Transient Global Amnesia

Abstract

Background and Purpose-A hypoxic-ischemic origin of transient global amnesia (TGA) has been suggested on the basis of the observation of infarctlike diffusion-weighted imaging (DWI) abnormalities in some affected individuals. We tested this hypothesis by comparing vascular risk factors, magnetic resonance imaging (MRI) markers of cerebral small-vessel disease, and other evidence of a cerebrovascular disorder between TGA patients with (DWIϩ) and without (DWIϪ) DWI lesions and normal community-based controls. Methods-We retrospectively identified 86 patients hospitalized for TGA (meanϮSD age, 65.9Ϯ10.9 years; 62% female).Brain MRI at 1.5 T was assessed for DWI lesions exhibiting restricted diffusion (ie, DWIϩ), white-matter hyperintensities, lacunes, and chronic infarcts (median time lag to clinical onset, 66.6Ϯ54.6 hours). Vascular risk factors and findings from duplex sonography, ECG, and echocardiography were recorded. A 1:2 age-and sex-matched sample of 172 elderly subjects (meanϮSD age, 65.6Ϯ9.3 years; 62% female) free of neuropsychiatric disease served for comparison. Results-DWI lesions were observed in 10 patients with TGA (11.5%; meanϮSD age, 68.3Ϯ5.4 years; 8 women). They were all small and located in the mesiotemporal region (9 left hemisphere, 5 right hemisphere). The vascular risk profile of TGA patients and concomitant changes on brain MRI were comparable with those of healthy controls and did not show significant differences between DWIϩ and DWIϪ subjects. A comprehensive diagnostic workup also provided no evidence for a higher rate of cerebrovascular disorder-related abnormalities in either the total group of TGA patients or TGA DWIϩ patients. Conclusions-These

Internal Jugular Vein Valve Incompetence Is Highly Prevalent in Transient Global Amnesia

“…Несмотря на это, M. Kushner и W. Hauser [7] не подтвердили эти выводы. В исследованиях с исполь-зованием диффузионно-взвешенной магнитно-резо-нансной томографии (ДВ-МРТ) были обнаружены незначительные, остро возникшие изменения в меди-альных областях височных долей у небольшого числа пациентов с клиническим диагнозом ТГА [8]. Другие авторы предположили наличие связи ТГА с эпилепсией [9,10] и опухолями головного мозга [11,12].…”

“…Studies with diffusion-weighted magnetic resonance imaging (MRI) have found small, acute changes in the mesial temporal areas in a minority of patients with a clinical diagnosis of TGA. 8 Other authors have suggested an epileptic etiology 9,10 and association with brain tumors. 11,12 In recent years, the theory of brain venous congestion has been proposed.…”

High-Resolution Diffusion-Weighted Imaging Increases Lesion Detectability in Patients with Transient Global Amnesia

“…However, previous studies reported relatively lower incidence of multiplicity, ranging from 5% to 38%. 7,10,22,23 This may be due to increased detectability of high-resolution DWI for smaller lesions, which were missed on lower resolution by partial volume averaging effects. 7,9,22 Therefore, we think that high-resolution DWI with less partial volume averaging might improve lesion contrast in our study.…”

Internal Jugular Vein Valve Incompetence in Transient Global Amnesia

“…10 In line with this theory, magnetic resonance imaging (MRI) studies reported a variable percentage of hippocampal abnormalities displaying restricted diffusion in patients with TGA who lacked vascular risk factors, large-artery stenoses or small-vessel disease, and underlying sources of cardioembolism. 11 In addition, 30-day follow-up MRIs did not show any pathologic findings indicative of previous arterial ischemia. 12 Although these results were fairly consistent, studies evaluating IJV competence and MRI findings in the same patients are not available.…”

“…In the population investigated by Cejas et al, IJV valve incompetence was observed more frequently on the right side, whereas MRI abnormalities were more often detected in the left mesiotemporal region. [11][12][13] Indeed, MRI diffusion restriction is not a specific finding, as it is also observed in ischemic depolarization and cortical spreading depression. Can venous ischemia and cortical spreading depression represent 2 notmutually exclusive mechanisms?…”