Changes in heart rate variability over time from symptom onset of transient global amnesia.

Transient global amnesia (TGA) often involves precipitating events associated with changes in autonomic nervous system (ANS), and heart rate variability (HRV) reflects the ANS state. This study aimed to investigate HRV changes after TGA. A retrospective analysis of HRV included patients diagnosed with TGA between January 2015 and May 2020. The time and frequency domains of HRV were compared among three groups: early (< 1 week after TGA, n = 19), late (1-4 weeks after TGA, n = 38), and healthy control (HC, n = 19). The Pearson's correlation between time and time-domain HRV was also examined. The standard deviation of NN intervals (SDNN) (early, 47.2; late, 35.5; HC, 41.5; p = 0.033) and root mean square of successive RR interval differences (RMSSD) (early, 38.5; late, 21.3; HC, 31.0; p = 0.006) differed significantly among the three groups. Post-hoc analysis showed statistically significant differences only in the early and late groups in both SDNN (p = 0.032) and RMSSD (p = 0.006) values. However, the frequency domain with total power, low-frequency and high-frequency powers, and low-frequency/high-frequency ratio did not differ. SDNN (Pearson correlation coefficient =- 0.396, p = 0.002) and RMSSD (Pearson correlation coefficient =- 0.406, p = 0.002) were negatively correlated with time after TGA. Changes in HRV occurred over time after the onset of TGA, with the pattern showing an increase in the first week and then a decrease within 4 weeks.

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.

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.

Does dietary intake of caffeine have an effect on transient global amnesia?

AIM: Amnesia is a cognitive disorder that may lead to memory loss. Caffeine is a psychoactive substance which have an effect on memory and cognitive functions. This study aimed to assess the association of transient global amnesia (TGA) with dietary intake of caffeine. METHODS: This cross-sectional study was conducted on the Sabzevar Persian cohort data of 258 patients with TGA and 520 healthy individuals in Sabzevar, Iran. The Nutritional data were gathered in face-to-face interviews using a valid Food Frequency Questionnaire. Different models of logistic regression were used to determine the association between TGA and dietary caffeine intake after adjusting the confounders including age, sex, education, job, marital status, physical activity, BMI, and calorie intake. RESULTS: There was no significant difference in terms of dietary calorie intake of (2279.5 ± 757.9 vs. 2365.5 ± 799.5, p = 0.19), protein (70.79 ± 25.27 vs. 72.94 ± 24.83, p = 0.31), fat (59.97 ± 23.79 vs. 60.13 ± 26.38, p = 0.93), carbohydrate (376 ± 134 vs. 393.1 ± 137.8, p = 0.14), and caffeine (196.4 ± 127.9 vs. 186.3 ± 128.5, p = 0.36) between the groups. No significant association was found between TGA and dietary intake of caffeine (OR: 0.99, 95% CI: 0.99-1.01, p = 0.36). The results did not change after adjusting the confounders. CONCLUSIONS: No significant association was found between TGA and dietary intake of caffeine. Further prospective studies are required to confirm this finding.

Automated CT perfusion analysis reveals medial temporal perfusion abnormalities during transient global amnesia.

INTRODUCTION: The underlying pathophysiology of Transient global amnesia (TGA) remains elusive. Reports of perfusion abnormalities in TGA were inconsistent, but semi-automated analysis of perfusion CT (CTP) may improve reliability and precision of perfusion deficit detection. METHODS: Per institutional protocol, all TGA patients undergo multiphasic contrast-CT with arch to vertex CT angiography, intracranial CT venography, MRI, and EEG upon admission. During the study period consecutive patients diagnosed with TGA underwent CTP during the early acute amnestic phase. We retrospectively reviewed the clinical and radiological findings. RESULTS: Five patients (3 female. median age 71, range 47-74) fulfilled entry criteria. Automated CTP analysis revealed the absence of an ischemic core (defined by CBF < 30%) or conventionally defined clinically relevant hypoperfusion area (defined by Time-to-maximum (Tmax) >6 s) in any of the patients. However, four of the five patients demonstrated territories of benign oligemia defined as Tmax>4 s in areas supplied by the Posterior Cerebral Artery. Three of these four patients had clear involvement of the bilateral medial temporal lobes. None of the patients had epileptic activity on their EEG. Both CTA and MRI were normal apart for small foci of restricted diffusion in the hippocampus of four patients. DISCUSSION: Deficits in perfusion were found in the hippocampi of 60% of patients in the acute phase of TGA using automated image analysis software. This method may provide a quick and simple method to detect these abnormalities. These perfusion abnormalities could help solidify the diagnosis at an early stage and may advance our understanding of this elusive syndrome.

Involvement of the default mode network in patients with transient global amnesia: multilayer network.

INTRODUCTION: We aimed to investigate the alterations in the multilayer network in patients with transient global amnesia (TGA). METHODS: We enrolled 124 patients with TGA and 80 healthy controls. Both patients with TGA and healthy controls underwent a three-teslar brain magnetic resonance imaging (MRI). A gray matter layer matrix was created using a morphometric similarity network derived from the T1-weighted imaging, and a white matter layer matrix was constructed using structural connectivity based on the diffusion tensor imaging. A multilayer network analysis was performed by applying graph theoretical analysis. RESULTS: There were no significant differences in global network measures between the groups. However, several regions, related to the default mode network, showed significant differences in nodal network measures between the groups. Multi-richness in the left pars opercularis, multi-rich-club degree in the right posterior cingulate gyrus, and weighted multiplex participation in the right posterior cingulate gyrus were higher in patients with TGA compared with healthy controls (15.47 vs. 12.26, p = 0.0005; 41.68 vs. 37.16, p = 0.0005; 0.90 vs. 0.80, p = 0.0005; respectively). The multiplex core-periphery in the left precuneus was higher (0.96 vs. 0.84, p = 0.0005), whereas that in the transverse temporal gyrus was lower in patients with TGA compared with healthy controls (0.00 vs. 0.02, p = 0.0005). CONCLUSION: We newly find the alterations in the multilayer network in patients with TGA compared with healthy controls, which shows the involvement of the default mode network. These changes may be related to the pathophysiology of TGA.

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.

The link between reversible cerebral vasoconstriction syndrome and transient global amnesia.

Reversible cerebral vasoconstriction syndrome (RCVS) and transient global amnesia (TGA) are acute and self-limiting intra-cerebral conditions. Although previously studied as independent phenomena, there are increasing reports of co-occurrence of these two pathologies. We report a 55-year-old male who presented to the hospital with recurrent thunderclap headaches over the course of 1 week with sudden onset of anterograde memory loss. His medications included a selective serotonin reuptake inhibitor and intermittent use of pseudoephedrine. On examination he was amnestic to recent events and notably perseverating. Magnetic resonance imaging of the brain without contrast showed a small, punctate focus of restricted diffusion in the left hippocampus. He was diagnosed with TGA based on his clinical presentation. His headaches and amnesia resolved over the next 12 h throughout the course of his stay with acetaminophen and oral verapamil and he was discharged. Repeat computed tomography angiogram at 2 weeks revealed diffuse and segmental narrowing of the anterior and posterior intracranial circulation, which resolved on follow-up imaging at 3 months, confirming RCVS. The acute and reversible nature of these conditions and increasing reports of co-occurrence suggests a common pathophysiologic link. We review the literature highlighting similar cases and the presumed pathophysiology.