Department of Neurology, University Hospital Aachen, Aachen, Germany.
Ultrasound Med Biol. 2010 Oct;36(10):1581-7. doi: 10.1016/j.ultrasmedbio.2010.06.016.
Despite of precipitous blood pressure falls in Parkinson's Disease (PD) patients, they may not experience syncope or postural complaints. Can cerebral blood flow regulation explain why orthostatic hypotension (OH) has often no accompanying symptoms? In patients with PD and OH (18 asymptomatic; 8 symptomatic), arterial blood pressure (ABP) as well as Doppler-detected cerebral blood flow velocity (CBFV) in middle and posterior cerebral arteries (MCA and PCA) were monitored during head-up tilt and compared with 25 controls and eight non-PD-OH patients. Analysis included the transfer function between slow spontaneous pressure and flow-oscillations. ABP and CBFV were maintained at significantly higher levels in asymptomatic than symptomatic PD-OH (ABP: 85.7 ± 10.5 vs. 66.9 ± 12.5%; MCA-FV: 83.3 ± 9.3 vs. 66.1 ± 6.8%; PCA-FV: 84.4 ± 12.2 vs. 65.9 ± 9.3% of supine). When orthostatic complaints occurred, CBFV depended directly on ABP changes (MCA r(2) = 0.64; PCA r(2) = 0.62; both p < 0.05). Despite of a tilt-induced blood pressure instability in PD-OH, the transfer function parameters did not differ from normal [phase: MCA: 46.6 ± 20.5°; PCA 39.2 ± 28.8°, gain: MCA 2.0 ± 0.7; PCA 2.9 ± 1.6)]. Results showed a normal autoregulatory response to downward blood pressure shifts in PD. Moreover, orthostatic blood pressure instability is compensated equally sufficient in anterior and posterior parts of cerebral circulation. Whether in PD patients, OH becomes symptomatic rather seems to depend on blood pressure falling below the autoregulated range.
尽管帕金森病（PD）患者的血压急剧下降，但他们可能不会出现晕厥或姿势性抱怨。脑血流调节能否解释为什么直立性低血压（OH）通常没有伴随症状？在 PD 和 OH 患者（18 例无症状；8 例有症状）中，在头高位倾斜期间监测动脉血压（ABP）以及中脑和后颅动脉（MCA 和 PCA）的多普勒检测脑血流速度（CBFV），并与 25 名对照者和 8 名非 PD-OH 患者进行比较。分析包括慢自发性压力与血流波动之间的传递函数。无症状 PD-OH 患者的 ABP 和 CBFV 维持在显著高于有症状 PD-OH 患者的水平（ABP：85.7 ± 10.5 对 66.9 ± 12.5%；MCA-FV：83.3 ± 9.3 对 66.1 ± 6.8%；PCA-FV：84.4 ± 12.2 对 65.9 ± 9.3%卧位）。当出现直立性不适时，CBFV 直接依赖于 ABP 变化（MCA r(2) = 0.64；PCA r(2) = 0.62；均 p < 0.05）。尽管 PD-OH 患者在倾斜时血压不稳定，但传递函数参数与正常情况没有差异[相位：MCA：46.6 ± 20.5°；PCA 39.2 ± 28.8°，增益：MCA 2.0 ± 0.7；PCA 2.9 ± 1.6)]。结果表明 PD 患者存在对向下血压变化的正常自动调节反应。此外，前循环和后循环的脑循环对直立性血压不稳定的补偿同样充分。OH 是否在 PD 患者中出现症状，似乎更多地取决于血压是否下降到自动调节范围以下。
Zotero 插件