DefinitionPick's disease is a rare and permanent form of dementia that is similar to Alzheimer's disease, except that it tends to affect only certain areas of the brain.Alternative NamesSemantic dementia; Dementia - semantic; Frontotemporal dementia; Arnold Pick's diseaseCauses, incidence, and risk factorsPeople with Pick's disease have abnormal substances (called Pick bodies and Pick cells) inside nerve cells in the damaged areas of the brain.Pick bodies and Pick cells contain an abnormal form of a protein called tau. This protein is found in all nerve cells. But some people with Pick's disease have an abnormal amount or type of this protein.The exact cause of the abnormal form of the protein is unknown. Many different abnormal genes have been found that can cause Pick's disease. Many cas