[Posterior cortical atrophy. Pathology, diagnosis and treatment of a rare form of dementia].

The syndrome of posterior cortical atrophy (PCA) is a rare clinical manifestation of several neurodegenerative diseases which affect the parieto-occipital cortex. The most frequent underlying pathology is Alzheimer's disease but some cases are caused by Lewy body disease, progressive subcortical gliosis, corticobasal degeneration or prion diseases. The most prominent clinical feature of PCA is complex visual disturbances including object agnosia, simultanagnosia, optical ataxia and oculomotor apraxia while basic visual functions remain intact. These deficits lead to multiple impairments in activities of daily living that require visual control. On progression of the disease amnestic, apraxic and dysexecutive symptoms occur so that a global dementia gradually emerges. At the core of the diagnostic work-up are a detailed patient history, accurate analysis of behavior and neuropsychological testing. Structural and functional brain imaging are suitable to demonstrate the localization of the disease process. Measurement of cerebrospinal fluid proteins (e.g. beta amyloid, tau, phospho-tau and 14-3-3) serves to confirm or exclude Alzheimer's disease or prion diseases. The mainstay of treatment are non-pharmacological interventions to support activities of daily living and personal independence. These treatments include cognitive training and compensatory strategies which can be prescribed as neuropsychological treatment or occupational therapy. If Alzheimer's disease or Lewy body disease is the likely cause, a treatment with cholinesterase inhibitor may be tried. Caregiver education and support are another essential part of the treatment regimen as with all forms of dementia.