Summary
Benson's syndrome or Posterior Cortical Atrophy (PCA) is a rare degenerative disorder clinically distinct from Alzheimer's disease (AD) (see this term). Its frequency is unknown. PCA refers to a clinical syndrome in which higher order visual processing is disrupted owing to a neurodegenerative disorder. The patients present with progressive and severe visual agnosia (inability to recognize and identify familiar objects or persons) and apraxia (loss in the ability to execute or perform skilled familiar movements). Manifestations include simultanagnosia, optic ataxia, oculomotor apraxia, prosopagnosia, alexia, and environmental disorientation. Patients have also contructional and dressing apraxia, ideomotor apraxia, agraphia, acalculia. Memory, language, insight, and judgment are relatively preserved until late in the disease course. Brain Magnetic Resonance Imagery (MRI) shows bilateral atrophy in the parieto- and temporo-occipital areas that is more severe in right hemisphere. Brain single photon emission computed tomography (SPECT) or positron emission tomography (PET) show hypometabolism of the brain posterior areas. The most commonly associated neuropathology is that of AD. Deposition of neuritic plaques and neurofibrillary tangles are specifically revealed in posterior cerebral areas and sometimes in primary visual areas. Management of PCA is based on visual aids and antidepressant treatments. *Author: Dr B. Croisile (September 2004).*
