I. Patient shows gradually progressive deterioration by history and/or testing

II. Clinical diagnosis of sbvFTD: Patient must have two out of the core features A–C and two out of the supportive features D–F: Core features: A. Loss of empathy (difficulty understanding emotions) B. Difficulty naming and identifying known people C. Complex compulsions or rigid thought process Supportive features: D. Object naming difficulties E. Spared visuospatial functions including preserved perceptual matching and drawing reproduction F. Spared motor speech and phonology

III. Imaging-supported sbvFTD: All the following must be present: A. Meets criteria for sbvFTD and B. Imaging results consistent with sbvFTD: Laterality is right-sided in right-handed but could be left-sided in non-right-handed individuals.  (i) Anterior temporal lobe volume loss and relative sparing of the frontal cortex on MRI or CT; or  (ii) Anterior temporal lobe hypometabolism and relative sparing of the frontal cortex on FDG-PET

IV. SbvFTD with definite pathology All the following must be present: A. Clinical diagnosis of sbvFTD B. Histopathological or genetic evidence:  (i) Histopathology of a specific neurodegenerative pathology (e.g. FTLD-TDP, FTLD-tau, other); or  (ii) Presence of known pathogenic mutation