Stojanovic-Radic Jelena, Wylie Glenn, Voelbel Gerald, Chiaravalloti Nancy, DeLuca John
Kessler Foundation, Neuropsychology and Neuroscience Laboratory, 300 Executive Drive, Suite 70, West Orange, NJ, 07052, USA.
Brain Imaging Behav. 2015 Jun;9(2):302-11. doi: 10.1007/s11682-014-9307-y.
The present study utilized functional near infrared spectroscopy (fNIRS) to detect neural activation differences in the orbitofrontal brain region between individuals with multiple sclerosis (MS) and healthy controls (HCs) during a working memory (WM) task. Thirteen individuals with MS and 12 HCs underwent fNIRS recording while performing the n-back WM task with four levels of difficulty (0-, 1-, 2-, and 3-back). Subjects were fitted with the fNIRS cap consisting of 30 'optodes' positioned over the forehead. The results revealed different patterns of brain activation in MS and HCs. The MS group showed an increase in brain activation, as measured by the concentration of oxygenated hemoglobin (oxyHb), in the left superior frontal gyrus (LSFG) at lower task difficulty levels (i.e. 1-back), followed by a decrease at higher task difficulty (2- and 3-back) as compared with the HC group. HC group achieved higher accuracy than the MS group on the lower task loads (i.e. 0- and 1-back), however there were no performance differences between the groups at the higher task loads (i.e. 2- and 3-back). Taken together, the results suggest that individuals with MS experience a task with the lower cognitive load as more difficult than the HC group, and the brain activation patterns observed during the task confirm some of the previous findings from functional magnetic resonance imaging (fMRI) studies. This study is the first to investigate brain activation by utilizing the method of fNIRS in MS during the performance of a cognitive task.
本研究利用功能近红外光谱技术（fNIRS），检测多发性硬化症（MS）患者与健康对照者（HCs）在工作记忆（WM）任务期间眶额叶脑区的神经激活差异。13名MS患者和12名HCs在执行具有四个难度级别的n-back WM任务（0-back、1-back、2-back和3-back）时接受了fNIRS记录。受试者佩戴了由30个“光极”组成的fNIRS帽，这些光极位于前额。结果显示，MS患者和HCs的大脑激活模式不同。MS组在较低任务难度水平（即1-back）时，左侧额上回（LSFG）的脑激活增加，这通过含氧血红蛋白（oxyHb）浓度来衡量，而在较高任务难度（2-back和3-back）时与HC组相比则下降。HC组在较低任务负荷（即0-back和1-back）时的准确率高于MS组，然而在较高任务负荷（即2-back和3-back）时两组之间没有表现差异。综合来看，结果表明，MS患者比HC组更难完成认知负荷较低的任务，并且在任务期间观察到的大脑激活模式证实了先前功能磁共振成像（fMRI）研究的一些发现。本研究是首次在MS患者执行认知任务期间利用fNIRS方法研究大脑激活情况。
