Relationship between Social Cognition and traditional cognitive impairment in Progressive Multiple Sclerosis and possible implicated neuroanatomical regions

Background: Cognitive impairment is a relevant contributor of the medical and social burden in Progressive MS. Social Cognition, the neurocognitive processes underlying social interaction, has been explored mainly in European and North American cohorts, influencing social aspects of quality of life (QOI) of early MS patients and families. Few studies have studied Social Cognition in Progressive MS and the literature on its neuroanatomical bases or brain atrophy measurements is still scarce. Objectives: To explore the relationship between Social Cognition performance and its correlations with traditional cognitive domains, brain atrophy and QOL in primary and secondary Progressive MS patients. Methods: Cross-sectional analysis including: mini-Social-Cognition-and-Emotional-Assessment (mini-SEA), neuropsychological battery, disability, depression, fatigue, QOL, and brain volume. Results: Forty-three MS patients, 23 primary and 20 secondary Progressive, 65% women, mean age and disease duration of 57.2 and 15.7 years, respectively, with high levels of disability (median EDSS 6.0) and a widespread impairment in traditional domains (mostly episodic verbal/visual and working memories) were assessed. The Mini-SEA score was correlated with executive functions (cognitive shifts Rho: 0.55; p = 0.001) analyzing the whole group, and with visual episodic memory (Rho: 0.58, p = 0.009) in the primary Progressive MS group. Mini-SEA score was also correlated with total normalized grey matter volume (Rho: 0.48; p = 0.004). Particularly, atrophy within bilateral cortical regions of orbitofrontal, insula and cerebellum, and right regions of fusiform gyrus and precuneus were significantly associated with higher Social Cognition impairment. In this cohort, QOL was not correlated with Social Cognition, but with EDSS, fatigue and depression. Conclusions: In Progressive MS, Social Cognition is directly correlated with traditional cognitive domains such as executive function and episodic memory. It is also associated with global grey matter atrophy and regional atrophy within associative visual and executive cortical areas, but no correlations with QOL were found in this cohort. These findings may contribute to the understanding of the pathological bases behind Social Cognition in Progressive MS.