Brain functional imaging of frontotemporal lobar degeneration

Frontotemporal lobar degeneration (FTLD) is one of the common diseases causing dementia by including degenerative changes within the brain. The clinical subtypes of FTLD comprise frontotemporal dementia (FTD), progressive nonfluent aphasia (PNFA), and semantic dementia (SD). In this review, the role of the brain functional imaging on diagnosing of FTLD is described. Regionally distinct patterns of hypoperfusion on single-photon emission computed tomography (SPECT) or hypometabolism on positron emission tomography (PET) are helpful in differentiation of FTLD, Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and corticobasal degeneration (CBD). The recently developed techniques show great promise in detecting specific neuropathological changes in dementia such as amyloid and tau pathology.