Facial Emotion Recognition Deficit in Amnestic Mild Cognitive Impairment and Alzheimer Disease

Abstract

A deficit in facial emotion recognition was described in patients with Alzheimer disease (AD). However, this issue has been underexplored in subjects with amnestic mild cognitive impairment (a-MCI). Thus, the authors aimed to determine whether a deficit in facial emotion recognition is present in a-MCI phase and whether this is intensity dependent. A secondary aim was to investigate relationships between facial emotion recognition and cognitive performances. Case-control study. Memory clinic. Fifty a-MCI patients, 50 mild AD patients, and 50 comparison subjects (COM) were enrolled. Information about facial emotion recognition was obtained from Penn Emotion Recognition Test. The Mental Deterioration Battery was used to measure cognitive impairment. Mild AD patients were more impaired in the recognition of almost all emotional stimuli of all intensities than a-MCI and COM subjects. However, there was an increased progression only in low-intensity facial emotion recognition deficit from COM to a-MCI to mild AD patients. In particular, a-MCI subjects differed significantly from COM in low-intensity fearful face recognition performance. This deficit in a-MCI patients was explained by the short-term verbal memory impairment, whereas the same deficit in mild AD patients was explained by the long-term verbal memory impairment. Emotion recognition progresses from a deficit in low-intensity fearful facial recognition in a-MCI phase to a deficit in all intensities and emotions in mild AD. This could be an effect of the progressive degeneration of brain structures modulating emotional processing. An early detection of emotional impairment in MCI phases of dementia may have clinical implications.