Episode Of Transient Global Amnesia Research Articles

The Clinical Concurrence of Migraine and Transient Global Amnesia: Case Series of ‘Migramnesia’?

ABSTRACTComplaint of transient impairment or loss of memory as an attendant feature in some migraine attacks has long been recognised. In some cases, migraine may be a trigger or precipitating factor for the syndrome of transient global amnesia (TGA); however, the exact frequency of this concurrence is unknown. Here, the authors present three cases of TGA in the context of migraine headache, consider possible reasons why this concurrence might be under‐recognised, review possible shared pathogenetic mechanisms and suggest a new terminology—‘migramnesia’—which may encourage clinicians to address the possible significance of migraine in the context of an episode of TGA.

Retrospective analysis of cases of transient global amnesia admitted to the hospital

Introduction. Transient global amnesia (TGA) is a clinical syndrome, the main clinical manifestation of which is sudden development of anterograde and retrograde amnesia, lasting not more than 24 hours, without other general cerebral or focal neurological symptoms.The aim of the work was to reveal the peculiarities of clinical manifestations and data of additional methods of examination of patients with TGA syndrome referred to the primary vascular department with suspected acute cerebral circulation disorder (ACCD).Materials and methods. The study included 16 patients with transient global amnesia diagnosed according to the diagnostic criteria of Hodges and Warlow (1990). All patients underwent a detailed neurological and general medical examination. Electrocardiography, multispiral computer tomography of the head, echocardiography, ultrasound duplex scanning of the main arteries of the head and neck, laboratory examination (lipid spectrum) were performed. The Brief Mental Status Rating Scale was used to assess cognitive impairment.Results. The majority of patients had elevated blood pressure (BP). The leading trigger factor of transient global amnesia was stress. The duration of amnesia ranged from 1.5 to 5 hours. There was a significant impairment of short-term memory. On the first and second days of hospitalization, 50% of patients had normal cognitive functions on a brief mental status assessment scale, but by the 5th−7th day only 12.5 % of patients had abnormalities. Ultrasound markers of atherosclerosis in the form of intima-media complex thickening and dyslipidemia were found in 6 patients. Signs of left ventricular hypertrophy were found in the majority of patients. Discussion TGA is a relatively rare condition and an understudied syndrome. Due to its suddenness of clinical manifestation, TGA requires differential diagnostics with acute cerebral circulatory disorders, epilepsy, acute hypertensive encephalopathy and psychogenic amnesia.Conclusion. The clinical features of TGA identified in the patients were a history of arterial hypertension, elevated BP during an episode of TGA. The leading provoking factor was stress. TGA episode occurred predominantly in the first half of the day. The majority of patients had complaints of headache on admission. Cognitive disorders detected in patients on the first and second days of the disease quickly regressed to normal. Left ventricular hypertrophy was detected in most patients.

P26 TRANSIENT GLOBAL AMNESIA AS A POSSIBLE CONSEQUENCE OF ICA DISSECTION: A CASE REPORT

Abstract Case Report A 42–year–old woman was carried to emergency room lamenting sudden memory loss. Her husband witnessed the onset of the episode. No recent head trauma was reported, blood pressure was under control. Anterograde and retrograde memory loss was present and confirmed by a neurologist. No other neurological signs were elicitable. Blood exams and toxicological analysis were negative. ECG, chest radiography, and cerebral TC showed no abnormalities. At physical examination a carotid bruit could be appreciated. The patient was asymptomatic. Subsequently an eco–colour–Doppler of carotid artery was performed showing a left common and internal carotid artery dissection. The diagnosis of ICA dissection was confirmed with a contrast CT furthermore excluding the coexistence of an aortic dissection. The anterograde amnesia resolved 15 h after the admission. A neurologist confirmed that the patient experimented an episode of transient global amnesia. After a vascular surgery consultation, a conservative treatment was deemed appropriate. After a 6 month follow up the patient didn’t complain of any other neurological symptom or sign. Transient global amnesia (TGA) is characterized by reversible anterograde and retrograde amnesia of sudden onset that resolves spontaneously within 24 h. The pathophysiological mechanisms underlying this puzzling neurological syndrome are yet not completely clarified. Some studies support an ischemic aetiology for TGA and cases of TGA following ICA–stenting or aortic dissection with involvement of the supra–aortic branches are reported in literature, thus supporting the hypothesis that a cause–effect relationship between ischemic pathologies of supra–aortic trunks and TGA might be present. In the case here presented, a Doppler ultrasound of carotid arteries performed in a patient presenting with TGA, asymptomatic for neck pain, led to a diagnosis of ICA dissection. In order to not miss a spontaneous ICA dissection as a rare ethology of TGA, we suggesto perform an eco–colour–Doppler of the epi–aortic vessels in patients affected by such amnesic syndrome.

