Purpose of review: Within the continuously growing body of knowledge in the field of dementia, frontotemporal degeneration stands out in importance as the second most common cause of early-onset dementia after Alzheimer disease. Neurologists, neuropsychologists, and speech pathologists are particularly involved in the diagnosis and recognition of etiologies for patients with deficits in frontal lobe function and language.
Recent findings: The recent discovery of a novel mutant gene (C9ORF72) and the new nomenclature adopted for subclassification have significantly promoted our understanding of this disorder.
Summary: This article relates the most recent consensus criteria for diagnosis of the two forms of frontotemporal degeneration (ie, behavioral and primary progressive aphasia variants) to basic neurologic principles and remind clinicians of the neuropsychiatric and neuroradiologic components that clarify frontotemporal degeneration diagnoses and guide management.