Abstract for presentation at The Australian and New Zealand Association of Neurologists Annual Scientific Meeting 2007

A 55 year old female presented with a symptomatic incongruous left inferior quadrantanopia, confirmed by formal Humphrey visual field testing. Exhaustive ophthalmic investigations were unremarkable. Neurological examination 2 years after presentation disclosed marked visuospatial and visuoperceptual deficits but no other overt cognitive abnormalities. Although magnetic resonance imaging (MRI) showed no structural pathology in the optic radiation or visual cortices, FDG-positron emission tomography (PET) revealed marked glucose hypometabolism in both parietal and occipital association cortices, and moderate glucose hypometabolism in the right mesial occipital cortex. Formal neuropsychological confirmed a pattern of deficits consistent with the posterior cortical atrophy (PCA) syndrome, most likely due to an atypical variant of Alzheimer’s dementia. A high index of suspicion for neurodegenerative disease should be maintained in patients presenting with isolated visual field defects in the absence of demonstrable structural pathology.