Rahman Saeedur, Sadeque Jafor, Tan Garryck, Rahman Jesmin
Department of Stroke Medicine, Dartford and Gravesham NHS Trust, Dartford, GBR.
Department of Radiology, Dartford and Gravesham NHS Trust, Dartford, GBR.
Cureus. 2025 May 7;17(5):e83642. doi: 10.7759/cureus.83642. eCollection 2025 May.
Transient global amnesia (TGA) is a common acute amnestic syndrome characterised by sudden-onset predominant anterograde amnesia lasting up to 24 hours. Patients with TGA frequently ask repetitive questions reflecting disorientation and may have some degree of inability to recall general or personal information (retrograde amnesia) while the episode lasts. During the episode of TGA, other cognitive functions are normal. Episodes are self-limited and, by definition, resolve within 24 hours, with recovery of memory function symptoms, except for what happened during the episode. Although diagnosis is primarily clinical, neuroimaging plays a crucial role in excluding alternative causes. Recent evidence suggests that characteristic findings on diffusion-weighted imaging (DWI) may support the diagnosis of TGA. Here, we present three cases of TGA evaluated at Darent Valley Hospital, Kent, UK, with acute onset of confusion and anterograde memory loss. Case 1 was a 53-year-old man who presented to the emergency department with a new onset of confusion, which completely resolved within three hours. Subsequent MRI of the brain showed a punctate area of restricted diffusion involving both hippocampi, which later fully resolved without any residual damage on a follow-up MRI after one week. Case 2 was a 63-year-old woman who became acutely confused while working as a caterer organising a large event. The episode lasted for approximately six to seven hours. MRI of the brain showed a punctate area of restricted diffusion involving the right hippocampus, which fully resolved on an interval MRI scan performed two weeks later. Case 3 was a 59-year-old man who was brought to the hospital due to the sudden onset of confusion noticed by his wife, which lasted for 12 hours. An initial MRI of the brain, conducted four hours after symptom onset, showed no definitive abnormalities. A repeat scan 24 hours after symptom onset revealed an interval appearance of restricted diffusion involving the tail and head of the right and left hippocampi, respectively. All three cases were diagnosed as TGA based on their clinical presentation and MRI findings. The prevalence of typical MRI findings related to TGA varies widely and has been reported to be as high as 85% in some studies. However, these findings may be underdetected without a high index of clinical suspicion from the radiologist. MRI of the brain, in conjunction with clinical history, can improve diagnostic confidence in cases of TGA.
短暂性全面性遗忘症（TGA）是一种常见的急性遗忘综合征，其特征为突然发作的以顺行性遗忘为主，持续长达24小时。TGA患者经常反复提问，表现出定向障碍，在发作期间可能在一定程度上无法回忆一般或个人信息（逆行性遗忘）。在TGA发作期间，其他认知功能正常。发作是自限性的，根据定义，在24小时内缓解，记忆功能症状恢复，但发作期间发生的事情除外。虽然诊断主要依靠临床，但神经影像学在排除其他病因方面起着关键作用。最近的证据表明，弥散加权成像（DWI）上的特征性表现可能支持TGA的诊断。在此，我们介绍在英国肯特郡达伦特谷医院评估的3例TGA病例，均有急性起病的意识模糊和顺行性记忆丧失。病例1是一名53岁男性，因新发意识模糊就诊于急诊科，3小时内完全缓解。随后的脑部MRI显示双侧海马体有一个点状扩散受限区域，1周后的随访MRI显示该区域完全缓解，无任何残留损伤。病例2是一名63岁女性，在作为餐饮服务商组织一场大型活动时突然出现意识模糊。发作持续约6至7小时。脑部MRI显示右侧海马体有一个点状扩散受限区域，在两周后进行的间隔MRI扫描中完全缓解。病例3是一名59岁男性，因妻子注意到其突然出现意识模糊而被送往医院，持续了12小时。症状发作4小时后进行的首次脑部MRI未发现明确异常。症状发作24小时后的重复扫描显示，双侧海马体的尾部和头部分别出现了间隔性的扩散受限表现。根据临床表现和MRI结果，所有3例均诊断为TGA。与TGA相关的典型MRI表现的患病率差异很大，在一些研究中报告高达85%。然而，如果放射科医生没有高度的临床怀疑，这些表现可能未被充分发现。脑部MRI结合临床病史，可以提高TGA病例的诊断信心。
