Increased Risk of Dementia after Transient Global Amnesia: A Nationwide Population-Based, Longitudinal Follow-Up Study in South Korea.

INTRODUCTION: The long-term cognitive outcomes after transient global amnesia (TGA) have been contradictory in the literature. Our study aimed to longitudinally investigate the association between TGA and incident dementia using long-term data from a nationwide population-based cohort in South Korea. METHODS: The study population was recruited between 2002 and 2020 using the International Classification of Diseases (Tenth Revision; ICD-10) codes from the Korean National Health Insurance Service database. The cumulative incidence curve was plotted to compare the incidence of dementia between the TGA (ICD-10 code G45.4; n = 10,276) and non-TGA (n = 27,389) groups, determined using 1:3 propensity score matching. Using Cox proportional hazard regression models, we obtained crude and adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the incident dementia in patients with TGA compared to non-TGA controls. To examine independent variables determining dementia in the TGA group, logistic regression analysis was performed, and adjusted odds ratios (aORs) and 95% CIs were calculated. RESULTS: The TGA group had a significantly higher cumulative incidence of dementia than the non-TGA group (p < 0.001, log-rank test). TGA was significantly associated with incident dementia in the univariate and multivariate Cox models (HR 1.34, 95% CI 1.28-1.39 and aHR 1.40, 95% CI 1.34-1.46, respectively). The adjusted logistic regression for incident dementia in the TGA group showed that age (per 1 year, aOR 1.09, 95% CI 1.09-1.10), female sex (aOR 1.31, 95% CI 1.18-1.45), diabetes (aOR 1.21, 95% CI 1.08-1.35), stroke (aOR 1.30, 95% CI 1.16-1.46), depression (aOR 1.53, 95% CI 1.33-1.76), anxiety (aOR 1.24, 95% CI 1.01-1.39), and rural residence (aOR 1.24, 95% CI 1.10-1.41) were independently associated with incident dementia. CONCLUSION: Our results suggest a longitudinal association of TGA with incident dementia.

Is there a relationship between opioid use and transient global amnesia?

BACKGROUND AND PURPOSE: Opioid-associated amnestic syndrome (OAS) and transient global amnesia (TGA) are conditions with clinical overlap. We therefore sought to determine whether opioid use might be associated with TGA. METHODS: Data from the Massachusetts Department of Public Health Syndromic Surveillance program were queried to ascertain the frequency of opioid use among emergency department (ED) encounters for TGA compared to that for all other ED visits between January 2019 and June 2023. RESULTS: A total of 13,188,630 ED visits were identified during the study period. Of 1417 visits for TGA, one visit met the exposure definition for opioid use. There were 13,187,213 visits for other indications, 57,638 of which were considered opioid-exposed. The odds ratio for the relationship between opioid use and TGA was 0.16 (95% confidence interval 0.02, 1.14). CONCLUSION: Despite the clinical overlap between OAS and TGA, surveillance data from ED visits in Massachusetts do not suggest that opioid use is a risk factor for TGA, indicating that OAS and TGA are distinct entities.

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.

Transient global amnesia - hippocampal lesions in magnetic resonance imaging.

BACKGROUND: Transient global amnesia is a benign syndrome characterized by a sudden onset loss of anterograde amnesia with full recovery. Magnetic resonance of the brain including diffusion-weighted imaging of patients with transient global amnesia revealed the presence of punctate hyperintense signal abnormalities in the hippocampus. OBJECTIVE: Analysis of the presence of hippocampal lesions in brain magnetic resonance imaging in patients with transient global amnesia and the possible influence of additional factors on their appearance. METHODS: In this retrospective, an observational study we assessed brain magnetic resonance imaging in 38 consecutive patients with transient global amnesia. The incidence of brain magnetic resonance imaging lesions was analyzed for the coexisting cardiovascular risk factors and precipitating events. RESULTS: Hippocampal brain magnetic resonance imaging lesions were detected in 47% of patients with transient global amnesia. Of those, 65% had unilateral lesions, 82% were left-sided, and 28% were right-sided. Most lesions were located in the CA1 subfield. The incidence of hypertension in patients with transient global amnesia was higher than in the general population. Stress and exercise preceded the onset of transient global amnesia only in 13% and 16% of patients, respectively. There was no higher incidence of migraine in transient global amnesia patients (13%). CONCLUSIONS: We found that nearly 50% of patients with transient global amnesia had hyperintense hippocampal brain magnetic resonance imaging lesions. In addition to hypertension, individuals with transient global amnesia had similar cardiovascular risk factors as the general population. We did not identify any precipitating events prior to the onset of transient global amnesia.

