We report two patients who complained of transient anterograde amnesia and repetitive questioning, that developed after taking zolpidem and lasted for several hours. The clinical manifestations of these patients fulfill the clinical criteria for transient global amnesia (TGA). The typical clinical manifestation of TGA following the consumption of zolpidem suggests a possible relationship associated with its drug mechanism.
Amnesia, Anterograde ; Amnesia, Transient Global ; Humans

We report a case of profound amnesia, anterograde and retrograde, in a patient, who had been premedicated with midazolam and underwent a posterior fusion of the cervical spine under inhalation anesthesia. The patient's memory was restored immediately after intravenous injections of the benzodiazepine antagonist flumazenil.
Amnesia ; Amnesia, Anterograde ; Amnesia, Retrograde* ; Anesthesia, Inhalation ; Benzodiazepines ; Flumazenil* ; Humans ; Injections, Intravenous ; Memory ; Midazolam* ; Spine

Background and purpose: Transient global amnesia (TGA) is a rare amnestic syndrome characterized by the sudden onset of a selective anterograde and retrograde amnesia with a time course of up to 24 hours. Recent studies have found a high frequency of small high-signal abnormalities in the hippocampus on diffusion-weighted imaging (DWI), and accordingly ischemia has been proposed as an etiology of TGA. We hypothesized that TGA lesions occur preferentially in the CA1 region of the hippocampus, which is known to be susceptible to ischemia. Methods: Twenty consecutive patients with a clinical diagnosis of TGA underwent DWI both within 24 hours of symptom onset and 3 days later. Twenty patients with high-signal abnormalities in the hippocampus on the initial DWI underwent subsequent DWI and T2-weighted imaging in the coronal plane to precisely localize the lesions. Results: Seventeen patients had small high-signal abnormalities (with diameters of 1-3 mm) in the hippocampus unilaterally on DWI. One of these patients had two lesions in one hippocampus. Three of the 20 patients had lesions bilaterally in the hippocampus, 1 of whom had 3 bilateral lesions. A total of 25 lesions were identified: 5 in the hippocampal head, 19 in the body, and 1 in the tail. Six patients had unilateral lesions on the left,11 patients had them on the right, and 3 patients had bilateral lesions. Conclusions: In this study, lesions associated with TGA were localized mostly to the lateral portion of the hippocampus, corresponding to CA1. This finding supports the ischemic etiology of TGA, but the underlying pathophysiologic mechanism requires further investigation.
Amnesia, Retrograde ; Amnesia, Transient Global ; Head ; Hippocampus ; Humans ; Ischemia

BACKGROUND AND PURPOSE: Transient global amnesia (TGA) is a stereotypic condition characterized by anterograde and retrograde amnesia that typically resolves within 24 hours. The pathophysiology of TGA is still unclear. We noted that patients hospitalized with TGA tend to appear in seasonal clusters, and decided to investigate this phenomenon. METHODS: Every patient with acute presentation of amnesia at our medical center is hospitalized for observation and evaluation. We reviewed the monthly occurrence of TGA in our patient population between 2000 and 2014, and compared this to non-TGA hospitalizations during the same time period. RESULTS: During the analysis period, 154 patients who met the criteria for TGA were hospitalized, as well as 259,007 non-TGA hospitalizations. The annual occurrence of TGA ranged from 5 to 16 hospitalizations. There were 91 TGA events in women and 63 in men, in subjects aged 62.8±10.6 years (mean±SD). The incidence was maximal during December [odds ratio (OR)=2.83, 95% confidence interval (CI)=1.20–6.67] and March (OR=2.77, 95% CI=1.17–6.56), and minimal from April to August. The incidence exhibited an increase followed by a decrease from October to February. A seasonal trend was observed as well, with incidence peaks occurring in winter (OR=1.82, 95% CI=1.12–2.96) and spring (OR=1.80, 95% CI=1.10–2.94). CONCLUSIONS: Our findings suggest that the incidence of TGA exhibits seasonal variations. This observation may help to improve the understanding of the pathophysiology underlying TGA.
Amnesia ; Amnesia, Retrograde ; Amnesia, Transient Global* ; Female ; Hospitalization ; Humans ; Incidence* ; Male ; Seasons*

