Developing a rational strategy for visual rehabilitation after cortical lesions

制定皮质损伤后视力康复的合理策略

• 批准号: 10091313
• 负责人: Stelios Manolis Smirnakis
• 金额: --
• 依托单位: VA BOSTON HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10091313
• 关键词: Activities of Daily Living; Address; Adverse effects; Area; Attention; Behavioral; Blindness; Brain; Contralateral; Data; Discrimination; Environment; Feeling; Feeling suicidal; Functional Magnetic Resonance Imaging; Goals; Health; Hemianopsia; Homonymous Hemianopia; Human; Impairment; Infarction; Injury; Lesion; Libraries; Maps; Measurement; Measures; Mediating; Methods; Minor; Motion Perception; Neurosciences; Noise; Optics; Parietal; Pathway interactions; Patients; Performance; Perimetry; Population; Primary Lesion; Quality of life; Radiation; Recovery; Rehabilitation therapy; Reporting; Residual state; Resistance; Scotoma; Signal Transduction; Son; Stimulus; Stroke; Supervision; Testing; Training; Veterans; Vision; Visual; Visual Cortex; Visual Fields; Visual Motion; Visual Pathways; Visual Perception; Visual impairment; Work; area V1; area striata; clinically significant; cooking; design; disability; dysphoria; experience; extrastriate; extrastriate visual cortex; imaging approach; imaging modality; improved; information processing; middle cerebral artery; population based; post stroke; receptive field; rehabilitation strategy; response; sight restoration; stroke survivor; visual information; visual performance; visual processing

Visual field loss is a common corollary of stroke (Pollock et al,The Cochrane Library:John Wiley & Sons; 2011,p p. 1-83) that is prevalent in the VA population. Posterior and middle cerebral artery infarcts often injure visual cortical networks resulting in partial or complete homonymous hemianopia or quadrantanopia. The most common clinically significant visual cortical injury involves the primary visual cortex and adjacent regions (area V1+). Area V1 is the chief relay of visual input to higher (extrastriate) cortical areas, and V1 lesions result in a dense contralateral scotoma within which visual perception is severely impaired. The resulting visual deficit is long thought to be resistant to rehabilitation, i.e. to be essentially irreversible, and impairs quality of life significantly. Visual field loss impairs many activities of daily living, including the ability to ambulate safely, drive, read, cook, supervise minors, and others, markedly reducing the independence of the patient (Veterans Health Initiative 2002: Visual Impairment and Blindness). Loss of visual motion perception is particularly problematic for navigating the environment and for avoiding collision with moving objects. Here we focus on studying rehabilitation of visual motion perception. Several studies demonstrated that visual cortex can be driven from the interior of the scotoma, i.e. from areas of the visual field where there is no visual perception. One such area that can be visually modulated in the absence of V1 input is hV5/MT+, an area important for visual motion perception. Although this modulation is weak and does not generally confer useful vision (“blindsight”), it raises the hope that appropriately designed new rehabilitative strategies may be able to strengthen these partially functioning pathways promoting recovery. Recent work (Huxlin et al. J Neuroscience 29(13):3981-91, 2009) has shown that intensive training in a visual motion discrimination task can improve visual motion perception in some subjects with cortical V1 lesions (see fig 5-6). However, this work is still at the preliminary stage. Specifically, not all subjects appear to benefit (section C2), it is not clear which parts of the visual field are amenable to visual rehabilitation, and the mechanism of recovery remains unclear. Our goal here is twofold: 1) To pilot functional magnetic resonance imaging (fMRI) population receptive field mapping methods for identifying regions of the visual field that are more amenable to visual rehabilitation after lesions of the primary visual cortex (area V1+). 2) To probe the mechanisms underlying the recently reported rehabilitation-induced improvement in visual performance that occurs in some subjects (preliminary data fig. 5-7). We will address the following specific aims: Aim 1: We will show that functional magnetic resonance imaging (fMRI) population receptive field mapping methods can identify regions of the visual field that are more amenable to visual motion perception rehabilitation after lesions of the primary visual cortex (area V1+). Hypothesis 1: Regions of the scotoma that elicit visually driven fMRI activity in both spared area V1 and hV5/MT+ (see fig.1) will be easier to rehabilitate, and will reach higher behavioral thresholds, compared to regions that activate only area hV5/MT+. Aim 2: Study how the strength of visual modulation changes in early visual areas, in hV5/MT+, and in fronto- parietal networks subserving attention & higher-order visual processing, following rehabilitative training. Determine whether observed changes are correlated with recovery. Hypothesis 2: Training will increase the signal to noise ratio of the response to visual motion stimuli in area hV5/MT+, while responses in spared V1+ and early extrastriate areas will remain relatively unchanged. Increase in hV5/MT+ response strength will correlate best with recovery. The change in hV5/MT+ response strength will likely be mediated via top down pathways, potentially associated with attentional networks (see [43] [44] and preliminary data fig. 5-7). Our long-term goal is to use information obtained from fMRI methods to implement a principled strategy for developing rehabilitative treatments following visual cortex injury.

