Social cognition deficits and the role of amygdala in relapsing remitting multiple sclerosis patients without cognitive impairment

Background: Social cognition (SC) can be impaired in multiple sclerosis (MS) patients; however, most studies have not controlled for generalized cognitive impairment (CI), nor have they examined the role of the amygdala using advanced structural neuroimaging. Whether deficits in SC occur in the disease even before the concomitant manifestation of CI, with a specific interest in the role of bilateral amygdala. Methods: In this study, we enrolled 31 RRMS patients and 38 healthy controls (HC). SC was examined with the Reading the Mind in the Eyes (RME), a task of facial affect recognition (FAR), and the empathy quotient (EQ). 3T MRI scans were obtained for all patients with special interest in quantifying amygdala lesions by cortical lesion volume (CLV) estimation. Results: The results showed that the RRMS group did worse as compared to HC in the RME (p < .001), the FAR task (p = .001), and the EQ (p = .022). Patients had mainly difficulties in recognition the negative emotions of fear (p < .001) and anger (p = .036). Finally, CLV of bilateral amygdala was a significant predictor of RME (p < .001) and FAR (p = .005). Conclusion: We conclude that SC can be impaired in several domains in RRMS patients even in the absence of CI and that it is related specifically to bilateral amygdala damage as measured by CLV.