{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T06:01:46Z","timestamp":1785391306603,"version":"3.55.0"},"reference-count":16,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T00:00:00Z","timestamp":1785369600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Transient global amnesia (TGA) often shows tiny punctate hippocampal CA1 lesions on diffusion-weighted imaging (DWI). Whether these lesions represent truly transient structural alterations remains unsettled. Ultra\u2013high-field 7-tesla (7\u202fT) MRI increases spatial resolution and lesion conspicuity. However, the evolution of hippocampal T2 signal at 7\u202fT from the acute phase through short-term follow-up has not been systematically examined.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To determine, using serial 7\u202fT MRI, whether hippocampal T2-weighted imaging (T2WI) abnormalities visible in acute TGA are consistently detectable acutely and completely disappear by approximately 2\u202fweeks.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Single-center consecutive case series of six patients with clinically defined TGA and DWI-confirmed CA1 lesions who underwent serial 7\u202fT MRI, including acute imaging and follow-up at 14\u201318\u202fdays. The primary outcome was complete resolution of hippocampal T2 hyperintensity. Secondary outcomes were acute T2 detection rate, lesion distribution, and concordance with DWI.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Six patients (4\u202fmen), median age 69\u202fyears (range 50\u201376), all fulfilled the diagnostic criteria of TGA and no neurological deficits. Acute 7\u202fT MRI was performed at a median of 37\u202fh after symptom onset. Acute phase: All 6\/6 showed focal hippocampal CA1 hyperintensity on 7\u202fT T2WI, colocalizing with DWI\/ADC abnormalities. Follow-up (day\u202f15\u201318): T2 hyperintensity resolved in 6\/6 with no visible residual signal abnormality or structural atrophy. Follow-up 7\u202fT DWI demonstrated complete disappearance of the previously identified diffusion abnormalities in all patients. Interpretation: Even at ultra-high field, hippocampal T2 abnormalities are fully reversible within approximately 2\u202fweeks.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Serial 7\u202fT MRI demonstrates that hippocampal T2WI lesions in TGA are consistently visible acutely and uniformly disappear by 2\u202fweeks, providing high-field structural evidence that typical TGA is a transient phenomenon. These findings refine the temporal profile of hippocampal signal evolution and contribute to mechanistic understanding of CA1 vulnerability in TGA.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fneur.2026.1875469","type":"journal-article","created":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T05:39:12Z","timestamp":1785389952000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Serial 7\u202fT MRI demonstrates reversible hippocampal T2 abnormalities in transient global amnesia"],"prefix":"10.3389","volume":"17","author":[{"given":"Yoshitaka","family":"Ishiguro","sequence":"first","affiliation":[{"name":"Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naoto","family":"Jingami","sequence":"additional","affiliation":[{"name":"Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]},{"name":"Department of Neurology, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomohisa","family":"Okada","sequence":"additional","affiliation":[{"name":"Human Brain Research Center, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sachi","family":"Okuchi","sequence":"additional","affiliation":[{"name":"Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasutaka","family":"Fushimi","sequence":"additional","affiliation":[{"name":"Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuji","family":"Nakamoto","sequence":"additional","affiliation":[{"name":"Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryosuke","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Department of Neurology, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Riki","family":"Matsumoto","sequence":"additional","affiliation":[{"name":"Department of Neurology, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shigeru","family":"Ohtsuru","sequence":"additional","affiliation":[{"name":"Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine","place":["Kyoto, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,30]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"635","DOI":"10.1056\/NEJMra2213867","article-title":"Transient global amnesia","volume":"388","author":"Ropper","year":"2023","journal-title":"N Engl J Med"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"475","DOI":"10.1002\/ana.21189","article-title":"Evolution of hippocampal CA-1 diffusion lesions in transient global amnesia","volume":"62","author":"Bartsch","year":"2007","journal-title":"Ann Neurol"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"1324","DOI":"10.3174\/ajnr.A1105","article-title":"Optimal diffusion-weighted imaging protocol for lesion detection in transient global amnesia","volume":"29","author":"Weon","year":"2008","journal-title":"AJNR Am J Neuroradiol"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1680","DOI":"10.3348\/kjr.2020.1462","article-title":"Diagnostic yield of diffusion-weighted brain magnetic resonance imaging in patients with transient global amnesia: a systematic review and Meta-analysis","volume":"22","author":"Lim","year":"2021","journal-title":"Korean J Radiol"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"477","DOI":"10.1016\/j.neuroimage.2016.11.031","article-title":"Key clinical benefits of neuroimaging at 7\u202fT","volume":"168","author":"Trattnig","year":"2018","journal-title":"NeuroImage"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"3406","DOI":"10.21037\/qims-21-969","article-title":"Neuroimaging at 7 tesla: a pictorial narrative review","volume":"12","author":"Okada","year":"2022","journal-title":"Quant Imaging Med Surg"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"639","DOI":"10.1093\/brain\/113.3.639","article-title":"The aetiology of transient global amnesia. 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