Recurrent Transient Global Amnesia Research Articles

Clinical differences between transient epileptic amnesia (TEA) and recurrent transient global amnesia (r-TGA)

Both transient epileptic amnesia (TEA) and transient global amnesia (TGA) are clinically characterized by temporary amnesic symptoms. TEA involves recurring amnesic episodes, while TGA typically manifests as a singular occurrence. TGA rarely occurs repeatedly, known as recurrent TGA (r-TGA), which complicates differentiation, and raises the possibility of overlap between two disorders. Given the effectiveness of suitable antiseizure medications (ASMs) in treating TEA, accurate diagnosis of the initial event is crucial. In this study, We retrospectively analyzed cases of sudden-onset amnesia at Juntendo University Hospital over the past 14 years. Our investigation identified a total of 17 patients with TEA who met the criteria established by Zeman, along with a total of 9 patients with r-TGA meeting Hodges’ criteria.Compared to r-TGA, TEA exhibited a higher recurrent rate, shorter symptoms, more additional symptoms, and increased structural abnormalities on head magnetic resonance imaging (MRI), and more abnormalities electroencephalography (EEG).Moreover, individual amnestic episode duration varied in both TEA and r-TGA. Our study reveals that TGA retains key features in recurrent cases and demonstrates distinctions from TEA. Nevertheless, distinguishing between the two conditions based solely on initial episodes remains challenging.

Recurrent Transient Global Amnesia with Contralateral Hippocampal Restricted Diffusion MRI Changes: A Case Report (P4-4.001)

<h3>Objective:</h3> To describe a case of recurrent transient global amnesia (TGA) with temporally spaced bilateral hippocampal restricted diffusion on MRI. <h3>Background:</h3> TGA is defined as a sudden onset of anterograde and retrograde amnesia that lasts 24 hours, and can recur over time. Multiple mechanisms have been proposed to explain this condition, including cortical spreading depression, venous congestion, hypoxic-ischemic events, epileptic phenomena, and ineffective connectivity in bilateral hippocampal structures (subiculum-fimbria, entorhinal cortex-CA4) due to vascular impairment. Bilateral hippocampal involvement has been described in the setting of TGA with focal mesial hippocampal diffusion restriction in diffusion-weighted imaging (DWI). Herein we postulate that recurrent TGA results from neuroanatomical network and vascular supply impairment. <h3>Design/Methods:</h3> Retrospectively chart review of a patient with recurrent TGA. <h3>Results:</h3> A 59-year woman with history of head injury in her 30s, migraine, B12 deficiency, benign paroxysmal positional vertigo, degenerative spine disease, post-traumatic stress disorder, and tobacco use, presented with typical symptoms of TGA. Brain MRI demonstrated punctate restricted diffusion in the right hippocampus. A repeat MRI sixteen months after showed complete resolution in DWI. The patient presented with a second similar episode twelve months later; MRI demonstrated punctate lesions in DWI in the left hippocampus. The patient had a negative evaluation for stroke and epilepsy. Of note the patient did report a migraine during each episode. <h3>Conclusions:</h3> To our knowledge, this is the first reported case of recurrent TGA in which there is temporally spaced bilateral hippocampal restricted diffusion on MRI. Our case report aligns with recent theories that recurrent TGA might be related to neuroanatomical network and vascular supply impairment rather than an isolated lesional defect. <b>Disclosure:</b> Dr. Mora Munoz has nothing to disclose. Dr. McKee has nothing to disclose. Dr. Buletko has nothing to disclose. Dr. Mays has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Dynamed Plus (EBSCO Industries, Inc.). Dr. Mays has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for CoolTech Medical. Dr. Mays has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biodelivery Science International. Dr. Mays has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Amgen. Dr. Mays has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Abbvie. Dr. Mays has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for DynaMed Plus .

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.

Can Artificial Intelligence Diagnose Transient Global Amnesia Using Electroencephalography Data?

