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. The three main subtypes or variant syndromes are a behavioral variant (bvFTD) previously known as Picks 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.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.FTD was first described by Arnold Pick in 1892 and was originally called Picks disease, a term now reserved only for behavioral variant FTD which shows the presence of Pick bodies and Pick cells. Second only to Alzheimers disease (AD) in prevalence,  FTD accounts for less than, or actually, 20% (number is perhaps rounded) of degenerative dementia cases found at autopsy.Signs and symptoms typically manifest in late adulthood, more commonly between the ages of 45 and 65, approximately equally affecting men and women.Common signs and symptoms include significant changes in social and personal behavior, apathy, blunting of emotions, and deficits in both expressive and receptive language.
History
The syndrome is named after Douglas Reye, who, along with fellow physicians Graeme Morgan and Jim Baral, published the first study of the syndrome in 1963 in The Lancet. In retrospect, the occurrence of the syndrome may have first been reported in 1929. Also in 1964, George Johnson and colleagues published an investigation of an outbreak of influenza B that described 16 children who developed neurological problems, four of whom had a profile remarkably similar to Reye syndrome. Some investigators refer to this disorder as Reye-Johnson syndrome, although it is more commonly called Reye syndrome. In 1979, Karen Starko and colleagues conducted a case-control study in Phoenix, Arizona, and found the first statistically significant link between aspirin use and Reye syndrome. Studies in Ohio and Michigan soon confirmed her findings pointing to the use of aspirin during an upper respiratory tract or chickenpox infection as a possible trigger of the syndrome. Beginning in 1980, the CDC cautioned physicians and parents about the association between Reye syndrome and the use of salicylates in children and teenagers with chickenpox or virus-like illnesses. In 1982 the U.S. Surgeon General issued an advisory, and in 1986 the Food and Drug Administration required a Reye syndrome-related warning label for all aspirin-containing medications. References
External links
NINDS Reyes Syndrome Information Page