Abstract:
Traumatic brain injury (TBI) triggers progressive neurodegeneration resulting in brain atrophy that continues months-to-years following injury. However, a comprehensive characterization of the spatial and temporal evolution of TBI-related brain atrophy remains incomplete. Utilizing a sensitive and unbiased morphometry analysis pipeline optimized for detecting longitudinal changes, we analyzed a sample consisting of 37 individuals with moderate-severe TBI who had primarily high-velocity and high-impact injury mechanisms. They were scanned up to three times during the first year after injury (3 months, 6 months, and 12 months post-injury) and compared with 33 demographically matched controls who were scanned once. Individuals with TBI already showed cortical thinning in frontal and temporal regions and reduced volume in the bilateral thalami at 3 months post-injury. Longitudinally, only a subset of cortical regions in the parietal and occipital lobes showed continued atrophy from 3 to 12 months post-injury. Additionally, cortical white matter volume and nearly all deep gray matter structures exhibited progressive atrophy over this period. Finally, we found that disproportionate atrophy of cortex along sulci relative to gyri, an emerging morphometric marker of chronic TBI, was present as early as 3 month post-injury. In parallel, neurocognitive functioning largely recovered during this period despite this pervasive atrophy. Our findings demonstrate msTBI results in characteristic progressive neurodegeneration patterns that are divergent across regions and scale with the severity of injury. Future clinical research using atrophy during the first year of TBI as a biomarker of neurodegeneration should consider the spatiotemporal profile of atrophy described in this study.
摘要:
创伤性脑损伤(TBI)引发进行性神经变性,导致脑萎缩,该脑萎缩在损伤后持续数月至数年。然而,TBI相关脑萎缩的时空演变的综合表征仍不完整。利用针对检测纵向变化而优化的灵敏且无偏的形态计量学分析管道,我们分析了由37例中重度TBI患者组成的样本,这些患者主要具有高速和高冲击的损伤机制.在受伤后的第一年(3个月,6个月,和受伤后12个月),并与33个人口统计学匹配的对照组进行了一次扫描。TBI患者在伤后3个月时,额叶和颞区的皮质变薄,双侧丘脑的体积减少。纵向,在损伤后3~12个月,顶叶和枕叶中只有一部分皮质区域显示出持续萎缩.此外,皮质白质体积和几乎所有深灰质结构在此期间表现出进行性萎缩。最后,我们发现相对于回,沿着沟的皮质不成比例的萎缩,一种新出现的慢性TBI的形态学标记,早在受伤后3个月就出现了。并行,尽管存在这种广泛性萎缩,但在此期间神经认知功能基本恢复。我们的发现表明,msTBI导致特征性进行性神经变性模式,这些模式在不同区域和尺度上随损伤的严重程度而不同。未来使用TBI第一年萎缩作为神经变性生物标志物的临床研究应考虑本研究中描述的萎缩的时空特征。