尔茨海默病（AD）中，非语言技能往往比语言介导的过程保持完整的时间长得多。四名（1名女性，3名男性）临床诊断为阿尔茨海默型早期痴呆（CDDAT）的参与者和八名神经典型个体（NTs；4名女性，4名男性）在进行血氧水平依赖性功能磁共振成像（fMRI）时完成了情绪效价测定测试（EVDT）。我们预期CDDAT参与者在EVDT上的表现与NTs一样好，并在双侧杏仁核和右侧前扣带回皮质（r-ACC）内显示出活动增加。我们假设这种活动将反映出由于疾病导致额顶叶区域持续神经元丧失，对这些结构的依赖增加以进行补偿。我们还使用扩散张量成像（DTI）来确定额顶叶区域是否也发生了白质（WM）损伤。CDDAT参与者具有相似的行为表现，并且在杏仁核或r-ACC内的脑活动或连接模式方面未观察到差异。然而，双侧上纵束和后扣带回皮质（PCC）的分数各向异性（FA）值有所降低。我们将这些发现解释为表明在疾病的这个阶段，情绪效价测定和非语言技能集在很大程度上是完整的，但可能的WM恶化揭示了未来衰退的先兆。了解非语言技能集如何在基本保持完整的情况下发生改变，为如何在AD患者护理中更成功地实施非语言沟通提供了新的见解，并突出了DTI作为症状前生物标志物的潜在作用。
