<unk>  <unk> , also called Benson's syndrome, is a rare form of dementia which is considered a visual variant or an atypical variant of Alzheimer's disease (AD). The disease causes atrophy of the<unk>  part of the cerebral cortex, resulting in the progressive disruption of complex visual processing.<unk>  was first described by D. Frank Benson in 1988.<unk>  usually affects people at an earlier age than typical cases of Alzheimer's disease, with initial symptoms often experienced in people in their mid-fifties or early sixties. This was the case with writer Terry Pratchett (1948-2015), who went public in 2007 about being diagnosed with<unk> . In rare cases,<unk>  can be caused by dementia with Lewy bodies and Creutzfeldt–Jakob disease.
Posterior cortical atrophy
Geographic atrophy
Pellucid marginal degeneration
Hippocampal sclerosis
Polymicrogyria
Cerebral atrophy
Central chromatolysis
Neurofibrillary tangle