Sad and happy facial emotion recognition impairment in progressive supranuclear palsy in comparison with Parkinson's disease

The severity of motor and non-motor symptoms of progressive supranuclear palsy (PSP) has a profound impact on social interactions of affected individuals and may, consequently, contribute to alter emotion recognition. Here we investigated facial emotion recognition impairment in PSP with respect to Parkinson's disease (PD), with the primary aim of outlining the differences between the two disorders. Moreover, we applied an intensity-dependent paradigm to examine the different threshold of encoding emotional faces in PSP and PD. The Penn Emotion Recognition Test (PERT) was used to assess facial emotion recognition ability in PSP and PD patients. The 2 groups were matched for age, disease duration, global cognition, depression, anxiety, and daily L-Dopa intake. PSP patients displayed significantly lower recognition of sad and happy emotional faces with respect to PD ones. This applied to global recognition, as well as to low-intensity and high-intensity facial emotion recognition. These results indicate specific impairment of recognition of sad and happy facial emotions in PSP with respect to PD patients. The differences may depend upon diverse involvement of cortical-subcortical loops integrating emotional states and cognition between the two conditions, and might represent a neuropsychological correlate of the apathetic syndrome frequently encountered in PSP.