Transient Global Amnesia: Risk Factors, Imaging Features, and Prognosis.

Background and Aim: Transient global amnesia (TGA) was first described by Bender in 1956 and is characterized by sudden, temporary, and anterograde memory loss. This study aimed to explore the possible mechanisms of and lesions responsible for TGA. Methods: Retrospective data were collected from all patients with TGA admitted to Zhongshan Hospital, affiliated with Xiamen University, between October 1, 2011, and October 30, 2018. Information about the TGA condition, previous history, and clinical examination of the TGA and control groups was recorded. Functional magnetic resonance imaging was performed on the patients to explore the possible lesions responsible for TGA. Results: A total of 73 patients with TGA and 73 age- and gender-matched controls were included in the analysis. The differences in the migraine history (9/2, p = 0.038) were statistically significant in both groups, but no statistically significant difference was observed regarding the history of hypertension, diabetes, and other diseases. In addition, seven patients with TGA had lesions located in the hippocampal CA1 region; the dome column and hippocampal CA1 region exist in the same functional loop and play a synergistic role. The average follow-up period in the groups was 36 months. During the follow-up period, no significant differences in cerebral infarction, cerebral hemorrhage, CHD, or TGA attack between the groups were observed. Conclusion: Migraine may be a risk factor of TGA, and cerebral infarction may be one of the pathogeneses. The brain area responsible for TGA may involve a memory loop comprising the hippocampal CA1 region and the fornix column among other parts. [ABSTRACT FROM AUTHOR]