Posterior cortical atrophy (PCA), also called Benson's syndrome, is a form of dementia which is usually considered an atypical variant of Alzheimer's disease.[1] The disease causes atrophy of the posterior part of the cerebral cortex, resulting in the progressive disruption of complex visual processing.[2] PCA was first described by D. Frank Benson in 1988.In rare cases, PCA can be caused by dementia with Lewy bodies and Creutzfeldt–Jakob disease.