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

描述(申请人提供)：本申请的目的是研究直立性低血压对帕金森病患者认知功能的影响。帕金森病中OH的患病率估计在20%到60%之间，这表明需要对其影响有充分的了解。最可能的病因是心脏交感神经病变，影响心率变异性和心输出量。多巴胺能药物也可能在加重帕金森病中的OH方面发挥作用。到目前为止，还没有研究调查羟基对帕金森病患者认知的急性影响。这项研究将使用包括心电图、动脉压和经颅多普勒血流仪在内的自主神经功能的客观测量来评估60度直立倾斜对交感神经兴奋和重力代偿反应的影响。这些生理测量将与在仰卧和倾斜状态下实施的几项神经心理测试措施进行对比分析。参与者组将包括有OH的PD患者，没有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。以前的研究表明，在直立状态下，OH会导致大脑低灌流，导致头晕、头晕和疲劳的症状。假设有OH的帕金森病患者在倾斜时会在认知功能的多个领域表现出受试者内的损害，而有OH的PD患者在仰卧位时的整体表现将比没有OH的PD参与者和正常对照组参与者更差。测试措施包括对工作记忆、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。据报道，帕金森病患者存在各种各样的认知缺陷，一小部分研究表明，患有OH的帕金森病患者在几个领域表现较差。通过了解OH对帕金森病患者认知的影响，强调控制对姿势变化的代偿反应将允许更独立地提高生活质量。此外，在疾病持续期间，保持充足的脑血流可能会使认知能力更好。

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.