Theory of Mind in Patients with Epilepsy: a Systematic Review and Meta-analysis

The ability to understand our own thoughts, intentions, beliefs and emotions and those of others (Theory of Mind; ToM) is a high-order social cognitive skill that is vital for social interaction and which has been found to be impaired in patients with epilepsy. Studies examining ToM in patients with epilepsy, however, have yielded inconsistent findings. The main aim of this study is to determine whether the magnitude of ToM deficits varies as a function of the site of epilepsy focus and/or the type of ToM task used. Electronic databases searches included Psychinfo, Medline/PubMed and EMBASE. Studies were included if they examined a group of patients with epilepsy and a group of healthy controls, reported original research, were published in the English language in peer reviewed journals, and used one of five empirically validated measures of ToM: False Belief, Reading the Mind in the Eyes Task (RMET), Faux-pas, Strange Stories, Cartoon ToM vignettes. Twelve studies were identified, ten included adults and two included children with epilepsy. Findings revealed marked ToM deficits in adults with focal seizures emanating from core brain regions underpinning ToM: temporal and frontal lobes (frontal lobe epilepsy, FLE; temporal lobe epilepsy, TLE), but not in adults with focal seizures outside the temporal and frontal lobes (extra-TLE/FLE). ToM deficits were also observed in children with generalised seizures (idiopathic generalised epilepsy, IGE). ToM deficits were documented across ToM tasks. In conclusion, ToM deficits represent a robust finding in adults with frontal and temporal epilepsy, but are also found in children with generalised seizures. Further research into ToM is needed, especially in children with epilepsy as early ToM may have cumulative, negative effects on development of social skills that continues into adulthood.