This study aimed to determine the ability of deep learning using convolutional neural networks (CNNs) to diagnose transient global amnesia (TGA) based on electroencephalography (EEG) data, and to differentiate between patients with recurrent TGA events and those with a single TGA event. We retrospectively enrolled newly diagnosed patients with TGA and healthy controls. All patients with TGA and the healthy controls underwent EEG. The EEG signals were converted into images using time-frequency analysis with short-time Fourier transforms. We employed two CNN models (AlexNet and VGG19) to classify the patients with TGA and the healthy controls, and for further classification of patients with recurrent TGA events and those with a single TGA event. We enrolled 171 patients with TGA and 68 healthy controls. The accuracy and area under the curve (AUC) of the AlexNet and VGG19 models in classifying patients with TGA and healthy controls were 70.4% and 71.8%, and 0.718 and 0.743, respectively. In addition, the accuracy and AUC of the AlexNet and VGG19 models in classifying patients with recurrent TGA events and those with a single TGA event were 71.1% and 88.4%, and 0.773 and 0.873, respectively. We have successfully demonstrated the feasibility of deep learning in diagnosing TGA based on EEG data, and used two different CNN models to distinguish between patients with recurrent TGA events and those with a single TGA event.

Limbic covariance network alterations in patients with transient global amnesia.

We compared limbic structure volumes and graph theory parameters of the limbic covariance network between patients with transient global amnesia (TGA) and healthy controls, and between patients with single and recurrent TGA events. We retrospectively enrolled 122 patients with TGA (single event, n = 107; recurrent events, n = 15) and 50 healthy controls who underwent three-dimensional T1-weighted MRI imaging of the brain. Volumetric analysis of the subcortical limbic structures, including the hippocampus, amygdala, thalamus, mammillary body, hypothalamus, basal forebrain, septal nuclei, fornix, and nucleus accumbens, was performed. We examined the limbic covariance network using a graph theory. Limbic structure volumes did not differ between patients with TGA and healthy controls, and between patients with a single event and those with recurrent events. However, the radius of the limbic covariance network was significantly greater in patients with TGA than in healthy controls (6.595 vs. 4.564, p = 0.040). Furthermore, the radius, diameter, eccentricity, and characteristics path length were greater (4.066 vs. 2.000, p = 0.009; 7.062 vs. 3.645, p = 0.029; 5.633 vs. 2.774, p = 0.013; 3.373 vs. 1.688, p = 0.004; respectively), whereas the average strength, global efficiency, local efficiency, mean clustering coefficient, transitivity, and small-worldness index were lower (5.595 vs. 10.831, p = 0.004; 0.350 vs. 0.642, p = 0.002; 0.531 vs. 1.724, p = 0.004; 0.304 vs. 0.624, p = 0.006; 0.456 vs. 0.935, p = 0.003; 0.913 vs. 0.993, p = 0.017; respectively), in patients with recurrent events than in those with a single event. The limbic covariance network shows significant alterations in patients with TGA, as well as differences between patients with recurrent events and those with a single event. These findings suggest that changes in the limbic covariance network could be related to the pathogenesis of TGA.

Glymphatic System Function in Patients with Transient Global Amnesia.

The purpose of this study was to examine glymphatic system function in patients with transient global amnesia (TGA), as well as to conduct a recurrence analysis. We enrolled patients with TGA and healthy controls from our hospital retrospectively. The patients and healthy controls were all scanned with the same 3T scanner, which included diffusion tensor imaging (DTI). We investigated the function of the glymphatic system using DTI analysis along the perivascular space (DTI-ALPS). The ALPS index was compared between patients with TGA and healthy controls, as well as between patients who had recurrent TGA events and those who had only a single TGA event. Seventy-two patients with TGA and 53 healthy controls were enrolled. Sixty-five patients with TGA had a single TGA event, while seven patients had recurrent TGA events. The ALPS index did not differ significantly between patients with TGA and healthy controls (1.665 vs. 1.618, p = 0.436). The ALPS index, on the other hand, varied significantly according to recurrence in patients with TGA. The ALPS index was significantly higher in patients with recurrent TGA events compared to those with a single event (1.928 vs. 1.636, p = 0.049). We investigated the glymphatic system function in patients with TGA compared to healthy controls for the first time using the DTI-ALPS method. We discovered that these groups did not differ in terms of glymphatic system function. However, glymphatic system function in patients with TGA may differ according to recurrence. Additional research is required to substantiate these findings.

