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This study aimed to investigate the differences in cerebellar volumes and intrinsic cerebellar networks between patients with transient global amnesia (TGA) and healthy controls. We retrospectively enrolled patients with TGA and age- and sex-matched healthy controls. We used three-dimensional T1-weighted imaging at the time of TGA diagnosis to obtain cerebellar volumes, and the intrinsic cerebellar network was calculated by applying graph theory based on cerebellar volumes. The nodes were defined as individual cerebellar volumes, and edges as partial correlations, controlling for the effects of age and sex. The cerebellar volumes and intrinsic cerebellar networks were compared between the two groups. We enrolled 44 patients with TGA and 47 healthy controls. The volume of the left cerebellar white matter in patients with TGA was significantly lower than that in healthy controls (1.0328 vs. 1.0753%, p = 0.0094). In addition, there were significant differences in intrinsic cerebellar networks between the two groups. The small-worldness index in patients with TGA was higher than that in the healthy controls (0.951 vs. 0.880, p = 0.038). In the correlation analysis, the volumes of the right cerebellar cortex and lobules VIIIB were significantly correlated with age in patients with TGA (r = -0.323, p = 0.033; r = -0.313, p = 0.038, respectively). Patients with TGA exhibit alterations in cerebellar volumes and intrinsic cerebellar networks compared with healthy controls. These findings may contribute to a better understanding of the pathophysiology of the TGA., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Transient global amnesia (TGA) is a clinical syndrome characterized by anterograde amnesia, mild retrograde amnesia, and confusion up to 24 hours. Most commonly seen in patients older than 50 years, TGA results from the temporary impairment of short-term memory formation. Clinically, patients have time disorientation and often ask repeated questions regarding the day's events. Vomiting, headache, blurry vision, dizziness, and nausea may be present. A physically or psychologically stressful precipitating event, such as emotional stress, significant physical exertion, exposure to extreme temperatures, high-altitude conditions, Valsalva maneuver, acute illness, or sexual intercourse, is often the cause. The pathophysiology of TGA is not well understood but may be related to impaired venous drainage of the hippocampus. The diagnosis is primarily clinical, but recent studies suggest that magnetic resonance imaging may be helpful. TGA is self-limited and resolves within 24 hours. There is no established treatment for episodes. The lifetime recurrence rate is 2.9% to 23.8%. Recent evidence suggests an association between TGA and migraine headaches as well as takotsubo cardiomyopathy. No apparent increased risk of cerebrovascular events occurs in patients who have had an episode of TGA. There is conflicting evidence as to whether an episode of TGA predisposes to future seizures or dementia.

Triple intrinsic brain networks including the salience network (SN), default mode network (DMN), and central executive network (CEN), are known to be important in human cognition. Therefore, investigating those intrinsic brain networks in transient global amnesia (TGA) may offer novel insight useful for the pathophysiology of TGA. Fifty TGA patients underwent the resting state functional magnetic resonance imaging (rsfMRI) within 24 h, at 72 h, and 3 months after TGA onset. Twenty-five age, gender matched controls also underwent rsfMRI. Within 24 h of TGA onset, TGA patients showed greater functional connectivity in the SN and lower functional connectivity in the DMN, while relatively preserved functional connectivity was observed in the CEN. Interestingly, TGA patients continued to show decreased connectivity in the DMN, while no alterations were shown in the SN 72 h after illness onset. Three months after TGA onset, alterations of functional connectivity in the SN or the DMN were normalized. Our findings suggest that TGA is associated with transient greater functional connectivity in the SN and lower connectivity in the DMN., (© 2021. The Author(s).)

Background and Purpose: Transient global amnesia (TGA) is a sudden onset of anterograde and retrograde amnesia. We aimed to assess differences in terms of cortical thickness and structural brain connectome between patients with TGA (at acute and delayed postrecovery stages) and matched controls., Materials and Methods: We report on 18 consecutive patients with TGA who underwent 3T MR imaging, including DTI and MPRAGE sequences, at the acute (mean delay postonset: 44 hours) and delayed post-recovery (mean delay: 35 days) stages. Structural connectome was assessed in patients with TGA and in 18 age- and sex-matched controls by using probabilistic fiber- tracking and segmentation of 164 cortical/subcortical structures ("nodes"). Connectivity graphs were computed and global network metrics were calculated. Network-based statistical analysis (NBS) was applied to compare patients with TGA at each stage with controls. We also compared cortical thickness between patients with TGA and healthy controls., Results: Global network metrics were not altered in patients with TGA. NBS-analysis showed structural connectome alterations in patients with TGA compared with controls, in core regions involving the limbic network, with 113 nodes and 114 connections (33 left intrahemispheric, 31 right intrahemispheric, and 50 interhemispheric connections) showing significantly decreased structural connectivity ( P < .05 NBS corrected, t -values ranging from 3.03 to 8.73). Lower cortical thickness compared with controls was associated with these structural alterations in patients with TGA, involving the orbitofrontal, cingulate, and inferior temporal cortices. All the abnormalities were visible at both acute and delayed postrecovery stages., Conclusions: Our preliminary study suggests there are structural abnormalities of the limbic network in patients with TGA compared with controls, including decreased structural connectivity and cortical thickness., (© 2020 by American Journal of Neuroradiology.)

Transient global amnesia (TGA) can be triggered by a high level of blood cortisol. We assessed whether patients had a higher level of cortisol during the TGA than shortly after. We included 52 patients, 21 with blood collected during the TGA episode and 31 shortly thereafter. We compared these two groups after adjustment for time of blood collection. The cortisol level was significantly higher in the per-ictal group (P=0.03) and negatively correlated with the time elapsed from symptom onset (P=0.005). The results are consistent with of the hypothesis of a hyperreactivity of the hypothalamic-pituitary-adrenal axis., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Day-to-day life involves the perception of events that resemble one another. For the sufficient encoding and retrieval of similar information, the hippocampus provides two essential computational processes. Pattern separation refers to the differentiation of overlapping memory representations, whereas pattern completion reactivates memories based on noisy or degraded input. Evidence from human and rodent studies suggest that pattern separation specifically relies on neuronal ensemble activity in hippocampal subnetworks in the dentate gyrus and CA3. Although a role for CA1 in pattern separation has been shown in animal models, its contribution in the human hippocampus remains elusive. In order to elucidate the contribution of CA1 neurons to pattern separation, we examined 14 patients with an acute transient global amnesia (TGA), a rare self-limiting dysfunction of the hippocampal system showing specific lesions to CA1. Patients' pattern separation performance was tested during the acute amnestic phase and follow-up using an established mnemonic similarity test. Patients in the acute phase showed a profound deficit in pattern separation (p < .05) as well as recognition memory (p < .001) that recovered during follow-up. Specifically, patients tested in a later stage of the amnesia were less impaired in pattern separation than in recognition memory. Considering the time dependency of lesion-associated hippocampal deficits in early and late acute stages of the TGA, we showed that the pattern separation function recovered significantly earlier than recognition memory. Our results provide causal evidence that hippocampal CA1 neurons are critical to pattern separation performance in humans., (© 2019 Wiley Periodicals, Inc.)

