IntroductionIsolated infarction of the fornix is a relatively rare stroke syndrome frequently associated with amnesia. The long-term cognitive outcome in cases of acute fornix infarction is poorly understood. This is largely due to the limited number of case studies that have documented cognitive outcomes beyond the acute recovery phase on quantifiable neuropsychological measures. We describe a patient who developed acute amnesia and was subsequently diagnosed on cerebral MRI with bilateral infarction in the anterior columns of the fornix.MethodComprehensive neuropsychological review was undertaken prospectively at baseline, early and late phases of recovery.ResultsAt 9 months post-stroke, there was some reduction in the severity of memory dysfunction, but a significant anterograde amnesia persisted.ConclusionThis is one of the very few cases in the literature where neuropsychological function has been comprehensively and serially examined over the first year post-isolated bilateral fornix infarction. It is concluded that amnesia can persist well beyond 6 months in these cases, with associated functional impairment in daily life.