To evaluate the impact of Social Cognition (SC) assessment on the Amyotrophic lateral sclerosis-frontotemporal spectrum disorder (ALS-FTSD)  categorization, and to explore the correlation of SC with executive functions (EF) and behaviour changes in a cohort of ALS patients. 

SC deficits are included in the ALS-FTDS revised diagnostic criteria. However, the impact of SC assessment on the cognitive classification and  cognitive-behavioural correlates of SC remain unclear.

We enrolled 121 patients and 56 healthy controls attending the Turin ALS Center. Patients and controls underwent a cognitive/behavioural testing, included the SC subdomains of facial emotion recognition (FER), cognitive and affective theory of mind (ToM).

Patients performed significantly worse than controls in all SC explored domains, and 45% of patients showed a deficit in at least one SC test, dissociated from the presence of EF deficits. In 14% of cases the SC deficit was isolated and subclinical, and mainly involved male patients with spinal onset. The SC assessment determined the attribution of cognitive impairment in 12% of patients. Through a statistical clustering approach we found that ToM shows only a partial overlap with EF, while behaviour changes associate with emotional disorders (anxiety and depression).

These findings suggest that SC is overall independent from EF in ALS, with ToM only partially associating with specific EF measures, and not with behaviour changes. The influence of SC on the cognitive categorization and the quite frequent identification of a subclinical SC impairment have implications in a clinical setting, considering the strong impact of cognitive impairment on disease burden and therapeutic choices. In the research setting these findings may help to disentangle the cognitive and behavioural manifestations of the ALS-FTDS spectrum, and prompt to explore the potential role of SC impairment as early marker of cognitive or behavioural dysfunction.