Conventional cardiovascular risk factors in Transient Global Amnesia: Systematic review and proposition of a novel hypothesis.

Transient Global Amnesia (TGA) is an enigmatic amnestic syndrome. We conducted a systematic review to investigate the relationship between the conventional cardiovascular risk factors and TGA. MEDLINE, CENTRAL, EMBASE and PsycINFO were comprehensively searched and 23 controlled observational studies were retrieved. The prevalence of hypertension, diabetes mellitus, dyslipidemia and smoking was lower among patients with TGA compared to Transient Ischemic Attack. Regarding the comparison of TGA with healthy individuals, there was strong evidence suggesting a protective effect of diabetes mellitus on TGA and weaker evidence for a protective effect of smoking. Hypertension was associated with TGA only in more severe stages, while dyslipidemia was not related. In view of these findings, a novel pathophysiological hypothesis is proposed, in which the functional interactions of Angiotensin-II type-1 and N-methyl-D-aspartate receptors are of pivotal importance. The whole body of clinical evidence (nature of precipitating events, associations with migraine, gender-based association patterns) was integrated.

Acute neurological disease as a trigger or co-occurrence of transient global amnesia: a case series and systematic review.

BACKGROUND: Transient global amnesia (TGA) represents a benign neurological syndrome of unknown pathophysiology, often accompanied by vanishing hippocampal punctate lesions on diffusion-weighted imaging (hippocampal punctate diffusion lesion, HPDL). The recent literature suggests that TGA may be triggered by acute neurological conditions. OBJECTIVE: To study patients with TGA triggered by an acute neurological disease. METHODS: We retrospectively reviewed patients from two neurology centres with TGA (with or without HPDL) in whom an acute neurological condition could be identified as trigger. We also performed a systematic review of the literature of this situation using predefined search terms. RESULTS: We identified 38 patients (median age 62 years, 55.3% female): 6 from our centres and 32 from the literature. Acute neurovascular diseases that preceded or were associated with TGA included ischemic and haemorrhagic strokes, convexity subarachnoid haemorrhage, and reversible cerebral vasoconstriction syndrome. As non-vascular acute neurological diseases, we identified migraine and peripheral-origin vertigo. The clinical manifestation of the neurological trigger showed a variable temporal relation with TGA onset; in some cases preceding and in others co-occurring with TGA manifestation. In some cases, presumed neurological triggers were asymptomatic and diagnosed from the neuroimaging done for the TGA. CONCLUSIONS: Acute vascular and non-vascular neurological events may trigger TGAs or may occur simultaneously. In the first case, such an acute neurological disease may activate direct pathways within the nervous systems leading to TGA, or alternatively elicit a bodily sympathetic overactivity cascade. In the second case, both neurological events may be the result of a common external stressor.

Transient Global Amnesia.

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.

[Transient Global Amnesia in the Reykjavik area].

