383.2 🩺 國考版

383.2.1 高頻考點

383.2.1.1 FTD Epidemiology

  • 2nd most common dementia in < 65 yo
  • M = F

383.2.1.2 Three Syndromes

  • bvFTD (most common)
  • PPA (svPPA, nfvPPA, lvPPA)
  • FTD-motor (ALS, PSP, CBS)

383.2.1.3 bvFTD Features

  • Apathy
  • Disinhibition
  • Loss of empathy
  • Perseveration
  • Hyperorality (sweet tooth)
  • Executive dysfunction
  • Relatively preserved memory + visuospatial early

383.2.1.4 PPA Subtypes Distinguishing

Feature svPPA nfvPPA lvPPA
Anomia + + +
Loss of word meaning ++ – –
Agrammatism – ++ –
Apraxia of speech – ++ –
Repetition impaired – + (long) ++
Surface dyslexia + – –
Object recognition – preserved preserved
Pathology FTD-TDP-C FTD-tau or TDP AD

383.2.1.5 Pathology

  • FTD-TDP (most, including C9orf72)
  • FTD-tau (Pick, PSP, CBD, MAPT)
  • FTD-FUS (younger)

383.2.1.6 Genetics

  • C9orf72 (most common AD, also ALS)
  • MAPT
  • GRN
  • TBK1, VCP, CHMP2B

383.2.1.7 C9orf72 Hexanucleotide

  • Most common FTD-ALS
  • Often family history
  • Autosomal dominant
  • Repeat > 30 pathogenic

383.2.1.8 Imaging

  • MRI: frontotemporal atrophy
  • FDG-PET: hypometabolism
  • Amyloid PET: negative (helps distinguish lvPPA = AD)

383.2.1.9 Treatment

  • No disease-modifying
  • SSRIs for behavior
  • AVOID cholinesterase inhibitors
  • Speech therapy for PPA

383.2.1.10 FTD vs AD

Feature FTD AD
Onset Often < 65 Often > 65
First symptom Behavior or language Memory
Memory Relatively preserved early Impaired early
Insight Often impaired early Variable
Atrophy Frontotemporal Hippocampal/temporal
Genetics 30-50% < 5% familial
Treatment No DMT, SSRI ChEI + memantine + anti-amyloid

383.2.2 Specific Features

383.2.2.1 bvFTD Behavioral

  • “Frontal” disinhibition
  • KlÃŒver-Bucy-like (hyperorality, hypersexuality, placidity)
  • Loss of social cognition
  • Family often distressed

383.2.2.2 svPPA Specifics

  • “What is this called?” → “I don’t know”
  • “What is this?” → can describe function but not name
  • Surface dyslexia: “yacht” → “yatched”
  • Behavioral changes later
  • Right temporal variant: prosopagnosia + emotional changes

383.2.2.3 nfvPPA Specifics

  • Effortful speech
  • Distortions
  • “telegraphic” speech
  • Can lose ability to speak

383.2.2.4 lvPPA Specifics

  • Often AD pathology — anti-amyloid mAb may be considered
  • Confirm with amyloid PET or CSF

383.2.2.5 C9orf72 Features

  • AD inheritance
  • FTD + ALS overlap
  • Psychosis common
  • Genetic anticipation possible