Abstract Body

Objective: to compare social cognition profile of patients with amyotrophic lateral sclerosis (ALS) and with behavioral variant frontotemporal dementia (bvFTD).

Methods: twenty-one patients with ALS, 20 patients with bvFTD and 21 healthy controls were recruited from two neurological clinics from Brazil and Chile, and underwent a cognitive battery. The assessment included: i) the abbreviated version of the Social Cognition and Emotional Assessment (Mini-SEA), composed by the faux pas test (theory of mind-ToM) and the Facial Emotion Recognition Test (FERT), ii) Mini-Mental State Examination (MMSE), iii) Frontal Assessment Battery (FAB), iv) lexical fluency (F-A-S), v) category fluency (animals/minute), vi) digit span (direct and backwards), and vii) Hayling test. A post hoc analysis was conducted to divide the ALS patients into two subgroups: patients with cognitive impairment ALSci (n=8) and patients without cognitive impairment ALScn (n=13).

Results: No significant difference was found between groups when comparing age, sex and education. Patients with ALS and bvFTD had similar disease duration. Patients with bvFTD performed worse than controls in executive and social cognition. By contrast, there was no significant difference between ALScn and controls.The ALSci subgroup performed poorly when compared with controls, in the total scores of Mini-SEA (p<0.002), including faux pas (p<0.004) and FERT (p<0.001).

Discussion: Our findings highlight the cognitive heterogeneity of ALS, supporting the existence of a cognitive continuum between ALS and bvFTD. While ALSci group performed similarly to bvFTD group, patients with ALScn performed similar to controls.