Department of Neurology, Haga Red Cross Hospital, Tochigi, Japan.
Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan.
Cogn Behav Neurol. 2021 Mar 3;34(1):70-75. doi: 10.1097/WNN.0000000000000254.
Global autobiographical amnesia is a rare disorder that is characterized by a sudden loss of autobiographical memories covering many years of an individual's life. Generally, routine neuroimaging studies such as CT and MRI yield negative findings in individuals with global autobiographical amnesia. However, in recent case reports, functional analyses such as SPECT and fMRI have revealed changes in activity in various areas of the brain when compared with controls. Studies using iomazenil (IMZ) SPECT with individuals with global autobiographical amnesia have not been reported. We report the case of a 62-year-old Japanese woman with global autobiographical amnesia who had disappeared for ∼4 weeks. [123I]-IMZ SPECT showed reduced IMZ uptake in her left medial temporal lobe and no significant reduction on N-isopropyl-[123I] p-iodoamphetamine (IMP) SPECT in the identical region. Because IMZ binds to the central benzodiazepine receptor, this dissociation between IMZ and IMP SPECT was thought to reflect the breakdown of inhibitory neurotransmission in the left medial temporal lobe. Moreover, when the woman recovered most of her memory 32 months after fugue onset, the IMZ SPECT-positive lesion had decreased in size. Because the woman had long suffered verbal abuse from her former husband's sister and brother, which can also cause global autobiographical amnesia, it is difficult to conclude whether the IMZ SPECT-positive lesion in the left medial temporal lobe was the cause or the result of her global autobiographical amnesia. Although only one case, these observations suggest that IMZ SPECT may be useful in uncovering the mechanisms underlying global autobiographical amnesia.
全球自传性遗忘症是一种罕见的疾病，其特征是个体突然失去涵盖其多年生活的自传性记忆。一般来说，对患有全球自传性遗忘症的个体进行常规神经影像学研究，如 CT 和 MRI，结果均为阴性。然而，在最近的病例报告中，与对照组相比，功能性分析，如 SPECT 和 fMRI，显示大脑各个区域的活动发生了变化。尚未有关于使用 iomazenil（IMZ）SPECT 对患有全球自传性遗忘症的个体进行研究的报道。我们报告了一例 62 岁的日本女性患有全球自传性遗忘症，她已经失踪了大约 4 周。[123I]-IMZ SPECT 显示她的左内侧颞叶摄取 IMZ 减少，而在同一区域的 N-异丙基-[123I]p-碘安非他命（IMP）SPECT 没有明显减少。由于 IMZ 与中枢苯二氮䓬受体结合，因此 IMZ 和 IMP SPECT 之间的这种分离被认为反映了左内侧颞叶抑制性神经传递的中断。此外，当这名女性在发作性遗忘症发作 32 个月后恢复了大部分记忆时，IMZ SPECT 阳性病变的大小已经减小。由于该女性长期遭受前夫姐姐和哥哥的言语虐待，也可能导致全球自传性遗忘症，因此难以确定左内侧颞叶的 IMZ SPECT 阳性病变是她全球自传性遗忘症的原因还是结果。尽管只有一例，但这些观察结果表明，IMZ SPECT 可能有助于揭示全球自传性遗忘症的发病机制。