Transient global amnesia: A case summary

AimThe aim of this case study was to describe the cognitive profile of a gentleman who was assessed at an NHS Memory Service with a complex presentation of transient global amnesia, dementia worry and a preoccupation with his health.CaseA 63 year old intelligent gentleman was referred to the Memory Service following two episodes of transient global amnesia resulting in residual mild cognitive symptoms which resolved after six months. A clinical interview and neuropsychological assessment battery were conducted via video conferencing due to Covid-19 restrictions.ResultsThere was no clear pattern of objective cognitive impairments to indicate that Mr X was suffering from a neurodegenerative disease.ConclusionDiscussions were held regarding managing Mr X’s preoccupation with his health whilst following NICE guidelines of further investigating the potential causes for the episodes of transient global amnesia.ConsentMr X was provided with an information sheet detailing the purpose for his participation in this case study. He kindly provided informed written consent for the case study to be published within an academic journal. Some demographic details have been amended to protect his identity.

Clinical Course and Recurrence in Transient Global Amnesia: A Study From the TEMPiS Telestroke Network.

While the clinical hallmarks of transient global amnesia (TGA) are well defined, its pathophysiological causes are poorly understood. Specifically, risk factors for recurrences are yet to be determined. This retrospective study analyzed TGA cases diagnosed and treated within the TEMPiS telestroke network and a university stroke center in Germany. Demographic and clinical data were assessed and characteristics of TGA episodes were recorded, such as season of occurrence, trigger factors, duration, and concomitant symptoms. Follow-up of the potential recurrence of TGA was performed using a standardized questionnaire. Overall 109 patients were included (age 64±8 years [mean±SD], 59.6% female). The most common vascular risk factor was arterial hypertension (60.6%), and other concomitant conditions included migraine (11.9%), hypothyroidism (22.9%), and atrial fibrillation (4.6%). The most frequent concomitant clinical feature accompanying the TGA episode at admission was elevated blood pressure (48.6%). Nineteen patients experienced at least one recurrent TGA episode. Migraine and hypothyroidism were only observed in subjects with a single TGA episode without recurrence (migraine: 14.4% without recurrence vs. none in the recurrence group, p=0.02; hypothyroidism: 27.8% without recurrence vs. none in the recurrence group, p=0.009). In contrast, atrial fibrillation was more common in subjects with TGA recurrence (p<0.001). Arterial hypertension is prevalent in TGA patients, with elevated blood pressure being the most-frequent concomitant condition. In our cohort, recurrence of TGA occurred in approximately one-fifth of patients. Concomitant conditions such as migraine, hypothyroidism, and atrial fibrillation occurred at different frequencies in the two groups.

564 AN UNUSUAL PRESENTATION OF ICA DISSECTION. A CASE OF TRANSIENT GLOBAL AMNESIA IN A PATIENT WITH PAINLESS SPONTANEOUS INTERNAL CAROTID ARTERY DISSECTION

Abstract Image focus A 42-year-old woman was carried to emergency room lamenting sudden memory loss. Her husband witnessed the onset of the episode. No recent head trauma was reported, blood pressure was under control. Anterograde and retrograde memory loss was present and confirmed by a neurologist. No other neurological signs were elicitable. Blood exams and toxicological analysis were negative. ECG, chest radiography, and cerebral TC showed no abnormalities. At physical examination a carotid bruit could be appreciated. We performed an eco-color-Doppler of carotid artery that showed a left common and internal carotid artery dissection (figure 1). The diagnosis of ICA dissection was confirmed with a contrast CT. The coexistence of an aortic dissection was excluded with the same imaging technique. The anterograde amnesia resolved 15 h after the admission. A neurologist confirmed that the patient experimented an episode of transient global amnesia (TGA). After a vascular surgery consultation, a conservative treatment was deemed appropriate. After a 6 month follow up the patient didn't complain of any other neurological symptom or sign. Transient global amnesia (TGA) is characterized by reversible anterograde and retrograde amnesia of sudden onset. This amnesic syndrome resolves spontaneously within 24 h. Annual incidence rate for all ages of spontaneous ICA dissection is approximately of 2.6 per 100 000 inhabitants, however data are extremely variable among different studies. TGA has never been associated with a spontaneous ICA dissection. In order to not miss a spontaneous ICA dissection as a rare ethology of TGA, we suggest performing an eco-color-Doppler of the epi-aortic vessels in patient affected by such amnesic syndrome.

