The article discusses the 2011 revised diagnostic criteria for behavioral variant frontotemporal dementia (bvFTD), developed by an international consortium to improve early and accurate diagnosis. bvFTD is characterized by progressive behavioral and cognitive changes, often including social and emotional impairments, compulsive behaviors, and dietary changes. The revised criteria, formulated by the International bvFTD Criteria Consortium, offer a hierarchical approach with varying levels of diagnostic certainty: possible, probable, and definite bvFTD. The criteria emphasize observable behavioral patterns, functional decline, and neuroimaging, underscoring the necessity of both clinical and neuroimaging evidence in diagnosis.

1. Possible bvFTD

• Progressive behavioral or cognitive decline, confirmed by a knowledgeable informant.
• Three of the following six features:
  • Early Behavioral Disinhibition: Socially inappropriate behavior, loss of manners, impulsive actions.
  • Apathy or Inertia: Observable apathy or inertia.
  • Loss of Sympathy or Empathy: Diminished response to others' needs, reduced social warmth.
  • Compulsive or Ritualistic Behavior: Simple repetitive movements, ritualistic behaviors, stereotyped speech.
  • Hyperorality and Dietary Changes: Changes in food preferences, binge eating, or oral exploration of inedible objects.
  • Neuropsychological Profile: Executive function deficits with relatively preserved memory and visuospatial skills.

2. Probable bvFTD

• Meets all criteria for possible bvFTD.
• Significant functional decline reported by a caregiver or through standardized scales.
• Imaging findings consistent with bvFTD, including:
  • Frontal and/or Anterior Temporal Atrophy on MRI or CT.
  • Frontal and/or Anterior Temporal Hypoperfusion or Hypometabolism on PET or SPECT.

3. bvFTD with Definite FTLD Pathology

• Meets criteria for possible or probable bvFTD.
• Histopathological evidence of FTLD through:
  • Biopsy or Post-Mortem findings.
  • Known Pathogenic Mutation associated with FTLD.

4. Exclusionary Criteria for bvFTD

• Symptoms not better explained by non-degenerative neurological or medical disorders.
• Behavioral symptoms not better explained by a psychiatric diagnosis.
• Absence of biomarkers strongly indicative of Alzheimer's disease or other neurodegenerative processes.