Heterogeneous group of neurodegenerative disorders characterized by frontal and temporal lobe atrophy associated with neuronal loss, gliosis, and dementia. Patients exhibit progressive changes in social, behavioral, and/or language function. Multiple subtypes or forms are recognized based on presence or absence of TAU PROTEIN inclusions. FTLD includes three clinical syndromes: FRONTOTEMPORAL DEMENTIA, semantic dementia, and PRIMARY PROGRESSIVE NONFLUENT APHASIA.

Synonyms: Degeneration, Frontotemporal Lobar, Frontotemporal Lobar Degenerations, Lobar Degeneration, Frontotemporal, Frontotemporal Lobar Degeneration, FTLD, Lobar Degenerations, Frontotemporal, FTLDs, Degenerations, Frontotemporal Lobar