What causes transient global amnesia?
What causes transient global amnesia?
复制标题
是什么导致短暂性全面遗忘症？
作者：
D. Tong;M. Grossman
短暂性全面遗忘症（TGA）是一个戏剧性的事件。在没有任何警告的情况下，患者突然出现顺行性记忆丧失。1,2⇓ 遗忘综合症一旦出现，通常会在 24 小时内消失。没有明显的长期后遗症，复发也不常见。
TGA 的原因是什么？多年来这个问题一直争论不休。各种支持者都主张由缺血、偏头痛和癫痫引起。3 甚至有人提出了神经心理学原因。3 不幸的是，缺乏支持这些机制的明确证据。
最近，Lewis 假设 TGA 与逆行静脉脑血流导致的静脉充血有关，因为普遍报道 TGA 与导致静脉回流减少和逆行静脉血流的情况（例如性活动、压力、瓦尔萨尔瓦动作）之间存在关联。 4 有趣的是，这一假设得到了一些支持。该小组报告称，与对照组相比，TGA 患者在接受 Valsalva 治疗后发生颈静脉回流的比例明显更高。5,6⇓
MRI 可以帮助提供答案吗？记忆缺陷的深刻本质引发了人们的猜测……
Transient global amnesia (TGA) is a dramatic event. Without warning, the patient suddenly experiences antegrade memory loss.1,2⇓ As quickly as the amnesic syndrome appears, it resolves, usually within 24 hours. There are no apparent long-term sequelae, and recurrence is uncommon.
What causes TGA? For years this question has been debated. Various proponents have advocated ischemic, migrainous, and epileptic causes.3 Even a neuropsychological cause has been proposed.3 Unfortunately, definitive evidence supporting any of these mechanisms has been lacking.
More recently, Lewis hypothesized that TGA was related to venous congestion due to retrograde venous cerebral blood flow, because of the commonly reported association between TGA and situations that result in reduced venous return and retrograde venous blood flow (e.g., sexual activity, stress, Valsalva maneuver).4 Interestingly, there is some support for this hypothesis. The same group has reported that a significantly higher percentage of TGA patients possess jugular venous backflow with Valsalva compared with controls.5,6⇓
Can MRI help provide answers? The profound nature of the memory deficit has encouraged speculation that …