Transient Global Amnesia (TGA): Younger Age and Absence of Cerebral Microangiopathy Are Potentially Predisposing Factors for TGA Recurrence.

Background: Transient global amnesia (TGA) is defined by an acute memory disturbance of unclear etiology for a period of less than 24 h. TGA occurs as a single event in most cases. Prevalence rates of recurrent TGA vary widely from 5.4 to 27.1%. This retrospective study aimed to determine predictors for TGA recurrence.Methods: Cardiovascular risk profile and magnetic resonance imaging (MRI) of 340 hospitalized TGA patients between 2011 and 2020 were retrospectively analyzed. The median follow-up period amounted to 4.5 ± 2.7 years. Comparisons were made between TGA patients with and without subsequent recurrence.Results: TGA patients with subsequent recurrence were significantly younger (recurrent vs. single episode, 63.6 ± 8.6 years vs. 67.3 ± 10.5 years, p = 0.032) and showed a lower degree of cerebral microangiopathy compared to TGA patients without recurrence. The mean latency to recurrence was 3.0 years ± 2.1 years after the first episode. In a subgroup analysis, patients with at least five years of follow-up (N = 160, median follow-up period 7.0 ± 1.4 years) had a recurrence rate of 11.3%. A 24.5% risk of subsequent TGA recurrence in the following five years was determined for TGA patients up to 70 years of age without microangiopathic changes on MRI (Fazekas' score 0).Conclusion: Younger TGA patients without significant microangiopathy do have an increased recurrence risk. In turn, pre-existing cerebrovascular pathology, in the form of chronic hypertension and cerebral microangiopathy, seems to counteract TGA recurrence.

Recurrent attacks of transient global amnesia with intracranial vertebral artery dissection: Case report

Whether Transient global amnesia (TGA) is related to ischemic pathogenesis remains unclear. The recurrence of TGA is rare. We report a rare case of recurrent attacks of TGA with intracranial vertebral artery dissection in young men without other triggers and any associated factor. A 39-year-old man was hospitalized for amnesia. Diffusion-weighted imaging (DWI) revealed a tiny focus of high-intensity signals in the left. High-resolution MRI showed the dissecting aneurysm of the V4 portion of the right vertebral artery. Two years later, the patient experienced sudden memory loss again. On DWI, a new punctate restricted diffusion lesion was observed in the left hippocampus. Considering the recurrence in young men with no other triggers, this case raises the hypothesis that a pure TGA in a young patient could potentially be a vertebrobasilar TIA. Therefore, when a patient presents with TGA, without any associated factors, it is important to investigate and exclude sinister causes of global amnesia and we recommend that a vascular examination be conducted.

Brain networks in patients with isolated or recurrent transient global amnesia.

The aim of this study was to investigate differences in cerebral blood flow (CBF) and functional networks between transient global amnesia (TGA) patients with a single event and those with recurrent events using arterial spin labeling (ASL) MRI. We enrolled patients with TGA and classified them into two groups according to the number of TGA events: TGA patients with a single event and those with recurrent events. MRI scans were performed within 24h after TGA ictal onset in all patients. We quantified CBF and analyzed the functional network based on CBF using graph theory, and determined the differences in CBF and functional networks between the groups. We enrolled 44 patients with TGA. Among them, 6 patients had recurrent TGA events, whereas 38 patients had a single TGA event. No regions had significantly different CBFs between TGA patients with recurrent events and those with a single event. The global functional network analysis found that the eccentricity was significantly higher in TGA patients with recurrent events than in those with a single event (5.829 vs. 4.657, p=.001). The local functional network analysis showed that several regions had significantly different betweenness centrality and eccentricity measures between TGA patients with recurrent events and those with a single event. We demonstrated the differences in the functional network based on CBF using graph theory according to recurrence in patients with TGA. These findings suggest that TGA is a network disease, and functional network alterations in TGA are related to clinical symptoms.