Transient global amnesia (TGA) is a clinical syndrome characterized by retrograde and anterograde amnesia without other neurological deficits. Although electroencephalography (EEG) methods are commonly used in both clinical and research setting with TGA patients, few studies have investigated neurophysiological pattern in TGA using quantitative EEG (qEEG). The main aim of the present study was to extend these previous findings by exploring EEG power spectra differences between patients with acute TGA and healthy controls using the exact low-resolution brain electromagnetic tomography software (eLORETA). EEG was recorded during 5 minutes of resting state. Sixteen patients (mean age: 66.81 ± 7.94 years) during acute TGA and 16 healthy subjects were enrolled. All patients showed hippocampal or parahippocampal signal abnormalities in diffusion-weighted magnetic resonance imaging performed from 2 to 5 days after the onset of TGA. Compared with healthy controls, TGA patients showed a decrease of theta power localized in the temporal lobe (Brodmann areas, BAs 21-22-38) and frontal lobe (BAs 8-9-44-45). A decrease of EEG beta power in the bilateral precuneus (BA 7) and in the bilateral postcentral gyrus (BAs 3-4-5) was also observed in TGA individuals. Taken together, our results could reflect the neurophysiological substrate of the severe impairment of both episodic memory and autobiographical memory which affect TGA patients during the acute phase.

Introduction: Simultaneous occurrence of transient global amnesia and Takotsubo syndrome has been only rarely reported. Here we report another patient with a transient global amnesia and concomitant Takotsubo syndrome., Case Presentation: Our patient is a 64-year-old white man with a previous history of myocarditis from borreliosis who developed sudden-onset confusional state with perseverations and repetition of the same questions during a funeral for his brother-in-law. Upon neurological work-up and after spontaneous resolution of most of the neurological deficits, transient global amnesia was diagnosed. Blood tests revealed moderate renal insufficiency, elevated troponin-T, and elevated N-terminal prohormone of brain natriuretic peptide. Electrocardiography showed left anterior hemiblock and negative T-waves in V2-V6. Upon transthoracic echocardiography the apical type of a Takotsubo syndrome was suspected. Since coronary angiography was normal and electrocardiography and echocardiographic abnormalities resolved under candesartan, bisoprolol, acetyl-salicylic acid, and atorvastatin within a few days after onset, Takotsubo syndrome was diagnosed., Conclusions: Since Takotsubo syndrome may be associated with transient global amnesia a causal relation may exist. A possible trigger for both conditions could be severe emotional stress from the loss of a close relative. A possible common pathomechanism could be overstimulation of adrenergic receptors in the myocardium, the cerebrum, or the coronary or cerebral arteries. Whether pre-existing myocardial compromise promotes the development of Takotsubo syndrome requires further investigations.

Introduction: Stress-related transient inhibition of memory formation in the hippocampus has been hypothesized as one of the underlying pathomechanisms of transient global amnesia (TGA). TGA episodes, during which patients cannot encode and recall new information (anterograde amnesia affecting episodic long-term memory), are frequently preceded by a psychologically or physically stressful event., Methods: We measured salivary cortisol during acute TGA in 14 patients, as well as cortisol day-profiles and the effect of experimental exposure to stress (using the socially evaluated cold pressor test) on cortisol levels during the subacute phase. We assessed psychiatric comorbidity as well as depression, trait anxiety and chronic stress. These findings were compared with data of 20 healthy controls., Findings: Nine patients reported a precipitating stressor and all 14 developed typical hippocampal lesions on follow-up MRI. During TGA, salivary cortisol levels were more than 3-fold higher compared to time-matched day levels. While there was no difference in mean cortisol levels of the diurnal rhythm, we found a significant interaction between groups during experimental stress exposure (p = 0.049) with the TGA group revealing a higher cortisol increase. The TGA group reported higher levels of depressive symptomatology (CES-D) and higher scores of chronic stress (TICS) compared with the control group and there was a significant correlation between cortisol increase during TGA and the results of self-rating according to the CES-D (r = 0.615; p = 0.004), as well as to the STAI (r = 0.702; p = 0.001)., Conclusion: Our findings of enhanced secretion of cortisol in acute TGA patients correlating with symptoms of depression and anxiety and a persisting hyperreactivity to experimental stress in the subacute phase support the hypothesis that stress might be significant for the pathogenesis of TGA., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: The risk of recurrence of new amnesia events in patients having previously experienced transient global amnesia (TGA) ranges between 2.9-23.8%. Our objective was to search for recurrence predictors in TGA patients., Methods: Retrospective analysis to identify recurrence predictors in a cohort of 203 TGA patients from a single center in Buenos Aires, Argentina, diagnosed between January 2011 and March 2017 Clinical features and complementary studies (laboratory results, jugular vein Doppler ultrasound and brain MRI) were analyzed. Comparison between patients with recurrent versus single episode TGA was performed, applying a multivariate logistic regression model., Results: Mean age at presentation was 65 years (20-84); 52% were female. Median time elapsed between symptom onset and ER visit was two hours, with the average episode duration lasting four hours. Mean follow-up was 22 months. Sixty-six percent of patients referred to an identifiable trigger. Jugular reflux was present in 66% of patients; and 22% showed images with hippocampus restriction on diffusion-weighted MRI. Eight percent of patients had TGA recurrence. Patients with recurrent TGA had a more frequent history of migraine than patients without recurrence (37.5% vs. 14%; p = 0.03). None of the other clinical characteristics and complementary studies were predictors of increased risk of recurrence., Conclusions: Patients with migraine may have a higher risk of recurrent TGA. None of the other clinical characteristics evaluated allowed us to predict an increased risk of recurrence. Although the complementary studies allowed us to guide the diagnosis, they did not appear to have a significant impact on the prediction of recurrence risk.

