Perception of emotion in frontotemporal dementia and Alzheimer disease

Frontotemporal dementia (FTD) is the second cause of degenerative dementia. Behavioral changes occur before the cognitive decline and remain the major feature. A poor perception of emotion could account for some behavioral sy mptoms. The aim of this study was to assess the perception of emotion in pa tients with FTD and to compare it with that of patients with Alzheimer dise ase (AD). Fifty subjects performed the tests: 20 patients with probable AD, 18 patients with FTD, and 12 matched controls. The two patient groups did not differ in age, sex, severity of dementia, duration of the disease, and language tests. Subjects bad to recognize and point out the name of one of seven basic emotions (anger, disgust, happiness, fear, sadness, surprise, a nd contempt) on a set of 28 faces presented on slides. The three groups wer e equally able to distinguish a face displaying affect from, one not displa ying affect. Naming of emotion was worse in patients with FTD than in patie nts with AD (correct answers 46% vs. 62%; p = 0.0006) who did not differ si gnificantly fi om controls (72%). Anger, sadness, and disgust were less rec ognized in FTD than in AD patients who did not differ from controls, wherea s fear and contempt were poorly recognized in both groups of patients compa red with controls. These findings argue for different neural substrates und erlying the recognition of various basic emotions. Behavioral disorders in FTD may be partly due to an impaired interpretation of the emotional enviro nment.