Transient global amnesia with transient anosmia: a curious case suggestive of middle cerebral artery occlusion

Transient global amnesia (TGA) is an enigmatic amnestic syndrome and affects people in middle or older age. During an episode of TGA, a person is not able to make new memories, which indicates hippocampal damage. The symptom anosmia may be associated with memory impairment. A 70-year-old woman presented to our emergency room with transient spatial memory loss. She also complained of a sudden loss of smell. Magnetic resonance angiography confirmed occlusion of the right middle cerebral artery. The mechanism causing the transient anosmia may have resulted in a transient loss of hippocampal function, resulting in amnesia. This rare case is consistent with recent research showing that olfaction has developed as a navigation system.

Chronobiology of transient global amnesia

IntroductionThe etiology of transient global amnesia (TGA) is still a matter of debate. Based, among others, on the observation of a close temporal relation between certain events and subsequent TGA episodes, recent proposals discuss the relevance of stress-associated processes impacting on hippocampal functioning. Circadian, infra- and ultradian rhythmicity has been found to play a relevant role in the multifactorial pathomechanisms of various disorders but has not been thoroughly studied in TGA.MethodsData of patients with a final diagnosis of TGA were collected in Mannheim, Germany (06/1999–01/2018, n = 404), and in the Kansai district, Japan (04/2006–03/2018, n = 261). Chronological patterns of TGA occurrence were determined.ResultsSignificant circadian rhythmicity of TGA occurrence with bimodal peaks (mid-morning, late afternoon) was found for the entire population (p = 0.002) and for either sub-cohort (Mannheim: p = 0.003, Kansai: p = 0.007). This finding was confirmed for either sex (women: p = 0.004, men: p = 0.004) and different age groups (< 65 years: p = 0.0009, ≥ 65 years: p = 0.003). There was no variation according to day of the week, month or season, but the proportion of patients with a weekday episode was significantly higher in the Mannheim cohort (p = 0.002).DiscussionWe identified a robust circadian rhythm in TGA occurrence which remarkably applied to either of the two study sites located on different continents and which was independent of sex and age. In light of abundant evidence of circadian rhythmicity of both, components of the human stress response system and memory, chronobiological analyses may provide an opportunity to further uncover the mechanisms underlying TGA.

Sex-related differences in stressful events precipitating transient global amnesia – A retrospective observational study

IntroductionPhysically or emotionally charged events have consistently been reported as precipitating an episode of transient global amnesia (TGA). In conjunction with evidence of hippocampal involvement from neuroimaging, this has promoted the hypothesis that TGA is a stress-related disorder. MethodsIn this retrospective observational study, medical records of 389 patients with TGA were analysed regarding documented precipitating events, which were classified according to previously suggested criteria. Moreover, comorbidities and results of magnetic resonance imaging were collected. FindingsIn our cohort of TGA patients, 231 were female (59.4%). A precipitating factor was identified in 266 patients (68.4%). Of these, 136 patients (51.1%) reported physical triggers, the most common being physical exertion (64.0%). Another 122 patients (45.9%) presented with an emotional trigger, most frequently classified as an interpersonal conflict (42.7%). In 8 cases (2.1%), TGA was preceded by a medical procedure. Emotional triggers were more often experienced by women (37.2% vs 22.8%, p = 0.003), while physical stressors were more often present in men (30.7% vs 41.1%, p = 0.035). Women had a significantly higher number of hippocampal MRI lesions than men (mean 1.13 vs 0.92; p = 0.042). ConclusionOur data suggest a female predominance in TGA occurrence and a sex-related difference in susceptibility to certain triggering events in TGA patients. In light of recent research on sex-specific differences in vulnerability to stress, these findings support the hypothesis that this might be a significant contributing factor in the pathogenesis of TGA.

The syndrome of transient epileptic amnesia: a combined series of 115 cases and literature review.

