Department of Medical Gerontology, Trinity College Dublin, Dublin, Ireland.
Falls and Syncope Unit, Dublin, Ireland.
QJM. 2020 Apr 1;113(4):239-244. doi: 10.1093/qjmed/hcz257.
Psychogenic pseudosyncope (PPS), a conversion disorder and syncope mimic, accounts for a large proportion of 'unexplained syncope'. PPS is diagnosed by reproduction of patients' symptoms during head-up tilt (HUT). Electroencephalogram (EEG), a time consuming and resource intensive technology, is used during HUT to demonstrate absence of cerebral hypoperfusion during transient loss of consciousness (TLOC). Near-infrared spectroscopy (NIRS) is a simple, non-invasive technology for continuous monitoring of cerebral perfusion. We present a series of patients for whom PPS diagnosis was supported by NIRS during HUT.
Eight consecutive patients with suspected PPS referred to a syncope unit underwent evaluation. During HUT, continuous beat-to-beat blood pressure (BP), heart rate (HR) and NIRS-derived tissue saturation index (TSI) were measured. BP, HR and TSI at baseline, time of first symptom, presyncope and apparent TLOC were measured. Patients were given feedback and followed for symptom recurrence.
Eight predominantly female patients (6/8, 75%) aged 31 years (16-54) were studied with (5/8, 63%) having comorbid psychiatric diagnoses, and (5/8, 63%) presenting with frequent episodes of prolonged TLOC with eyes closed (6/8, 75%). All patients experienced reproduction of typical events during HUT. Systolic BP (mmHg) increased from baseline (129.7 (interquartile range [IQR] 124.9-133.4)) at TLOC (153.0 (IQR 146.7-159.0)) (P-value = 0.012). HR (bpm) increased from baseline 78 (IQR 68.6-90.0) to 115.7 (IQR 93.5-127.9) (P-value = 0.012). TSI (%) remained stable throughout, 71.4 (IQR 67.5-72.9) at baseline vs. 71.0 (IQR 68.2-73.0) at TLOC (P-value = 0.484).
NIRS provides a non-invasive surrogate of cerebral perfusion during HUT. We propose HUT incorporating NIRS monitoring in the diagnostic algorithm for patients with suspected PPS.
心因性假性晕厥（PPS）是一种转换障碍和晕厥模拟，占“不明原因晕厥”的很大比例。PPS 通过在头高位倾斜（HUT）期间再现患者的症状来诊断。脑电图（EEG）是一种耗时且资源密集的技术，用于在 HUT 期间证明短暂意识丧失（TLOC）期间大脑灌注不足。近红外光谱（NIRS）是一种简单、非侵入性的脑灌注连续监测技术。我们提出了一系列患者的病例，在 HUT 期间，NIRS 支持 PPS 的诊断。
8 例疑似 PPS 的连续患者被转至晕厥单位进行评估。在 HUT 期间，连续测量逐搏血压（BP）、心率（HR）和 NIRS 衍生的组织饱和度指数（TSI）。测量基线、首次症状、先兆晕厥和明显 TLOC 时的 BP、HR 和 TSI。给予患者反馈并随访症状复发情况。
8 例患者均为女性（6/8，75%），年龄 31 岁（16-54 岁），其中（5/8，63%）合并精神科诊断，（5/8，63%）表现为频繁发作伴有闭眼的长时间 TLOC（6/8，75%）。所有患者在 HUT 期间均再现典型事件。收缩压（mmHg）从 TLOC 时的基线值（129.7（四分位距[IQR] 124.9-133.4））升高至 153.0（IQR 146.7-159.0）（P 值=0.012）。心率（bpm）从基线的 78（IQR 68.6-90.0）增加至 115.7（IQR 93.5-127.9）（P 值=0.012）。TSI（%）在整个过程中保持稳定，基线值为 71.4（IQR 67.5-72.9），TLOC 时为 71.0（IQR 68.2-73.0）（P 值=0.484）。
NIRS 在 HUT 期间提供了脑灌注的非侵入性替代指标。我们建议在疑似 PPS 患者的诊断算法中纳入 HUT 合并 NIRS 监测。
