Visuospatial Function in Parkinson's Disease

描述（由申请人提供）：帕金森病（PD）是一种常见的与年龄相关的神经退行性疾病，其视觉空间认知功能的多个方面受损。空间功能障碍是由大脑高阶关联区域的病理改变引起的，但也由低阶视觉处理区域输入的缺陷引起。视力缺陷在PD中很普遍，但实际上对这种疾病的视力、认知和日常功能之间的关系一无所知。尽管PD几乎总是单侧发病的神经变性和明确的证据将空间异常与右半球功能障碍联系起来，但尚不清楚的是初始运动损伤侧的认知后遗症。我们提出了一种多层次的方法来检查PD的视觉空间功能障碍。一个主要的焦点是视觉缺陷的视觉空间后果，特别是对比敏感度下降导致的信号强度降低。这项研究的一个创新方面是我们使用倍频技术和光学相干断层扫描来评估视觉（包括视网膜）功能。第二个重点是运动损伤的发病侧，对侧半球以基底神经节功能障碍为主。我们计划进行运动系统和前额叶功能的控制测试，以确定枕区和顶叶区在影响PD的空间功能方面的独立程度。此外，我们将通过自我报告问卷和客观的开放式步态曲率测量来评估视觉和视觉空间障碍与日常功能的关系。评估将在基线和一年随访时进行。我们拟检测36例左起性PD （LPD）患者、36例右起性PD （RPD）患者、36例年龄匹配的健康成年人和36例健康年轻人的视力和视觉空间功能测试能力。PD患者在大多数视觉和视觉空间功能测试中的表现可能比同龄成年人差，而同龄成年人的表现又比年轻人差。我们进一步预期LPD将比RPD表现出更广泛的视觉空间障碍，并且障碍的模式将区分两个亚组。我们的测试针对患者自己报告的视觉和视觉空间症状，确保阐明机制将具有临床相关性。LPD和RPD的不同表现将支持PD选择性视觉空间缺陷的论点，并提出不同的视觉、认知和功能增强策略。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is a common age-related neurodegenerative disorder in which multiple aspects of visuospatial cognitive function are impaired. Spatial dysfunction arises from pathological changes in high- order association areas of the brain but also from defective input from lower-level visual processing areas. Deficits in vision are prevalent in PD but virtually nothing is known about the relation between vision, cognition, and daily function in this disorder. Also unknown are the cognitive sequelae of the side of initial motor impairment, despite PD nearly always having unilateral onset of neurodegeneration and unequivocal evidence linking spatial abnormalities to right-hemisphere dysfunction. We propose a multi-level approach to examining visuospatial dysfunction in PD. One major focus is on the visuospatial consequences of visual deficits, specifically the reduced signal strength that results from contrast sensitivity loss. An innovative aspect of the study is our use of frequency doubling technology and optical coherence tomography to assess visual (including retinal) function. A second focus is on the side of onset of motor impairment, contralateral o the hemisphere with predominant basal ganglia dysfunction. We plan to conduct control tests of motor- system and prefrontal function to ascertain the extent of independence of the occipital and parietal areas in affecting spatial function in PD. Further, we will conduct an exploration of the relation of visual and visuospatial impairments to daily function as assessed through self-report questionnaires and with an objective open-field measure of gait curvature. Assessment will occur at baseline and at one-year follow-up. We propose to examine the ability of 36 patients with left-onset PD (LPD), 36 with right-onset PD (RPD), 36 healthy age-matched adults, and 36 healthy young adults to perform on tests of vision and visuospatial function. Individuals with PD will likely exhibit poorer performance on most tests of vision and visuospatial function than age-matched adults, who in turn will exhibit poorer performance than young adults. We further expect that LPD will show more extensive visuospatial impairments than RPD, and that the pattern of impairments will distinguish the two subgroups. Our tests target visual and visuospatial symptoms reported by the patients themselves, ensuring that the elucidation of mechanisms will have clinical relevance. Demonstration of different profiles of performance in LPD and RPD would bolster arguments of selective visuospatial deficits in PD and suggest differential visual, cognitive, and functional enhancement strategies.