A case report on concomitant reversible cerebral vasoconstriction syndrome and transient global amnesia.

Reversible Cerebral Vasoconstriction Syndrome clinically presents as severe headaches with or without neurological deficits accompanied by multilocal caliber variation of the cerebral arteries on imaging studies. Transient Global Amnesia is a benign neurological condition that implies sudden temporary antero- and retrograde amnesia. The exact pathophysiological mechanisms involved in transient global amnesia and reversible cerebral vasoconstriction syndrome remain unclear but suggest similar pathways as both can be triggered by factors that activate the sympathetic nervous system. We herein discuss a potential relationship of the two conditions in a 65-year-old woman that initially presented herself to the emergency department with temporary memory impairment, indicating Transient Global Amnesia. Four days later, the patient revealed a thunderclap headache accompanied by a subarachnoid hemorrhage with transient segmental narrowing of the arteries of the anterior circulation on neuroimaging. In this case report we hypothesize that Reversible Cerebral Vasoconstriction Syndrome might be a potential cause for the clinical symptoms and imaging patterns with Transient Global Amnesia as a possible prodromal stage of Reversible Cerebral Vasoconstriction Syndrome.

Case of transient global amnesia-like syndrome after recreational cold-water swimming.

We document a case of a transient global amnesia (TGA)-like syndrome following open water swimming. This case was atypical for TGA, in that symptoms were prolonged and ischaemic infarct was considered within the differential. MRI did not demonstrate any changes associated with acute ischaemia although did show a mild degree of small vessel change. With amnesia taking greater than 24 hours to resolve, we have labelled this case to be a TGA-like syndrome, provoked by the commonly reported TGA precipitant of cold water immersion. The possibility of a tiny, strategic infarct causing these symptoms was considered and antiplatelet therapy commenced.

Incidence and Risk Factors of Transient Global Amnesia.

INTRODUCTION: Transient global amnesia (TGA) is a spontaneously resolving, anterograde amnesia that lasts mostly <24 h and often occurs with retrograde amnesia. The etiology of TGA remains unclear, although in recent decades, many risk factors and preceding events have been identified. There are few up-to-date reports on the TGA incidence in Northern Europe. In this study, we report the incidence and risk factors associated with TGA in Finland. MATERIALS AND METHODS: The study included all patients with suspected TGA that were referred to Kuopio University Hospital (KUH) in 2017. The hospital catchment area included 246,653 individuals. Risk factors and demographic data were collected from medical records. The TGA incidence rates were calculated as the number of patients with TGA divided by the number of individuals at risk in different age groups. RESULTS: In 2017, 56 patients were treated for TGA at KUH. Of these, 46 had a first-ever TGA. The most common event preceding TGA was physical effort (n = 28, 50%), followed by emotional stress (n = 11, 19.6%) and water contact or a temperature change (n = 11, 19.6%). The most common comorbidities were hypercholesterolemia (n = 22, 39.3%), hypertensive disease (n = 21, 37.5%), hypothyroidism (n = 11, 19.6%), coronary artery disease (n = 8, 14.3%), and migraine (n = 7, 12.5%). TGA occurred most often in December (n = 9, 16.0%), March (n = 8, 14.3%), or October (n = 8, 14.3%), and least often in November and May (n = 2, 3.6% in both months). The crude incidence of a first TGA in Eastern Finland was 18.6/100,000 inhabitants, and when standardized to the European population in 2010, it was 14.3/100,000 inhabitants. Therefore, the TGA incidence was higher than previously reported in European countries. DISCUSSION: The most common precipitating factors for TGA were physical effort, emotional stress, and water contact/temperature change. The incidence of TGA was high in the Eastern Finnish population.

Global Transient Amnesia as the Predominant Symptom of Cardiac Myxoma: A Case Report.

