Posterior cortical atrophy. Two case reports and a review of the literature.

We present two cases of progressive early-onset dementia with apraxia and visuospatial disability as initial manifestations. In the later stages of the illness Gerstmann's and Balint's syndromes developed. Structural neuroimaging demonstrated parieto-occipital atrophy and functional imaging revealed bilateral hypometabolism and hypoperfusion in these areas. These cases fulfil the diagnostic criteria of posterior cortical atrophy (PCA). Frontal lobe involvement became evident as the disease progressed. Alzheimer's disease also typically features this anterior spread and possibly this is the underlying pathological substrate for this clinical syndrome, although definite pathology is lacking. In this report, we describe longitudinal evolution in these two cases of PCA.