Factors associated with recurrent transient global amnesia: systematic review and pathophysiological insights.

The examination of the risk factors that affect the recurrence of transient global amnesia (TGA) may shed light on the pathophysiological substrate of the disease. A systematic review was performed to identify the factors associated with the recurrence of TGA. MEDLINE, EMBASE, CENTRAL and PsycINFO were meticulously searched. Observational controlled studies involving patients with single (s-TGA) and recurrent TGA (r-TGA) according to Hodges and Warlow's criteria were retrieved. Differences in the demographic characteristics, personal and family medical history, previous exposure to precipitating events and laboratory findings were examined. Retrieved evidence was assessed in the context of the individual article validity, based on the numerical power and methodological quality of each study. Nine cohort studies with retrospective, prospective or mixed design were retrieved. In total, 1989 patients with TGA were included, 269 of whom suffered from r-TGA (13.5%). R-TGA presented an earlier age of onset. Evidence was suggestive of a relationship between recurrence and a family or personal history of migraine, as well as a personal history of depression. There was weaker evidence that associated recurrence with a positive family history of dementia, a personal history of head injury and hippocampal lesions in diffusion-weighted MRI. On the other hand, no connection was found between recurrence and electroencephalographic abnormalities, impaired jugular venous drainage, cardiovascular risk factors, atrial fibrillation, previous cerebrovascular events, exposure to precipitating events, a positive family history of TGA and hypothyroidism. Important pathophysiological insights that arised from these findings were discussed.

Concussion Causing Transient Global Amnesia: Further Insights Into Pathophysiology?

To review a rare presentation of Transient Global Amnesia (TGA) in context of concussion with reversible imaging findings. TGA is characterized by sudden temporary loss of anterograde memory accompanied by repetitive questioning without focal neurologic deficits. While risk factors of age above 50 and migraines remain constant, a clear cause is unknown. The association between TGA and concussion is not well defined beyond 2 case reports in the literature. We review the existing literature and examine a case of TGA in temporal relationship to mild traumatic brain injury (mTBI) or concussion. Case Report. A healthy 38-year-old male with no prior concussions or headaches, sustained a concussion after falling backward on pavement. He presented to the emergency room with retrograde amnesia of events 1 hour prior to his injury with subsequent anterograde amnesia. His exam demonstrated normal language and speech and no other focal neurologic deficits. He was diagnosed with TGA with symptoms lasting for 16 hours before fully resolving. Approximately 24 hours after his injury, he developed a migraine headache and tinnitus that was worse with exertion, lasting for roughly 12 hours. His initial CT head while symptomatic demonstrated an area of hypodensity within the left anterior temporal lobe. 2 days after his presentation, he had an MRI with DWI/SWI as well as an EEG, all of which were completely normal, with complete resolution of the finding on CT. He had no further symptoms after his headache resolved and no recurrence of TGA after 12 months follow-up. TGA presenting after a concussion has rarely been reported. We report such a case with imaging findings present during the acute phase that were not present on subsequent MRI suggesting possible reversible vasogenic edema. This may provide insights into the pathophysiology of TGA in this population.

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.

Factors determining recurrence in transient global amnesia

BackgroundAetiology of transient global amnesia (TGA) remains uncertain, though many have been proposed, including ischaemic, migrainous or epileptic pathologies.MethodsWe 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.ResultsAmong 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.ConclusionsDWI 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.

Transient global amnesia: Isolated event or healthy predictor? Clinical experience of an Italian Emergency Department

Transient global amnesia (TGA) is a clinical syndrome characterized by reversible anterograde amnesia, in which the patient is alert, self-awareness appears intact and other neurological symptoms are absent. The diagnosis is based on the following criteria: i) witnessed event; ii) acute onset of anterograde amnesia; iii) no accompanying neurological symptoms; iv) no alteration of consciousness; v) no epileptic features; vi) resolution within 24 hours; vii) exclusion of other causes. We conducted a cohort study at the Department of Emergency Medicine on 119 patients with TGA diagnosis from 2010 to 2014, with follow-up evaluation by telephone interview. The objectives of our study were to evaluate the frequency of subsequent episodes, to identify predisposing factors, and to investigate whether TGA is a possible predictor of neurological disease. The frequency of comorbidity in our population was in line with literature. We observed a recurrence rate of 9.5%, with a prevalence for the male gender, while no other factor correlates with TGA recurrence. TGA was not a predictor of further neurological diseases. In conclusion, TGA is a benign pathology with a low probability of relapse. Accordingly, management in Emergency Department should be based on a correct initial clinical classification for rapid discharge.

