Facial emotion recognition and cerebral white matter lesions in myotonic dystrophy type 1

In order to investigate the cognitive and neurological bases of social cognitive impairment in myotonic dystrophy type 1 (DM1), we examined the facial expression recognition abilities and the cerebral lesions in a group of DM 1 (5 men, 4 women). We measured sensitivity to facial emotions and compared the findings with magnetic resonance image (MRI) findings evaluated using a semi-quantitative method. The DM1 patients showed lower sensitivity to disgusted and angry faces as compared to the healthy controls. The assessment of brain lesions revealed that more severe lesions occurred in the frontal, temporal, and insular white matters. Sensitivity to the emotion of disgust was negatively correlated with temporal lesions, and sensitivity to anger negatively correlated with frontal, temporal, and insular lesions. The results of this study indicate an association between lesions in the frontal, temporal, and insular subcortices and decreased emotional sensitivity to disgust and anger in DM1 patients. These areas are thought to play an important role in emotional processing in the normal brain. Our results suggest that social cognitive impairment in DM1 patients is attributable to impaired emotional processing linked to white matter lesions.