While the pathophysiology of transient global amnesia (TGA) is not understood, due to the specific nature of the clinical deficits, transient dysfunction in the medial temporal lobe, especially in the hippocampus, is assumed; however, concomitant disturbances in other brain regions and in executive function have been postulated. In this study, a cohort of 16 patients was prospectively recruited from the emergency department for resting-state functional MRI (fMRI) during the acute stage of TGA, as confirmed by a standardized neuropsychological assessment. Twenty age- and sex-matched controls, as well as twenty patients with a history of TGA, were recruited for comparison. Functional data were processed using independent component analysis (ICA), allowing the complete automatic (data-driven) identification of spontaneous network dynamics. We documented a severe disturbance in anterograde episodic long-term memory in all patients. Group-based ICA of resting-state data in acute TGA patients versus that of controls and patients with a past TGA episode demonstrated reduced FC mainly of structures belonging to the executive network (EN), but also the hippocampus, confirming its pathophysiological involvement in the disorder, as well as areas belonging to the salience network and other subcortical regions. No significant differences were found when comparing connectivity in patients with a history of TGA and controls. Our findings strengthen previous empirical and theoretical accounts of hippocampal and executive dysfunction in TGA. The disruption of frontal, parietal and insular control regions, together with disruption in the hippocampus, provides a new interpretation for the pathophysiology and neuropsychological profile of this neurological disorder on a large-scale network level., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

We describe a 68-year-old woman who had typical absence seizures since 14 years of age. The absences were refractory to treatment and persisted into adulthood, with no seizure-free periods until seizure control at 59 years of age. After six years of being seizure-free, she presented with an episode characterized by mental confusion, abnormal behaviour, and amnesia, lasting for several hours. An EEG performed the day after, when the patient had already recovered, was unremarkable. The episode was interpreted as transient global amnesia. After two and three years, respectively, she presented with two analogous episodes lasting >24 hours. An EEG disclosed, on both occasions, subcontinuous generalized spike-and-wave discharges, consistent with absence status epilepticus (AS). The last episode occurred at 68 years of age and was successfully treated with intravenous lorazepam. After one month of follow-up, no further episodes occurred. AS is common in juvenile absence epilepsy, however, our patient showed a rather atypical course, characterized by refractory and persistent absences during adolescence and adulthood, and a tendency for AS to recur with no more absences in later life. Despite the known epilepsy history, AS episodes were initially misdiagnosed. Moreover, EEG recording and subsequent treatment were not performed until the second day of status.

Objectives: Structural changes and metabolic stress have been reported on diffusion-weighted magnetic resonance imaging in the cornu ammonis 1 area of the hippocampus in patients with transient global amnesia (TGA), but a consensus on pathogenesis is still lacking. The aim of our study was to perform a comprehensive ultrasound analysis of the cerebrovascular circulation in our population of patients with TGA., Methods: One hundred patients with TGA and 50 age- and sex-matched control participants underwent ultrasound examinations of the cervicocranial circulation., Results: The most significant risk factor for TGA was arterial hypertension (P < .01). There were no significant atherosclerotic lesions on the large arteries of the neck (mean internal carotid artery stenosis ± SD, 28.7% ± 11.7%) or on the large intracerebral arteries (good structural and hemodynamic status; P > .05). Rarely detected microembolic signals or a right-left cardiopulmonary shunt excluded an emboligenic mechanism of TGA (P > .05). The internal jugular vein valves were incompetent in 54% of patients with TGA, and this condition was associated with an increased risk of TGA (odds ratio, 4.16; 95% confidence interval, 1.91-9.04). The mean values of the breath holding index and pulsatility index, as parameters of small-vessel function, were within normal ranges and without differences between the TGA and control groups (P > .05)., Conclusions: Our ultrasound examination did not detect significant structural atherosclerotic changes of cervicocranial arteries, and an emboligenic mechanism was excluded. Only a significant rise of blood pressure in TGA and significant valvular insufficiency of the internal jugular vein were established. New research should clarify whether these simultaneous functional circulatory changes have relevance for metabolic stress in the cornu ammonis of the hippocampus., (© 2017 by the American Institute of Ultrasound in Medicine.)

Background: We evaluated a brain network using graph theoretical analysis and microstructural abnormalities of the white matter in patients with transient global amnesia (TGA)., Methods: Twenty patients with TGA and healthy control subjects were recruited, and they underwent diffusion tensor imaging (DTI) scans. Graph theory was applied to obtain network measures based on DTI data. We investigated the network measures and microstructural abnormalities of white matter using tract-based spatial statistics (TBSS) analysis in the patients with TGA., Results: Measures of global topology were not different between the patients with TGA and healthy subjects. However, there were significant differences of hubs organization; the strength of the right superior and inferior orbitofrontal, the right inferior frontal operculum, the left superior parietal, and left postcentral gyrus, the cluster coefficient of the right middle orbitofrontal and left inferior parietal gyrus, the betweenness centrality of the left angular gyrus, and the pagerank centrality of the right superior and inferior orbitofrontal, right inferior frontal operculum, left superior parietal, and left postcentral gyrus in the patients with TGA were significantly lower than those in healthy subjects. Regarding the analysis of the white matter microstructure with TBSS, there were no differences in the fractional anisotropy and mean diffusivity values between the 2 groups., Conclusions: We newly identify a reorganization of network hubs of the brain network in patients with TGA, especially in the regions of the default-mode network. These alterations of the brain network may play a role in the pathophysiologic mechanism underlying TGA and suggest that TGA is a network disease., (© 2019 S. Karger AG, Basel.)