BACKGROUND The most common neurological symptoms from cardiac myxoma-induced stroke include territories of middle cerebral arteries, rendering posterior stroke less common. Although transient global amnesia usually has a benign prognosis, amnesia in the setting of concerning cerebellar symptoms should raise the suspicion for posterior circulation involvement. These benign-appearing symptoms can be manifestations of an acute cerebrovascular accident (CVA). This unusual presentation can delay workup for underlying pathology. CASE REPORT A 67-year-old woman presented to the local emergency department after an episode of global amnesia that lasted about 15 minutes and was associated with some dizziness. The patient also reported a history of chronic disequilibrium. The head CT scan was negative for any acute findings. A follow-up MRI of the brain demonstrated acute small lacunar infarcts within the left cerebellum and right parietal lobe. An echocardiogram was performed due to concern for the cardioembolic source, which revealed left atrial myxoma. She was transferred to a tertiary center for immediate surgical intervention due to the high risk of embolization associated with the condition. The patient subsequently underwent successful surgical excision of the lesion. CONCLUSIONS Cardiac myxoma, although a rare cause of posterior stroke, needs prompt intervention as it is associated with a high risk of systemic embolization, including recurrent CVA. Transient global amnesia is an atypical presentation of cardiac myxoma that can easily be overlooked, delaying timely diagnosis and prompt intervention. Early recognition and surgical resection are crucial to prevent potentially life-threatening consequences.

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

BACKGROUND: 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. CASE PRESENTATION: 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. DISCUSSION AND CONCLUSION: 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.

Acute-onset amnesia: transient global amnesia and other causes.

Acute-onset amnesia is a dramatic neurological presentation that can cause considerable concern to both patient and clinician. The patient typically presents with an inability not only to retain new memories but also to access previously acquired memories, suggesting disturbance of hippocampal function. Transient global amnesia (TGA) is the most common cause of acute-onset amnesia, and is characterised by a profound anterograde and retrograde amnesia that typically lasts for up to 24 hours. Although TGA has a strikingly stereotypical presentation, it can be challenging to distinguish from other causes of acute-onset amnesia, including posterior circulation strokes, transient epileptic amnesia, psychogenic amnesia, post-traumatic amnesia, and toxic/drug-related amnesia. Here, we describe the general approach to the patient with acute amnesia; summarise the clinical and neuropsychological differences between the potential causes; and, provide practical recommendations to aid diagnosis and management of acute amnesia. Regardless of cause and the dramatic presentation, non-ischaemic acute-onset amnesia generally has a favourable prognosis.

Impaired semantic memory during acute transient global amnesia.

As a clinical model of hippocampal dysfunction, transient global amnesia (TGA) causes reversible memory disturbance. While episodic memory deficits in TGA patients have been extensively described, data regarding semantic memory involvement are sparse and contradictory. We report impaired semantic fluency performance in 16 patients with hippocampal lesions on MRI during acute TGA compared to their performance one day later and to that of 20 healthy subjects. Our findings support the involvement of the hippocampus in semantic retrieval.

The long-term risk of epilepsy after transient global amnesia: A population-based cohort study.

OBJECTIVE: Transient global amnesia (TGA) is characterized by sudden onset of larger anterograde and milder retrograde amnesia lasting up to 24 h. We aimed to investigate the long-term risk of epilepsy up to 8 years in subjects after TGA in the population-based cohort study. PATIENTS AND METHODS: We conducted a control cohort study with an 8-year follow-up period. All data was collected retrospectively. From all potential participants more than 18 years of age without epilepsy and TGA history, we identified TGA subjects and non-TGA controls with age, gender and comorbidities matched in a 1:3 ratio. The yearly incidence of epilepsy was compared in TGA and non-TGA cohorts. The cumulative hazard ratio of epilepsy was estimated. The risk factors of epilepsy after TGA were investigated. RESULTS: A total of 185 TGA subjects and 555 non-TGA controls were included in the study. There were 7 epilepsy cases in the 185 TGA cohorts during the follow-up period with yearly incidence rates of 9.629 per 1000 person. The adjusted hazard ratio for epilepsy in TGA cohorts was 6.50 (95 % confidence interval 1.87-22.68, p = 0.003) compared with non-TGA cohorts after adjusting for age, gender and comorbidities. No notable factor was significantly associated with epilepsy after TGA. CONCLUSION: Our study highlighted TGA is associated with increased long-term risk of epilepsy.

