Monarch Disease Ontology term MONDO_0017276 (frontotemporal dementia) (FTD) comprises a group of neurodegenerative disorders, characterized by progressive changes in behavior, executive dysfunction and language impairment, as a result of degeneration of the medial prefrontal and frontoinsular cortices. Four clinical subtypes have been identified: semantic dementia, progressive non-fluent aphasia, behavioral variant FTD and right temporal lobar atrophy. Also known as: FTD, Wilhemsen-Lynch disease, frontotemporal lobar degeneration, multiple system tauopathy with presenile dementia, pallidopontonigral degeneration.