Background: The etiology of transient global amnesia (TGA) remains unclear. We studied the pathophysiology of TGA in 165 Japanese patients., Subjects and Methods: TGA was diagnosed in hospitalized patients from 2004 to 2015. We analyzed clinical characteristics, magnetic resonance imaging findings, and maximum intima-media thickness of the common carotid artery, and the reflux of internal jugular venous (IJV) flow by ultrasonography, and statistically compared patients with TGA with age-matched and sex-matched patients who have had a transient ischemic attack (TIA), small-vessel occlusion (SVO), and normal controls (each group, N = 165)., Results: Patients with TGA showed lower prevalence of vascular risk factors than patients with TIA and SVO did. Eleven patients (6.7%) had 2 episodes of TAG, but specific clinical variables could not be recognized in these patients. The maximum intima-media thickness was significantly thinner in TGA (1.1 ± .7 mm) than in SVO (1.6 ± .9 mm; P = .001). The percentages of cases whose IJV flow reflux was increased by Valsalva maneuver showed no difference (P = .573) between TGA (26.0 %) and SVO (29.4%). MR diffusion-weighted imaging yielded small hyperintense signals in the hippocampus in 64 of 90 (71.1%) patients between 24 and 72 hours. Potential precipitating specific factors or events before the attacks could be recognized in 40 cases (24.2%) of 165 patients., Conclusion: Arterial ischemia and IJV flow reflux might not contribute to TGA pathophysiology. The vulnerability of the hippocampus to physical or emotional stress might be suspected as an underlying mechanism in some patients with TGA., (Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Takotsubo cardiomyopathy (TTC) is associated with acute, reversible left ventricular (LV) dysfunction, while transient global amnesia (TGA) is a reversible disorder of the brain characterised by anterograde amnesia. We report an unusual case of TTC occurring concurrently in a patient with TGA, and propose that catecholamine surge induced cerebral venous congestion and cardiotoxicity is the shared aetiology that leads to the concurrent manifestation of these conditions. TTC and TGA are reversible disorders that can occur concurrently in a subset of patients due to a unifying aetiology, catecholamine excess, leading to pathophysiological changes within the brain and the myocardium., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objectives: Dot-like hippocampal hyperintensities (HHs) on diffusion-weighted MRI (DWI) have been reported as an interesting imaging finding of transient global amnesia (TGA) that is characterized by typical anterograde amnesia. However, we found that these dot-like HHs are occasionally seen in some patients without clinical symptoms of TGA., Methods: We identified 8 patients who did not show clinical symptoms of TGA, despite the presence of hippocampal lesions on DWI (No-TGA group, n=8). For the comparison group, 16 age-matched and sex-matched patients were selected from among patients who had been diagnosed with TGA (TGA group, n=16)., Results: No significant difference was found in vascular risk factors, years of education, or underlying cognitive function between the 2 groups. More than half of the patients in each group performed preceding Valsalva-associated activities. Multiple hippocampal lesions or concomitant lesions in the cingulate gyrus were found only in the TGA group., Conclusions: Dot-like HHs on DWI can be observed without the typical symptoms of TGA. Valsalva maneuver-associated activities could produce asymptomatic hippocampal lesions. The symptoms of TGA may be presented on a spectrum, from no symptoms to mild vegetative symptoms or to the typical symptoms of TGA, depending on individual susceptibility.

Learning and the formation of memory are reflected in various memory systems in the human brain such as the hippocampus based declarative memory system and the striatum-cortex based system involved in motor sequence learning. It is a matter of debate how both memory systems interact in humans during learning and consolidation and how this interaction is influenced by sleep. We studied the effect of an acute dysfunction of hippocampal CA1 neurons on the acquisition (on-line condition) and off-line changes of a motor skill in patients with a transient global amnesia (TGA). Sixteen patients (68 ± 4.4 yrs) were studied in the acute phase and during follow-up using a declarative and procedural test, and were compared to controls. Acute TGA patients displayed profound deficits in all declarative memory functions. During the acute amnestic phase, patients were able to acquire the motor skill task reflected by increasing finger tapping speed across the on-line condition, albeit to a lesser degree than during follow-up or compared to controls. Retrieval two days later indicated a greater off-line gain in motor speed in patients than controls. Moreover, this gain in motor skill performance was negatively correlated to the declarative learning deficit. Our results suggest a differential interaction between procedural and declarative memory systems during acquisition and consolidation of motor sequences in older humans. During acquisition, hippocampal dysfunction attenuates fast learning and thus unmasks the slow and rigid learning curve of striatum-based procedural learning. The stronger gains in the post-consolidation condition in motor skill in CA1 lesioned patients indicate a facilitated consolidation process probably occurring during sleep, and suggest a competitive interaction between the memory systems. These findings might be a reflection of network reorganization and plasticity in older humans and in the presence of CA1 hippocampal pathology., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Acute perturbation of the hippocampus, one of the connector hubs in the brain, is a key step in the pathophysiological cascade of transient global amnesia (TGA). We tested the hypothesis that network efficiency, meaning the efficiency of information exchange over a network, is impaired during the acute stage of TGA. Graph theoretical analysis was applied to resting-state EEG data collected from 21 patients with TGA. The EEG data were obtained twice, once during the acute stage (< 24 hours after symptom onset) and once during the resolved stage (> 2 months after symptom onset) of TGA. Characteristic path lengths and clustering coefficients of functional networks constructed using phase-locking values were computed and normalized as a function of the degree in the delta, theta, alpha, beta 1, beta 2 and gamma frequency bands of the EEG. We investigated whether the normalized characteristic path length (nCPL) and normalized clustering coefficients (nCC) differed significantly between the acute and resolved stages of TGA at each frequency band using the Wilcoxon signed-rank test. For networks where the nCPL or nCC differed significantly between the two stages, we also evaluated changes in the connections of the brain networks. During the acute stage of TGA, the nCPL of the theta band networks with mean degrees of 8, 8.5, 9 and 9.5 significantly increased (P < 0.05). During the acute stage, the lost edges for these networks were mostly found between the anterior (frontal and anterior temporal) and posterior (parieto-occipital and posterior temporal) brain regions, whereas newly developed edges were primarily found between the left and right frontotemporal regions. The nCC of the theta band with a mean degree of 5.5 significantly decreased during the acute stage (P < 0.05). Our results indicate that TGA deteriorates the network efficiency of the theta frequency band. This effect might be related to the desynchronization between the anterior and posterior brain areas., Competing Interests: The authors have declared that no competing interests exist.

