Frontotemporal lobar degeneration（FTLD）is a common form of dementia

particularly in patients younger than 65 years. It contains a group of neurodegenerative diseases characterized by progressive deficits in behaviour

executive function

or language. Diverse underlying genetic and neuropathological causes give rise to the frontotemporal dementia clinical phenotype with overlapping symptoms and neuroimaging findings. The clinical

genetics and pathological heterogeneity of FTLD pose a great challenge for early accurate diagnosis and treatment of disease.