Tao Y, Schnur T T, Ding J H, Martin R, Rapp B
Department of Cognitive Science, Johns Hopkins University, Baltimore, Maryland, USA.
Physical Medicine and Rehabilitation, University of Texas Health Houston, Houston, Texas, USA.
bioRxiv. 2025 Mar 13:2025.03.10.642404. doi: 10.1101/2025.03.10.642404.
The functional organization of the brain consists of multiple subsystems, or modules, with dense functional communication within modules (i.e., visual, attention) and relatively sparse but vital communications between them. The two hemispheres also have strong functional communications, which presumably supports hemispheric lateralization and specialization. Subsequent to stroke, the functional organization undergoes neuroplastic changes over time. However, empirical longitudinal studies of human subjects are lacking. Here we analyzed three large-scale, whole-brain resting-state functional MRI connectivity measures: , (based on ), and in a group of 17 participants at 1-month, 3- months, and 12-months after a single left-hemisphere stroke. These measures were also compared to a group of 13 age-matched healthy controls. The three measures exhibited different trajectories of change: (1) steadily decreased across the 12-month period and became statistically inferior to control values at 12 months, indicating a less modular organization; (2) values were abnormally low at 1-month and then increased significantly in the first 6 months, leveling off at levels not significantly below control levels by 12 months, suggesting that the two hemispheres diverged initially after the unilateral damage, but improved over time; and (3) exhibited a U-shaped function with a significant decrease from 1-6 months and then an increase from 6-12 months, to levels that were not significantly different from controls. The results revealed a complex picture of the dynamic changes the brain undergoes as it responds to abrupt onset damage.
大脑的功能组织由多个子系统或模块组成，模块内部存在密集的功能连接（如视觉、注意力方面），而它们之间的连接相对稀疏但至关重要。两个半球也有强大的功能连接，这大概支持了半球的侧化和专业化。中风后，功能组织会随着时间发生神经可塑性变化。然而，缺乏对人类受试者的实证纵向研究。在此，我们分析了一组17名参与者在单次左半球中风后1个月、3个月和12个月时的三项大规模全脑静息态功能磁共振成像连接性测量指标：[具体指标1]、[具体指标2]（基于[相关依据]）和[具体指标3]。这些测量指标还与一组13名年龄匹配的健康对照者进行了比较。这三项测量指标呈现出不同的变化轨迹：（1）[具体指标1]在12个月期间稳步下降，在12个月时在统计学上低于对照值，表明模块化组织程度降低；（2）[具体指标2]在1个月时异常低，然后在最初6个月显著增加，到12个月时稳定在不显著低于对照水平，这表明单侧损伤后两个半球最初出现分离，但随着时间推移有所改善；（3）[具体指标3]呈现出U形函数，从1 - 6个月显著下降，然后从6 - 12个月增加，到与对照无显著差异的水平。结果揭示了大脑在应对突发损伤时所经历的动态变化的复杂图景。
