Acute amnestic syndrome in isolated bilateral fornix stroke.

Abstract

Acute onset of amnestic syndrome may represent a challenging diagnostic issue. In addition to non-vascular etiology, thalamic strokes or infarction involving several temporal lobe structures have been reported. We describe three patients in whom an isolated bilateral anterior fornix infarction presented with an acute amnestic syndrome. Clinical presentation, differential diagnosis and magnetic resonance images are discussed for each patient and vascular anatomy of the involved brain regions is also considered. Bilateral anterior columns of the fornix showed cytotoxic edema and bilateral narrowing of anterior cerebral artery was demonstrated. We suggest that bilateral fornix infarction should always be considered in the diagnostic work-up of an amnestic syndrome with acute onset.