Frontotemporal Lobe Dementia

Abstract

Frontotemporal dementia (FTD) is a spectrum of clinical syndromes characterized by neuronal degeneration involving the frontal and anterior temporal lobes of the brain.[1][2] In patients age ≥ 65, it is the third most common cause of dementia and is the second most common cause of early-onset dementia (age <65) and usually involves patients with age ranges from 45 to 65. Arnold Pick was the first to report frontotemporal associated clinical syndromes in 1892. Onari and Hugo Spatz coined the term “Picks disease” in 1926 for frontotemporal lobe atrophy with the presence of cytoplasmic inclusion bodies known as Pick bodies. It was later replaced by the term FTD based on distinct clinical and histopathological criteria, assigned by a research group from the United Kingdom and Sweden in 1994.[3] FTD targets brain areas that are responsible for personality, behavior, language learning, motivation, abstract thinking, and executive function. Behavior changes and or language difficulty are the presenting clinical features followed by loss of executive function and cognitive abilities.[4] It is classified into two distinct clinical types; behavior variant (bvFTD) and language type. The language type of FTD is further classified into non-fluent variant primary progressive aphasia (nfvPPA), and semantic variant primary progressive aphasia (svPPA) depending on the areas of neuronal loss in frontal and temporal lobes.[5][6]