Unlike Alzheimer's disease, which generally affects most areas of the brain, frontotemporal dementia is an umbrella term for a group of disorders that primarily affect the frontal and temporal lobes of the brain - the areas generally associated with personality, behaviour, emotions, language, speech, abstract thinking and movement. In most cases of FTD, brain cells in these areas shrink or die. In other cases, the brain cells in these areas get larger, containing round, silver "Pick's bodies". The diagnosis is then Pick's disease or behavioural variant Frontotemporal Dementia (bvFTD), the most common frontotemporal disorder.