Gilmore Casey S, Camchong Jazmin, Davenport Nicholas D, Nelson Nathaniel W, Kardon Randy H, Lim Kelvin O, Sponheim Scott R
Defense and Veterans Brain Injury Center Minneapolis Minnesota; Minneapolis Veterans Affairs Health Care System Minneapolis Minnesota.
Department of Psychiatry University of Minnesota Minneapolis Minnesota.
Brain Behav. 2016 Mar 23;6(5):e00454. doi: 10.1002/brb3.454. eCollection 2016 May.
Approximately, 275,000 American service members deployed to Iraq or Afghanistan have sustained a mild traumatic brain injury (mTBI), with 75% of these incidents involving an explosive blast. Visual processing problems and cognitive dysfunction are common complaints following blast-related mTBI.
In 127 veterans, we examined resting fMRI functional connectivity (FC) of four key nodes within the visual system: lateral geniculate nucleus (LGN), primary visual cortex (V1), lateral occipital gyrus (LO), and fusiform gyrus (FG). Regression analyses were performed (i) to obtain correlations between time-series from each seed and all voxels in the brain, and (ii) to identify brain regions in which FC variability was related to blast mTBI severity. Blast-related mTBI severity was quantified as the sum of the severity scores assigned to each of the three most significant blast-related injuries self-reported by subjects. Correlations between FC and performance on executive functioning tasks were performed across participants with available behavioral data (n = 94).
Greater blast mTBI severity scores were associated with lower FC between: (A) LGN seed and (i) medial frontal gyrus, (ii) lingual gyrus, and (iii) right ventral anterior nucleus of thalamus; (B) V1 seed and precuneus; (C) LO seed and middle and superior frontal gyri; (D) FG seed and (i) superior and medial frontal gyrus, and (ii) left middle frontal gyrus. Finally, lower FC between visual network regions and frontal cortical regions predicted worse performance on the WAIS digit-symbol coding task.
These are the first published results that directly illustrate the relationship between blast-related mTBI severity, visual pathway neural networks, and executive dysfunction - results that highlight the detrimental relationship between blast-related brain injury and the integration of visual sensory input and executive processes.
大约27.5万部署到伊拉克或阿富汗的美国军人遭受了轻度创伤性脑损伤（mTBI），其中75%的事件涉及爆炸冲击。视觉处理问题和认知功能障碍是爆炸相关mTBI后的常见症状。
在127名退伍军人中，我们检查了视觉系统内四个关键节点的静息功能磁共振成像（fMRI）功能连接（FC）：外侧膝状体（LGN）、初级视觉皮层（V1）、枕外侧回（LO）和梭状回（FG）。进行了回归分析：（i）以获得每个种子的时间序列与大脑中所有体素之间的相关性，以及（ii）识别FC变异性与爆炸mTBI严重程度相关的脑区。爆炸相关mTBI严重程度通过受试者自我报告的三种最严重的爆炸相关损伤的严重程度评分总和来量化。对有可用行为数据的参与者（n = 94）进行了FC与执行功能任务表现之间的相关性分析。
更高的爆炸mTBI严重程度评分与以下之间较低的FC相关：（A）LGN种子与（i）额内侧回、（ii）舌回和（iii）右侧丘脑腹前核；（B）V1种子与楔前叶；（C）LO种子与额中回和额上回；（D）FG种子与（i）额上回和额内侧回，以及（ii）左侧额中回。最后，视觉网络区域与额叶皮质区域之间较低的FC预测了韦氏成人智力量表数字符号编码任务的较差表现。
这些是首次发表的直接说明爆炸相关mTBI严重程度、视觉通路神经网络和执行功能障碍之间关系的结果——这些结果突出了爆炸相关脑损伤与视觉感觉输入和执行过程整合之间的有害关系。
