Frontotemporal dementia (FTD), or frontotemporal degeneration disease, or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of frontal and temporal lobes. FTDs broadly present as behavioral or language disorders with gradual onsets. Common signs and symptoms include significant changes in social and personal behavior, apathy, blunting of emotions, and deficits in both expressive and receptive language. Currently, there is no cure for FTD, but there are treatments that help alleviate symptoms. Frontotemporal dementias are mostly early-onset syndromes that are linked to frontotemporal lobar degeneration (FTLD), which is characterized by progressive neuronal loss predominantly involving the frontal or temporal lobes, and a typical loss of more than 70% of spindle neurons, while other neuron types remain intact. The three main subtypes or variant syndromes are a behavioral variant (bvFTD) previously known as Pick's disease, and two variants of primary progressive aphasia – semantic variant (svPPA), and nonfluent variant (nfvPPA). Two rare distinct subtypes of FTD are neuronal intermediate filament inclusion disease (NIFID), and basophilic inclusion body disease. Other related disorders include corticobasal syndrome and FTD with amyotrophic lateral sclerosis (ALS) FTD-ALS also called FTD-MND. Signs and symptoms tend to appear in late adulthood, typically between the ages of 45 and 65. Men and women appear to be equally affected. FTD is the second most prevalent type of early onset dementia after Alzheimer's disease. Considered individually, each of the subtypes is relatively rare. Features of FTD were first described by Arnold Pick between 1892 and 1906. The name Pick's disease was coined in 1922. This term is now reserved only for the behavioral variant of FTD which shows the presence of the characteristic Pick bodies and Pick cells first described by Alois Alzheimer in 1911.