The term transient epileptic amnesia was coined in 1990 to describe a form of epilepsy causing predominantly amnestic seizures which could be confused with episodes of Transient Global Amnesia. Subsequent descriptions have highlighted its association with ‘atypical’ forms of memory disturbance including accelerated long-term forgetting, disproportionate autobiographical amnesia and topographical amnesia. However, this highly treatment-responsive condition remains under-recognized and undertreated. We describe the clinical and neuropsychological features in 65 consecutive cases of transient epileptic amnesia referred to our study, comparing these to our previous cohort of 50 patients and to those reported in 102 literature cases described since our 2008 review. Findings in our two cohorts are substantially consistent: The onset of transient epileptic amnesia occurs at an average age of 62 years, giving rise to amnestic episodes at a frequency of around 1/month, typically lasting 15–30 min and often occurring on waking. Amnesia is the only manifestation of epilepsy in 24% of patients; olfactory hallucinations occur in 43%, motor automatisms in 41%, brief unresponsiveness in 39%. The majority of patients describe at least one of the atypical forms of memory disturbance mentioned above; easily provoked tearfulness is a common accompanying feature. There is a male predominance (85:30). Epileptiform changes were present in 35% of cases, while suspected causative magnetic resonance imaging abnormalities were detected in only 5%. Seizures ceased with anticonvulsant treatment in 93% of cases. Some clinical features were detected more commonly in the second series than the first, probably as a result of heightened awareness. Neuropsychological testing and comparison to two age and IQ-matched control groups (n = 24 and 22) revealed consistent findings across the two cohorts, namely elevated mean IQ, preserved executive function, mild impairment at the group level on standard measures of memory, with additional evidence for accelerated long-term forgetting and autobiographical amnesia, particularly affecting episodic recollection. Review of the literature cases revealed broadly consistent features except that topographical amnesia, olfactory hallucinations and emotionality have been reported rarely to date by other researchers. We conclude that transient epileptic amnesia is a distinctive syndrome of late-onset limbic epilepsy of unknown cause, typically occurring in late middle age. It is an important, treatable cause of memory loss in older people, often mistaken for dementia, cerebrovascular disease and functional amnesia. Its aetiology, the monthly occurrence of seizures in some patients and the mechanisms and interrelationships of the interictal features—amnestic and affective—all warrant further study.

A case report of a patient with mild cognitive impairment preceded by transient global amnesia with hypometabolism on FDG‐PET

AbstractBackgroundThis is the case of a 61‐year‐old Filipino female who presented with two episodes of transient global amnesia at the ages of 56 and 57.MethodThe patient underwent serial cranial MRI, cranial FDG‐PET/CT scan, and cognitive assessments over a period of five years.ResultCranial MRI at the time of the first episode in 2014 showed foci of restricted diffusion abnormality in the left hippocampus. Baseline cognitive assessment was negative for any impairment. On recurrence of TGA in 2015, brain FDG‐PET/CT scan was done which showed mild hypometabolism in the temporal and parietal cortices and hypometabolism in the posterior cingulate cortex. A second comprehensive cognitive assessment was negative for any impairment. Three years after the first episode (2017), she developed subtle changes in memory and thinking and had mild impairment in categorical fluency on neuropsychologic examination. Follow‐up cranial MRI (2017) showed slight decrease in hippocampal volumetry from the 43rd percentile to the 41st normative percentile. Follow‐up cranial FDG‐PET (2019) showed small mildly hypometabolic areas in the frontal, parietal and temporal lobes. The clinical assessment for the patient at this time is very mild cognitive impairment, non‐amnestic, probably secondary to a neurodegenerative process.ConclusionThis case study shows that transient global amnesia can recur and it may be a risk for cognitive impairment. It also illustrates that existing brain pathology related to a neurodegenerative process can be evident on neuroimaging despite very subtle clinical and neuropsychological cognitive changes. These findings also support aggressive preventive measures of delaying cognitive impairment.

Risk factors predicting recurrence of transient global amnesia.

To assess risk factors of transient global amnesia (TGA) recurrence. Retrospective study of a case series of patients with the diagnosis of TGA in our neurology center in the last 8years, identified through an anonymized database search. TGA was identified by applying Hodges and Warlow criteria. Seventy patients (70% female, average age 64.8 ± 7.8years) were enrolled; mean follow-up was 16.5months. More frequent co-morbidities were hypertension (50%), depression (25.7%), diabetes mellitus (17.1%), migraine (15.7%), and cerebrovascular disease (8.6%). Average TGA episode duration was 4h. Forty-one percent had an identifiable trigger-emotional stress (25.7%), physical effort (8.6%), and sexual intercourse (4.3%). Five patients (7.1%) had hippocampus restriction on diffusion weighted MRI. Nineteen patients (27.1%) had TGA recurrence. Patients with recurrent TGA were more likely to be female and have history of depression, shorter duration episode, and hippocampus hyperintensity on brain MRI. None of the other clinical characteristics and complementary studies were predictors of recurrence. In the multivariate analysis, history of depression was the only factor found to predict which patients had a higher risk of recurrence. We present a cohort of TGA patients with a considerable recurrent rate (27%), alerting for the possibility of recurrence of this clinical entity. TGA recurrence was associated with the following factors: female sex, depression, shorter episode duration, and hippocampal hyperintensity on brain MRI. History of depression was found to be the most important recurrence predictor in our study.

