Meta-analysis of social cognition in amyotrophic lateral sclerosis.
Amyotrophic lateral sclerosis (ALS) is associated with executive dysfunction and behavioural impairment. Recent studies suggested that social cognitive deficits might also be a prominent feature of ALS. Current meta-analysis aimed to summarize available evidence for deficits in social cognition including theory of mind (ToM) and emotion recognition in ALS. In this meta-analysis of 15 studies, facial emotion recognition and ToM performances of 389 patients with ALS and 471 healthy controls were compared. ALS was associated with significant impairments with medium effect sizes in ToM (d = .65) and facial emotion recognition (d = .69). Among individual emotions recognition of disgust and surprise were particularly impaired. Deficits in perspective taking (d = .73) aspects of ToM (ToM-PT) was more pronounced in comparison to decoding (d = .28) aspects of ToM (ToM-decoding). The severity of social cognitive impairment was similar to level of executive dysfunction and there was a significant relationship between social cognition and executive dysfunction. Deficits in social cognition are part of the cognitive phenotype of ALS.