Brain Activations During Optokinetic Stimulation in Acute Right-Hemisphere Stroke Patients and Hemispatial Neglect: An fMRI Study
Brain Activations During Optokinetic Stimulation in Acute Right-Hemisphere Stroke Patients and Hemispatial Neglect: An fMRI Study
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DOI：
10.1177/1545968319855038
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发表时间：
2019-07-01
影响因子：
4.2
通讯作者：
Machner, Bjoern
中科院分区：
文献类型：
--
作者：
von der Gablentz, Janina;Koenemund, Inga;Machner, Bjoern
Objective.左侧视动刺激（OKS）是一种很有前途的治疗右半球脑卒中合并左半球空间忽视的方法。我们质疑假定的神经基础是否是参与眼球运动和空间注意控制的额顶叶脑区的激活。方法.我们使用功能性磁共振成像来研究急性右半球卒中患者（RHS，n = 19）与健康对照受试者（HC，n = 9）在OKS期间的脑激活。在神经心理学测试的基础上，我们确定了所有RHS患者的同侧注意偏向，11例表现为明显的半侧空间忽视。结果在HC受试者中，任何方向的OKS均导致视觉皮层（V1-V4）、额叶（FEF）和辅助（SEF）视野、顶内沟（IPS）、基底神经节和丘脑的双侧激活。与HC相比，RHS患者的激活普遍减少。然而，CANOKS双侧激活视觉皮层（V1-V4），FEF，SEF，IPS和丘脑。对OKS的神经反应与患者的行为障碍呈负相关：个体注意偏差/忽视越大，大脑激活越弱。结论在RHS患者中，EPOKS激活额顶叶区域（FEF，IPS），这些区域不受结构性脑损伤的影响，并在功能上参与眼球控制和空间注意力。这可能为OKS治疗半侧空间忽略的已知疗效提供神经基础。在急性中风阶段，与忽视严重程度相关的激活水平降低表明潜在的背侧注意网络的功能下调。因此，慢性RHS患者恢复后的网络干扰不太严重的忽视可能更适合OKS康复。
Objective. Leftward optokinetic stimulation (OKS) is a promising therapeutic approach for right-hemisphere stroke patients with left hemispatial neglect. We questioned whether the putative neural basis is an activation of frontoparietal brain regions involved in the control of eye movements and spatial attention. Methods. We used functional magnetic resonance imaging to investigate brain activations during OKS in acute right-hemisphere stroke patients (RHS, n = 19) compared with healthy control subjects (HC, n = 9). Based on neuropsychological testing we determined the ipsilesional attention bias in all RHS patients, 11 showed manifest hemispatial neglect. Results. In HC subjects, OKS in either direction led to bilateral activation of the visual cortex (V1-V4), frontal (FEF) and supplementary (SEF) eye fields, intraparietal sulcus (IPS), basal ganglia, and thalamus. RHS patients' activations were generally reduced compared with HC. Nevertheless, leftward OKS bilaterally activated the visual cortex (V1-V4), FEF, SEF, IPS, and thalamus. The neural response to OKS was negatively correlated with patients' behavioral impairment: The greater the individual attention bias/neglect the weaker the brain activations. Conclusion. In RHS patients, leftward OKS activates frontoparietal regions (FEF, IPS) that are spared from structural brain damage and functionally involved in both oculomotor control and spatial attention. This may provide a neural basis for the known therapeutic effects of OKS on hemispatial neglect. In acute stroke stages, reduced activation levels correlating with neglect severity indicate functional downregulation of the underlying dorsal attention network. Therefore, chronic RHS patients with less severe neglect after recovery of network disturbances may be more suitable candidates for OKS rehabilitation.