J Korean Neurol Assoc.  2016 Nov;34(5):312-317. 10.17340/jkna.2016.4.4.

Comparison of Clinical Characteristics between Transient Global Amnesia with and without Acute Focal Lesion in Hippocampus

• Kang HG
• Chung JY
• Ha JM
• Choo IS
• Kim HW
• Kim JH
• Ahn SH

• KMID: 2359441
• DOI: http://doi.org/10.17340/jkna.2016.4.4

Abstract

BACKGROUND
Transient global amnesia (TGA) might be related to an ischemic event with characteristic findings in diffusion-weighted images (DWIs). However, acute lesions are uncommon. The aim of this study was to identify any clinical or radiological differences between TGA patients with and without acute lesions.
METHODS
From January 2010 through March 2015, we identified retrospectively TGA patients with DWIs within 7 days from onset. According to the presence of an acute lesion in the hippocampus, clinical features, vascular risk factors, electroencephalography (EEG) findings, and the regional perfusion status in single-photon-emission computed tomography (SPECT) images were compared.
RESULTS
Of 57 TGA patients (mean age=60.5 years; 40 females), 19 patients (33.3%) had acute focal lesions in the hippocampus (3.53±0.74 mm, mean±SD). In terms of clinical features, the symptom duration was shorter in the lesion-negative group than in the lesion-positive group (mean=5 hours, interquartile range [IQR]=2-9 hours vs. mean=8 hours, IQR=5-13.5 hours; p=0.072). However, there were no differences between TGA patients with and without DWI lesions in cerebrovascular risk factors, laboratory results, or EEG findings. In 6 of 22 patients who underwent cerebral SPECT (2 of 9 DWI lesions and 4 of 13 without lesions), mild perfusion defects were exhibited without significant differences in both medial temporal regions and in the left frontal and left frontotemporal regions.
CONCLUSIONS
Symptom duration was the only clinical difference-including perfusion defects and epileptic evidence-between TGA patients with and without DWI lesions. This suggests that there is a low probability of hypoperfusion or focal seizure in TGA patients without acute lesions.

Keyword

Diffusion-weighted MRI; Electroencephalography; Hippocampus; Single photon emission computed tomography; Transient global amnesia

MeSH Terms

Amnesia, Transient Global*
Electroencephalography
Hippocampus*
Humans
Perfusion
Retrospective Studies
Risk Factors
Seizures
Temporal Lobe
Tomography, Emission-Computed, Single-Photon