Dot-like hippocampal hyperintensities on diffusion-weighted magnetic resonance imaging (MRI) have been reported as an interesting imaging finding of transient global amnesia (TGA). We report three patients with such dot-like hippocampal hyperintensities who did not present with anterograde amnesia. Episodes associated with the Valsalva maneuver such as nausea or vomiting might have produced the dot-like hippocampal hyperintensities in these patients. However, depending on the individual susceptibility to hippocampal lesions, clinical symptoms of TGA might not be present even when hippocampal lesions are present.
Amnesia, Anterograde ; Amnesia, Transient Global* ; Hippocampus ; Humans ; Magnetic Resonance Imaging* ; Nausea ; Valsalva Maneuver ; Vomiting

Transient global amnesia (TGA) causes retrograde amnesia, but there have been few reports of retrograde amnesia as a presenting symptom in TGA. A 52-year-old male who had acute amnesia for the past 4 years presented with TGA and recovered within 1 day. Brain magnetic resonance imaging revealed a lesion in the left hippocampus, and brain single-photon emission computed tomography revealed decreased blood flow in the left temporal and frontal areas. We speculated that hippocampal lesion with a frontal perfusion defect can be a cause of TGA.
Amnesia ; Amnesia, Retrograde ; Amnesia, Transient Global ; Brain ; Hippocampus ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Perfusion ; Tomography, Emission-Computed

The effect of inhalation anesthetics on memory was studied using 26 male Sprague-Dawley rats. In the control group the trained rats were tested the first performance time of T-maze and left them to anesthetic chamber for 120min. and checked second performance time 24hours later (Group A). For the experimental group the first performance time was tested and animals were exposed to the anesthetics (1% Halothane with N20:02=2:1) for 120min. and checked second performance time 24hours after cessation of exposure to evaluate retrograde amnesia (Group B). For the test of anterograde amnesia (Group C) rats were anesthetized before test the first performance time and checked second performance time 24hours later. The mean perfor- mance ratio (II/I) (i.e., I is the score in the first performance time and II is the score in the second performance time) was compared between anesthetized and non-anesthetized control group. In the group A the ratio was 102.8+/-19 but in group B it was 96.4+/-13 during anesthesia, 79.+/-19 after anesthesia and 92.3+/-11 in overaU anesthetized group, and was 100.2+/-17 in group C. All data of group B were significantly different with group A (p<0.01). But no statistical difference between group C and A was observed (p=0.174). These results suggest that post- training exposure to volatile anesthetics facilitates memory and no anterograde amnesia observed by pretraining exposure. These may be volatile anesthetics facilitate memory by enhancement of memory consolidation and/or retention or interference reduction.
Amnesia, Anterograde ; Amnesia, Retrograde ; Anesthesia ; Anesthetics ; Anesthetics, Inhalation* ; Animals ; Halothane ; Humans ; Inhalation* ; Male ; Memory* ; Rats* ; Rats, Sprague-Dawley

BACKGROUND: The dot-like hippocampal signal intensity in diffusion-weighted MR images is well-known as a characteristic imaging feature in transient global amnesia, a neurological syndrome in which sudden forward-and-backward memory loss occurs that is slowly recovered within 24 hours. We here report on patients with this dot-like hippocampal hyperintensity who did not present with anterograde amnesia except for headaches. CASE REPORT: Two women without a specific medical history presented with sudden-onset headaches on the same day. Neither had any trauma or infection history before the symptom or any sudden emotional or postural changes. Brain MRI showed tiny hippocampal high signal intensity on diffusion-weighted images (DWI). CONCLUSIONS: Dot-like hippocampal lesions seen on DWI may be present without memory impairment, and more studies are needed to determine whether there is any association with headache as in this case.
Amnesia, Anterograde ; Amnesia, Transient Global* ; Brain ; Diffusion* ; Female ; Headache* ; Hippocampus ; Humans ; Magnetic Resonance Imaging ; Memory ; Memory Disorders

Transient global amnesia (TGA) is characterized by abrupt onset temporary dysfunction of anterograde and retrograde amnesia without other neurologic deficits. We encountered a 53-year-old man who developed recurrent TGA while working in a hot and humid machinery room (33degrees C and 64% relative humidity). Heat exposure and physical exertion may facilitate the leakage of cytokines into the systemic circulation so as to cause a cerebral endothelial insult. Functional insufficiency of the hippocampus and its connections caused by physical and environmental factors may be related to recurrent attacks.
Amnesia, Retrograde ; Amnesia, Transient Global* ; Cytokines ; Hippocampus ; Hot Temperature ; Humans ; Middle Aged ; Neurologic Manifestations ; Physical Exertion

No abstract available.
Amnesia, Transient Global* ; Infarction*