The Long-Term Risk of Dementia after Transient Global Amnesia: A Population-Based Cohort Study in Taiwan.

BACKGROUND: Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of larger anterograde and milder retrograde amnesia that lasts up to 24 h. OBJECTIVES: We aimed to investigate the long-term risk of dementia up to 8 years in subjects with TGA. METHOD: We conducted a control cohort study using the Taiwan National Health Insurance Research database from 2005 to 2012 with an 8-year follow-up period. From all potential participants >18 years of age without dementia history, we identified TGA subjects and non-TGA controls with age, gender and comorbidities matched in a 1:3 ratio. The yearly incidence of dementia was compared in TGA and non-TGA cohorts. The cumulative hazard ratio (HR) of dementia was estimated. The risk factors of dementia after TGA were investigated. RESULTS: A total of 181 TGA subjects and 543 non-TGA controls were included in the study. There were 14 dementia cases in the 181 TGA cohorts during the follow-up period with yearly incidence rates of 20.14 per 1,000 person. The adjusted HR for dementia in TGA cohorts was 2.23 (95% CI 1.12-4.44, p = 0.023) compared with non-TGA cohorts after adjusting for age, gender and comorbidities. Age and diabetes were significantly associated with dementia in TGA. CONCLUSIONS: TGA increased the long-term risk of dementia. Age and diabetes were notable factors associated with dementia after TGA.

Long-Term Risk of Stroke After Transient Global Amnesia in Two Prospective Cohorts.

Background and Purpose- Transient global amnesia (TGA) is known as a benign syndrome, but recent data from neuroradiological studies support an ischemic cause in some cases, which might suggest an increased susceptibility to cerebrovascular events. We determined the long-term risk of stroke after a first TGA in 2 independent prospective cohorts. Methods- In 2 independent prospective cohorts of patients with TGA (OXVASC [Oxford Vascular Study], population-based; NU (Northern Umbria) cohort, TGA registry), cardiovascular risk factors and long-term outcomes, including stroke and major cardiovascular events, were identified on follow-up. Cardiovascular risk factors were treated according to primary prevention guidelines. In OXVASC, the age-/sex-adjusted risk of stroke during follow-up was compared with that expected from the rate in the underlying study population. Results- Among 525 patients with TGA (425 NU and 100 OXVASC), mean (SD) age was 65.1 (9.5) years and 42.5% male. Hypertension (58.1%), dyslipidemia (40.4%), and smoking (36.4%) were the most frequent cardiovascular risk factors. The risk of stroke was similar in the 2 cohorts, with a pooled annual risk of 0.6% (95% CI, 0.4-0.9) and a 5-year cumulative risk of 2.7% (1.1-4.3). Moreover, the stroke risk in OXVASC cases was no greater than that expected in the underlying study population (adjusted relative risk=0.73; 0.12-4.54; P=0.74). Conclusions- TGA does not carry an increased risk of stroke, at least when cardiovascular risk factors are treated according to primary prevention guidelines.

Myocardial injury in transient global amnesia: a case-control study.

