Alberici Elisa, Pichiecchio Anna, Caverzasi Eduardo, Farina Lisa Maria, Persico Alessandra, Cavallini Anna, Bastianello Stefano
Neuroradiology Unit, IRCCS, C. Mondino Institute of Neurology Foundation, Via Mondino, 2-27100 Pavia, Italy.
Funct Neurol. 2008 Jul-Sep;23(3):149-52.
Transient global amnesia (TGA) is an episodic dysfunction of declarative memory that usually resolves within 12 hours and whose underlying pathophysiological mechanisms are still unclear. Recent studies, on the basis of transient focal high-signal abnormalities in the hippocampus on diffusion-weighted imaging (DWI), suggest involvement of memory circuits in the temporo-mesial region. Out of a total of 65 patients presenting with acute or subacute TGA between May 2004 and May 2008, we retrospectively analysed 21 in whom a DWI sequence was performed. Five patients showed a focal hippocampal signal alteration both on DWI and on conventional T2; this alteration was no longer detectable on follow-up MRI two months later. The presence of transient DWI and T2 alterations in the hippocampal formation suggests that TGA could have a multifactorial, non-vascular aetiology. The presence of local susceptibility to neuronal metabolic stress emerges as a likely hypothesis.
短暂性全面性遗忘症（TGA）是一种陈述性记忆的发作性功能障碍，通常在12小时内缓解，其潜在的病理生理机制仍不清楚。最近的研究基于扩散加权成像（DWI）上海马区短暂性局灶性高信号异常，提示颞叶内侧区域的记忆回路受累。在2004年5月至2008年5月期间出现急性或亚急性TGA的65例患者中，我们回顾性分析了21例进行了DWI序列检查的患者。5例患者在DWI和常规T2上均显示海马区局灶性信号改变；两个月后的随访MRI上不再能检测到这种改变。海马结构中短暂性DWI和T2改变的存在提示TGA可能有多因素、非血管性病因。对神经元代谢应激的局部易感性的存在成为一个可能的假说。