Transient global amnesia is a clinically distinct syndrome characterized by the acute inability to form new memories. It can last up to 24 hours. The diagnosis is dependent on eliminating other more serious etiologies including toxic ingestions, acute strokes, complex partial seizures, and central nervous system infections. Transient global amnesia confers no known long-term risks; however, when abnormal signs or symptoms are present, they take precedence and guide the formulation of a differential diagnosis and investigation. In witnessed transient global amnesia with classic features, a minimalist approach is reasonable, avoiding overtesting, inappropriate medication, and medical interventions in favor of observation, ensuring patient safety, and reassuring patients and their families. This review provides a detailed framework for distinguishing transient global amnesia from its dangerous mimics and managing its course in the emergency department. [Points & Pearls is a digest of Emergency Medicine Practice].

We report two extremely rare cases involving the development of transient selective retrograde amnesia for simple machine operation lasting for several hours. A 61-year-old male taxi driver suddenly became unable to operate a taximeter, and a 66-year-old female janitor suddenly became unable to use a fax machine. They could precisely recount their episodes to others both during and after the attacks, and their memories during their attacks corresponded to the memory of the witness and the medical records of the doctor, respectively. Therefore, it appears that these individuals remained alert and did not develop anterograde amnesia during their attacks. On day 4, they underwent high-resolution magnetic resonance imaging (MRI), and diffusion-weighted MRI with 2-mm section thickness revealed small high-intensity signal lesions in the left hippocampal cornu ammonis area 1 (CA1) region. However, these lesions disappeared during the chronic phase. This is the first report describing lesions detected by MRI in patients with transient selective amnesia without anterograde amnesia. Reversible damage to the hippocampal CA1 region may cause transient selective amnesia by impairing the retrieval of relevant memories.

In previous studies of transverse sinus (TS) hypoplasia, discrepancies between TS diameter measured by magnetic resonance venography (MRV) and contrast T1-weighted magnetic resonance (contrast T1) were observed. To investigate these discrepancies, and considering that TS hypoplasia is associated with neurological disorders, we performed a post hoc analysis of prospectively collected data from 3 case-control studies on transient global amnesia (TGA), transient monocular blindness (TMB), and panic disorders while retaining the original inclusion and exclusion criteria. Magnetic resonance (MR) imaging of 131 subjects was reviewed to evaluate TS diameter and the location and degree of venous flow stenosis and obstruction.MRV without contrast revealed that TS hypoplasia was observed in 69 subjects, whom we classified into 2 subgroups according to the concordance with contrast T1 observations: concordance indicated anatomically small TS (30 subjects), and discrepancy indicated that the MRV diagnosis is in fact flow-related and that TS is not anatomically small (39 subjects). The latter subgroup was associated with at least 1 site of venous compression/stenosis in the internal jugular vein (IJV) or the left brachiocephalic vein (BCV) (P < 0.001), which was significantly larger in patients than controls. Compensatory dilatation of contralateral TS diameter was only observed with MRV, not with contrast T1 imaging.The clinical implication of these results is that using MRV only, IJV/BCV compression/stenosis may be misdiagnosed as TS hypoplasia. And contralateral TS have no compensatory dilatation in its diameter in contrast T1 imaging, just compensatory increased flow volume., Competing Interests: The authors have no conflicts of interest to disclose.

Acute perturbation of the corticohippocampal circuitry is a primary pathophysiological mechanism underlying transient global amnesia (TGA). With regard to memory, 2 distinct corticohippocampal circuitries potentially exist: the anterior temporal network and the posterior medial network. We used electroencephalography (EEG) spectral analysis to determine which network is disrupted during the acute stage of TGA. Patients with TGA who visited Seoul National University Bundang Hospital within 24 hours after symptom onset were retrospectively identified. Twenty patients underwent EEG twice, once in the acute stage (<24 hours after symptom onset) and once in the resolved stage (>2 months after symptom onset). A fast Fourier transform was applied to compute the spectral power of the 6 frequency bands: delta, theta, alpha, beta 1, beta 2, and gamma. We assumed that the frontocentral and temporal regions belonged to the anterior temporal network, whereas the parieto-occipital regions belonged to the posterior medial network. A paired Student's t test was used to evaluate the difference in the regional spectral powers in each frequency band between the acute and resolved TGA stages. Compared with the resolved stage, relative theta power in the left parieto-occipital region was increased and relative alpha power in the right parieto-occipital region was reduced during the acute stage of TGA, with a statistical significance of P<.05 (uncorrected). The cortical regions that belonged to the posterior medial network showed alterations of neuronal activity, which reflects disruption of the posterior medial network during the acute stage of TGA., (© EEG and Clinical Neuroscience Society (ECNS) 2014.)

Background: The pathophysiology of transient global amnesia (TGA) is not fully understood. Previous studies using single photon emission computed tomography (SPECT) have reported inconclusive results regarding cerebral perfusion. This study was conducted to identify the patterns of regional cerebral blood flow (rCBF) in TGA patients via longitudinal SPECT analysis. An association between the observed SPECT patterns and a pathophysiological mechanism was considered., Methods: Based on the TGA registry database of Seoul National University Bundang Hospital, 22 TGA patients were retrospectively identified. The subjects underwent initial Tc-99m-ethyl cysteinate dimer (ECD) SPECT within 4 days of an amnestic event and underwent follow-up scans approximately 6 months later. The difference in ECD uptake between the two scans was measured via voxel-based whole brain analysis, and the quantified ECD uptake was tested using a paired t-test., Results: The TGA patients had significantly decreased cerebral perfusion at the left precuneus (P<0.001, uncorrected) and at the left superior parietal and inferior temporal gyrus according to the voxel-based whole brain analysis (P<0.005, uncorrected). A difference in the quantified ECD uptake between the 2 scans was also found at the left precuneus among the 62 cortical volumes of interest (P = 0.018, Cohen's d = -0.25)., Conclusion: We identified left hemispheric lateralized hypoperfusion that may be related to posterior medial network disruption. These findings may be a contributing factor to the pathophysiology of TGA.