BACKGROUND: Transient Global Amnesia (TGA) is a benign syndrome characterized by sudden anterograde memory loss, that resolves spontaneously within 24 hours. TGA appears without other focal neurological symptoms. The aim of this study was to study TGA in the greater Reykjavik-area. METHODS: We retrospectively analysed the medical history of patients with a diagnosis of TGA (ICD-10 G45.4) at the University Hospital in Iceland in 2010-2021. Medical records were reviewed, and information about year and age at diagnosis, sex, symptoms, precipitating events, imaging results and risk factors were collected. Statistical processing was performed with Excel and Rstudio. RESULTS: Overall, 348 attacks of TGA were identified with a mean frequency of 29 attacks/year, where 9.9% had an earlier history of TGA. The mean age was 64.1, with 50% of subjects between 58-70 years old. The sex distribution was equal (49.9% female). Possible precipitating events were found in 53.7% of cases, with physical activity being the most common one (24.4%), followed by sudden temperature change and emotional stress. In 96% of patients a computerized tomography was performed (no sign of acute changes were found), and magnetic resonance imaging (MRI) in 36.2% of cases. MRI showed restricted diffusion in the hippocampal area in 10.3% of cases. DISCUSSION: TGA is not a rare but a benign syndrome. Our findings regarding age, sex distribution and precipitating events were in accordance with other studies. TGA is thought to result from a temporary hippocampal dysfunction supported by the clinical presentation and MRI findings. The cause of TGA is however still unknown.

Prevalence of Mimics and Severe Comorbidity in Patients with Clinically Suspected Transient Global Amnesia.

BACKGROUND: Transient global amnesia (TGA) is a syndrome featuring acute anterograde amnesia as the most striking clinical symptom. Its etiology is still a matter of debate. Most neurological guidelines allow the diagnosis on the basis of clinical criteria only; a more extensive evaluation is recommended only for patients with "red flags" like severe headache, nausea or vomiting, or metabolic abnormalities. The aim of our study was to assess the frequency of a severe underlying disease or alternative diagnoses (mimics) in patients fulfilling the clinical criteria. METHODS: We evaluated the medical records and the imaging data of an unselected consecutive cohort of patients with suspected TGA over a 7-year period. All patients were hospitalized and received a neurological workup including brain imaging, color-coded duplex sonography of the brain supplying arteries, electroencephalography, and laboratory studies of blood and (in selected cases) cerebrospinal fluid. RESULTS: 163 patients with 166 episodes of suspected TGA were hospitalized (3 patients twice). After the workup, the diagnosis of TGA was confirmed in 148/166 (89.2%) episodes ("simple TGA"). Eighteen patients (10.8%) either had an alternative diagnosis or a severe comorbidity that was assumed to have had an impact on the occurrence of the amnestic episode ("complicated TGA/mimic"). The most important differential diagnosis was stroke (11 patients, 6.6% of all TGA suspects and 61.1% of the complicated TGA/mimic group). Other mimics were transient epileptic amnesia (2 patients) and steroid-induced delirium (1 patient). Important comorbidities that had not been obvious at the time of presentation were severe sleep apnea (2 patients), triptan overuse (1 patient), and an involuntary amlodipine intoxication during TGA. CONCLUSION: As approximately every tenth patient with suspected TGA either had an alternative diagnosis or a severe comorbidity, which had not been obvious at the time of admission, we consider in-patient treatment of all suspected TGA cases as appropriate, preferably in the setting of a stroke unit, as ischemic stroke was the by far most important diagnosis mimicking TGA.

The distribution of the transient global amnesia in the province of Ferrara, Italy, a clue to the pathogenesis?