Transient global amnesia: clinical features and prognostic factors suggesting recurrence.

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

Recurrent transient global amnesia: is there a link to familial history?

Although most episodes of transient global amnesia (TGA) are single or unique, there is a low recurrence rate. The factors associated with recurrence are uncertain. In this article, Dr Larner describes a patient with recurrent TGA and a positive family history, which prompted consideration of the possible role of genetic factors in TGA recurrence.

Long-Term Outcome in Patients With Transient Global Amnesia: A Population-Based Study

ObjectiveTo study the long-term risk of cerebrovascular events, seizures, and cognitive impairment in patients with transient global amnesia (TGA). Patients and MethodsData for all patients diagnosed with possible TGA in Olmsted County, Minnesota, between January 1, 1985, through December 31, 2010, were retrieved from the Rochester Epidemiology Project database. Transient global amnesia was defined clinically. End points were cerebrovascular event (stroke or transient ischemic attack), seizure, or cognitive impairment (mild cognitive impairment or dementia) during follow-up. End points were studied using Kaplan-Meier survival plots and log-rank test. ResultsA total of 221 patients with TGA were identified and 221 age- and sex-matched controls were included in the analysis. The mean duration of follow-up was 12 years in both groups (range, 0.07-29.93). Prevalence of vascular risk factors and history of seizures were similar between both groups. Previous migraine was more common in the TGA group (42 patients [19.1%] vs 12 patients [5.4%]; P<.001). There was no statistically significant difference between survival curves for the TGA group and the control group using time to any type of cerebrovascular event (log-rank P=.30), time to seizures event (log-rank P=.55), and time to cognitive impair event (log-rank P=.88) as end points. The TGA recurrence occurred in 5.4% of patients after a median interval of 4.21 years (interquartile range, 2.82-8.44). Modified Rankin scale and death rates at last follow-up were also similar between both groups. ConclusionOur findings indicate that having an episode of TGA does not increase the risk of subsequent cerebrovascular events, seizures, or cognitive impairment.

潰瘍性大腸炎の再燃に伴い一過性全健忘の再発作をきたした症例

潰瘍性大腸炎の初回診断時に一過性全健忘を呈した症例が，潰瘍性大腸炎の再燃時に一過性全健忘の再発作をきたした．精神的ストレス，疼痛等が一過性全健忘の誘因となると報告されているが，潰瘍性大腸炎の再燃も誘因となる可能性が示唆された．プライマリケア医を含め，潰瘍性大腸炎の治療に携わる医師は一過性全健忘の合併につき知っておく必要がある．

The structural connectivity of the recurrent transient global amnesia

One of recent interesting hypotheses of transient global amnesia (TGA) pathophysiology is the preexisting vulnerability of the memory network in patients with TGA. To verify the hypothesis that patients with recurrent amnestic attacks may have more disrupted structural connectivity than patients of a single TGA event, we compared the brain imaging of patients with repeated episodes of TGA with those who experienced a single attack. Seven patients who were having recurrent TGA and 14 age- and sex-matched control subjects who had only a single episode of TGA participated in the study. Diffusion tensor images from both groups were assessed and analyzed using tract-based spatial statistics. The fractional anisotropy and mean diffusivity values were not reduced in any lesion within the memory pathway of recurrent patient group when compared with those of single event group. No disruptions in the structural connectivity of the memory pathway were observed in patients with recurrent TGA attacks, refuting the hypothesis that recurrent TGA patients present predisposing weakness of the memory network. The stability of structural connectivity suggests that repeated hippocampal lesions associated with TGA do not affect the microstructure of the brain.