BACKGROUND AND PURPOSE: Elevation of cardiac troponin (cTn), a sensitive biomarker of myocardial injury, is frequently observed in severe acute neurological disorders. Case reports suggest that cardiac dysfunction may also occur in patients with transient global amnesia (TGA). Until now, no study has systematically assessed this phenomenon. METHODS: We performed a case-control study using data of consecutive patients presenting with TGA from 2010 to 2015. Multiple logistic regression analysis accounting for age, sex and cardiovascular risk factors was performed to compare the likelihood of myocardial injury [defined as elevation of cTn > 99th percentile (≥14 ng/L); highly sensitive cardiac troponin T assay] in TGA with three reference groups: migraine with aura, vestibular neuritis and transient ischaemic attack (TIA). RESULTS: Cardiac troponin elevation occurred in 28 (25%) of 113 patients with TGA. Patients with TGA with cTn elevation were significantly older, more likely to be female and had higher blood pressure on admission compared with those without. The likelihood of myocardial injury following TGA was at least more than twofold higher compared with all three reference groups [adjusted odds ratio, 5.5; 95% confidence interval (CI), 1.2-26.4, compared with migraine with aura; adjusted odds ratio, 2.2; 95% CI, 1.2-4.4, compared with vestibular neuritis; adjusted odds ratio, 2.3; 95% CI, 1.3-4.2, compared with TIA]. CONCLUSIONS: One out of four patients with TGA had evidence of myocardial injury as assessed by highly sensitive cTn assays. The likelihood of myocardial injury associated with TGA was even higher than in TIA patients with a more pronounced cardiovascular risk profile. Our findings suggest the presence of a TGA-related disturbance of brain-heart interaction that deserves further investigation.

Prolonged allocentric navigation deficits indicate hippocampal damage in TGA.

OBJECTIVE: To investigate long-term recovery of allocentric and egocentric spatial orientation as a sensitive marker for hippocampal and extrahippocampal network function in transient global amnesia (TGA). METHODS: A group of 18 patients with TGA performed an established real-space navigation paradigm, requiring allo- and egocentric spatial orientation abilities, 3 days (postacute stage) and 3 months (follow-up) after symptom onset. Visual exploration behavior and navigation strategy were documented by a gaze-controlled, head-fixed camera. Allo- and egocentric spatial orientation performance was compared to that of 12 age-matched healthy controls. Navigation-induced brain activations were measured using [18F]-fluorodeoxyglucose-PET in a subgroup of 8 patients in the postacute stage and compared to those of the controls. RESULTS: In the postacute stage, the patients navigated worse and had higher error rates than controls in allocentric (p = 0.002), but not in egocentric, route planning (p = 0.30), despite complete recovery of verbal (p = 0.58) and figural memory (p = 0.11). Until follow-up, allocentric navigation deficits improved, but higher error rates and reduced use of shortcuts persisted (p < 0.0001). Patients still exhibited relatively more fixations of unique landmarks during follow-up (p = 0.05). PET measurements during the postacute stage showed increased navigation-induced brain activations in the right hippocampus, bilateral retrosplenial, parietal, and mesiofrontal cortices, and cerebellar dentate nucleus in patients compared to controls (p < 0.005). CONCLUSIONS: Patients with TGA show selective and prolonged deficits of allocentric spatial orientation. Activations in right hippocampal and extrahippocampal hubs of the cerebral navigation network functionally substitute for the deficit in creating and updating the internal cognitive map in TGA.

Risk factors of transient global amnesia: Three case reports.

INTRODUCTION: Transient global amnesia (TGA) is characterized by a sudden onset of anterograde and retrograde amnesia, sometimes associated with mild subclinical neuropsychological deficits and vegetative symptoms, lasting for days after the episode. Migraine history, cardiovascular risk factors, and emotional stress are considered possible risk factors. TGA usually occurs during the seventh decade of life, that is, when risk factors and concomitant pathologies have a higher incidence. CASE PRESENTATION: We report 3 cases of TGA triggered by different causes (cardiovascular risk factors, emotional stress, and orgasm) with an unusual young onset (patient 1 was a 40-year-old woman, patient 2 was a 21-year-old woman, and patient 3 a 32-year-old man). The patients underwent neuroimaging and cardiovascular examination, and neuropsychological evaluation, without important abnormalities. TGA completely recovery within 1 to 7 days. CONCLUSIONS: The occurrence of different precipitating events and accurate questioning (in the absence of head trauma) seem to be key features in making the diagnosis of TGA, besides a complete neuropsychiatric and cardiovascular assessment.

