Frontotemporal degeneration (FTD): Degeneration of the cells in the frontal and temporal lobes of the brain causes this group of brain disorders. It is also referred to as frontotemporal dementia, frontotemporal lobar degeneration (FTLD), or Pick's disease. FTD typically occurs in younger people than Alzheimer's disease, with most cases occurring between the ages of 45 and 64. It can develop in ages ranging from the 20s to the 80s. Symptoms include a gradual decline in function related to behavior, language, or movement. Memory is usually relatively preserved in people with FTD.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.