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

Cognitive deficits and course of recovery in transient global amnesia: a systematic review

OBJECTIVE

Published evidence suggests that cognitive impairment during a TGA (transient global amnesia) spell may not be confined to episodic memory. We undertook a systematic review to determine the pattern of cognitive deficits during a TGA episode. As a secondary objective, we aimed to delineate the course of cognitive recovery.

METHODS

MEDLINE, EMBASE, CENTRAL, and Google scholar were systematically searched up to October 2023. Observational controlled studies including 10 or more TGA patients (Hodges and Warlow criteria) were retrieved. Data from case-control, cross-sectional, and cohort studies were reviewed and qualitatively synthesized.

RESULTS

Literature search yielded 1302 articles. After the screening of titles and abstracts, 115 full texts were retrieved and 17 of them were included in the present systematic review. During the acute phase, spatiotemporal disorientation, dense anterograde and variable retrograde amnesia, semantic memory retrieval difficulties, and working memory deficits comprised the neuropsychological profile of patients with TGA. Visuospatial abilities, attention and psychomotor speed, semantic memory, confrontation naming, and other measures of executive function (apart from semantic fluency and working memory) were consistently found normal. In the course of recovery, after the resolution of repetitive questioning, the restoration of spatiotemporal orientation follows, working memory and semantic memory retrieval ensue, while episodic memory impairment persists for longer. Meticulous evaluations may reveal subtle residual memory (especially recognition) deficits even after 24 h.

CONCLUSIONS

Μemory impairment, spatiotemporal disorientation, and working memory deficits constitute the pattern of cognitive impairment during a TGA spell. Residual memory deficits may persist even after 24 h.

[Transient global amnesia - benign memory blackout]

Transient global amnesia (TGA) is a typical clinical syndrome characterized by acute, predominantly anterograde amnesia. New epidemiological data assume a significantly higher annual incidence than previously assumed, namely around 15 cases per 100,000 people. Those affected, usually over the age of 50, cannot remember new memory content for longer than 30-180 seconds and therefore ask repetitive questions about current events. All other cognitive functions are unimpaired, and everything previously learnt, e.g. driving or cooking, can be carried out. The episodes are self-limiting and by definition subside within 24 hours. At least 10% of those affected will experience 1-5 recurrences in the future. The punctate lesions in the hippocampus, which are found on MRI in at least 50% of patients after 24-72 hours, are distributed 2/3 unilaterally and 1/3 bilaterally. Using 7 Tesla MRI the frequency of detected lesions increases to 90% compared to 50% with 1.5 or 3 Tesla. Beyond the punctiform hippocampal lesions, other memory-related network disorders, including the default network, are also suggested to be involved in the pathomechanism of TGA. TGA etiology and pathophysiology are not known in detail. Vascular, migraine-like, epilepsy-like, and psychogenic mechanisms are discussed. Triggers of the episodes are often physical exertion with a Valsalva character. Management is aimed at identifying the syndrome based on the typical clinical presentation and ruling out possible differential diagnoses with similar symptoms. During the TGA, the usually anxious relatives should be reassured of the benign and inconsequential nature of the episode.

Simultaneous occurrence of transient global amnesia and Takotsubo syndrome triggered by caring for a terminally ill relative

Takotsubo syndrome and transient global amnesia can occur simultaneously, not only in the context of acute but also long-standing emotional stress. Probably, hypothyroidism and migraine make the patient more susceptible to both of these disorders.

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

BACKGROUND AND PURPOSE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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 (TGA): Sex-Specific Differences in Blood Pressure and Cerebral Microangiopathy in Patients with TGA

Transient global amnesia (TGA) is defined by an acute memory disturbance of unclear aetiology for a period of less than 24 h. Observed psychological, neuroanatomical and hormonal differences between the sexes in episodic memory suggest sex-specific differences in memory disorders such as TGA. The aim of this study was to determine sex-specific differences in cardiovascular risk profiles, recurrences and magnetic resonance imaging (MRI). In total, 372 hospitalised TGA patients between 01/2011 and 10/2021 were retrospectively analysed. Comparisons were made between female and male TGA patients and compared to 216 patients with acute stroke. In our sample, women were overrepresented (61.8%), especially compared to the general population in the 65−74 age category (χ2 = 10.6, p < 0.02). On admission, female TGA patients had significantly higher systolic blood pressure values and a higher degree of cerebral microangiopathy compared to male TGA patients, whereas acute stroke patients did not. No sex-specific differences were observed with respect to recurrences or hippocampal DWI lesions. Our data demonstrate sex-specific differences in TGA. The higher blood pressure on admission and different degree of cerebral microangiopathy in female TGA patients supports the theory of blood pressure dysregulation as a disease trigger. Distinct precipitating events in female and male patients could lead to differences in the severity and duration of blood pressure abnormalities, possibly explaining the higher incidence in female patients.

Forgetting the Unforgettable: Transient Global Amnesia Part II: A Clinical Road Map

Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of a temporary memory disorder with profound anterograde amnesia and a variable impairment of the past memory. Usually, the attacks are preceded by a precipitating event, last up to 24 h and are not associated with other neurological deficits. Diagnosis can be challenging because the identification of TGA requires the exclusion of some acute amnestic syndromes that occur in emergency situations and share structural or functional alterations of memory circuits. Magnetic Resonance Imaging (MRI) studies performed 24–96 h after symptom onset can help to confirm the diagnosis by identifying lesions in the CA1 field of the hippocampal cornu ammonis, but their practical utility in changing the management of patients is a matter of discussion. In this review, we aim to provide a practical approach to early recognition of this condition in daily practice, highlighting both the lights and the shadows of the diagnostic criteria. For this purpose, we summarize current knowledge about the clinical presentation, diagnostic pathways, differential diagnosis, and the expected long-term outcome of TGA.

The remains of the day: neuropsychological findings in postacute transient global amnesia

INTRODUCTION

Current clinical diagnostic criteria of transient global amnesia (TGA) require the episode to completely resolve within 24 h. Small case series investigating the neuropsychological profiles obtained during the first days after TGA are inconclusive, with some suggesting the persistence of memory deficits.

METHODS

In this retrospective observational study, neuropsychological data of 185 TGA patients obtained during the first days following an attack were analysed. Data of cognitive functions assessed in at least 50 patients were evaluated and dichotomised according to z-values as "impaired" or "unimpaired". Moreover, the results of magnetic resonance imaging (MRI) were collected.

RESULTS

Neuropsychological assessment was performed within the first 3 days after TGA in 158 (85.4%) of all patients. The majority of patients showed no significant neuropsychological sequelae in the postacute phase of TGA. However, Mini-Mental Status Examination showed impairment in 22.6% of 159 patients, and we found subtle reductions of patients' performance in tests of verbal long-term memory and executive function in 16.3-24.6% of patients. Patients with hippocampal diffusion-weighted imaging (DWI) lesions performed significantly worse in a verbal recognition task than those without DWI lesions.

DISCUSSION

Our findings reflect subtle performance reductions in different cognitive domains in a small subgroup of TGA patients. This implies that the gradual resolution of subclinical symptoms may take longer than the 24 h required as maximum episode duration by current diagnostic criteria.