Transient Global Amnesia: A Clinical and Sonographic Study

Abstract

Background: The aetiology of transient global amnesia (TGA) is still unknown. The aim of this study was to identify potential risk factors for TGA, vascular risk factors, the role of patent foramen ovale (PFO) and of retrograde jugular venous flow. Methods: 138 subjects entered the study, including 48 patients with TGA, 42 age-matched patients with transient ischaemic attack (TIA) and 48 controls. PFO was studied by contrast transcranial duplex sonography. Retrograde jugular venous flow was tested with air contrast ultrasound venography (ACUV). Results: TGA patients and controls showed a lower prevalence for vascular risk factors than TIA patients. No statistical difference was found between the 3 groups with regard to PFO. ACUV detected jugular valve incompetence in 72.9% TGA, 35.7% TIA and 39.5% controls (TGA vs. TIA and TGA vs. controls p < 0.01). Conclusions: TGA patients have fewer vascular risk factors than TIA patients. Paradoxical embolism due to PFO as a cause of TGA is not confirmed in our study. Cerebral venous hypertension due to incompetence of the internal jugular valve may play a role in the pathogenesis of TGA.

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

“…16,18,19 In contrast to the study of Chung et al, 17 we did not find an exclusively left-sided reflux. Our technique did not allow for insonation of the left brachiocephalic vein.…”

“…In agreement with other investigations, we found a predominance of right-sided IJV. 18,20 Further research may establish whether this finding is related to differences in the diameter between right and left IJVs. 25 This investigation might suggest a role for IJV valve incompetence in the pathophysiology of TGA.…”

“…Our findings are similar to those reported by other authors using similar or other methods of evaluation. [17][18][19][20]22 In this prospective study, we followed standardized criteria for the assessment of patients with TGA and controls, and every subject was evaluated by an experienced neurologist.…”

“…Этот результат подтверж-дает гипотезу, что ретроградная венозная гипертензия, приводящая к транзиторной церебральной ишемии, является ключевым звеном патогенеза ТГА. Результаты предварительных исследований с использованием уль-трасонографии показали высокую распространенность недостаточности клапана ВЯВ при проведении пробы Вальсальвы у пациентов с ТГА [18][19][20][21][22].…”

Transient global amnesia following a transoceanic flight

“…44,45 Valsalva strain leads to venous stagnation in the mesial temporal lobes. 46 During airplane descent, there may be difficulty in equalizing pressure of the middle ear with that of the surrounding environment and some passengers may use the Valsalva maneuver to actively equalize the pressure differential. 47 We do not know if this occurred in the present case.…”