What are other names for frontotemporal dementia (FTD)?

Other Names for Frontotemporal Dementia (FTD)

Frontotemporal dementia (FTD) is commonly referred to by several alternative names including behavioral variant frontotemporal dementia (bvFTD), frontotemporal lobar degeneration (FTLD), and primary progressive aphasia (PPA) depending on the specific clinical presentation and affected brain regions. 1

Main Terminology and Subtypes

• FTD (Frontotemporal Dementia) - The umbrella term for the clinical syndrome characterized by progressive degeneration of the frontal and temporal lobes 1, 2
• FTLD (Frontotemporal Lobar Degeneration) - Refers to the larger group of disorders of which FTD is a subgroup; describes the pathological changes in the brain 2, 3
• bvFTD (Behavioral variant Frontotemporal Dementia) - Characterized by changes in personality, behavior, and executive function 1
• PPA (Primary Progressive Aphasia) - Language variant of FTD with two main subtypes 4, 2:
  • nfvPPA/avPPA (Nonfluent/agrammatic variant PPA) - Characterized by effortful speech and grammatical errors 4, 5
  • svPPA (Semantic variant PPA) - Characterized by impaired word finding and loss of meaning of words and objects 4, 5

Associated Clinical Syndromes

• Right temporal variant of FTD - The "mirror image" of semantic variant PPA, with predominant right anterior temporal lobe atrophy 5
• FTD-ALS (Frontotemporal Dementia with Amyotrophic Lateral Sclerosis) - When FTD occurs with motor neuron disease 1, 6
• Atypical parkinsonian syndromes associated with FTD 4:
  • CBS (Corticobasal Syndrome) - When FTD presents with asymmetric parkinsonism and apraxia 4
  • PSP (Progressive Supranuclear Palsy) - When FTD presents with vertical gaze palsy and falls 4

Historical and Less Common Terms

• Pick's disease - A historical term referring to a specific pathological subtype of FTD with tau-positive inclusions (Pick bodies) 2, 3
• Frontal lobe dementia - An older term emphasizing the frontal lobe involvement 1
• LOF (Late-Onset Frontal lobe syndrome) - Used in some research contexts for late-onset behavioral changes 1

Pathological Classifications

• FTLD-tau - FTD with tau protein accumulation 2, 3
• FTLD-TDP - FTD with TDP-43 (transactive response DNA-binding protein) accumulation 3
• FTLD-FUS - FTD with fused in sarcoma protein accumulation 3
• FTLD-U - FTD with ubiquitinated inclusions 2

Genetic Subtypes

• C9orf72-associated FTD - FTD caused by hexanucleotide repeat expansions in the C9orf72 gene 1
• GRN-associated FTD - FTD caused by mutations in the progranulin gene 1
• MAPT-associated FTD - FTD caused by mutations in the microtubule-associated protein tau gene 1

Clinical Considerations

• Early diagnosis of FTD is challenging due to symptom overlap with psychiatric disorders, leading to frequent misdiagnosis 1, 7
• About 50% of bvFTD patients initially receive a psychiatric diagnosis, most commonly major depression 1
• Diagnostic delay is common, averaging 5-6 years from symptom onset 1
• Genetic testing is recommended for probable bvFTD with at least one first-degree relative with bvFTD, late-onset psychiatric disorders, ALS, or other early-onset neurodegenerative disease 1
• C9orf72 testing should be performed in all possible/probable bvFTD cases or suspected cases with strong psychiatric features 1