视野损失是中风的常见推论（Pollock等，Cochrane库：John Wiley＆Sons; 2011，P 第1-83页）在VA人群中普遍存在。 皮质网络最多，是部分或编译同源性的半偏见或Quadrantanopia 常见的临床视觉皮质损伤涉及主要视觉皮层和邻接（区域） V1+）面积V1是对较高（外部）皮质区域的视觉输入的芯片，V1病变导致 视觉上的密集的scotoma严重受损。 长期以来一直是康复的重新安置 视力损失很大。 阅读，烹饪，监督未成年人等，明显降低了患者的独立性（退伍军人健康 主动性2002：视觉障碍和失明）。 导航举动并避免与移动物体发生碰撞。 视觉运动感知的康复。 几项研究表明，视觉皮层可以从Scotoma的内部驱动 那里没有视觉感知的视野。 V1输入的缺乏是HV5/MT+，这对于视觉运动感知很重要。 弱，通常不会赋予有用的愿景（“盲目”），它提出了适当设计的希望 新的康复策略可能能够加强促进恢复的副业途径。 最近的工作（Huxlin等人J Neuroscience 29（13）：3981-91，2009）表明，在视觉上进行了深入的培训 运动歧视任务可以改善某些具有皮质V1病变的受试者的视觉运动渗透（请参见） 图5-6）。 （C2节），尚不清楚视野的哪一部分适合视觉康复，而您 恢复机制尚不清楚，我们的目标是双重的：1） 成像（fMRI）种群接受现场映射方法，用于识别视野的区域 在主要视觉皮层病变后，更适合视觉康复（区域V1+）。 最近报道的康复引起的视觉性能改善的机制 发生在某些受试者中（初步数据图。 AIM 1：我们将显示功能磁共振共振成像（fMRI）种群接受场映射 方法可以识别视野的区域，更容易对视觉运动感知康复。 主要视觉皮层病变（区域V1+）。 在宽敞的区域V1和HV5/MT+中，驱动的fMRI活性（见图1）将更容易康复，并且将达到 与仅激活面积HV5/mt+的区域相比，行为阈值更高。 AIM 2：研究视觉调制的强度如何在早期视觉区域，HV5/MT+以及额叶中变化 在康复培训后，对培养网络维持阶级和高苏式视觉处理。 确定观察到的变化是否与恢复相关。 hv5/mt+区域视觉运动刺激的噪声比的信号与噪声比，而宽敞的V1+中的响应 和早期的外部区域将保持相对不变。 与恢复最佳相关。 途径，可能与Attental网络相关（请参见[43] [44]和预启示数据图5-7）。 我们的长期目标是使用从fMRI方法获得的信息来实施原则性的策略 视觉皮层损伤后开发康复治疗。