Emotional quotient in frontotemporal dementia vs. Alzheimer's disease: the role of socioemotional agnosia.

Introduction: Socioemotional dysfunction distinguishes behavioural variant frontotemporal dementia (bvFTD) from other dementias. Patients with bvFTD not only have early social impairment and emotional blunting, but they also have agnosia of their socioemotional dysfunction.

Methods: To investigate the relationship between agnosia and dysfunction, we assessed self-knowledge of socioemotional dysfunction with an emotional quotient (EQ) scale administered to 12 patients with bvFTD and a comparison group of 12 age-matched patients with Alzheimer's disease (AD), and compared these self-ratings to caregiver ratings of social dysfunction and emotional blunting.

Results: The bvFTD patients self-rated as having higher EQs than the AD patients, particularly higher self-ratings of their Social Skills, an EQ subscale which correlated with increased emotional blunting. On within-groups analysis, the bvFTD patients' high self-ratings of their EQ Appraisal of Emotions correlated with increased socioemotional dysfunction, whereas all of the AD patients' self-ratings correlated appropriately with their degree of dysfunction.

Conclusions: Large socioemotional agnosia scores (EQ minus function) distinguishes bvFTD from AD. Additionally, in bvFTD, agnosia specifically for their ability to appreciate others' emotions correlates with the degree of socioemotional dysfunction, suggesting a role for socioemotional agnosia in increasing socioemotional dysfunction.