Takotsubo cardiomyopathy and transient global amnesia: a shared aetiology.

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.

Reversible Cerebral Vasoconstriction Syndrome Presenting with Transient Global Amnesia.

A 65-year-old man who had been diagnosed with transient global amnesia (TGA) 15 years previously was admitted to hospital with complaints of amnesia and headache. His symptoms improved on day-2. The initial brain MRI and electroencephalography findings were normal. He was diagnosed with a recurrence of TGA and discharged. However, he returned with right leg weakness and complained of a thunderclap headache. MRI demonstrated subarachnoid hemorrhage and multifocal segmental narrowing of the left posterior cerebral artery (PCA) and large intracranial arteries, and he was diagnosed with reversible cerebral vasoconstriction syndrome (RCVS). He was discharged on day-30 without any neurological deficits. This case suggested that TGA should be interpreted as one of the symptoms of RCVS or a prodromal symptom of RCVS.

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

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

Influence of depressive symptoms on memory in transient global amnesia.

INTRODUCTION: Recent studies have shown that patients with transient global amnesia (TGA) experience a depressive mood during the episode. However, little evidence has been found of possible mood congruency effects on memory, which are probably masked by the massive anterograde amnesia. An implicit assessment could provide a means of settling this question. METHODS: First, we measured patients' emotional states on psychopathological scales. Second, we administered a lexical decision task to assess three priming effects: Semantic priming (SP; table-chair), emotional priming (EP; murder-garbage), and emotional plus semantic priming (ESP; cemetery-coffin). RESULTS: Patients displayed a more depressed mood than controls. For patients, we found a SP effect in the ESP condition and a striking inhibition effect (i.e., negative target recognized more slowly when preceded by a negative prime rather than a neutral one) in the EP condition. For controls, a priming effect was found in the SP and ESP conditions, but not the EP condition. Finally, whereas the priming effect was greater in SP than in the other two conditions for controls, for patients it was the EP condition that stood out from the other two, being the only condition that led to an inhibition effect. CONCLUSIONS: We highlighted a mood congruency effect in TGA which could impel patients to focus their attention on negative information. While the negative valence of items always led to a slowdown in reaction times for both patients and controls, attesting to a negativity bias, this bias was greater in patients, leading to an inhibition effect.

A Case of Transient Global Amnesia with Small Left Putamen Infarction.

A 67-year-old right-handed woman experienced a sudden anterograde and retrograde short-term memory deficit that recovered on the next day. Magnetic resonance imaging (MRI) showed a spotty high-intensity lesion in the left putamen in the diffusion-weighted and fluid-attenuated inversion recovery images. Transient global amnesia due to lacunar infarction of the left putamen was diagnosed. Transient global amnesia is characterized by a sudden onset of anterograde amnesia that disappears within 24 hours. The cause of transient global amnesia is still uncertain. Some studies with MRI showed small lesions in the hippocampus at 24-74 hours after the episode. These lesions disappear within several weeks. However, our case of transient global amnesia showed a small lesion in the left putamen, not the hippocampus. Some studies with functional MRI reported that the stratum plays an important role in short-term memory and cognitive function. This case showed only a left putamen lesion, which indicates that a putamen lesion can cause transient global amnesia.

Posterior hippocampal stroke presenting with transient global amnesia.

The acute onset of isolated amnesia is an intriguing challenge for neurologist, because the lack of associated signs can be misleading for diagnosis. The most common cause is transient global amnesia (TGA), a benign condition, but rarely it results from abuse of substance/alcohol or cerebrovascular diseases. In the latter, the brain region involved is the hippocampus. We describe a patient with presenting symptoms of TGA, but affected by an ischemic hippocampal stroke. The computed tomography angiography helped the etiologic diagnosis showing an hemodynamic stenosis of the posterior P2P segment. Interestingly, neuropsychological features were consistent with those found in patients suffering TGA.