Factors Associated With Risk of Recurrent Transient Global Amnesia

Transient global amnesia (TGA) is usually considered a benign event with a low recurrence rate. However, recurrence rates vary considerably among studies and there are no known risk factors for TGA. To examine risk factors for the recurrence of TGA. This retrospective cohort study involved medical record review of patients with isolated or recurrent TGA presenting to the Mayo Clinic in Rochester, Minnesota, between August 1, 1992, and February 28, 2018. A total of 1491 cases were reviewed and 1044 met diagnostic inclusion criteria for TGA, with the remainder excluded owing to indeterminate or alternate diagnoses or limited information available in the medical record. Single vs recurrent episodes of TGA. Demographics, precipitating factors, migraine history, imaging and electrodiagnostic findings, and family history of TGA were collected. The main outcome measure was TGA recurrence. Of 1044 included patients, 575 (55.1%) were male, and the mean (SD) age at inclusion was 75.0 (11.5) years. A total of 901 patients (86.3%) had a single episode of TGA and 143 (13.7%) had recurrent episodes of TGA. The 2 groups were similar in age at inclusion, sex, identifiable triggers, and duration of anterograde amnesia. The number of recurrences ranged from 1 to 9, with 137 individuals (95.8%) having 3 or fewer recurrences. The mean (SD) age at first episode of TGA was 65.2 (10.0) years for individuals with a single episode vs 58.8 (10.3) years for those with recurrent episodes (P < .001). There was a personal history of migraine in 180 individuals (20.0%) with a single episode of TGA and 52 individuals (36.4%) with recurrent episodes of TGA (P < .001), and a family history of migraine in 167 individuals (18.5%) with a single episode of TGA and 44 individuals (30.8%) with recurrent episodes of TGA (P = .001). There were no electroencephalographic findings associated with increased risk of TGA recurrence. Acute and subacute temporal lobe abnormalities on results of magnetic resonance imaging were seen rarely and did not require intervention. A family history of TGA was identified in 12 individuals (1.3%) with a single episode of TGA and 4 individuals (2.8%) with recurrent episodes of TGA. This study suggests that, in this large cohort of patients with TGA, recurrent TGA was associated with earlier age at the time of first TGA episode and higher prevalence of both personal and family history of migraine compared with isolated cases. These results can be used to counsel patients about risks of recurrence and may have implications for the understanding of TGA pathophysiology.

Serum cortisol levels in patients with a transient global amnesia

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.

Transient Global Amnesia - Risk Factors and Putative Background.

Transient global amnesia (TGA) is a temporary short-term reversible memory loss. Etiology of TGA remains unclear with various hypotheses. We analyzed clinical characteristics, neuroimaging, and electrophysiological findings as well as comorbidities and seasonal variation in TGA patients with regard to possible background of the syndrome. A total of 56 patients (42 women and 14 men) with TGA hospitalized from 2008 to 2016 in the Department of Neurology, Wrocław Medical University. A total of 52 patients (92.9%) underwent their first-ever episode of TGA. The potential triggers or events before episode could be recognized in 22 patients (39.3%). 35.7% patients had TGA in summer and 26.8% in winter months. In 92.9% patients chronic diseases were found, included: Hypertension (60.7%), dyslipidemia (48.2%), autoimmune thyroiditis (17.9%), and ischemic heart disease (14.3%). One patient (1,8%) suffered from migraine. Doppler ultrasonography of carotid arteries revealed abnormalities in 29 patients (51.8%). Electroencephalography abnormalities were observed in 10 (17.6%) of patients. Our findings suggest a putative cerebrovascular background of transient global amnesia. No evidence has been provided for the association between TGA and epilepsy or migraine. Among comorbidities, autoimmune thyroiditis deserves further investigation with regard to its potential links with TGA.

