Zhuo Jiachen, Raghavan Prashant, Li Jiang, Roys Steven, Njonkou Tchoquessi Rosy Linda, Chen Hegang, Wickwire Emerson M, Parikh Gunjan Y, Schwartzbauer Gary T, Grattan Lynn M, Wang Ze, Gullapalli Rao P, Badjatia Neeraj
Center for Advanced Imaging Research, University of Maryland School of Medicine, Baltimore, MD, United States.
Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States.
Front Neurol. 2024 Aug 7;15:1443496. doi: 10.3389/fneur.2024.1443496. eCollection 2024.
Traumatic brain injury (TBI) even in the mild form may result in long-lasting post-concussion symptoms. TBI is also a known risk to late-life neurodegeneration. Recent studies suggest that dysfunction in the glymphatic system, responsible for clearing protein waste from the brain, may play a pivotal role in the development of dementia following TBI. Given the diverse nature of TBI, longitudinal investigations are essential to comprehending the dynamic changes in the glymphatic system and its implications for recovery.
In this prospective study, we evaluated two promising glymphatic imaging markers, namely the enlarged perivascular space (ePVS) burden and Diffusion Tensor Imaging-based ALPS index, in 44 patients with mTBI at two early post-injury time points: approximately 14 days (14Day) and 6-12 months (6-12Mon) post-injury, while also examining their associations with post-concussion symptoms. Additionally, 37 controls, comprising both orthopedic patients and healthy individuals, were included for comparative analysis.
Our key findings include: (1) White matter ePVS burden (WM-ePVS) and ALPS index exhibit significant correlations with age. (2) Elevated WM-ePVS burden in acute mTBI (14Day) is significantly linked to a higher number of post-concussion symptoms, particularly memory problems. (3) The increase in the ALPS index from acute (14Day) to the chronic (6-12Mon) phases in mTBI patients correlates with improvement in sleep measures. Furthermore, incorporating WM-ePVS burden and the ALPS index from acute phase enhances the prediction of chronic memory problems beyond socio-demographic and basic clinical information.
ePVS burden and ALPS index offers distinct values in assessing glymphatic structure and activity. Early evaluation of glymphatic function could be crucial for understanding TBI recovery and developing targeted interventions to improve patient outcomes.
创伤性脑损伤（TBI）即使是轻度形式也可能导致长期的脑震荡后症状。TBI也是晚年神经退行性变的已知风险因素。最近的研究表明，负责清除大脑中蛋白质废物的类淋巴系统功能障碍可能在TBI后痴呆症的发展中起关键作用。鉴于TBI的多样性，纵向研究对于理解类淋巴系统的动态变化及其对恢复的影响至关重要。
在这项前瞻性研究中，我们评估了44例轻度创伤性脑损伤（mTBI）患者在伤后两个早期时间点（伤后约14天（14天）和6 - 12个月（6 - 12个月））的两个有前景的类淋巴成像标志物，即扩大的血管周围间隙（ePVS）负担和基于扩散张量成像的ALPS指数，同时还研究了它们与脑震荡后症状的关联。此外，纳入了37名对照，包括骨科患者和健康个体进行比较分析。
我们的主要发现包括：（1）白质ePVS负担（WM - ePVS）和ALPS指数与年龄显著相关。（2）急性mTBI（14天）时升高的WM - ePVS负担与更多的脑震荡后症状显著相关，尤其是记忆问题。（3）mTBI患者从急性期（14天）到慢性期（6 - 12个月）ALPS指数的增加与睡眠指标的改善相关。此外，结合急性期的WM - ePVS负担和ALPS指数可增强对慢性记忆问题的预测，超越社会人口统计学和基本临床信息。
ePVS负担和ALPS指数在评估类淋巴结构和活动方面具有独特价值。早期评估类淋巴功能对于理解TBI恢复和制定针对性干预措施以改善患者预后可能至关重要。