The pathophysiology of transient global amnesia (TGA) is still uncertain. In the province of Ferrara (Fe-province), Italy, given the health organization and the alarming clinical features, the cases of TGA in the resident population virtually correspond to the resident outpatients diagnosed as TGA cases in the ER of the University Hospital of Ferrara. Thanks to this, a retrospective survey identified 35 (14 men, 21 women) first-ever TGA cases in the resident population in 2018 (346,975 inhabitants) giving a crude incidence rate of 10.10/100,000 (95% CI 7.00-14.00), 8.40/100,000 (95% CI 4.60-14.10) for men, and 11.60/100,000 (95% CI 7.20-17.80) for women, a non-significant gender difference. The incident cases of TGA were evenly distributed according to both season and month. The monthly cases of TGA followed the Poisson distribution (goodness-of-fit test: λ = 2.9, χ2 = 2.557, 5 degrees of freedom, p > 0.70). The incidence of TGA in the Fe-province was higher in the highest level of urbanization (21.40/100,000 95% CI 13.10-33.00) than in the lowest one (4.20/100,000 95% CI 1.92-8.00). The incident cases of TGA increased with the level of urbanization (χ2 trend test = 19.940, p < 0.001) and the population density (inhabitants/km2) level (χ2 trend test = 46.684, p < 0.001). Since urbanization is likely involved in stress-related disorders, these findings achieved in a well-defined homogeneous population seem to support the hypothesis of the involvement of stress, maybe in vulnerable individuals, in TGA.

Risk factors predicting recurrence of transient global amnesia.

OBJECTIVE: To assess risk factors of transient global amnesia (TGA) recurrence. METHODS: Retrospective study of a case series of patients with the diagnosis of TGA in our neurology center in the last 8 years, identified through an anonymized database search. TGA was identified by applying Hodges and Warlow criteria. RESULTS: Seventy patients (70% female, average age 64.8 ± 7.8 years) were enrolled; mean follow-up was 16.5 months. 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 4 h. 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. CONCLUSION: 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.

Time trends, frequency, characteristics and prognosis of short-duration transient global amnesia.

BACKGROUND AND PURPOSE: Transient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia lasting up to 24 h. One major differential for TGA is transient epileptic amnesia, which typically lasts < 1 h. However, TGA can also be short in duration and little is known about the time trends, characteristics and prognosis of TGA cases lasting < 1 h. METHODS: We compared the clinical features of TGA ascertained in two independent cohort studies in Oxfordshire, UK [Oxford cohort 1977-1987 versus Oxford Vascular Study (OXVASC) 2002-2018] to determine the time trends of clinical features of TGA. Results were validated in another independent contemporary TGA cohort in Italy [Northern Umbria TGA registry (NU) 2002-2018]. We compared the risk factors, clinical features and long-term prognosis (major cardiovascular events, recurrent TGA and seizure/epilepsy) of patients presenting with episodes lasting < 1 h versus those lasting ≥ 1 h. RESULTS: Overall, 639 patients with TGA were included (114 Oxford cohort, 100 OXVASC, 425 NU). Compared with the original Oxford cohort, there were more cases with TGA lasting < 1 h in OXVASC [32 (32.0%) vs. 9 (8.8%)] and NU (11.8% vs. 8.8% in Oxford cohort). In both OXVASC and NU, patient age, vascular risk factors and clinical features were largely similar between those with TGA lasting < 1 h versus those lasting ≥ 1 h. Moreover, there was no difference in the long-term risk of seizure/epilepsy or major cardiovascular events between TGA lasting < 1 h versus TGA lasting ≥ 1 h. CONCLUSIONS: Short-duration TGA episodes (<1 h) were not uncommon and were more frequent than in earlier studies. The clinical features and long-term prognosis of short-duration TGA did not differ from more typical episodes lasting ≥ 1 h.

Factors determining recurrence in transient global amnesia.

