Lunkova Ekaterina, Chen Jen-Kai, Saluja Rajeet Singh, Ptito Alain
Department of Neurology & Neurosurgery, McGill University, Montreal, Canada.
McGill University Health Centre Research Institute, Montreal, Canada.
Neurotrauma Rep. 2024 Jul 3;5(1):628-639. doi: 10.1089/neur.2024.0018. eCollection 2024.
Mild traumatic brain injury (mTBI), or concussion, is a major public health problem, and ambiguity still exists regarding its diagnosis. While functional magnetic resonance imaging (fMRI) has been identified as a helpful screening tool for concussion, its limited accessibility in clinical or field settings necessitates a more efficient alternative. Oculomotor function deficit is an often-reported pathology in mTBI. Due to the neuroanatomical overlap between eye-movement circuitry and mTBI pathophysiology, visual deficits are expected. In this study, we investigate the possibility of using an oculomotor assessment tool for finding biomarkers in concussion. We used fMRI with tasks evaluating oculomotor functions: smooth pursuit (SP), saccades, anti-saccades, and optokinetic nystagmus (OKN). Before the scanning, the testing with a system of virtual reality goggles with integrated eye- and head-tracking was used where subjects performed the same tasks as those used in fMRI. Twenty-nine concussed symptomatic adults (CSA) within 1-month postconcussion and 29 age- and sex-matched healthy controls (HCS) were tested to examine blood oxygen level-dependent (BOLD) fMRI alterations associated with performances in oculomotor function after mTBI and evaluate the efficacy of the oculomotor assessment in detecting oculomotor and gaze deficits following mTBI. Comparing CSA with HCS, significant differences were observed in anti-saccades and OKN performance. CSA group exhibited elevated %BOLD signal change on each task compared with HCS: in the superior frontal gyrus during the smooth pursuit, inferior frontal gyrus during the saccades, putamen and dorsolateral prefrontal cortex (DLPFC) during the anti-saccades, and lingual gyrus and IFG during the OKN. Key findings include the following: (1) oculomotor deficits in concussed subjects compared with controls, (2) abnormal activation patterns in areas related to the regulation and control of oculomotor movements, suggesting concussion-induced disruptions, and (3) the potential of oculomotor assessment as a promising approach for mTBI biomarkers, with anti-saccades and OKN identified as the most sensitive tasks.
轻度创伤性脑损伤（mTBI），即脑震荡，是一个重大的公共卫生问题，其诊断仍存在不确定性。虽然功能磁共振成像（fMRI）已被确定为脑震荡的一种有用筛查工具，但其在临床或现场环境中的可及性有限，因此需要一种更有效的替代方法。动眼神经功能缺陷是mTBI中经常报告的病理情况。由于眼球运动神经回路与mTBI病理生理学之间存在神经解剖学重叠，预计会出现视觉缺陷。在本研究中，我们调查了使用动眼神经评估工具寻找脑震荡生物标志物的可能性。我们使用fMRI结合评估动眼神经功能的任务：平稳跟踪（SP）、扫视、反扫视和视动性眼震（OKN）。在扫描前，使用带有集成眼动和头部跟踪功能的虚拟现实护目镜系统进行测试，受试者执行与fMRI中相同的任务。对29名脑震荡后1个月内有症状的成年脑震荡患者（CSA）和29名年龄及性别匹配的健康对照者（HCS）进行测试，以检查与mTBI后动眼神经功能表现相关的血氧水平依赖（BOLD）fMRI改变，并评估动眼神经评估在检测mTBI后动眼神经和凝视缺陷方面的有效性。将CSA与HCS进行比较，在反扫视和OKN表现方面观察到显著差异。CSA组在每项任务上的%BOLD信号变化均高于HCS：平稳跟踪期间在额上回，扫视期间在额下回，反扫视期间在壳核和背外侧前额叶皮质（DLPFC），OKN期间在舌回和额下回。主要发现如下：（1）与对照组相比，脑震荡患者存在动眼神经缺陷；（2）与动眼神经运动调节和控制相关区域的激活模式异常，提示脑震荡引起的破坏；（3）动眼神经评估作为mTBI生物标志物的一种有前景的方法的潜力，其中反扫视和OKN被确定为最敏感的任务。