Transient global amnesia (TGA) is a neurological syndrome that usually occurs in middle-aged or older people. It is characterized by the abrupt onset of profound anterograde amnesia, associated with more variable retrograde amnesia and repetitive questioning. The whole episode lasts no more than 24 h. Almost 60 years after its first descriptions, the etiology of TGA remains unknown. Until now, TGA has been described exclusively as a memory disorder, but there is a growing body of evidence to show that emotional and psychological factors (as anxious and depressive symptoms) are present at different times of TGA. Their role therefore needs to be clarified. First, these factors seem to play a part in triggering TGA, at least for a subgroup of patients, suggesting the existence of an emotional TGA subtype. Second, recent research shows that almost all the TGA patients displayed modifications of their emotional state during the episode, possibly linked to sudden memory loss. The level of depressive and anxious symptoms could even reach a pathological threshold in patients with the so-called "emotional TGA subtype". Third, the persistence of these depressive and anxious symptoms after the end of the episode could account for lasting memory disorders in some patients. Finally, the analysis of these emotional syndrome and emotional factors and the recent data in neuroimaging could allow us to gain a better understanding of the pathophysiological mechanisms behind TGA. The aim of this review was thus to discuss whether the anxious and depressive symptoms are causative, resultant or coincidental of TGA.

Purpose: Evidence of intracranial venous reflux flow due to jugular venous reflux (JVR) on time of flight (TOF) MR angiography (MRA) is thought to be highly associated with transient global amnesia (TGA)-evidence that supports the venous congestion theory of TGA pathophysiology. However, recent studies indicate that intracranial JVR on TOF MRA is occasionally observed in normal elderly. Therefore, the purpose of this study was to compare the prevalence of intracranial JVR on TOF MRA in patients with TGA and two control groups., Methods: Three age- and sex-matched groups of subjects that received MRI and MRA were enrolled. The groups comprised 167 patients with TGA, 167 visitors to the emergency room (ER) and 167 visitors to a health promotion centre (HPC). Intracranial JVR was defined as abnormal venous signals in the inferior petrosal, sigmoid and/or transverse sinuses on TOF MRA. The prevalence of intracranial JVR was assessed across the three groups., Results: Intracranial JVR was seen in seven (4.2 %) TGA patients, eight (4.8 %) ER visitors and three (1.8 %) HPC visitors, respectively. No statistically significant differences were observed among the three groups., Conclusion: TGA patients showed a low prevalence of intracranial JVR on TOF MRA, and no statistical differences were found in comparison with control groups.

Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of anterograde amnesia (the inability to encode new memories), accompanied by repetitive questioning, sometimes with a retrograde component, lasting up to 24 hours, without compromise of other neurologic functions. Herein, we review current knowledge on the epidemiology, pathophysiology, clinical diagnosis, and prognosis of TGA. For this review, we conducted a literature search of PubMed, with no date limitations, using the following search terms (or combinations of them): transient global amnesia, etiology, pathophysiology, venous hypertension, migraine, magnetic resonance imaging, computed tomography, electroencephalography, prognosis, and outcome. We also reviewed the bibliography cited in the retrieved articles. Transient global amnesia is a clinical diagnosis, and recognition of its characteristic features can avoid unnecessary testing. Several pathophysiologic mechanisms have been proposed (venous insufficiency, arterial ischemia, and migrainous or epileptic phenomena), but none of them has been proved to consistently explain cases of TGA. Brain imaging may be considered and electroencephalography is recommended when episodes are brief and recurrent, but otherwise no investigations are necessary in most cases. Data on long-term prognosis are limited, but available information suggests that the relapse rate is low, the risk of stroke and seizures is not considerably increased, and cognitive outcome is generally good., (Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Background and Purpose: The current theories to explain the pathophysiology of transient global amnesia (TGA) involve epilepsy, migraine, and hippocampal ischemia which might be determined by venous congestion or arterial vasoconstriction triggered by Valsalva-associated maneuvers in susceptible individuals., Methods: Seventy-five TGA patients [mean age 60.3 ± 8.0 years, 44 (59%) females] and 75 age- and gender-matched controls were enrolled into a case-control study and underwent extracranial and transcranial arterial echo-color Doppler sonography., Results: Intracranial arterial obstructions of the posterior circulation were neither observed in TGA patients nor in controls. There was no significant difference between the two groups with regard to intima-media thickness of the common carotids (.73 ± .07 vs. .72 ± .06), cervical vessel atherosclerosis (13% vs. 15%), >50% intracranial stenosis of the anterior circulation arteries (3% vs. 3%), resistance index values of the vertebral arteries at rest and during Valsalva maneuver (.69 ± .08 vs. .67 ± .09) and pulsatility index values of the major intracranial arteries at rest and during Valsalva maneuver. No difference in all study items was found between patients assessed during or soon after the TGA episode., Conclusions: Extra-intracranial atherosclerosis does not play a pathogenic role in TGA and no supporting evidence for the arterial vasoconstriction hypothesis of TGA emerged from this study., (Copyright © 2014 by the American Society of Neuroimaging.)

Spreading depolarization (SD) is a wave of almost complete depolarization of the neuronal and glial cells. Nowadays there is sufficient evidence demonstrating its pathophysiological effect in migraine with aura, transient global amnesia, stroke, subarachnoid hemorrhage, intracerebral hemorrhage, and traumatic brain injury. In these cases, occurrence of SD has been associated with functional neuronal damage, neuronal necrosis, neurological degeneration, and poor clinical outcome. Animal models show that SD can be modulated by drugs that interfere with its initiation and propagation. There are many pharmacological targets that may help to suppress SD occurrence, such as Na⁺, K⁺, Cl⁻, and Ca²⁺ channels; Na⁺/K⁺ -ATPase; gap junctions; and ligand-based receptors, for example, adrenergic, serotonin, sigma-1, calcitonin gene-related peptide, GABAA, and glutamate receptors. In this regard, N-methyl-d-aspartate (NMDA) receptor blockers, in particular, ketamine, have shown promising results. Therefore, theoretically pharmacologic modulation of SD could help diminish its pathological effects.