BACKGROUND: Aetiology of transient global amnesia (TGA) remains uncertain, though many have been proposed, including ischaemic, migrainous or epileptic pathologies. METHODS: We attempted to determine risk factors for TGA, as well as prognostic factors that may cause recurrence. We evaluated clinical history, family history and magnetic resonance diffusion-weighted imaging (DWI) studies of 93 prospective patients with TGA. Patients were followed from 2004 to 2016. Fifteen of 93 (16%) patients experienced a recurrence of TGA. RESULTS: Among precipitating events, physical activities inducing Valsalva-like manoeuvres were most common, followed by emotional stress. Eighty-four patients had possible comorbidities or risk factors for TGA, though no single risk factor was ubiquitous. Risk factors associated with recurrence were head injury (isolated vs. recurrent, 16.7% vs. 53.5%, p < 0.01), depression (isolated vs. recurrent, 15.4% vs 46.7%, p = 0.01) and family history of dementia (isolated vs. recurrent, 20.5% vs. 46.7%, p = 0.03). Of 15 patients with confirmed recurrent TGA, two developed dementia and four subjective memory impairment. DWI lesions were observed in 24 patients and were located anywhere within the hippocampus. CONCLUSIONS: DWI lesions were not significantly associated with outcomes (recurrence, subjective memory impairment, dementia). We have found that depression, previous head injury and family history of dementia may predict TGA recurrence.

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.

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.

The Risk of Takotsubo Cardiomyopathy in Acute Neurological Disease.

BACKGROUND: Case series have reported reversible left ventricular dysfunction, also known as stress cardiomyopathy or Takotsubo cardiomyopathy (TCM), in the setting of acute neurological diseases such as subarachnoid hemorrhage. The relative associations between various neurological diseases and Takotsubo remain incompletely understood. METHODS: We performed a cross-sectional study of all adults in the National Inpatient Sample, a nationally representative sample of US hospitalizations, from 2006 to 2014. Our exposures of interest were primary diagnoses of acute neurological disease, defined by ICD-9-CM diagnosis codes. Our outcome was a diagnosis of TCM. Binary logistic regression models were used to examine the associations between our pre-specified neurological diagnoses and TCM after adjustment for demographics. RESULTS: Among acute neurological diagnoses, the strongest associations were seen with subarachnoid hemorrhage (odds ratio [OR] 11.7; 95% confidence interval [CI] 10.2-13.4), status epilepticus (OR 4.9; 95% CI 3.7-6.3), and seizures (OR 1.3; 95% CI 1.1-1.5). In a sensitivity analysis including secondary diagnoses of acute neurological diagnoses, associations were also seen with transient global amnesia (OR 2.3; 95% CI 1.5-3.6), meningoencephalitis (OR 2.1; 95% CI 1.7-2.5), migraine (OR 1.7; 95% CI 1.5-1.8), intracerebral hemorrhage (OR 1.3; 95% CI 1.1-1.5), and ischemic stroke (OR 1.2; 95% CI 1.1-1.3). In addition, female sex was strongly associated with Takotsubo (OR 5.1; 95% CI 4.9-5.4). CONCLUSION: TCM appears to be associated with varying degrees with several acute neurological diseases besides subarachnoid hemorrhage.

Transient epileptic and global amnesia: Real-life differential diagnosis.

OBJECTIVE: Transient epileptic amnesia (TEA) is an underestimated condition in emergency clinical setting, where most of transient amnesic episodes tend to be classified as transient global amnesia (TGA). We designed this study to evaluate the actual frequency of TEA in a real-life scenario and to highlight the features that can help clinicians distinguishing it from TGA. METHODS: We retrospectively collected clinical data of 83 patients who accessed our emergency ward for an abrupt onset of amnesic disorder, initially interpreted as TGA. All patients underwent neurological evaluation, magnetic resonance imaging (MRI) scan, and standard 21-channel scalp electroencephalography (EEG) recording (standard EEG [st-EEG]). Moreover, patients with borderline epileptiform abnormalities on st-EEG or with normal st-EEG but high clinical suspicion for TEA underwent a 16-channel 24-hour ambulatory EEG (24-h EEG). Clinical features, neurophysiological, and neuroimaging data were analyzed and compared in the two groups (TEA and TGA). RESULTS: Diagnosis of TEA, according to Zeman's criteria, was made in 15 patients (18%). From a clinical point of view recurrence (p < .001) and atypical symptoms such as confusion or language disorder (TGA plus manifestations), appear to be key elements in order to discriminate between TEA and TGA (80% of patients with TEA vs 7.8% of patients with TGA; p < .001). In our sample, duration of the episodes did not significantly differ between TGA and TEA, even though it is usually described as shorter for TEA. This result could be related with a prolonged postictal state in these patients. The analysis of st-EEG results evidenced low sensitivity for interictal epileptiform abnormalities (IEAs) detection (52.3%), with not conclusive data in distinguishing TEA from TGA. On the contrary, 24-h EEG showed IEAs in all patients with epilepsy, mostly during sleep, suggesting an essential diagnostic role of long-lasting EEG recording for TEA. Finally, structural abnormalities were more frequent in patients with TEA (26.6%). In the group with TGA, the only imaging alteration found was diffusion weighted imaging (DWI) hippocampal hyperintensity. CONCLUSION: Our findings show that in a real-life clinical scenario, TEA is frequent but often overlooked. However, simple clinical data and widely available neurophysiological examinations can truly help to effectively distinguish TEA from TGA.

