Department of Neurology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
Department of Neurology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel; Department of Neurology, Ziv Medical Center, Safed, Israel; The Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel.
J Neurol Sci. 2023 Dec 15;455:122796. doi: 10.1016/j.jns.2023.122796. Epub 2023 Nov 14.
The underlying pathophysiology of Transient global amnesia (TGA) remains elusive. Reports of perfusion abnormalities in TGA were inconsistent, but semi-automated analysis of perfusion CT (CTP) may improve reliability and precision of perfusion deficit detection.
Per institutional protocol, all TGA patients undergo multiphasic contrast-CT with arch to vertex CT angiography, intracranial CT venography, MRI, and EEG upon admission. During the study period consecutive patients diagnosed with TGA underwent CTP during the early acute amnestic phase. We retrospectively reviewed the clinical and radiological findings.
Five patients (3 female. median age 71, range 47-74) fulfilled entry criteria. Automated CTP analysis revealed the absence of an ischemic core (defined by CBF < 30%) or conventionally defined clinically relevant hypoperfusion area (defined by Time-to-maximum (Tmax) >6 s) in any of the patients. However, four of the five patients demonstrated territories of benign oligemia defined as Tmax>4 s in areas supplied by the Posterior Cerebral Artery. Three of these four patients had clear involvement of the bilateral medial temporal lobes. None of the patients had epileptic activity on their EEG. Both CTA and MRI were normal apart for small foci of restricted diffusion in the hippocampus of four patients.
Deficits in perfusion were found in the hippocampi of 60% of patients in the acute phase of TGA using automated image analysis software. This method may provide a quick and simple method to detect these abnormalities. These perfusion abnormalities could help solidify the diagnosis at an early stage and may advance our understanding of this elusive syndrome.
短暂性全面遗忘症（TGA）的潜在病理生理学仍然难以捉摸。TGA 中的灌注异常的报告不一致，但灌注 CT（CTP）的半自动分析可能会提高灌注缺损检测的可靠性和精度。
根据机构协议，所有 TGA 患者在入院时均进行多期对比 CT 检查，包括主动脉弓至颅顶 CT 血管造影、颅内 CT 静脉造影、MRI 和 EEG。在研究期间，连续诊断为 TGA 的患者在急性遗忘期早期进行 CTP 检查。我们回顾性地回顾了临床和影像学发现。
五名患者（3 名女性，中位年龄 71 岁，范围 47-74 岁）符合入选标准。自动 CTP 分析显示，在任何患者中均不存在缺血核心（定义为 CBF<30%）或传统定义的临床相关低灌注区域（定义为 Tmax>6 s）。然而，五名患者中的四名患者表现出良性低灌注区域，定义为 Tmax>4 s 的区域由大脑后动脉供应。这四名患者中的三名有双侧内侧颞叶的明显受累。患者的 EEG 上均无癫痫活动。除了四名患者的海马区有小块弥散受限外，CTA 和 MRI 均正常。
使用自动图像分析软件，在 TGA 急性期 60%的患者中发现了灌注缺陷。这种方法可能提供一种快速简单的方法来检测这些异常。这些灌注异常可以帮助在早期阶段确定诊断，并可能加深我们对这种难以捉摸的综合征的理解。
