MRI Findings in Transient Global Amnesia

Transient global amnesia (TGA) is a condition characterized by a sudden, temporary lapse in memory without focal neurological deficits, usually in middle aged adults, sometimes precipitated by an inciting event. We describe a case of a young patient, who presented with a constellation of symptoms consistent with TGA post-concussion with a right temporal lobe hypodensity on CT head. This patient’s memory returned to baseline within 24 hours, with only a mild residual headache which resolved within the next day and no MRI findings 48 hours after, illustrating that his clinical trajectory favours TGA rather than post-concussive amnesia. While the pathophysiology of TGA is still a mystery, clinicians and researchers continue to hypothesize the anatomical basis of this condition.

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Isolated punctuate hippocampal infarction and transient global amnesia are indistinguishable by means of MRI

International Journal of Stroke ◽

10.1177/1747493016676613 ◽

2016 ◽

Vol 12 (3) ◽

pp. 292-296 ◽

Cited By ~ 9

Author(s):

A Förster ◽

M Al-Zghloul ◽

H Wenz ◽

J Böhme ◽

C Groden ◽

...

Keyword(s):

Clinical Presentation ◽

Clinical Symptoms ◽

Transient Global Amnesia ◽

Final Diagnosis ◽

Mri Findings ◽

Diffusion Weighted Images ◽

Diffusion Weighted ◽

Typical Finding ◽

Adc Values ◽

Global Amnesia

Background Small punctuate lesions in the hippocampus on diffusion-weighted images are a typical finding in transient global amnesia. Consequently, it has been suggested that diffusion-weighted images findings might corroborate the diagnosis of transient global amnesia. However, isolated punctuate hippocampal infarction might be a differential diagnosis of transient global amnesia. Aim Evaluation of isolated punctuate hippocampal infarction frequency and comparison of its clinical presentation and MRI findings to transient global amnesia. Methods From an MRI database, we identified 10 patients with isolated punctuate hippocampal infarction and compared these to 12 patients with transient global amnesia with diffusion-weighted images lesion with regard to clinical symptoms and MRI findings. Results Disorientation and memory deficits were more common in transient global amnesia patients, whereas dysphasia/aphasia and vertigo were more common in hippocampal infarction patients. MRI findings in isolated punctuate hippocampal infarction and transient global amnesia did not differ significantly, neither regarding the affected hemisphere, lesion distribution, size, nor relative ADC values. Conclusions Differentiation of isolated punctuate hippocampal infarction and transient global amnesia based on neuroimaging findings is not possible. Thus, in the case of isolated punctuate hippocampal diffusion-weighted images lesions the final diagnosis of hippocampal infarction or transient global amnesia should be based on the clinical presentation.

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Transient global amnesia: Diffusion MRI findings

Indian Journal of Radiology and Imaging ◽

10.4103/ijri.ijri_12_17 ◽

2018 ◽

Vol 28 (1) ◽

pp. 6 ◽

Cited By ~ 1

Author(s):

TarunP Jain ◽

Ronak Patel ◽

Yash Gawarikar

Keyword(s):

Diffusion Mri ◽

Transient Global Amnesia ◽

Mri Findings ◽

Global Amnesia

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Highlighting the classical MRI findings in transient global amnesia

BJR|case reports ◽

10.1259/bjrcr.20190111 ◽

2020 ◽

Vol 6 (2) ◽

pp. 20190111

Author(s):

Stephanie Vella ◽

Reuben Grech

Keyword(s):

Short Term Memory ◽

Memory Loss ◽

Transient Global Amnesia ◽

Imaging Features ◽

Mri Findings ◽

Multiple Risk Factors ◽

Ca1 Region ◽

Cornu Ammonis ◽

Global Amnesia ◽

Mri Changes

Transient global amnesia (TGA) is a disorder characterised by a temporary, reversible disruption of short-term memory. While the diagnosis of TGA is based on its clinical features, neuroimaging is important to exclude other sinister causes of global amnesia. Furthermore, classical MRI changes in TGA have been well described in the literature. These consist of unilateral or bilateral punctuate areas of hyperintensity in the hippocampal cornu ammonis 1 (CA1) region on diffusion-weighted imaging. We describe a case of a 61-year-old gentleman, presenting with symptoms of transient memory loss and confusion. A stroke was initially suspected in view of his multiple risk factors. Timely MRI demonstrated the typical findings associated with TGA. Recognition of these imaging features is of the utmost importance for radiologists in order to allow for an accurate diagnosis and differentiation from ischaemic pathology.

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A case of recurrent transient global amnesia showing different symptom duration and MRI findings

Rinsho Shinkeigaku ◽

10.5692/clinicalneurol.cn-001318 ◽

2019 ◽

Vol 59 (9) ◽

pp. 575-578

Author(s):

Go Hashimoto ◽

Koji Ishitsuka ◽

Miyuki Kuwano ◽

Juro Jinnouchi ◽

Tetsuro Ago ◽

...

Keyword(s):

Transient Global Amnesia ◽

Symptom Duration ◽

Mri Findings ◽

Global Amnesia

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Diffusion-weighted MRI in transient global amnesia and its diagnostic implications

Neurology ◽

10.1212/wnl.0000000000009783 ◽

2020 ◽

Vol 95 (2) ◽

pp. e206-e212 ◽

Cited By ~ 3

Author(s):

Kristina Szabo ◽

Carolin Hoyer ◽

Louis R. Caplan ◽

Roland Grassl ◽

Martin Griebe ◽

...

Keyword(s):

Time Window ◽

Transient Global Amnesia ◽

Lesion Size ◽

Diffusion Weighted Mri ◽

Mri Findings ◽

Diffusion Weighted ◽

Diagnostic Certainty ◽

Minimum Delay ◽

Global Amnesia ◽

Different Levels

ObjectiveTo analyze how the evidence of hippocampal diffusion-weighted imaging (DWI) lesions may support the clinical diagnosis of transient global amnesia (TGA).MethodsIn this retrospective observational study, 390 consecutive patients with isolated TGA were analyzed, who were evaluated at our institution between July 1999 and August 2018. The size, location, and number of lesions and time-dependent lesion detectability were examined. The incidence of DWI lesions was reviewed with regard to different levels of clinical diagnostic certainty upon presentation to the emergency department.ResultsHippocampal DWI lesions were detected in 272 (70.6%) patients with TGA, with a mean of 1.05 ± 0.98 (range 0–6) and a mean lesion size of 4.01 ± 1.22 mm (range 1.7–8.6 mm). In the subgroups of lower diagnostic certainty (amnesia witnessed by layperson or self-reported amnestic gap), DWI was helpful in supporting the diagnosis of TGA in 76 (69.1%) patients. In 187 patients with information about the exact onset, DWI lesions were analyzed in relation to latency between onset and MRI. Lesions could be detected at all time points and up to 6 days after symptom onset in individual patients; the highest rate of DWI-positive MRI (93%) was in the 12–24 hours time window.ConclusionMRI findings can support the diagnosis of TGA and may be particularly valuable in situations of low clinical certainty. DWI—ideally performed with a minimum delay of 20 hours after onset—should therefore be considered a useful adjunct to the diagnosis of TGA.

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