Significance: Monitoring of cerebral perfusion rather than blood pressure changes during a head-up tilt test (HUTT) is proposed to understand the pathophysiological effect of orthostatic intolerance (OI), including orthostatic hypotension (OH), in Parkinson's disease (PD) patients. Aim: We aim to characterize and distinguish the cerebral perfusion response to a HUTT for healthy controls (HCs) and PD patients with OI symptoms. Approach: Thirty-nine PD patients with OI symptoms [10 PD patients with OH (PD-OH) and 29 PD patients with normal HUTT results (PD-NOR)], along with seven HCs participated. A 108-channel diffuse optical tomography (DOT) system was used to reconstruct prefrontal oxyhemoglobin (HbO), deoxyhemoglobin (Hb), and total hemoglobin (HbT) changes during dynamic tilt (from supine to 70-deg tilt) and static tilt (remained tilted at 70 deg). Results: HCs showed rapid recovery of cerebral perfusion in the early stages of static tilt. PD-OH patients showed decreasing HbO and HbT during dynamic tilt, continuing into the static tilt period. The rate of HbO change from dynamic tilt to static tilt is the distinguishing feature between HCs and PD-OH patients. Accordingly, PD-NOR patients were subgrouped based on positive-rate and negative-rate of HbO change. PD patients with a negative rate of HbO change were more likely to report severe OI symptoms in the COMPASS questionnaire. Conclusions: Our findings showcase the usability of DOT for sensitive detection and quantification of autonomic dysfunction in PD patients with OI symptoms, even those with normal HUTT results.

中文翻译：

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头部倾斜测试中患有立位不耐受的帕金森氏病患者的脑血流动力学监测。

意义：建议在抬头向上倾斜测试（HUTT）期间监测脑灌注而不是血压变化，以了解帕金森病（PD）患者的体位不耐症（OI）包括体位性低血压（OH）的病理生理作用。目的：我们的目的是针对健康对照（HCs）和具有OI症状的PD患者，表征和区分对HUTT的脑灌注反应。方法：三十九名具有OI症状的PD患者[10例OH的PD患者（PD-OH）和29例HUTT结果正常的PD患者（PD-NOR）]，以及7例HCs参与了研究。使用108通道漫射光学层析成像（DOT）系统来重建前额叶氧合血红蛋白（HbO），脱氧血红蛋白（Hb），总血红蛋白（HbT）在动态倾斜（从仰卧到70度倾斜）和静态倾斜（保持在70度倾斜）期间发生变化。结果：HCs在静态倾斜的早期显示出脑灌注的快速恢复。PD-OH患者在动态倾斜期间显示出HbO和HbT降低，一直持续到静态倾斜期间。HbO从动态倾斜到静态倾斜的变化率是HCs和PD-OH患者之间的区别。因此，PD-NOR患者根据HbO变化的阳性率和阴性率进行分组。HbO变化率为负的PD患者更有可能在COMPASS调查表中报告严重的OI症状。结论：我们的发现证明了DOT在具有OI症状的PD患者中用于敏感检测和定量自主神经功能障碍的可用性，