Transient epileptic amnesia (TEA) is an epileptic syndrome characterized by recurrent, brief episodes of amnesia. Transient epileptic amnesia is often associated with the rapid decline in recall of new information over hours to days (accelerated long-term forgetting - 'ALF'). It remains unknown how recognition memory is affected in TEA over time. Here, we report a systematic study of picture recognition in patients with TEA over the course of one week. Sixteen patients with TEA and 16 matched controls were presented with 300 photos of everyday life scenes. Yes/no picture recognition was tested 5min, 2.5h, 7.5h, 24h, and 1week after picture presentation using a subset of target pictures as well as similar and different foils. Picture recognition was impaired in the patient group at all test times, including the 5-minute test, but it declined normally over the course of 1week. This impairment was associated predominantly with an increased false alarm rate, especially for similar foils. High performance on a control test indicates that this impairment was not associated with perceptual or discrimination deficits. Our findings suggest that, at least in some TEA patients with ALF in verbal recall, picture recognition does not decline more rapidly than in controls over 1week. However, our findings of an early picture recognition deficit suggest that new visual memories are impoverished after minutes in TEA. This could be the result of deficient encoding or impaired early consolidation. The early picture recognition deficit observed could reflect either the early stages of the process that leads to ALF or a separable deficit of anterograde memory in TEA. Lastly, our study suggests that at least some patients with TEA are prone to falsely recognizing new everyday visual information that they have not in fact seen previously. This deficit, alongside their ALF in free recall, likely affects everyday memory performance., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Transient Global Amnesia (TGA) is a clinical syndrome characterized by temporary inability to form new memories described as anterograde amnesia. It is associated with retrograde amnesia and repetitive questioning. During the attack patients remain conscious and communicative and personal identity is preserved. Focal neurological symptoms and epileptic features are absent and general conditions appear intact. The ability to store new memories gradually recovers and subjects return to normal conditions except for a substantial amnestic gap for the duration of the attack. TGA has an incidence of 3-8 per 100 000 people per year. It usually affects patients between the ages of 50 and 70 years, at an average age of 61 years; occurrence in patients younger than 40 years of age is rare. The rate of recurrence is between 6% and 10% per years. No gender prevalence has been recorded. The patients with definite TGA have a very good prognosis; their rate of subsequent major vascular events is less than 1% per year.

Purpose: Transient global amnesia (TGA) is a syndrome of unknown etiology. Electroencephalographic (EEG) abnormalities in TGA have been reported previously. We analyzed the frequency and characteristics of EEG abnormalities in patients with TGA., Methods: We collected EEGs of patients with a clinical diagnosis of TGA who had visited the emergency room or the outpatient clinic over a period of 8 years and compared clinical and demographic characteristics of the patients with normal EEGs with those with abnormal EEGs., Results: EEG abnormalities were found in 35 (22.9%) out of 153 patients and epileptiform discharges were seen in 26 (74.3%) out of these 35 patients. Spikes or sharp waves were detected on the left side only (48.6%) or on both sides (25.7%), but none of the patients showed spikes or sharp waves on right side only. In six patients the EEG had normalized within three months of presentation, in ten within six months, and in twelve by one year. The EEG remained abnormal in eleven out of the 23 patients one year after presentation., Conclusion: In this largest consecutive EEG study at one center, the proportion of patients with TGA in whom epileptiform discharges were demonstrated within days of the episode of TGA was significantly higher than in the previous literature. EEG abnormalities such as spikes or sharp waves spontaneously disappeared in almost half of cases over one-year of follow-up. There was a clear left dominance of EEG abnormalities in patients with TGA., (Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Transient epileptic amnesia is a seizure disorder, usually with onset in the middle-elderly and good response to low dosages of antiepileptic drugs. We describe the clinical, electroencephalography (EEG), and neuroimaging features of 11 patients with a temporal lobe epilepsy characterized by amnesic seizures as the sole or the main symptom. We outline the relevance of a detailed clinical history to recognize amnesic seizures and to avoid the more frequent misdiagnoses. Moreover, the response to monotherapy was usually good, although the epileptic disorder was symptomatic of acquired lesions in the majority of patients.

Objective: Transient global amnesia (TGA), an abrupt occurrence of severe anterograde episodic amnesia accompanied by repetitive questioning, has been known for more than 50 years. Despite extensive research, there is no clear evidence for the underlying pathophysiological basis of TGA. Moreover, there is no neuroimaging method to evaluate TGA in real time., Methods: Here we used resting-state functional magnetic resonance imaging recorded in 12 patients during the acute phase of TGA together with connectivity and cluster analyses to detect changes in the episodic memory network in TGA., Results: Our results show a significant reduction in functional connectivity of the episodic memory network during TGA, which is more pronounced in the hyperacute phase than in the postacute phase. This disturbance is bilateral, and reversible after recovery. Although the hippocampus and its connections are significantly impaired, other parts of the episodic memory network are also impaired. Similar results were obtained for the analysis of the episodic memory network whether it was defined in a data-driven or literature-based manner., Interpretation: These results suggest that TGA is related to a functional disturbance in the episodic memory network, and supply a neuroimaging correlate of TGA during the acute phase., (© 2014 American Neurological Association.)

Transient global amnesia (TGA) is a sudden and severe anterograde memory disturbance accompanied by various degrees of retrograde amnesia and sometimes executive dysfunction. TGA affects elderly individuals and men and women equally. During the episode, patients cannot recall novel episodic information and therefore repeatedly ask the same questions. They are not fully oriented to space and time. Diagnostic criteria first established in 1985, and elaborated in 1990, demand that there is no clouding of consciousness, other impairments of cognition, or a history of epilepsy or head trauma. An episode of TGA resolves within 24 h leaving a memory gap for the length of the attack. While in rare cases TGA might happen repeatedly, it mostly occurs as a single attack. TGA is considered a benign disorder as memory deficits resolve completely and do not lead to long-term sequelae. In up to 90% of reported TGA cases, a precipitating event - mainly described as physical or emotional stress - is present. The cause of TGA has been a matter of long-standing debate among researchers. In search of an answer, several possible causes (ischemia, migraine, epileptic seizures, or, more recently, a disturbance of venous hemodynamics) have been hypothesized. However, to date there is no scientific proof of any of these mechanisms. By using diffusion-weighted MRI 24-48 h after a TGA episode, small dot-like lesions have been detected in the hippocampus. This has led to the implication that the selective vulnerability of CA1 neurons to metabolic stress might play a role in the pathophysiology of TGA., (© 2014 S. Karger AG, Basel)