Medical Procedure-Related Transient Global Amnesia.

BACKGROUND: Transient global amnesia (TGA) is an interesting clinical syndrome characterized by sudden memory loss for recent events and an inability to retain new memories usually lasting several hours and recovering spontaneously. We conducted a literature search of medical procedure-related TGA and its predisposing conditions. METHODS: We performed PubMed searches using the keyword "transient global amnesia" combined with "procedure," "test," "therapy," or various other individual medical procedures. In addition, we described 2 cases of gastroscopy-related TGA. RESULTS: Eighty-nine patients with medical procedure-related TGA in 49 articles were summarized. The most common procedure was cerebral angiography (n = 45), followed by coronary angiography (n = 10) and general anesthesia (n = 9). After categorization, neurological procedures were most common (n = 46, 51.7%), followed by cardiac (n = 17, 19.1%), anesthetic (n = 11, 12.4%), gastrointestinal (n = 4, 4.5%), and pulmonary (n = 2, 2.2%) procedures. CONCLUSIONS: Diverse cases of medical procedure-related TGA have been reported in the literature. Valsalva-associated activities, emotional stress with anxiety, and acute pain were predisposing conditions. An understanding of medical procedure-related TGA may be important for clinicians who perform such medical procedures.

Ischemic Amnesia: Causes and Outcome.

BACKGROUND AND PURPOSE: We aimed to describe the frequency and characteristics of acute ischemic stroke and transient ischemic attacks presenting predominantly with amnesia (ischemic amnesia) and to identify clinical clues for differentiating them from transient global amnesia (TGA). METHODS: We retrospectively analyzed and described all patients presenting with diffusion-weighted imaging magnetic resonance imaging-confirmed acute ischemic stroke/transient ischemic attacks with antero- and retrograde amnesia as the main symptom over a 13.5-year period. We also compared their clinical features and stroke mechanisms with 3804 acute ischemic stroke from our ischemic stroke registry. RESULTS: Thirteen ischemic amnesia patients were identified, representing 0.2% of all patients with acute ischemic stroke/transient ischemic attack. In 69% of ischemic amnesia cases, amnesia was transient with a median duration of 5 hours. Ischemia was not considered in 39% of cases. Fifty-four percent of cases were clinically difficult to distinguish from TGA, including 15% who were indistinguishable from TGA. 1.2% of all presumed TGA patients at our center were later found to have ischemic amnesia. Amnesic strokes were more often cardioembolic, multiterritorial, and typically involved the posterior circulation and limbic system. Clinical clues were minor focal neurological signs, higher age, more risk factors, and stroke favoring circumstances. Although all patients were independent at 3 months, 31% had persistent memory problems. CONCLUSIONS: Amnesia as the main symptom of acute ischemic cerebral events is rare, mostly transient, and easily mistaken for TGA. Although clinical clues are often present, the threshold for performing diffusion-weighted imaging in acute amnesia should be low.