Effects of Parkinson's Disease on Perception, Cognition, and Gait

帕金森病（PD）的非运动方面，如感觉、知觉和认知缺陷，是一种 导致日常功能和生活质量显著下降。其中最重要的日常 在PD中受影响的功能是视觉空间能力，其使感知和认知能力 视觉环境的理解和导航。这一领域的缺陷源于病理性的 大脑高级关联区域的变化以及来自更基本的视觉输入的缺陷 处理区，反映皮质纹状体回路特定方面的功能障碍。具有潜在的重要性， 了解PD的视觉空间后遗症是考虑到最初的运动障碍， 几乎总是单侧发病的神经变性，右半球特别参与 视觉空间处理的许多方面。我们的目标是定义基本视觉和视觉空间之间的关系 问题的PD和检查潜在的神经变化。特别是，我们的目标是阐明因果作用， 视觉空间认知中的特定皮质纹状体结构，并定义特定皮质纹状体结构之间的功能连接。 皮质区和纹状体区。我们假设，首先，PD的认知障碍反映了 涉及吻背尾状核的皮质纹状体环。第二，我们假设运动症状 视觉刺激的起始以及半视野呈现预测了大脑半球激活减退的偏侧性， 皮质纹状体环，对左侧体侧（LPD）（右侧基底）发作的患者影响更大 神经节）和左半视野呈现。我们的第三个重点是视觉和视觉空间的关系 日常功能障碍，包括步态、运动性冻结、主观生活质量、幻觉、情绪 以及其他以患者为中心的PD特征。为了实现我们的目标，我们将汇集科学家的专业知识， 从互补学科，包括神经心理学，视觉心理物理学，认知神经科学和 神经影像学和临床运动科学。我们提出的功能磁共振成像研究提供了一个直接的测试， 假设皮质纹状体回路的特定成分，特别是额纹状体和 parietostriatal循环，潜在的问题，具体的视觉空间和视觉认知任务的PD。因为大多数 皮质区域与纹状体相连，这些研究将填补理解可能的 皮质纹状体回路在认知中的普遍作用。心理物理、认知和成像的应用 能够预测PD患者更高水平认知和日常功能完整性的技术将是有用的 在临床上，使得能够在诊断时识别患者的潜在空间问题。我们的测试目标 患者自己报告的视觉、视觉空间和功能症状，确保 机制的阐明将具有临床意义。

Non-motor aspects of Parkinson's disease (PD) such as deficient sensation, perception, and cognition are a source of a significant decline in everyday function and quality of life. Among the most important of daily functions that is affected in PD is visuospatial ability, which enables the perceptual and cognitive comprehension and navigation of the visual environment. Deficits in this domain arise from pathological changes in high-order association areas of the brain as well as from defective input from more basic visual processing areas, reflecting dysfunction of specific aspects of corticostriatal loops. Of potential importance to understanding the visuospatial sequelae of PD is consideration of the side of initial motor impairment, as PD nearly always has unilateral onset of neurodegeneration, and the right hemisphere is especially engaged in many aspects of visuospatial processing. We aim to define the relation between basic vision and visuospatial problems in PD and to examine underlying neural changes. In particular, we aim to elucidate the causal role of specific corticostriatal structures in visuospatial cognition and to define functional connectivity between specific cortical areas and striatal regions. We hypothesize, first, that cognitive impairments in PD reflect dysfunction in corticostriatal loops involving the rostrodorsal caudate. Second, we hypothesize that side of motor symptom onset as well as hemifield presentation of visual stimuli predict the hemispheric laterality of hypoactivation in corticostriatal loops, with stronger effects for patients with onset on the left body side (LPD) (right basal ganglia) and for left visual hemifield presentation. Our third focus is on the relation of visual and visuospatial impairments to daily function, including gait, motoric freezing, subjective quality of life, hallucinations, mood and other patient-centered features of PD. To accomplish our goals, we will marshal the expertise of scientists from complementary disciplines, including neuropsychology, visual psychophysics, cognitive neuroscience and neuroimaging, and clinical movement science. Our proposed fMRI studies provide a direct test of the hypothesis that dysfunction in specific components of corticostriatal loops, especially frontostriatal and parietostriatal loops, underlie problems on specific visuospatial and visuocognitive tasks in PD. As most cortical regions are connected with the striatum, the studies will fill a significant gap in understanding the likely ubiquitous role of corticostriatal circuits in cognition. The application of psychophysical, cognitive and imaging techniques that could predict the integrity of higher-level cognitive and daily functions in PD will be useful clinically, enabling the identification of potential spatial problems for the patient at diagnosis. Our tests target visual, visuospatial, and functional symptoms reported by the patients themselves, ensuring that the elucidation of mechanisms will have clinical relevance.