Background: The pathophysiology of transient global amnesia (TGA) is not fully understood. This study was conducted to identify the cardiovascular risk factors of TGA compared to those of transient ischemic attack (TIA) and normal controls, using a large number of subjects. In addition to the comparison of risk factors, an association between the observed cardiovascular risk factors in the current study and a pathophysiological mechanism recently investigated was speculated upon., Materials and Methods: We performed a retrospective case-control study that compared 293 TGA patients to 632 TIA patients and 293 age- and sex-matched normal controls. Demographic details and cardiovascular risk factors were carefully recorded., Results: TGA patients had a significantly higher prevalence of ischemic heart disease and hyperlipidemia; however, they had a lower prevalence of hypertension, diabetes mellitus, ischemic stroke and atrial fibrillation when compared to TIA patients. When compared to age- and sex-matched normal controls, TGA patients also had a significantly higher prevalence of hyperlipidemia, previous ischemic stroke and ischemic heart disease., Conclusion: The cardiovascular risk factors identified in TGA patients in this study were different from those of previously reported studies. This disproportionate prevalence of cardiovascular risk factors may constitute possible evidence that TGA and TIA differ in their pathophysiological mechanism. In addition, some cardiovascular risk factors, such as hyperlipidemia and ischemic heart disease, should be regarded as possible risk factors of TGA.

Study Objective: Transient global amnesia (TGA) is a temporary memory loss characterized by an abrupt onset of antero-grade and retrograde amnesia, totally reversible. Since sleep plays a major role in memory consolidation, and in the storage of memory-related traces into the brain cortex, the aims of the present study were: (1) to evaluate changes in sleep macro-structure in TGA; (2) to assess modifications in sleep micro-structure in TGA, with particular reference to the arousal EEG and to cyclic alternating pattern (CAP); (3) to compare sleep parameters in TGA patients with a control group of patients with acute ischemic events ("minor stroke" or transient ischemic attack [TIA]) clinically and neuroradiologically "similar" to the TGA., Methods: TGA GROUP: 17 patients, (8 men and 9 women, 60.2 ± 12.5 years). Stroke or TIA (SoT) group: 17 patients hospitalized in the Stroke Unit for recent onset of minor stroke or TIA with hemispheric localization; healthy controls (HC) group: 17 healthy volunteers, matched for age and sex. Patients and controls underwent full-night polysomnography., Results: In the multivariate analysis (conditions TGA, SoT, and HC) a significant effect of the condition was observed for sleep efficiency index, number of awakenings longer 1 min, REM latency, CAP time, and CAP rate. TGA and SoT differed only for CAP time and CAP rate, which were lower in the TGA group., Conclusions: Microstructural modification associated with tga could be consequent to: (1) hippocampal dysfunction and memory impairment; (2) impairment of arousal-related structures (in particular, cholinergic pathways); (3) emotional distress.

Background: Migraine with aura is associated with patent foramen ovale and right-left-shunt. Jugular venous valve insufficiency is a further vascular anomaly. It is a frequent finding in transient global amnesia which is associated with migraine. Therefore, we investigated the prevalence of jugular venous valve insufficiency in migraine., Methods: Subjects included in this study were participants of the population based German Headache Study on the prevalence of primary headaches. In 36 patients with migraine with aura, 50 patients with migraine without aura and 43 controls without headaches duration of backward venous flow, peak velocity flow and diameters of the jugular venous valves were assessed by color-coded duplex and Doppler sonography and compared between groups. In all migraine patients, examination was performed between and not during migraine attacks. Therefore, 9 additional patients with chronic daily headache were investigated during headache., Results: We did not find statistically significant differences in duration of flow, peak velocity flow and diameter of the jugular venous valves in patients with migraine with aura (mean values 0.53 ± 0.43 sec; 35.47 ± 33.87 cm/sec; 8.84 ± 3.17 mm), migraine without aura (0.61 ± 0.63 sec; 33.39 ± 25.80 cm/sec; 8.15 ± 3.02 mm) or controls (0.64 ± 0.51 sec; 35.28 ± 31.76 cm/sec; 8.79 ± 2.97 mm) (group effects p-values >0.41). For all parameters results were the same for the left and the right side of jugular venae (side effects p-values >0.09). Also patients with chronic daily migraine with headache during the examination showed no differences to controls (0.52 ± 0.49 sec; 27.95 ± 21,75 cm/sec; 8.07 ± 2.71 mm) (all p-values > 0.23)., Conclusions: The prevalence of internal jugular venous valve insufficiency is not increased in persons with migraine.

Objective: The aim of this study is to evaluate changes in the latencies and amplitudes of event-related potential (ERP) components as well as cognitive habituation in patients with transient global amnesia (TGA) in order to further characterize the pathology of this syndrome., Methods: Clinical data of 43 consecutive patients with TGA was collected at a university neurology department. Follow-up examination was performed at an average of 17months after TGA. Results were compared to 43 age- and sex-matched healthy control subjects., Results: All ERP latencies of patients examined within 10days after the TGA period were significantly increased, and the P3 amplitude was significantly decreased as compared to healthy control subjects. The rate of pathological P3 latencies was significantly higher in TGA patients. A normal P3 latency habituation was detected in 84% of all healthy controls (mean habituation 10ms) and in 33% of all TGA patients (mean habituation -6ms). There was no significant improvement of all latencies and the other ERP parameters, including the loss of habituation, after a mean observation period of 17months. The data of three patients who were measured during the TGA period suggest a severe impairment of ERP during this period., Conclusions: Our findings give new insight into the pathology of TGA and put into question if TGA is an event of a simple transient character. In this first investigation of cognitive habituation in patients with TGA, we found a characteristic loss of cognitive habituation similar to observations in migraine., (Copyright © 2012 Elsevier B.V. All rights reserved.)

We report on a 66-year-old woman with segmental dystonia treated with chronic bilateral deep brain stimulation of the globus pallidus internus, in whom accidental high-voltage, high-frequency stimulation induced an episode of transient global amnesia (TGA) via an electrode contact which was misplaced in the right hippocampus. A possible mechanism underlying this TGA episode may have been the inhibition of local neuronal activity or fiber activation by high current density via direct electrical stimulation of hippocampal structures. While a unifying etiology of TGA has not been proven so far, our case demonstrates a possible link between focal electrical stimulation of hippocampal structures and the full clinical picture of the syndrome., (Copyright © 2013 S. Karger AG, Basel.)