The processing of emotion in patients with Huntington's Disease: Variability and differential deficits in disgust

Background: Some studies of emotion recognition in Huntington's disease (HD) have not supported early reports of selective impairment in the recognition of facial expressions of disgust.This inconsistency could imply that loss of disgust is not a feature of all patients with this disease. Objectives: This study examined whether disproportionate impairment in the recognition of disgust was present in some HD patients and not in others. Second, we examined whether patients unable to recognize facial disgust had parallel impairments in other aspects of the emotion. Method: Fourteen HD patients and 14 age-matched healthy controls and education-matched healthy controls were first assessed on facial emotion recognition, with follow-up of individual-level analyses on patients D.W. and M.J. Results: Although the group-level analyses revealed a broad profile of impaired recognition of negative emotions, individual-level analyses revealed a selective impairment of disgust in 47% of HD patients and of fear in 13%. Cross-modal impairments were only present for disgust, and then only in D.W. and M.J., who were unable to recognize disgust faces and had differential deficits on other emotion tasks: auditory recognition of vocal disgust expressions, matching the label "disgust" to a picture of a disgusting scene, and semantic knowledge of disgust elicitors. Conclusion: The findings support the view that impairment in the recognition of disgusted facial expressions may reflect processes involving the central aspects of disgust knowledge.