Department of Internal Medicine, Academic Medical Centre/University of Amsterdam, Amsterdam, The Netherlands.
Brain. 2009 Oct;132(Pt 10):2630-42. doi: 10.1093/brain/awp179. Epub 2009 Jul 8.
Detailed history taking is of paramount importance to establish a reliable diagnosis in patients with transient loss of consciousness. In this article the clinical symptoms and signs of the successive phases of a syncopal episode are reviewed. A failure of the systemic circulation to perfuse the brain sufficiently results in a stereotyped progression of neurological symptoms and signs culminating in loss of consciousness; when transient, this is syncope. Prior to loss of consciousness the affected individual tends to exhibit unclear thinking, followed by fixation of the eyes in the midline and a 'frozen' appearance. Narrowing of the field of vision with loss of colour vision ('greying' out) and finally a complete loss of vision (hence 'blacking' out) occurs. Hearing loss may occur following loss of vision. This process may take as little as approximately 7 s in cases of sudden complete circulatory arrest (e.g. abrupt asystole), but in other circumstances it may take longer depending on the rate and depth of cerebral hypoperfusion. Complete loss of consciousness occurs with the 'turning up' of the eyeballs. Profound cerebral hypoperfusion may be accompanied by myoclonic jerks.
详细的病史采集对于确定短暂性意识丧失患者的可靠诊断至关重要。本文回顾了晕厥发作各阶段的临床症状和体征。全身循环不足以充分灌注大脑会导致神经症状和体征的刻板进展，最终导致意识丧失；如果是短暂的，就是晕厥。在意识丧失之前，受影响的个体往往表现出思维不清，随后眼睛固定在中线，出现“冻结”的外观。视野变窄，失去色觉（“变灰”），最终完全失去视力（因此“变黑”）。视力丧失后可能会出现听力损失。在突然完全循环停止（例如突然心动停止）的情况下，这个过程可能只需大约 7 秒，但在其他情况下，由于脑灌注不足的速度和深度，可能需要更长的时间。眼球向上转动时会完全失去意识。严重的脑灌注不足可能伴有肌阵挛性抽搐。
