Background Impaired social behaviour, partly related to altered perception of emotions, is commonly reported in HD patients. Over the past few years the role of oxytocin (OT) as social hormone has been proposed and it is supported by the improvement of recognition of the expression of the faces after administration of intranasal OT.
Aims To investigate social cognition in HD and to evaluate the role of OT as social hormone.
Methods 8 symptomatic HD (stage II S&F) and 9 controls, matched for age and educational level were investigated for social cognition by means of an extensive battery of neuropsychological tests. The basal levels of OT were analysed in the whole study group and searching for relationship between blood levels and social cognition.
Results HD patients showed lower performances at Faux pas, Strange Stories test and in recognising face expression evaluated by KDEF scale (p < 0.05, p < 0.01). In general population younger subjects with higher education more easily recognise emotions from facial expressions. Similarly, better cognitive performance (MoCa score) well correlates with better performances on social cognitive tests. OT blood levels showed a trend for lower values in the HD group (average 7.9 ± 5.8 controls, 6.8 ± 2.6 HD). Moreover higher blood levels directly correlate with better performances on Faux Pas test. Regression analysis showed that MoCa scoring and blood OT levels were able to explain 55% about the variability of KDEF in the general population (p < 0.01), and even 70% in HD population (p < 0.05).
Conclusions The present study, albeit severely limited by sample size, shows an extensive impairment of social cognition in HD population. The impairment mainly involves the perception of emotions, dependent both on the cognitive impairment and on basal levels of OT. Our finding that social cognition, at least as regards to perception of emotions, may be in part related to OT might support the hypothesis of hypothalamic involvement in HD.
- social cognition