The Effects of Orthostatic Hypotension on Cognition in Parkinson's Disease

描述（由申请人提供）：拟议申请的目的是研究直立性低血压（OH）对帕金森病（PD）认知的影响。PD中OH的患病率估计在20%到60%之间，这表明需要充分了解其影响。最可能的病因是影响心率变异性和心输出量的心脏交感神经病变。多巴胺类药物也可能在PD患者OH加重中发挥作用。迄今为止，尚无研究调查OH对PD患者认知的急性影响。本研究将使用自主神经功能的客观测量，包括心电图、动脉压和经颅多普勒血流仪来评估60度仰卧对交感神经激活和重力代偿反应的影响。这些生理测量将与几个在仰卧位和倾斜位进行的神经心理学测试进行分析。参与者组将包括有OH的PD患者，无OH的PD患者，以及人口统计学上匹配的正常血压对照组参与者。先前的研究表明，OH会导致直立体位的大脑灌注不足，诱发头晕、头晕和疲劳的症状。假设有OH的PD参与者在倾斜时在几个认知功能领域会表现出受试者内部的损害，并且有OH的PD参与者在仰卧时的整体表现比没有OH的PD参与者和正常对照组的参与者都差。测试内容包括对工作记忆、注意力、执行功能的评估，以及对情绪和日常生活活动的评估。PD患者存在多种认知缺陷，少量研究表明，OH患者在多个领域表现较差。通过了解OH对PD患者认知的影响，强调控制体位变化的代偿反应将有助于提高生活质量和独立性。此外，保持足够的脑血流量可能会使患者在疾病期间有更好的认知能力。

DESCRIPTION (provided by applicant): The goal of the proposed application is to investigate the effects of Orthostatic Hypotension (OH) on cognition in Parkinson's Disease (PD). Prevalence estimations of OH in PD range from 20 to 60%, indicating a need for a full understanding as to its effects. The most likely etiology is a cardiac sympathetic neuropathy affecting heart-rate variability and cardiac output. Dopaminergic medications may also play a role in exacerbating OH in PD. To date, no study has investigated the acute effects of OH on cognition in PD. This study will use objective measures of autonomic function, including electrocardiogram, arterial pressures, and transcranial Doppler flowmetry to assess the effects of a sixty-degree head-up tilt on sympathetic activation and gravitational compensatory responses. These physiological measurements will be analyzed against several neuropsychological test measures administered in both the supine and tilted positions. The participant groups will include PD patients with OH, PD patients without OH, and demographically matched normotensive control participants. Previous research suggests that OH will lead to cerebral hypoperfusion in the upright position, inducing symptoms of lightheadedness, dizziness, and fatigue. It is hypothesized that PD participants with OH will show within- subject detriments in several domains of cognitive function while tilted, and that PD participants with OH will demonstrate poorer overall performance than both PD participants without OH and normal control participants while supine. Test measures will include assessments of working memory, attention, executive function, as well as assessments of mood and activities of daily living. A variety of cognitive deficits have been reported in PD, and a small body of research suggests that PD patients with OH demonstrate poorer performance across several domains. By understanding the effects of OH on cognition in PD, emphasis on controlling compensatory responses to postural change will allow for an increased quality of life with more independence. Furthermore, maintaining adequate cerebral blood flow may allow for better cognitive abilities for the duration of the disorder.