105 A presentation resembling transient global amnesia with underlying tako-tsubo cardiomyopathy and multifocal ischaemic stroke (with restricted diffusion in the left mesiotemporal lobe)

IntroductionWe present a case of a 65 year-old female with a presentation resembling transient global amnesia (TGA) with investigations revealing a Tako-tsubo cardiomoyopathy and multifocal punctate areas of restricted diffusion consistent with ischaemic stroke.MethodsSingle case report.ResultsA 65 year-old female presented altered behaviour with anterograde amnesia consistent with an episode of TGA. There was no clearly identifiable stressor to provoke this episode. The TGA-like symptoms persistent for 12 hours before the patient made a full recovery.During the presentation the patient complained of chest pain with elevated troponin. Cardiac investigation was notable for mild left ventricular dilation with mid- and apical hypokinesis on transthoracic echocardiogram and a normal coronary angiogram consistent with Tako-tsubo cardiomyopathy. Magnetic resonance imaging of the brain revealed multifocal infarcts including punctate foci of restricted diffusion within the left mesiotemporal lobe.ConclusionThis case is notable as it is rare to have a combined presentation with TGA-type symptoms with Tako-tsubo cardiomyopathy and multifocal ischaemia stroke.1 This is the first clinical case presentation involving the aforementioned triad and mesiotemporal lobe restricted diffusion. We hypothesise that the Tako-tsubo cardiomyopathy acted as the triggering event and the mesiotemporal lobe involvement caused the TGA-like symptoms thereby accounting for the clinical presentation and investigation findings. As mesiotemporal/hippocampal restricted diffusion may be seen with transient global amnesia,2 this case is of special interest mechanistically although we cannot exclude the alternative hypothesis that the episode of TGA resulted in the Tako-tsubo cardiomyopathy which subsequently caused the cardioembolic shower.ReferencesStollberger C, DeCillia N, Finsterer J. ‘Tako-tsubo cardiomyopathy with transient global amnesia and cerebellar embolic stroke triggered by existential fear.’Neurol Neurochir Pol 2018; 52(3):394–396.Enzinger C, Thimary F, Kapeller P, Ropele S, Schmidt R, Ebner F, Fazekas F. ‘Transient global amnesia: diffusion-weighted imaging lesions and cerebrovascular disease.’Stroke 2008;39(8):2219–2225.

Impaired Smooth Pursuit During Transient Global Amnesia.

Background and PurposeDuring transient global amnesia (TGA), selective impairment of episodic memory is assumed to occur due to alteration in the neuronal network between the hippocampus and parietooccipital cortices that also include a hub for smooth pursuit (SP) eye movements. This study aimed to determine whether SP is impaired during TGA, and to identify any anatomical and functional linkage present between the oculomotor and memory systems.MethodsWithin a median of 1.0 day of TGA, horizontal SP was evaluated in 145 patients with a target moving at peak velocities of 10°/s and 20°/s. The average SP gains of patients were compared with those of the age-matched controls.ResultsThe patients with TGA showed lower SP gains in both directions for both peak target velocities. While the normal controls showed symmetric SP in the rightward and leftward directions, in the TGA patients the SP gain was lower during rightward than leftward SP regardless of bilaterality or the side of the lesions.ConclusionsThe cortical regions processing information about visual motion appeared to be affected during or soon after an amnestic episode of TGA, and more so in the right hemisphere. This means that disturbed processing of dynamic visual information may be related to the impaired spatial orientation observed during TGA.

Resting-state connectivity alterations during transient global amnesia.

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

Enhanced cortisol secretion in acute transient global amnesia

IntroductionStress-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. MethodsWe 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. FindingsNine 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). ConclusionOur 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.

Subarachnoid hemorrhage after transient global amnesia caused by cerebral venous congestion: case report

BackgroundTransient global amnesia is reported to be caused by cerebral venous congestion. Internal jugular venous flow reversal in particular with the Valsalva maneuver leads to cerebral venous congestion. In addition, Valsalva maneuver can also induce subarachnoid hemorrhage. Transient global amnesia and subarachnoid hemorrhage might have common a pathophysiology in cerebral venous congestion.Case presentationWe report here the case of a 57-year-old woman who twice experienced convexal subarachnoid hemorrhage just after straining at stool following an episode of transient global amnesia. Digital subtraction angiography showed left temporal congestion. Left jugular vein ultrasonography revealed reflux with the Valsalva maneuver only in acute phase, indicating transient cerebral venous congestion.ConclusionsSubarachnoid hemorrhage followed by transient global amnesia indicates a common factor between them. Transient venous congestion is discussed in order to explain this rare phenomenon.